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Purpose To determine whether age modifies the effect of the number of motile spermatozoa inseminated (NMSI) as a predictor of success in Intrauterine Insemination (IUI). Methods This retrospective cohort study included all patients who underwent IUI at an academic infertility center between October 2004 and June 2018. The primary outcome was clinical pregnancy (CP; a gestational sac and fetal heartbeat on ultrasound). Results were analyzed by patient factors including age, NMSI, duration of infertility, and cause of infertility, along with treatment factors such as number of follicles and ovulation induction protocol. Factors associated with the odds of achieving a clinical pregnancy were analyzed using binary logistic generalized estimating equations to control for clustering effects by couple. Female age was categorized as

Objective Insulin is one of several molecules that transmit information about energy balance to the brain. It has been hypothesized that insulin resistance fosters non-homeostatic eating. The objective of the current study was to characterize corticolimbic brain responses to appetitive stimuli in subjects with insulin sensitivities ranging from resistant to normal. Design and Methods Sixteen women diagnosed with Polycystic Ovary Syndrome (PCOS) underwent functional magnetic resonance imaging (fMRI) while viewing pictures of high calorie (HC) foods, low calorie (LC) foods, and control (C) pictures. Results A region of interest analysis of the blood oxygen level dependent (BOLD) signal revealed widespread activation within corticolimbic regions in response to food pictures. Activated regions included the dorsolateral prefrontal cortex (DLPFC), medial prefrontal cortex (mPFC) , insula, nucleus accumbens (NAc), pallidum, ventral tegmental area (VTA), putamen, amygdala, caudate, substantia nigra, hippocampus, pulvinar, and midbrain. Activation of the anterior cingulate, dorsolateral prefrontal cortex (DLPFC), and midbrain by HC food pictures (HC — C) and activation of the lateral orbitofrontal cortex (OFC), pallidum, substantia nigra, ventral tegmental area (VTA), pulvinar, and midbrain by LC food pictures (LC — C) was negatively correlated with insulin sensitivity. In contrast, activation of the OFC, DLPFC, insula, hypothalamus, pallidum, substantia nigra, VTA, pulvinar, and midbrain by the HC — LC contrast was positively correlated with insulin sensitivity, whereas activation of the caudate was negatively correlated. Conclusions The association between insulin sensitivity and corticolimbic responses to food pictures may reflect abnormal brain responses to insulin feedback that contribute to the development and or perpetuation of obesity in PCOS.

Food intake is decreased during the late follicular phase and increased in the luteal phase of the menstrual cycle. While a changing ovarian steroid milieu is believed to be responsible for this behavior, the specific mechanisms involved are poorly understood. Brain activity in response to visual food stimuli was compared during the estrogen dominant peri-ovulatory phase and the progesterone dominant luteal phase of the menstrual cycle. Twelve women underwent functional magnetic resonance imaging during the peri-ovulatory and luteal phases of the menstrual cycle in a counterbalanced fashion. Whole brain T2* images were collected while subjects viewed pictures of high calorie (HC) foods, low calorie (LC) foods, and control (C) pictures presented in a block design. Blood oxygen level dependent (BOLD) signal in the late follicular phase and luteal phase was determined for the contrasts HC-C, LC-C, HC-LC, and LC-HC. Both HC and LC stimuli activated numerous corticolimbic brain regions in the follicular phase, whereas only HC stimuli were effective in the luteal phase. Activation of the nucleus accumbens (NAc), amygdala, and hippocampus in response to the HC-C contrast and the hippocampus in response to the LC-C contrast was significantly increased in the late follicular phase compared to the luteal phase. Activation of the orbitofrontal cortex and mid cingulum in response to the HC-LC contrast was greater during the luteal phase. These results demonstrate for the first time that brain responses to visual food cues are influenced by menstrual cycle phase. We postulate that ovarian steroid modulation of the corticolimbic brain contributes to changes in ingestive behavior during the menstrual cycle.

BACKGROUND Obesity affects many aspects of health, including reproduction. Despite unrelenting warnings about the health consequences of obesity, its prevalence continues to rise. Beginning with the discovery of leptin in 1994, the endocrinology of energy homeostasis has been significantly advanced. More recently, brain imaging studies have been providing novel insights into homeostatic and hedonic aspects of human ingestive behavior. METHODS A comprehensive MEDLINE search was conducted on the topic of neuroendocrine control of ingestive behavior with an emphasis on functional magnetic resonance imaging studies. Additional articles were collected by hand searching the bibliographies of all relevant articles retrieved. RESULTS This review describes recent advances in our understanding of endocrine signals that respond to acute and chronic energy states and regulate ingestive behavior so as to achieve a balance between energy intake and energy expenditure. Recently published brain imaging studies, describing the neural networks that process endocrine signals of energy state and hedonic cues associated with highly palatable foods, are highlighted. Brain responses to food cues are described in the context of appetite changes during the menstrual cycle both in normal physiology and under the conditions anorexia nervosa and bulimia nervosa. CONCLUSIONS The prevalence of obesity belies the plethora of endocrine signals in place to ensure energy homeostasis. However, satiety signals appear to be counteracted by hedonic signals derived from highly palatable foods typical of today's diet. A better understanding of the interaction between homeostatic and hedonic signals is needed to devise effective strategies for dealing with obesity. Menstrual cycle dependent changes in brain responses to food cues may provide insight into the normal physiological control of ingestive behavior as well as dysfunctional regulation associated with disordered eating.

Measurement of mid-gestation cervix length has become a common screening tool for preterm birth. Our study was designed to assess the value of cervix length and serum relaxin in the prediction of spontaneous preterm birth at35 and37 weeks' gestation in a general obstetric population.A prospective cohort of women with a singleton pregnancy had blood collected at 24 and 28 weeks' gestation for determination of serum relaxin immediately before transvaginal ultrasound measurement of cervical length. Patients and referring physicians were blinded to cervix length and relaxin levels to preclude changes in management. The primary outcomes were spontaneous delivery at35 and37 weeks' gestation.A total of 1004 women entered the study. Delivery data were not available for 20 women who delivered elsewhere. Twenty women were excluded because preterm delivery was undertaken because of pregnancy abnormalities. Of the 964 women with known gestational age at delivery, 46 (4.8%) delivered at37 weeks and 16 (1.7%) at35 weeks' gestation. Mean cervix length at 28 weeks (36.7 +/- 7.3 mm) was significantly shorter than at 24 weeks (37.8 +/- 7.1 mm) (P0.001). Cervix length at 24 and 28 weeks' gestation was equally predictive of preterm birth. A cervix length ofor = 30 mm at 28 weeks had a sensitivity of 57.1%, a specificity of 81.8%, and a positive predictive value of 4.5% for birth at35 weeks. Serum relaxin levels were not correlated with cervix length at either 24 or 28 weeks. Serum relaxin at 24 and 28 weeks' gestation was not associated with preterm birth before or after controlling for patient characteristics and cervix length.Serum relaxin levels at 24 and 28 weeks' gestation are not associated with preterm birth. Although cervix length is associated with preterm birth, its positive predictive value is low. Given the lack of proven therapies for those at risk, cervix length does not appear to be a useful screening tool for preterm delivery in the general obstetric population.

