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Present and future research into the electroproduction of kaons plays an important role at Mainz Microtron MAMI. With the Kaos spectrometer employed for kaon detection in the multi-spectrometer facility, cross section measurements of the exclusive p(e, e′K+)Λ, ∑0 reactions at low momentum transfers have been performed. Isobar and Regge-plus-resonance models were compared with the data. These measurements have clearly discriminated between effective Lagrangian models for photo- and electroproduction of strangeness. New experiments with polarized beam at low four-momentum transfer are addressing the imaginary part of the longitudinal-transverse response in this process, that can be separated by flipping the beam electron helicity. These studies are important for the understanding of basic coupling constants in the isobar models and the electromagnetic form factors of the hadrons and their resonances involved in the process.

Ammar, A. A., F. Sederholm, T. R. Saito, A. J. W. Scheurink, A. E. Johnson, and P. Sodersten. NPY-leptin: opposing effects on appetitive and consummatory ingestive behavior and sexual behavior. Am J Physiol Regulatory Integrative Comp Physiol 278: R1627-R1633, 2000.--Many studies have indicated that neuropeptide Y (NPY) stimulates and leptin inhibits food intake. In line with this, intracere-broventricular injection of NPY (10 [micro]g) stimulated and leptin (10 [micro]g) inhibited intake of a sucrose solution when female rats were required to obtain the solution from a bottle. However, NPY inhibited and leptin stimulated intake if the solution was infused intraorally. Thus NPY stimulates the responses used to obtain food but inhibits those used to consume food, and leptin has the opposite effects. To test the specificity of these responses the sexual behavior of male rats was examined. NPY-treated males showed minor deficits in sexual behavior but chose to ingest a sucrose solution rather than copulate with a female if offered the choice. By contrast, leptin-treated males ingested little sucrose and displayed an increase in ejaculatory frequency if given the same choice. It is suggested that NPY is not merely an orexigenic peptide, but one that directs attention toward food. Similarly, leptin may not be an anorexic peptide, but one that diverts attention away from food toward alternate stimuli. food intake; reproduction; peptides; behavioral choice

The HypHI experiment for precise hypernuclear spectroscopy with induced reactions of stable heavy ion beams and rare isotope beams is currently under preparation at GSI. The main goal of the HypHI project is to study neutron and proton rich hypernuclei and to measure directly hypernuclear magnetic moments at GSI and FAIR. In the first HypHI experiment (Phase 0) planned in 2009, the feasibility of precise hypernuclear spectroscopy with heavy ion beams will be demonstrated by observing π- decay channels of $_\Lambda ^3 {\rm{H}}$, $_\Lambda ^4 {\rm{H}}$ and $_\Lambda ^5 {\rm{He}}$ with 6Li projectiles at 2 A GeV impinging on a 12C target. An overview of the HypHI project and the details of the Phase 0 experiment will be discussed. [ABSTRACT FROM AUTHOR]

The FRS-RISING set-up at GSI uses secondary radioactive beams at relativistic energies for nuclear structure studies. At GSI the fragmentation or fission of stable primary beams up to 238U provide secondary beams with sufficient intensity to perform γ-ray spectroscopy. The RISING set-up is described and results of the first RISING campaign are presented. New experimental methods at relativistic energies are being investigated. Future experiments focus on state-of-the art nuclear structure physics covering exotic nuclei all over the nuclear chart. [ABSTRACT FROM AUTHOR]

At the Mainz Microtron MAMI, the first high-resolution pion spectroscopy from decays of strange systems was performed by electron scattering off a (9)Be target in order to study the Λ binding energy of light hypernuclei. Positively charged kaons were detected by a short-orbit spectrometer with a broad momentum acceptance at 0° forward angles with respect to the beam, efficiently tagging the production of strangeness in the target nucleus. Coincidentally, negatively charged decay pions were detected by two independent high-resolution spectrometers. About 10(3) pionic weak decays of hyperfragments and hyperons were observed. The pion momentum distribution shows a monochromatic peak at pπ≈133  MeV/c, corresponding to the unique signature for the two-body decay of hyperhydrogen Λ(4)H→(4)He+π(-), stopped inside the target. Its Λ binding energy was determined to be BΛ=2.12±0.01  (stat)±0.09  (syst)MeV with respect to the (3)H+Λ mass.

