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We previously demonstrated that protein kinase C (PKC) activators, i.e. L-alpha-1,2-dioctanoyl glycerol (C8) and phorbol 12-myristate 13-acetate (PMA), mimic the stimulatory effects of GnRH on both LH glycosylation and release. To further evaluate the roles of PKC, we determined: 1) the interaction between PKC activator and GnRH; and 2) the effects of depleting cellular PKC with a high dose of PMA on LH glycosylation vs. release. Anterior pituitaries excised from ovariectomized rats were enzymatically dispersed and cultured. In series 1 experiments, day 3 monolayer cells were incubated in the presence of radiolabeled precursors and GnRH (0, 1, or 100 nM), with or without C8 (200 microM). In series 2 experiments, day 2 cells were pretreated with either PMA (1 microM) or vehicle (0.08% dimethyl sulfoxide) for 24 h and then incubated with diluent, GnRH (1 nM), or PMA (20 nM), and radiolabeled precursors for 4 h. LH translation and glycosylation were monitored by measuring incorporation of [14C]alanine ([14C]A) and [3H]glucosamine ([3H]GA), respectively, into LH. Immunoreactive LH (IRLH) was measured by RIA. In series 1 experiments, C8 increased basal release of IRLH, potentiated IRLH release stimulated by 1 nM GnRH, but not by 100 nM GnRH. C8 elevated total [3H]GA-LH but had no additive effects with GnRH. In series 2 experiments, PMA pretreatment inhibited subsequent PMA-stimulated IRLH release. However, PMA pretreatment did not affect GnRH-induced IRLH release even though PMA pretreatment decreased cellular IRLH content. In comparison, PMA pretreatment reduced both GnRH- and PMA-stimulated total [3H]GA-LH. PMA pretreatment had no effects on total [14C]A-LH in the presence of GnRH or PMA, but reduced the basal level. In summary, PKC activators had no additive effects on either IRLH release or LH glycosylation stimulated by a maximal dose of GnRH. However, PMA pretreatment decreased GnRH-induced LH glycosylation without depressing LH release. These results suggest differential roles of PKC in the actions of GnRH on LH glycosylation vs. LH release.

In this study we attempted to dissociate big LH (BLH) into low molecular weight forms by treatment with either ribonuclease or mercaptoethanol. We compared the molecular nature of BLH and native LH (NLH) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Also, we explored the relationship between BLH and NLH by both continuous and pulse-chase labeling techniques on the premise that BLH represents a precursor to NLH. During the pulse periods, [‘4C1-alanine-Iabeled BLH was detected in the tissue before [‘4C)-NLH, and then the amounts of both forms increased linearly with time. At all times, the percentage of total 114C) -LH as BLH remained very high. �3 HJ-Glucosamine-labeled BLH and NLH were detected coincidentally in the tissue, and then 1� H)-BLH increased at a constant rate, whereas 1� H]-NLH increased at an increasing rate with time. The percentage of total �3 HJ-LH as BLH declined with time. The magnitude of change of radiolabeled LH varied with conditions during the chase periods, but similar trends were observed in all experiments. During the chase, (� Cl -BLH decreased

The ability of 67Ga citrate and 99mTc pyrophosphate cardiac imaging to detect myocarditis was assessed in an experimental rabbit model. Twenty-three rabbits were imaged approximately 72 hours after infusion of i.v. norepinephrine. Diffuse cardiac uptake was found in 13 of 15 rabbits scanned with 67Ga. Tissue distribution studies documented significant myocardial uptake of 67Ga in those with positive scans. Precordial imaging and tissue distribution studies revealed no cardiac uptake in the eight rabbits scanned with 99mTc. Histologic examination of all 23 hearts revealed qualitatively similar, typical lesions of myocarditis. This study suggests that cardiac imaging with 67Ga may be useful in the detection of myocarditis.