Peptide YY (PYY) is produced in L cells of the intestine and is released after eating. PYY circulates in a truncated form designated PYY 3–36 . PYY 3–36 is thought to be a physiologic anorexigenic peptide. The objective of the current study was to test the effect of exogenous PYY 3–36 on food intake in non-human primates exposed to different ovarian steroid milieus. The study was conducted in four ovariectomized cynomolgus monkeys replaced with estrogen alone for 2 weeks followed by estrogen in combination with progesterone for 2 weeks to mimic the menstrual cycle. The effect of PYY 3–36 on food intake was tested during each week of the simulated menstrual cycle by comparing the 2 h food intake following intracerebroventricular (icv) injection of artificial cerebrospinal fluid (aCSF) or PYY 3–36 . Despite considerable variation in food intake following aCSF, PYY 3–36 consistently inhibited food consumption, except during week 2 of estrogen plus progesterone replacement. PYY 3–36 reduced food consumption by 16.2 g (95% confidence interval (CI) = 4.5–27.9 g) and 26.6 g (95% CI = 7.3–45.9 g) in weeks 1 and 2 respectively of estrogen only treatment and by 38.2 g (95% CI = 26.1–50.2 g) in week 1 of estrogen plus progesterone treatment. In contrast, PYY 3–36 injected in week 2 of estrogen plus progesterone did not consistently inhibit food intake (13.1 g; CI = − 49.5–75.7). This is the first study to report the effect of PYY 3–36 on food consumption in female monkeys. We conclude that icv administration of PYY 3–36 has a strong anorexic effect in female cynomolgus monkeys and that sensitivity to PYY 3–36 may be influenced by the ovarian steroid milieu.

This paper reports the proceedings of a consensus meeting on the incidence and complications of multiple gestation in Canada. In addition to background presentations about current and possible future practice in Canada, the expert panel also developed a set of consensus points. The need for infertility to be understood, and funded, as a healthcare problem was emphasized, along with recognition of the emotional impact of infertility. It was agreed that the goal of assisted reproduction treatment is the delivery of a single healthy infant and that even though many positive outcomes have resulted from twin or even triplet pregnancies, the potential risks associated with multiple pregnancy require that every effort be made to achieve this goal. The evidence shows that treatments other than IVF (such as superovulation and clomiphene citrate) contribute significantly to the incidence of multiple pregnancy. There is an urgent need for studies to understand better the usage and application of these other fertility technologies within Canada, as well as the non-financial barriers to treatment. The final consensus of the expert panel was that with adequate funding and good access to treatment, it will be possible to achieve the goal of reducing IVF-related multiple pregnancy rates in Canada by 50%.

This study examined the effect of insulin sensitivity on the responsiveness of appetite regulatory brain regions to visual food cues.Nineteen participants diagnosed with polycystic ovary syndrome (PCOS) were divided into insulin-sensitive (n=8) and insulin-resistant (n=11) groups based on the homeostatic model assessment of insulin resistance (HOMA2-IR). Subjects underwent functional magnetic resonance imaging (fMRI) while viewing food pictures following water or dextrose consumption. The corticolimbic blood oxygen level dependent (BOLD) responses to high-calorie (HC) or low-calorie (LC) food pictures were compared within and between groups.BOLD responses to food pictures were reduced during a glucose challenge in numerous corticolimbic brain regions in insulin-sensitive but not insulin-resistant subjects. Furthermore, the degree of insulin resistance positively correlated with the corticolimbic BOLD response in the medial prefrontal cortex (mPFC), orbitofrontal cortex (OFC), anterior cingulate and ventral tegmental area (VTA) in response to HC pictures, and in the dorsolateral prefrontal cortex (DLPFC), mPFC, anterior cingulate, and insula in response to LC pictures following a glucose challenge. BOLD signal in the OFC, midbrain, hippocampus, and amygdala following a glucose challenge correlated with HOMA2-IR in response to HC-LC pictures.We conclude that the normal inhibition of corticolimbic brain responses to food pictures during a glucose challenge is compromised in insulin-resistant subjects. The increase in brain responsiveness to food pictures during postprandial hyperinsulinemia may lead to greater non-homeostatic eating and perpetuate obesity in insulin-resistant subjects.

Citalopram, a selective serotonin reuptake inhibitor (SSRI), has been used as a neuroendocrine probe to assess serotonin (5-HT) function in human subjects. In an effort to characterize the oral citalopram challenge, we hypothesized that oral racemic citalopram would increase plasma cortisol, prolactin and adrenocorticotropic hormone (ACTH) concentrations; ACTH had not been measured in previous studies on the neuroendocrine effects of citalopram. Nine healthy male subjects initially received 20 mg of citalopram in an open-label study, and subsequently received placebo and 40 mg of citalopram in a single-blind, randomized, cross-over study. The administration of citalopram 20 mg failed to produce a significant neuroendocrine response but 40 mg resulted in reliably increased plasma cortisol concentrations. The 40 mg dose, however, did not reliably influence the levels of plasma prolactin or plasma ACTH. The results of this study indicate that caution should be used in accepting oral racemic citalopram as a potential presynaptic serotonergic challenge agent. Further studies are needed to fully determine the validity of racemic citalopram and the active enantiomer, escitalopram, as 5-HT probes.

Adipocytes are the primary source of circulating leptin. Leptin inhibits eating, increases metabolism, and stimulates the reproductive axis. Numerous hypothalamic neuropeptides have been implicated in leptin's behavioral and neuroendocrine effects, including neuropeptide Y (NPY) and cocaine- and amphetamine-regulated transcript (CART). The aim of this study was to investigate the physiological relevance of leptin's signaling of nutritional status by comparing the effects of leptin with the effects of re-feeding on fasting-induced changes in the expression of the long form of the leptin receptor (Ob-Rb), NPY, and CART. Adult male rats were fasted for 48 h and treated with either intra cere broventricular (i.c.v.) or subcutaneous (s.c.) leptin throughout the fast, or fed ad libitum for 24 h after terminating the fast. Expression of NPY, Ob-Rb, and CART mRNA in the arcuate nucleus (ARC) was determined by in situ hybridization histochemistry and compared with vehicle-treated fed or fasted controls. Fasting increased NPY and Ob-Rb expression and decreased CART expression in the ARC. Leptin (regardless of route) and re-feeding were equally effective in normalizing CART mRNA expression. A similar trend was observed with Ob-Rb expression. In contrast, neither re-feeding nor s.c. leptin reversed the increased expression of NPY that was induced by fasting. Only i.c.v. leptin was effective in this regard. Our results indicate leptin and re-feeding are equally effective in normalizing fasting-induced changes in CART and Ob-Rb expression, but less effective in normalizing NPY expression. These results suggest that leptin is the primary nutritional signal regulating CART and Ob-Rb expression in the ARC, and highlight potential differences between CART and NPY neuron sensitivity to leptin signaling.Key words: CART, leptin receptor, NPY, neuropeptide gene expression, fasting, refeeding, hypothalamus.