Feline obesity generally results in aberrations to plasma metabolite levels, such as lipid concentrations and lipoprotein composition. This study sought to investigate the resultant effect of obesity on cholesterol lipoprotein composition and circulating adiponectin concentrations in cats. Plasma glucose, lipids (triglyceride, cholesterol and free fatty acid), insulin and adiponectin concentrations, and cholesterol lipoprotein composition were measured and compared between body condition score (BCS) determined normal healthy control and obese cats. Although the obese group demonstrated higher levels of plasma cholesterol, glucose, and triglycerides, as compared to healthy controls, the difference was insignificant thus indicating that the BCS determined obese cats may have been overweight and not morbidly obese. Plasma insulin levels were significantly higher (25-30%) versus healthy control animals thereby possibly hinting at the ensuing emergence of obesity induced insulin resistance. However, the BCS determined obese cat demonstrated a significant reduction (p<0.05) in plasma adiponectin concentration and a significant increase (p<0.05) in LDL-cholesterol % as compared to age matched healthy control animals. This would indicate that changes in plasma adiponectin concentration and cholesterol lipoprotein composition may be good early indicators of obesity in cats., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

In addition to the known four alternative first exons E1(1), E1(2), E1(3) and E1(4) of the rat prolactin receptor (PRL-R) gene, a novel first exon, E1(5), was identified by cDNA cloning of the 5'-end region of PRL-R mRNA in the rat liver. Genomic fragments containing E1(5) and its 5'- or 3'-flanking regions were also cloned from rat kidney genomic DNA. A sequence search for E1(5) revealed that E1(5) is located 49 kb upstream of exon 2 of the PRL-R gene in rat chromosome 2q16. RT-PCR analysis revealed that E1(5) was preferentially expressed in the liver, brain and kidney. Expression profiles of E1(2)-, E1(3)- and E1(5)-PRL-R mRNAs in the liver of male and female rats at 5 days of age and those at 8 weeks of age were examined by RT-PCR. The levels of E1(2)-PRL-R mRNA in the female rat increased remarkably in rats at 8 weeks of age compared with those at 5 days of age, and the levels of E1(5)-PRL-R mRNA in the male rat decreased markedly at 8 weeks of age compared with those at 5 days of age. In the female rat, the levels of E1(2)-PRL-R mRNA at 8 weeks of age decreased with ovariectomy performed at 4 weeks of age and recovered with the administration of beta-oestradiol. On the contrary, the levels of E1(5)-PRL-R mRNA increased with ovariectomy and decreased with the oestrogen treatment. In the male rat liver, the levels of E1(2)-PRL-R mRNA at 8 weeks of age increased strikingly with castration performed at 4 weeks of age and became undetectable with the administration of testosterone. The levels of E1(5)-PRL-R mRNA increased slightly with castration and were restored by testosterone treatment. Removal of gonadal tissues and sex steroid hormone treatment had no effect on the expression levels of E1(3)-PRL-R mRNA in both female and male rat livers. These results indicated that the expression of the PRL-R gene in the liver is regulated by the differential effects of sex steroid hormones on the transcription of the multiple first exons including the novel one.

Waveforms of isolation calls emitted from hamster pups, which were Syrian hamsters, Djungarian hamsters, and Chinese hamsters, were compared in a basic study on improving reproduction by decrease of cannibalism, because it was reported that maternal behavior was induced by isolation calls in rodents. Isolation calls of hamster pups, isolated from their mother and receiving cold stress, were collected by Real-Time Spectrogram (RTS), and calculated to spectrograms and power spectra by SIGNAL. Isolation calls consisted of ultrasonic vocalizations (USVs) and audible vocalizations (ADVs) in each species. Waveforms of isolation calls emitted by the hamster pups, were shown to have several characteristic features. In this study, the species specificity of isolation calls was shown in hamster pups. It would seem that the species specificity originates in the differences of sensitivity to cold stress via the autonomic nerve in hamsters.