We examined basal and gonadotropin-releasing hormone (GnRH)-stimulated luteinizing hormone (LH) release and synthesis in response to drugs that raise intracellular adenosine 3',5'-cyclic monophosphate (cAMP) levels. Anterior pituitaries from ovariectomized rats were incubated with or without drugs in the presence of GnRH and [3H]glucosamine. Neither 8-bromo-cAMP (8-Br-cAMP) (10 mM), cholera toxin (10 micrograms/ml), nor phosphodiesterase inhibitors [theophylline, 2 and 8 mM; 3-isobutyl-1-methylxanthine (MIX), 0.2 mM] had any detectable effect on release of immunoreactive LH (IR-LH) when used alone. However, 8-Br-cAMP and the inhibitors potentiated (P less than 0.01) GnRH-induced release of IR-LH. Total radiolabeled LH in the system was elevated (P less than 0.01) by either GnRH, 8-Br-cAMP for cholera toxin, but reduced (P less than 0.01) by 8 mM theophylline and unaffected by MIX or 2 mM theophylline. 8-Br-cAMP did not alter the effect of GnRH on radiolabeled LH in the total system, whereas MIX and 2 mM theophylline reduced (P less than 0.05) it. These results suggest that 1) cAMP does not effect LH release directly, but may interact with GnRH to potentiate it, 2) GnRH and cAMP have a similar mode of action on LH glycosylation, and 3) phosphodiesterase inhibitors have additional actions that interfere with LH glycosylation.

We determined if luteinizing hormone (LH) synthesis is Ca2+ dependent and coupled to LH release. We monitored LH synthesis when LH release was stimulated either by specific [gonadotropin-releasing hormone (GnRH)] or nonspecific stimuli (50 mM K+ and 2 or 20 microM Ca2+ ionophore A23187) and inhibited by Ca2+-reduced medium. LH synthesis was estimated by measuring incorporation of [3H]glucosamine (glycosylation) and [14C]alanine (translation) into total (cell and medium) immunoprecipitable LH by cultured rat anterior pituitary cells. Both GnRH (1 nM) and 50 mM K+ significantly stimulated LH release and glycosylation, but had no effect on LH translation. A23187 also stimulated LH release, but significantly depressed glycosylation of LH and total protein and [14C]alanine uptake. Deletion of Ca2+ from the medium depressed both GnRH-induced LH release and glycosylation. Addition of 0.1 mM EGTA to Ca2+-free medium not only inhibited GnRH-induced release and glycosylation of LH but also uptake of precursors and glycosylation and translation of total protein. Thus glycosylation and release of LH are Ca2+ dependent. Whether parallel changes in LH release and glycosylation reflect a cause and effect relationship remains to be determined.

A technique for the computer analysis of the uniformity of response of the Digital Autofluoroscope to a uniform radioactive source is presented.

Two-hundred-eighty-nine patients received treatment with chromic phosphate (/sup 32/P) colloidal suspension (CPCS) 346 times since 1964. One-hundred-seventy-eight patients received 200 intraperitoneal treatments. One-hundred-fifteen patients received 144 intrapleural treatments. Six patients received both intraperitoneal and intrapleural treatments. Two patients received two intrapericardial treatments. Results of therapy were evaluated three months later and then at yearly intervals. In those patients who survived three months, the referring physician observed improvement in 85% of intraperitoneal treatment and in 75% of intrapleural treatments.

These experiments investigated the effect of frontal hypothalamic deafferentation (HD) on basal LI-I levels and on estrogen-induced LH release in the ewe. HD was performed with a Halsz knife positioned with the aid of x-ray and stereotaxic apparatus. In ovariectomized ewes, serum LH levels were determined in samples collected by jugular venipuncture at 20-mm intervals for 3 h, once prior to HD and again approximately 4 weeks after HD. The ability of an injection of 50 �g of estradiol benzoate (EB) to elicit an LH surge also was determined both before and after HD of - ovariectomized ewes. Bilateral cuts, 8 mm in diameter, placed at the anterior edge of the arcuate nucleus, reduced mean basal LI-I from 8.2 ± 2.0 ng/mI to nearly nondetectable levels and oblitera- ted both pulsatile and EB-induced LH release. Bilateral cuts placed between the arcuate nucleus and the suprachiasmatic nuclei reduced mean basal LH levels from 7.5 ± 1.0 to 1.8 ± 0.3 ng/ml, but did not alter the pulsatile pattern and blocked EB-induced LH release. Bilateral cuts placed through the suprachiasmatic nuclei did not reduce mean LH levels or alter the pulsatile pattern, however, EB-induced LH release was either blocked or greatly reduced. In ovariectomized ewes subjected to sham HD or to posterior HD, LH secretion was unaltered. Frontal HD of intact ewes blocked ovu- lation. These data suggest that in the ewe, neural input from the suprachiasmatic or preoptic re- gions is not required for maintenance of basal LH levels, but is required for occurrence of an LH surge. Input from both the retrochiasmatic region and the MBH appears necessary for the mainten- ance of normal basal LH levels in ovariectomized ewes.