Clomiphene citrate is an effective inducer of ovulation, but pregnancy rates per cycle remain comparatively low, possibly because of an antiestrogenic effect on the endometrium. Letrozole, a potent, orally active aromatase inhibitor, suppresses the production of estrone from androstenedione and has markedly increased gonadotropin levels in animal studies. A possible role of letrozole in ovulation induction was explored in a randomized, double-blind, pilot study enrolling 19 ovulatory women ranging in age from 18 to 35 years. After a natural cycle, the women received either 2.5 mg of letrozole or 50 mg of clomiphene citrate daily on days 5 to 9 after menstruation. Ovarian follicle formation was monitored by transvaginal ultrasonography. The major measure of outcome was the number of mature follicles measuring at least 18 mm at the time of the LH surge. In the 16 women completing both study cycles, a comparable increase in the number of mature follicles at the LH surge was noted in both treatment groups. The mean number was 2.2 with clomiphene therapy and 1.7 in women given letrozole. Midcycle endometrial thickness averaged 10.1 mm in the clomiphene group and 10.6 mm in the letrozole group during the treatment cycle, not a significant difference. All letrozole-treated women but fewer than 60% of those given clomiphene citrate had trilaminar pattern endometrium at midcycle in the natural cycle. The numbers did not drop significantly in either group during the treatment cycle. Follicular gonadotropin profiles were comparable in the two groups in both natural and medicated cycles. Estradiol levels in treatment cycles were higher with clomiphene and lower than those in natural cycles when letrozole was administered. Letrozole seems to be equivalent to clomiphene citrate for stimulating follicle growth in normally ovulating women. This agent may make women more sensitive to FSH, enhance endometrial development (compared with clomiphene), and increase implantation rates through more physiological estradiol levels. Letrozole should be a useful alternative to clomiphene citrate for ovarian hyperstimulation in both intrauterine insemination and in vitro fertilization.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a widespread environmental contaminant that has profound deleterious effects on development and reproduction. TCDD may act at one or more levels to alter the hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonadal (HPG) axes. The objective of this study was to investigate whether TCDD modulates neuroendocrine systems by altering gene expression of arginine vasopressin (AVP), corticotrophin-releasing hormone (CRH), or pro-opiomelanocortin (POMC), which are important neuroregulators of the HPA and HPG axes. Four groups of female cynomolgus monkeys (Macaca fascicularis) were administered daily oral doses of gelatin capsule containing TCDD (0, 1, 5, or 25 ng/kg body weight) mixed with glucose 5 days a week for 1 year. At the end of the dosing period, animals were euthanized and brains were harvested. CRH, AVP, and POMC mRNA levels were semiquantified by in situ hybridization histochemistry on 30-microm coronal sections of the brain. Blood collected on the day of euthanasia was assayed for cortisol and progesterone. CRH mRNA levels in the paraventricular nucleus (PVN) were significantly increased by the 2 higher TCDD doses (5 and 25 ng/kg/day) compared to controls (p < 0.05). There was a trend towards increased AVP mRNA levels in both the supraoptic nucleus (SON) and PVN. No effect of TCDD on POMC was observed. Cortisol levels were significantly increased in TCDD-exposed animals. Progesterone concentrations and menstruation data indicated that TCDD did not interfere with ovulation. We conclude that TCDD stimulated the HPA axis by a central effect involving CRH, but had no effect on the HPG axis at the doses tested.

Objective: to review the potentid applications of photodynamic therapy (PDT) in gynaecology, using 5-aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) photosensitization. Methods: relevant publications were retrieved by searches on Medline between 1986 and 1996 using the following MeSH headings: 5-aminolevulinic acid, photofrin, haematoporphyrin derivative, endometrium, photodynamic therapy or using a combination of the above. References were also obtained from reference lists of known sources. Results: photodynamic therapy using ALA appears to offer the potentid of a simple, non-surgical approach to ablation of the endometrium. Its application as an office procedure would provide a major advance for women suffering from menorrhagia, and could eliminate the unwanted withdrawal bleeding experienced by post-menopausal women on hormone replacement therapy (HRT). Photodynamic therapy could be used to treat ectopic pregnancies in cases where laparoscopy is needed for diagnosis, and has the potentid for the detection and treatment of endometriosis. Photodynamic therapy has been employed for palliative treatment of advanced gynaecologic alignancies and may play a role in treating benign vulvar and vaginal lesions, for example, condylomata. Conclusions: 5-aminolevulinic acid-induced PpIX photosensitization has the potentid to play a significant role ingynaecology due to its specificity for desired target tissues in the pelvis. The major clinical applications of ALA-PDT are likely to be the ablation of the endometrium in women suffering from menorrhagia and the simplification of HRT in post-menopausal women.

Corticotropin-releasing Factor (CRF) is an important inhibitory neuromodulator of GnRH/LH secretion, and mediates in part the inhibitory effects of stress on the hypothalamic-pituitary-gonadal axis. The purpose of the present study was to further investigate CRF's role in regulating LH secretion in primates. This was accomplished by examining LH secretion in ovariectomized rhesus monkeys (n = 7) following cortisol synthesis inhibition with metyrapone. Infusion of metyrapone (5 mg/kg per h) for 4 h decreased cortisol levels to less than 20% of controls while increasing ACTH approximately 10-fold. LH concentrations were not affected by this acute activation of the hypothalamic-corticotroph axis. In a second experiment, metyrapone was infused for 10 h before collecting serial blood samples every 15 min for 6 h. Although this protocol produced a sustained increase in ACTH, no apparent effect on pulsatile LH secretion compared with saline controls was observed. Mean LH (+/- SEM) levels calculated for consecutive 2-h increments were 87.6 +/- 9.2 (0-2 h) 82.1 +/- 5.5 (2-4 h), and 80.7 +/- 4.8 (4-6 h) ng/ml in saline pretreated animals compared with 83.6 +/- 4.9, 79.8 +/- 5.8, and 72.5 +/- 6.2 ng/ml, respectively, in metyrapone pretreated monkeys. The same regimen of metyrapone infusion increased CRF messenger RNA levels in the paraventricular nucleus by approximately 33% (P < 0.0002). In a final experiment designed to examine the potential synergy between CRF and cortisol, the LH response to insulin-induced hypoglycemia was contrasted in saline and metyrapone pretreated monkeys. LH concentrations were reduced to approximately 40% of basal levels following insulin in both metyrapone and saline pretreated monkeys. Therefore, even though inhibition of cortisol synthesis leads to an increase in CRF messenger RNA in the paraventricular nucleus and a robust increase in ACTH secretion in rhesus monkeys, presumably due in part to increased neuroendocrine CRF secretion, LH secretion was not inhibited during either the acute or more chronic phase of corticotroph activation. Absence of LH inhibition was not due to low cortisol concentrations resulting from metyrapone because metyrapone did not prevent hypoglycemia-induced suppression of LH secretion. We conclude that increased neuroendocrine CRF secretion following metyrapone does not inhibit LH secretion under these conditions. Several explanations for this result are discussed.