The relationship among ultrasonic vocalization (USV), prolactin and maternal behavior was investigated in lactating rat mothers and their pups. The lactating mother had a cannula inserted into the external jugular vein, and was exposed to USVs emitted from a pup immediately. Changes of prolactin and maternal behavior were determined. Prolactin increased dramatically during exposure to USVs, when maternal search, retrieving and nest building behavior appeared significantly. These results suggested that the relationship among USV, prolactin and maternal behavior was included in communication between lactating mother and pup.

Natural killer T (NKT) cells are a newly discovered subset of lymphocytes. It appears that this subset has potential as important regulators of immune responses. But because there are relatively few NKT cells in lymphoid organs and because of technical difficulties in detecting NKT cells in most mouse strains, the roles of NKT cells have not been fully identified and little attention has been paid to the roles of NKT cells in immunological experiments in which NK1.1- strains were used. To examine the existence of functional NKT cells in various strains of experimental mice, including NK1.1- strains, we utilized alpha-galactosylceramide (KRN7000) which is thought to react specifically with NKT cells. Indeed, we could confirm that early cytokine (IL-4 and IFN-gamma) secretion at 2 h after the injection of KRN7000 was dependent on NKT cells. With this in vivo system, we have successfully detected the presence of functional NKT cells in various mouse strains, including AKR/N, BALB/c, C3H/HeJ, C3H/HeN, C57BL/6, C.B-17, CBA/N, NC, NOD, SJL, W/Wv, aly/aly and aly/+. Notable increases of serum IL-4 were detected in W/Wv and aly/+ strains, and defective response of IFN-gamma in SJL mice and that of IL-4 in NOD mice were observed. This is the first report to show the functional significance of NKT cells in cytokine secretion in various mouse strains in response to a ligand for the T cell receptor of NKT cells.

We studied whether marking behavior in Mongolian gerbils would be innate or learned behavior. The marking behavior was defined as "animals rubbing their abdominal scent glands on small protruding objects". Between 21 and 90 days of age, Mongolian gerbils, which were kept under such conditions that they would be unable to learn this behavior, were observed at intervals of 5-15 days to find out if there were signs of the behavior or not. Six male and four female Mongolian gerbils were used for observing. Neonate Mongolian gerbils during the age of 3 to 28 days were fostered by ICR mother mice. Weaning Mongolian gerbils were then individually kept away from the others. Marking behavior was observed in 2 out of 6 males at 50 days of age and 2 of 4 females at 60 days and the mean frequency of the marking behavior for 10 min was 3.5 in the males and 5.0 in the females. These results suggest that marking behavior was innate and not learned behavior in Mongolian gerbils.

In a preliminary test male rats were allowed to ingest a 1 M solution of sucrose from a drinking spout. After daily intake of sucrose became stabilized, the males were given a sexually receptive or non-receptive female and the bottle filled with sucrose solution simultaneously. The ingestive and copulatory behavior was observed for 60 min under illumination by a red lamp. The data obtained from this study showed that the ingestive behavior of males was suppressed by the presence of sexually receptive females and, conversely, the sexual behavior of males was not affected by the presence of a bottle of sucrose. These results suggest that the presence of a sexual partner inhibits appetitive ingestive behavior, i.e., the responses used by male rats to obtain food.

A marking-like behavior (defined by authors), a marking behavior, and growth of the scent glands were observed in young Mongolian gerbils of an inbred strain. In males and females, a marking-like behavior, in which animals rub their abdominal scent glands on the floor, began to be seen at the age of 19 days and could be seen in almost all the gerbils at 22 days of age during the suckling period. The frequency of this behavior was highest at 60 days of age (males: 17.9/10 min, females: 15.4/10 min) and there was no sex difference. Marking behavior, in which animals rub their abdominal scent glands on small protruding objects, began to be seen at the age of 40 days in males and 50 days in females. The frequency of this behavior tended to increase until 90 days of age in males (13.7/10 min), but the levels were low (2.5-5.0/10 min) in females. The values in the male group therefore tended to be higher than that in the female group. Macroscopic scent gland pads were clearly observed at the age of 30 days in males, but not until 45 days of age in females. At the age of 45-90 days, the length of the scent gland pad in males and females was 2.1-2.8 and 1.6-1.7 cm, respectively and the width was 0.3-0.5 in males and 0.2-0.3 cm in females. During this period, the length and depth of the pads in males were significantly greater than those in females (p < 0.05). Histological examination of the structure of the scent glands after the age of 45 days showed that the development of clusters of acinar cells in females occurred much later than that in males, but the basic structure of these glands was similar in both sexes. These results suggest that the marking-like behavior was manifested although during the period when the scent glands had not yet developed, whereas true marking behavior first occurred when the glands were moderately well developed.