We compared the effects of gonadotropin-releasing hormone (GnRH) and cyclic nucleotides on biosynthesis and release of luteinizing hormone (LH) by rat anterior pituitary glands (APs). APs from ovariectomized rats were incubated in the presence of test compounds, [3H]glucosamine, and [14C]alanine. GnRH significantly (P less than 0.01) increased both incorporation of [3H]glucosamine into LH (glycosylation) and release of immunoreactive LH (IR-LH) and [3H]LH. None of the cyclic nucleotides alone at 5 mM significantly stimulated release of IR-LH. Adenosine 3',5'-cyclic monophosphate (cAMP), N6,O2'-dibutyryl cAMP (DBcAMP), and 8-bromo-adenosine 3',5'-cyclic monophosphate (8-Br-cAMP) stimulated (P less than 0.01) glycosylation, whereas 8-Br-AMP, 8-bromoguanosine 5'-monophosphate (8-Br-GMP), cGMP, and 8-Br-cGMP had no detectable effect. Release of [3H]LH was increased by GnRH, 8-Br-cAMP, and DBcAMP, but not by other nucleotides. None of the cyclic nucleotides elevated [14C]LH, whereas GnRH elevated it (P less than 0.01) in the medium. Dose-response curves for glycosylation in response to 8-Br-cAMP and GnRH were parallel. In contrast, dose-response curves for release of both [3H]LH and IR-LH were nonparallel. It appears that cAMP can mimic the action of GnRH on LH glycosylation, but may have little direct effect on LH release.

A simple classification system for reporting mammograms is described, similar in format to a system formerly used for reporting Papanicolaou smears. Class 1 indicates an examination with normal findings. Class 2 indicates findings of a mass or masses that appear to be benign. Class 3 indicates findings of an indeterminate lesion, suggestive of possible malignancy. Class 4 indicates probable malignancy. Advantages of the classification system include effective triage of patients and easier computerized record keeping for long-term tracking.

The objectives were to determine if relative lengths of photoperiods that induce reproductive cycles in ewes affect the length of the subsequent breeding season, if duration of the refractoriness that terminates breeding is affected by photoperiod length, and if the resulting refractoriness to an inductive photoperiod is absolute. Groups of Welsh Mountain ewes were exposed to either 12L:12D (n = 12) or 8L:16D (n = 6) photoperiods beginning at the summer solstice when daylengths reach a maximum of 17.5 h at Bristol, England. A control group (n = 10) was exposed to natural daylengths. Ovarian cycles in the controls, as judged by monitored plasma progesterone levels, commenced in early October, about 1 mo later (p less than 0.001 in both cases) than in sheep exposed to 12L:12D or 8L:16D. The advancement in cycle onset was similar under 12L:12D and 8L:16D (69 +/- 2 and 77 +/- 4 days after the summer solstice compared with 102 +/- 2 days in the controls). Duration of the breeding season (100 +/- 4 days) in ewes exposed to 12L:12D was significantly shorter (p less than 0.001 in both cases) than in ewes exposed to natural daylengths or 8L:16D (153 +/- 3 and 133 +/- 5 days, respectively). Approximately 70 days after the ending of ovulatory cycles in the 12L:12D group, half of the animals (n = 6) were transferred to 8L:16D. This treatment greatly (p less than 0.001) reduced the duration of anestrus and cycles began again 62 +/- 4 days after transfer to 8L:16D, or about 90 days earlier than in ewes (n = 6) remaining in 12L:12D.(ABSTRACT TRUNCATED AT 250 WORDS)

A review of the Harrisburg Hospital experience in treatment of hyperthyroidism with low administered doses of I131 is presented. The incidence of hypothyroidism is 11 per cent. Hypothyroidism was most frequently diagnosed within 4 months of treatment.Three per cent of patients remain hyperthyroid. It is presumed that additional I131 in this group will result in a satisfactory clinical result.