We postulate that insulin regulation of food intake is compromised when insulin resistance is present. In order to investigate the effect of insulin sensitivity on appetitive brain responses, we conducted functional magnetic resonance imaging studies in a group of women diagnosed with polycystic ovary syndrome (PCOS) in which insulin sensitivity ranged from normal to resistant. Subjects (n=19) were imaged while viewing pictures of high calorie (HC) foods and low calorie (LC) foods after ingesting either 75 g glucose or an equivalent volume of water. The insulin sensitive group showed reduced blood oxygen level dependent (BOLD) signal in response to food pictures following glucose ingestion in numerous corticolimbic brain regions, whereas the insulin resistant group did not. There was a significant interaction between insulin sensitivity (sensitive vs resistant) and condition (water vs glucose). The largest clusters identified included the left insula, bilateral limbic/parahippocampal gyrus/culmen/midbrain, bilateral limbic lobe/precuneus, and left superior/mid temporal gyrus/parietal for HC and LC stimuli combined, the left parahippocampal gyrus/fusiform/pulvinar/midbrain for HC pictures, and the left superior/mid temporal gyrus/parietal and middle/inferior frontal gyrus/orbitofrontal cortex for LC pictures. Furthermore, BOLD signal in the anterior cingulate, medial frontal gyrus, posterior cingulate/precuneus, and parietal cortex during a glucose challenge correlated negatively with insulin sensitivity. We conclude the PCOS women with insulin resistance have an impaired brain response to a glucose challenge. The inability of postprandial hyperinsulinemia to inhibit brain responsiveness to food cues in insulin resistant subjects may lead to greater non-homeostatic eating.

OBJECTIVES: To evaluate the selectivity of endometrial photosensitization after intrauterine 5-aminolevulinic acid administration in nonhuman primates, and to assess acute and chronic systemic toxicity after intravenous (i.v.) delivery of 5-aminolevulinic acid. METHODS: Ovariectomized cynomolgus monkeys (n = 19) aged 6-18 years and ovariectomized rheusus monkeys (n = 3) aged 9-14 years were used in these studies, 5-aminolevulinic acid at various doses was administered by a transfundal (n = 8), transcervical (n = 3), or i.v. (n = 11) route. Spectrophoto-fluorometric readings and fluorescence microscopy were used to assess 5-aminolevulinic acid-induced photosensitization of uterine tissues; respiration, heart rate, blood biochemistry, and behavior were used to evaluate potential acute and delayed systemic toxicity. RESULTS: Endometrial fluorescence was achieved in all animals after administration of 5-aminolevulinic acid. Characteristic spectrophotofluorescence peaks of protoporphyrin IX (PpIX) in the endometrium but not myometrium confirmed selective endometrial PpIX production from 5-aminolevulinic acid. A transient (less than 1 week) increase in serum aspartate aminotransferase was observed after systemic instillation of 5-aminolevulinic acid in dosages 24-50-fold greater than that required to induce endometrial photosensitization after intrauterine injection. CONCLUSIONS: The endometrium but not myometrium in nonhuman primates is capable of converting 5-aminolevulinic acid into protoporphyrin IX. At large doses, systemic 5-aminolevulinic acid causes a transient increase in the serum aspartate aminotransferase level. No other evidence of acute or delayed systemic toxicity was observed.

OBJECTIVE: Our purpose was to evaluate and compare the conversion of 5-aminolevulinic acid into the endogenous photosensitizer protoporphyrin IX in experimentally induced endometriosis and in other normal tissues in a rat model. STUDY DESIGN: Fluorescence of experimental endometriotic lesions, uterus, peritoneum, bowel mesentery, bladder, eye, skin, and skeletal muscle was assessed 3 hours after either intravenous, oral, or intrauterine administration of 5-aminolevulinic acid with use of spectrophotofluorometry. In another experiment the fluorescence of surgically induced endometriosis and adjacent normal peritoneum was evaluated every 15 minutes after 5-aminolevulinic acid administration to assess the time course of protoporphyrin IX production. RESULTS: In the rat endometriosis model intralesional and systemic 5-aminolevulinic acid produced fluorescence within implants showing viable endometrial cells. Treatment with 5-aminolevulinic acid produced low-intensity fluorescence in peritoneum, bowel mesentery, and eye. Relatively intense fluorescence was seen in skin, bladder, and uterus. No fluorescence was observed in skeletal muscle. The intensity of fluorescence varied with the dosage and route of administration of 5-aminolevulinic acid. Fluorescence intensity of protoporphyrin IX was significantly greater in implants than in adjacent normal peritoneum between 2 and 4 hours after treatment. CONCLUSIONS: Protoporphyrin IX fluorescence in experimentally induced endometriosis lesions after intravenous and oral delivery of 5-aminolevulinic acid was significantly greater than the fluorescence detected in adjacent normal peritoneum. (AM J OBSTET GYNECOL 1996;174:154-60.)

Objective To evaluate the direct effect of photodynamic treatment with 5-aminolevulinic acid (ALA) on preimplantation mouse embryos in an in vitro setting. Design Preimplantation mouse embryos were incubated with or without ALA for 5hours and followed immediately by light exposure for 0, 5, or 15minutes. Comparison of the viability and blastocyst formation was made among different treatment groups. Setting A conventional laboratory setting with embryo culture facilities. Interventions Female CD1 mice were superovulated with pregnant mare serum gonadotropin and hCG before mating. Four- and eight-cell embryos and compacted morulae were flushed from the oviducts and incubated with 0, 0.1, 0.5, 1.0, or 5.0mM ALA for 5hours. Embryos subsequently were exposed to photoactivating light for 0, 5, or 15minutes. Main Outcome Measures Microscopic assessment of embryo quality at 12hours and determination of the percentage of embryos progressing to the blastocyst stage at 36 or 60hours. Results Incubation of embryos with 0.1, 0.5, 1.0, 5.0mM ALA without light resulted in 87.3%±1.6%, 84.9%±3.4%, 81.4%±1.8%, and 82.8%±4.7% of the embryos developing to blastocysts, respectively. In the absence of ALA, light exposure for 0, 5, or 15minutes resulted in 93.8%±2.3%, 92.3%±2.2%, and 85.9%±1.7% blastocyst formation. Combining treatment of ALA at the same concentrations with light resulted in 33.3%±2.1%, 0.7%±0.9%, 0%, 0% (5-minute light), 13.3%±1.0%, 0%, 1.6%±1.3%, 0% (15-minute light) blastocyst formation, respectively. When gross morphology was used to assess embryo viability at 12hours, similar results were observed. Measurement of the fluorescent spectrum of embryos incubated with ALA indicated that protoporphyrin IX had been formed. Conclusion Photodynamic ablation of mouse embryos was achieved with ALA under in vitro conditions. These results indicate that preimplantation mouse embryos are capable of converting ALA to the photosensitizer, protoporphyrin IX, and are susceptible to subsequent photoablation. A photodynamic effect on the embryo may be important to the successful application of this technique to the treatment of human ectopic pregnancy.

Objective To determine whether systemic 5-aminolevulinic acid (ALA) could produce photosensitization and photodynamic ablation of early pregnancy in the rat. Setting A conventional laboratory setting. Patients Female Sprague-Dawley rats, weighing 220 to 275 g at the time of breeding. Interventions Rats at 10 days of gestation were injected IV with saline, 20 or 200 mg/kg ALA. Three hours later, the abdominal cavity was opened to record the number of fetuses in both uterine horns. One or both uterine horns were exposed to photoactivating light at 630 nm for 0, 5, 15, or 30 minutes. Main Outcome Measures Mean fetal survival rate was determined 7 days after treatment. Results The mean ± SEM fetal survival rates in groups (n = 6) treated with saline, 20 or 200 mg/kg ALA followed by 30-minute light exposure were 90.8% ± 2.8%, 16.0% ± 4.9%, and 0%, respectively. The mean ± SEM fetal survival rates in groups (n = 6) treated with 200 mg/kg ALA followed by 0-, 5-, 15-, or 30-minute light exposure were 71.3% ± 11.8%, 8.9% ± 6.2%, 0.9% ± 1.3%, and 0%, respectively. Conclusions We conclude that systemic ALA followed by transmural exposure to photoactivating light (630 nm) results in resorption of early pregnancies in the rat. This approach could potentially be developed as a new treatment for human ectopic pregnancy.

We evaluated disruption of endometrial function after treatment with 5-aminolevulinic acid with or without light exposure.In a conventional laboratory setting adult Sprague-Dawley female rats were treated with various doses of 5-aminolevulinic acid in one uterine horn and saline in the contralateral horn. Three hours after treatment both uterine horns were exposed to light, and the rats were bred to a fertile male 10 or 60 days later. Ablation of endometrium was evaluated by both rate of implantation and histologic features.In the absence of light exposure 5-aminolevulinic acid had no significant effect on the rate of implantation, compared with saline (76% vs 92%, n = 25, p0.05). In contrast, 5-aminolevulinic acid treatment plus light exposure profoundly decreased the rate of implantation in the 5-aminolevulinic acid-treated uterine horns of rats bred 10 days (3.8% vs 100%, n = 26, p0.001) or 60 days after treatment (16.7% vs 100%, n = 24, p0.001). Histologic examination revealed that the 5-aminolevulinic acid plus light-treated uterine horns were completely devoid of endometrium.Photodynamic treatment with 5-aminolevulinic acid resulted in a persistent disruption of rat endometrial function and was consistent with the histologic evidence of complete endometrial ablation. In addition, a partial destruction of myometrium adjacent to endometrium was observed. The myometrial damage may be through a nonphotodynamic mechanism because myometrium is unable to synthesize protoporphyrin IX from 5-aminolevulinic acid.

Etude de l'influence d'un stimulus lumineux (photoperiode, rythme circadien) et d'un stimulus chimique (pheromone) sur la reproduction chez l'homme

A chronic negative energy balance due to low nutritional intake or increased energy expenditure alters several neuroendocrine axes. The reproductive and thyroid axes are inhibited while the adrenal axis is stimulated. In primates, anovulation resulting from a chronic negative energy balance is a condition often referred to as nutritional amenorrhea. The objective of the current study was to determine if hypoleptinemia induced by dietary restriction is responsible for these neuroendocrine changes, particularly anovulation. Five rhesus monkeys had their dietary intake gradually reduced to inhibit ovulation. Dietary restriction inhibited follicle-stimulating hormone (FSH) and triiodothyronine (T3) secretion and stimulated cortisol release. Recombinant human leptin (rhleptin) administered by continuous infusion into the lateral ventricle for 16 weeks inhibited cortisol secretion but failed to stimulate FSH, T3 or ovulation. An immune response to rhleptin was noted after 3 weeks of leptin administration. Realimentation resulted in weight gain and reversed all endocrine responses to dietary restriction, including ovulation. These results do not support a role for reduced leptin secretion in anovulation induced by dietary restriction. The inability of rhleptin to reverse anovulation induced by a negative energy balance in monkeys is in contrast to its stimulatory effect on ovulation in women with functional hypothalamic amenorrhea. Different outcomes may be attributed to the degree of negative energy balance, the immune response generated by interspecies leptin administration, and/or other experimental variables such as dose or route of administration. Attributing opposing outcomes to species differences is unwarranted until these variables can be further examined.

Leptin is a cytokine produced by white adipose tissue that circulates in direct proportion to adiposity and is an important signal of energy balance. Leptin inhibits food intake in rodents by inhibiting the orexigenic neuropetides neuropeptide Y (NPY) and agouti regulated peptide (AgRP) and stimulating the anorexigenic neuropeptides α-melanocyte-stimulating hormone (α-MSH) and cocaine-amphetamine-regulated transcript (CART). In order to extend our understanding of neuroendocrine regulation of appetite in the primate, we determined the effect of a metabolic challenge on CART, NPY, and leptin receptor (Ob-R) messenger ribonucleic acid (mRNA) in the nonhuman primate (NHP) hypothalamus. Ten adult female rhesus monkeys were either maintained on a regular diet or fasted for two days before euthanasia. CART, NPY, and Ob-R mRNA were measured by in situ hybridization histochemistry (ISHH). A 2-day fast decreased CART expression in the ARC, increased NPY gene expression in the supraoptic nucleus (SON) and paraventricular nucleus (PVN), and increased Ob-R expression in the ventromedial nucleus (VMN). This is the first report that fasting inhibits CART expression and stimulates Ob-R expression in monkeys. Increased NPY expression in the SON and PVN, but not the ARC of fasted monkeys also is novel. With some exceptions, our observations are confirmatory of findings in rodent studies. Similarities in the neuroendocrine responses to a metabolic challenge in monkeys and rodents support extending existing hypotheses of neuroendocrine control of energy homeostasis to primates.

Nutritional amenorrhea is defined as cessation of menstrual cycles resulting from a chronic negative energy balance. Although it is agreed that nutritional amenorrhea results from reduced secretion of GnRH, the neuroendocrine mechanisms leading to GnRH inhibition are poorly defined. Because the invasiveness of many neuroendocrine experimental approaches precludes its use in the clinical setting, we set out to establish a model of nutritional amenorrhea in rhesus monkeys. Studies were conducted in four normal-weight and one obese female rhesus monkey. Dietary intake was gradually reduced with the goal of achieving a 15-20% weight reduction. Dietary restriction inhibited ovulation in all animals. The weight loss required to inhibit ovulation ranged from 2-11% in the four normal-weight animals and was achieved with a 23% reduction in dietary intake. The time of initiating reduced food intake to first missed ovulation was 62 +/- 13 d. Greater weight loss (46% reduction) over a longer period (10 months) was required to inhibit ovulation in the obese monkey. The onset of anovulation was not preceded by changes in menstrual cycle length or progesterone secretion. Realimentation initiated ovulation at a weight that approximated the animal's weight at the time of the last ovulatory cycle during dietary restriction. By contrast, caloric intake at the return of ovulation during realimentation was 28% greater. This is the first demonstration that chronic dietary restriction can inhibit ovulation in rhesus monkeys. This model will be useful for studying the neuroendocrine mechanisms involved in diet-induced anovulation in primates.

We recently reported that caloric restriction inhibited ovulation in rhesus monkeys. The objective of the current study was to determine if caloric restriction affected the positive feedback response to ovarian steroids in non-human primates. Studies were conducted in four long-term ovariectomized rhesus monkeys. Animals were given an estrogen/progesterone challenge while maintained on a normal diet and on a diet that reduced body weight by approx 20%. In all cases, animals were maintained at the desired weight [based on a calculation of body mass index (BMI)] for a minimum of 4 wk before initiating the steroid challenge. Caloric restriction reduced BMI from 23.3 +/- 0.3 to 18.9 +/- 0.2 kg/m2. The estrogen/progesterone challenge elicited an LH and FSH surge in each animal maintained at a normal BMI. By contrast, gonadotropin surges were significantly compromised when monkeys were challenged at a low BMI. In addition to affecting the reproductive axis, caloric restriction stimulated cortisol release and suppressed T3 secretion. These endocrine effects of caloric restriction are consistent with our findings in ovary-intact monkeys. In summary, our previous reports in ovary-intact animals confirmed an effect of caloric restriction on tonic gonadotropin secretion leading to anovulation. Our current results suggest the effects of caloric restriction on the reproductive axis extend beyond inhibition of tonic gonadotropin secretion to include a disturbance of phasic gonadotropin secretion.

Acute administration of corticotrophin-releasing hormone (CRH) has been shown to inhibit gonadotropin secretion in several species including rodents, sheep, humans, and nonhuman primates. Similarly, a variety of acute stressors have been shown to inhibit tonic gonadotropin secretion and may do so through a CRH mechanism. Stress-induced inhibition of tonic gonadotropin secretion below levels required for follicular maturation would be expected to inhibit ovulation. An additional mechanism whereby acute stressors could interfere with ovulation is through inhibition of the preovulatory gonadotropin surge. In the present study, we determined the effect of acute activation of the hypothalamic-pituitary-adrenal (HPA) axis on phasic gonadotropin secretion in female rhesus monkeys. Activation of the HPA axis was achieved by either a hypoglycemic challenge or blockage of cortisol synthesis with metyrapone, 24 h after an estradiol benzoate challenge. Neither metyrapone nor insulin-induced hypoglycemia inhibited gonadotropin secretion. In fact, the initiation of the luteinizing hormone and follicle-stimulating hormone surge was advanced by 7.4 +/- 0.4 h (p0.001) and 4.8 +/- 1.4 h (p = 0.04) respectively, in metyrapone-treated monkeys compared with saline controls. By contrast, hypoglycemia did not affect the gonadotropin surge. The gonadotropin surge was preceded by increased progesterone secretion in metyrapone-treated but not insulin-treated monkeys. This difference in progesterone secretion likely explains the advancement of the gonadotropin surge in the metyrapone-treated animals.

Objective: To evaluate the potential of photodynamic therapy with aminolevulinic acid (ALA-PDT) for ablation of endometrial explants in a rat endometriosis model and to compare the effect of ALA-PDT, electrosurgery, and surgical resection on normal peritoneum. Design: Prospective controlled experimental trial. Setting: University medical center. Animal(s): Mature Sprague-Dawley female rats. Intervention(s): Induction of endometriosis and subsequent treatment with ALA-PDT; electrosurgery, and simple resection, and ALA-PDT of normal peritoneum. Main Outcome Measure(s): Histopathological assessment. Result(s): Systemic ALA followed by exposure to photoactivating light for 10 or 15 minutes resulted in ablation of all explants harvested 3–4 days after treatment. Permanent destruction was confirmed by absence of regrowth by week 3. Exposure of normal peritoneum to ALA-PDT resulted in initial necrosis, with complete recovery by day 16. Adhesions were present on day 16 in 50% of cases after electrosurgery and in 100% of cases after resection. No adhesions were present in ALA-PDT-treated animals. Conclusion(s): Systemic ALA followed by exposure to photoactivating light at relatively low power densities for periods as brief as 10 minutes resulted in ablation of endometriotic explants. Exposure of normal peritoneum to ALA-PDT resulted in complete resurfacing. Both electrosurgery and surgical resection resulted in a greater incidence of surface adhesions.

To test the effectiveness of 5-aminolevulinic acid (ALA)-induced photodynamic endometrial ablation in the rhesus monkey under varying conditions of light delivery (fractionated versus continuous) and steroid priming.Photodynamic endometrial ablation was carried out in 17 rhesus monkeys that were either postmenopausal or in the early proliferative phase. Four hours after intralumenal injection of ALA (250 mg in 1 mL hyskon), a quartz fiber with a diffusing tip was inserted. A KTP tunable dye laser delivered 300 mW of light (635 nm) for 60 minutes in either continuous or fractionated fashion (20 minutes on, 5 minutes off, and 40 minutes on). In some experiments, thermistors were used to monitor temperature in the lumen and myometrium during light treatment. Hysterectomy was performed 3 or 4 days after treatment, and endometrial damage was assessed histologically. Two additional monkeys (one rhesus and one cynomolgus monkey) were exposed to the same protocol, except hyskon was substituted for ALA to control for potential ablative effects due to light treatment alone.Endometrial ablation was evident in all ALA-photosensitized specimens. The degree of ablation around the light fiber ranged from moderate to complete. The depth of ablation ranged from 1.14 +/- 0.54 to 2.15 +/- 1.62 mm (mean +/- standard deviation). Ablation was most complete in uteri of menopausal monkeys. Light treatment after ALA increased lumenal temperature from 36 C to 50 C, whereas temperature was not significantly increased by light treatment in the controls.This is the first report of endometrial destruction in the primate using a photodynamic approach. Whereas clinical application of photodynamic therapy (PDT) requires complete endometrial ablation to produce long-lasting amenorrhea, our results suggest that PDT may offer a simple office-based approach to endometrial ablation.

Objective: To report our experience developing and implementing an introductory course on research methods for Canadian obstetrics and gynecology residents. Methods: A program entitled “An Introduction to Research,” originating at Queen’s University, developed into an annual series of regional courses across Canada, under the auspices of the Association of Professors of Obstetrics and Gynaecology of Canada. Didactic lectures, interactive workshops, and online computer demonstrations introduced participants to the basic elements of clinical research. Results: Since its inception, over 1000 participants have attended the program. Nearly all of the 296 respondents to a course evaluation agreed that the program was well organized, presented material at an appropriate level, and was useful. Conclusion: This course ensured that residents in obstetrics and gynecology across Canada were given a basic level of research training, as required by the Royal College of Physicians and Surgeons of Canada.

The objective of the present study was to determine if the concentration of protoporphyrin IX (PpIX) in the rat endometrium could be increased by administering 5-aminolevulinic acid (ALA) in multiple doses or by continuous infusion. The effect of pH, temperature and time in solution on the stability of ALA were also investigated. Estrogen-filled silastic capsules were implanted subcutaneously into ovary intact female rats (200–225 g) (n = 66). On the third day of hormonal priming, ALA (10 mg or 25 mg) dissolved in saline and adjusted to a pH of 5–5.5 was administered intrauterine either as a single bolus or as two injections 3 hours apart (n = 10). A fifth group of rats was infused with 25 mg ALA over a 12 hour period using an osmotic minipump (n = 6). In a second experiment, ALA (25 mg) was injected immediately after being dissolved in saline (pH 2) (n = 16) or after incubation at 37°C for 12 hour (pH 2) (n = 7). PpIX was then extracted from the endometrium and myometrium using a 1:1 methanol/perchloric acid solution and quantified spectrofluorometrically. A dose-response relationship was observed between 10 and 25 mg of ALA and endometrial PpIX concentrations. However, no differences in endometrial PpIX concentrations were detected between rats administered ALA either as a single bolus or as two doses. Continuous infusion of 25 mg of ALA resulted in statistically lower endometrial PpIX concentrations compared to 25 mg ALA injected either as a single bolus or as two injections. Neither pH, temperature, nor time in solution affected ALA-induced PpIX accumulation. We conclude that the simplest way of achieving the highest PpIX concentration in the rat endometrium in vivo is to administer a bolus injection of 25 mg of ALA.

To investigate whether danazol is more effective than placebo for the treatment of premenstrual syndrome (PMS), we conducted a randomized, double-blind, crossover study comparing three successive cycles of danazol (200 mg bid) to three cycles of placebo. Thirty-one women meeting rigorous criteria for a diagnosis of severe PMS over two pretreatment cycles were enrolled; 28 of these subjects completed at least one cycle of treatment with symptom recordings, which were entered into the analysis. A significant period effect confounded the planned within-subject analysis and therefore, the main treatment comparisons were confined to the first period only. Symptom scores on the Premenstrual Tension Self-Rating Scale (PMTS), Beck Depression Inventory (BDI), and a Visual Analogue Scale (VAS) were compared for the premenstrual week in the last cycle of treatment. For the 16 patients on danazol, scores on the PMTS decreased by an average of 14.0 (10.7) (standard deviation) points from a baseline of 25.4 (5.6) points. For the 12 patients on placebo, PMTS scores decreased by an average of 3.6 (9.5) points from a baseline of 23.5 (5.8) points (14.0 vs. 3.6; p = .0133, unpaired t-test). Seven (43.8%) of the subjects on danazol achieved a clinically relevant reduction of symptoms into the asymptomatic range (PMTS scores < or = 5) as compared to one (8.3%) of the subjects on placebo. Thus, danazol (200 mg bid) provided greater relief from severe PMS during the premenstrual week than did placebo.

Both low body weight and obesity can effect menstrual function and fertility. Although body weight is a significant factor current research suggests that a combination of physical psychological and nutritional stresses act additively in the determination of the onset and rate of pubertal progression menstruation and fertility. Abrupt or marked weight loss particularly when combined with physical or psychological stress has been shown to disrupt hypothalamic gonadotropin-releasing hormone leading at 1st to subtle endocrine abnormalities such as luteal phase defects and ultimately to oligomenorrhea or amenorrhea. The degree of hypothalamic dysfunction is in part linked to the percentage of body fat rather than body weight. In cases of obesity there appear to be complex pathophysiologic mechanisms involving changes in sex hormone binding globulin altered ovarian and adrenal androgen production changes in peripheral aromatization of androgens to estrogen and inappropriate gonadotropin secretion. Obese anovulatory women show higher concentrations of estrone and E2 than ovulatory obese women or women of normal weight. In most cases the process of weight reduction is sufficient to initiate resumption of menstrual cyclicity.

We previously observed that morphine stimulated luteinizing hormone (LH) secretion from ovariectomized rats when administered intravenously at a dose of 10 mg/kg body weight. The objectives of the present study were to determine: (1) if this paradoxical effect of morphine on LH secretion could be antagonized by naloxone; (2) whether beta-endorphin also stimulated LH secretion under similar conditions; (3) what influence, if any, the ovaries have on the expression of this opiate-induced LH secretion, and (4) whether this paradoxical effect of morphine extended to prolactin (PRL) secretion. An intravenous injection of morphine, 10 mg/kg body weight, to ovariectomized rats acutely increased both plasma LH and PRL concentrations. The LH and PRL responses were completely antagonized by the concurrent administration of the opiate antagonist naloxone (1 mg/kg body weight). In contrast, morphine suppressed LH concentrations and had no effect on PRL levels when injected at a dose of 1.0 mg/kg body weight. Intravenous injections of beta-endorphin, 1 mg/kg body weight, increased PRL concentrations to a level comparable to that observed following morphine, 10 mg/kg body weight, and produced a transient but insignificant inhibition of LH release. Intraventricular injections of much lower doses of beta-endorphin resulted in a dose-dependent suppression of LH release and a dose-dependent stimulation of PRL release in ovariectomized rats. Intravenous administrations of morphine (10 mg/kg), but not beta-endorphin (1 mg/kg), to normal female rats resulted in a 2-fold increase in LH concentrations similar to that observed in ovariectomized rats, whereas both treatments similarly increased PRL concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

The ability of dynorphin and beta h-endorphin (beta h-EP) to stimulate prolactin (PRL) release in male rats was examined. Rats were injected intraventricularly with either 1 or 10 microgram dynorphin, 1 or 10 microgram beta h-EP, 10 microgram dynorphin together with 20 microgram naloxone (NAL), or an equivalent volume (13 microliter) of saline. Dynorphin caused a dose-dependent release of PRL which was significant 10 min after injection but not at later sampling times. beta h-EP also increased serum PRL levels and maintained elevated PRL levels for at least 60 min. NAL, a specific opiate antagonist, completely blocked dynorphin-induced PRL release. These results indicate that dynorphin is a potent stimulator of PRL release, but its stimulatory activity is transient relative to the activity exhibited by beta h-EP. Furthermore, dynorphin's action is specific since NAL completely blocked dynorphin induced PRL release.

Morphological evidence suggests that GnRH may be released into cerebrospinal fluid (CSF) of the third ventricle. Therefore, a method of cannulating the third ventricle of monkey brains was developed for the purpose of examining GnRH secretion in primates. A stainless steel guide cannula was stereotaxically implanted into the third ventricle of 14 ovariectomized rhesus monkeys. A Silastic cannula for collecting CSF was inserted via the guide cannula into the ventral portion of the ventricle, permitting repeated CSF sampling for long time periods from the same animal. One week to 6 months after cannulation, CSF was collected continuously for periods of 5-10 h at 2 different rates (480 and 120 microliter/h) from conscious monkeys seated in chairs. Samples were divided into 15-min fractions, and the GnRH concentration in each was determined by RIA. In contrast to most previous studies, third ventricular CSF was found to contain significant concentrations of GnRH. GnRH was detected in 40 of 50 collections. Concentrations ranged from less than 8 to greater than 800 pg/ml, a range similar to that observed in hypophyseal portal blood. Furthermore, fluctuations within individual collections indicated that GnRH was released in pulses. The mean GnRH pulse frequency during the higher rate of CSF withdrawal was 0.43 +/- 0.06 pulses/h (n = 31), while the mean pulse amplitude was 91 +/- 7 pg/ml (n = 64). Neither parameter was influenced by the rate of CSF removal, as frequency was 0.52 +/- 0.08 pulses/h (n = 19) and amplitude was 94 +/- 11 pg/ml (n = 82) during the lower collection rate. However, the CSF withdrawal rate had a profound influence on LH secretion. In 12 of 17 collections at the higher rate, LH levels plummeted to undetectable concentrations during the first 2 h of CSF exfusion and remained low throughout the collection period. Pituitary responsiveness was not reduced, as a GnRH bolus (0.25 or 2.5 micrograms) after 6 h of CSF removal elicited a dose-dependent stimulation of LH secretion. In contrast, a higher incidence of normal pulsatile LH secretion (12 of 19 collections) was observed when the CSF withdrawal rate was reduced. During these 12 collections, LH and GnRH pulses occurred at regular intervals and exhibited similar pulse frequencies (mean +/- SE, 0.76 +/- 0.07 and 0.67 +/- 0.09 pulses/h for LH and GnRH, respectively). Most GnRH and LH pulses were synchronized, as 86% of all GnRH pulses (43 of 50) were accompanied by a LH pulse.(ABSTRACT TRUNCATED AT 400 WORDS)

The effect of electrical stimulation in the subfornical organ (SFO) on plasma luteinizing hormone (LH) concentrations has been examined in the conscious freely moving male Sprague-Dawley rat. Plasma LH levels were significantly elevated above basal levels 15 min following stimulation in the SFO. In contrast, stimulation in the adjacent hippocampal commissure caused no significant change in plasma concentrations of LH. These results correlate well with previous electrophysiological studies demonstrating that SFO stimulation activates putative LH-releasing hormone (LH-RH) containing neurons in the septum which project to the median eminence and add further support to the hypothesis that the SFO plays a significant role in the control of reproductive function.

The stability of GnRH stored in solution under different conditions was assessed employing both immunoassay and bioassay techniques. No appreciable loss of activity was encountered after 4 weeks of storage at either 4 degrees C or room temperature.

ACTH was measured with both C-terminal and midportion antibodies in monkey hypophyseal portal plasma, and compared to levels in monkey peripheral plasma, medial basal hypothalamus, and anterior pituitary. In nine female monkeys, mean hypophyseal portal blood C-terminal ACTH immunoactivity was 5290 +/- 2010 (SEM) pg/ml, whereas the mean midportion ACTH level was 949 +/- 178 pg/ml. These immunoactivities were not lower in two monkeys that were completely hypophysectomized 30 min before portal blood collection. The ratio of C-terminal to midportion ACTH immunoactivity was 4:1 in two monkey medial basal hypothalami, and 1:1 in four monkey anterior pituitary glands. Gel filtration of hypophyseal portal plasma extract and of medial basal hypothalamus showed that the C-terminal ACTH immunoactivity eluted in the same position as the corticotropin-like-intermediate lobe peptide standard. The similarity of the C-terminal to midportion ACTH ratios in monkey medial basal hypothalamus and portal blood, and the observation that ACTH immunoactivity was not significantly lower in two hypophysectomized monkeys suggests that portal blood C-terminal ACTH immunoactivity is of hypothalamic rather than pituitary origin. We conclude that monkey hypophyseal portal blood contains high levels of a C-terminal fragment of ACTH, which coelutes with corticotropin-like intermediate lobe peptide on gel filtration, and which is secreted from the brain directly into the portal circulation.

Morphine and the endogenous opioid peptides (EOP) exert similar effects on the neuroendocrine system. When adminstered acutely, they stimulate growth hormone (GH), prolactin (PRL), and adrenocorticotropin (ACTH) release, and inhibit release of luteinizing hormone (LH), follicle stimulating hormone (FSH),and thyrotropin (TSH). Recent studies indicate that the EOP probably have a physiological role in regulating pituitary hormone secretion. Thus injection of naloxone (opiate antagonist) alone in rats resulted in a rapid fall in serum concentrations of GH and PRL, and a rise in serum LH and FSH, suggesting that the EOP help maintain basal secretion of these hormones. Prior administration of naloxone or naltrexon inhibited stress-induced PRL release, and elevated serum LH in castrated male rats to greater than normal castrate levels. Studies on the mechanisms of action of the EOP and morphine on hormone secretion indicate that they have no direct effect on the pituitary, but act via the hypothalamus. There is no evidence that the EOP or morphine alter the action of the hypothalamic hypophysiotropic hormones on pituitary hormone secretion; they probably act via hypothalamic neurotransmitters to influence release of the hypothalamic hormones into the pituitary portal vessels. Preliminary observations indicate that they may increase serotonin and decrease dopamine metabolism in the hypothalamus, which could account for practically all of their effects on pituitary hormone secretion.