Ingestive behavior was activated in male rats by intraoral intake and intake from a bottle of 1-M solution of sucrose. Intraperitoneal injection of p-chloroamphetamine (PCA), releasing central 5-hydroxytryptamine (5-HT) from serotonergic nerve terminals, inhibited ingestion of the sucrose solution. Significant inhibition of sucrose intake by PCA was observed at 1.25 and 2.5 mg/kg dose in a bottle intake test, and at 5.0 mg/kg dose in an intraoral intake test. These findings suggested that 1.25 and 5.0 mg/kg of PCA suppressed appetitive ingestive behavior and consummatory ingestive behavior in male rats, respectively.

There is no report on the fine structure of three types of olfactory organs in Xenopus laevis. Their functional assignments in olfaction are not yet established. The fine structure of three types of olfactory organs, olfactory epithelium (OE), vomeronasal organ (VNO), and middle chamber epithelium (MCE), was examined in Xenopus laevis by light and electron microscopy. The olfactory cells of the OE and the sensory cells of the VNO were equipped with cilia and microvilli, respectively, similar to terrestrial animals that possess both the OE and the VNO. On the other hand, the sensory cells of the MCE were classified into two types, the sensory cells with cilia and the sensory cells with microvilli, like those of the OE in fish. These findings suggest that the OE and the VNO in Xenopus laevis detect different kinds of odoriferous molecules in air, whereas the MCE is involved in the perception of odorants in water.

The present study was undertaken to determine sperm motility and counts in semen yielded by para-chloroamphetamine (PCA)-induced ejaculation of aged rats which had lost their reproductive ability, and to attempt artificial insemination with suspensions of spermatozoa obtained in this way. The semen yielded by PCA-induced ejaculation from aged (75-week-old) rats had average sperm counts of 0.82 +/- 0.69 x 10(7), which were much lower than the average counts (9.42 +/- 1.65 x 10(7)) for semen spontaneously ejaculated by young adult rats (14 weeks old). However, 77.5% of the spermatozoa contained in the PCA-induced semen were rated as showing the most active movement. Spermatozoa collected in this way were injected into the upper parts of both uterine horns or into both ovarian bursae. Both methods made the females pregnant, but the results were better after injection into the ovarian bursae. The offspring born to these females showed no abnormalities.

The olfactory organs are equipped with their own associated glands, Bowman's glands (BG) of the olfactory epithelium (OE), and Jacobson's glands (JG) of the vomeronasal organ (VNO). Histology and ultrastructure of these glands in the adult were investigated in the Japanese reddish frog, Rana japonica, along with their development from hatching to the end of metamorphosis. In the adult, BG cells contained large, electron-opaque secretory granules, intensely PAS-positive by light microscopy, while JG cells contained middle-sized secretory granules with moderate electron density, only faintly PAS-positive. Embryologically, BG appeared within the OE at 44 days after hatch, increased in number and were situated in the lamina propria under the OE at 52 days after hatch. BG cells contained large, electron-opaque granules, and well-developed rER at this time. While, JG appeared much earlier than BG. The VNO appeared as a concave of the ventral part of the OE at 4 days after hatch, and JG appeared under the VNO at 10 days after hatch. JG cells contained well-developed rER at 12 days after hatch. Secretory granules appeared in a small number in JG at 24 days after hatch, and increased thereafter. These findings suggest that JG may take part in secretion earlier than BG in ontogeny.

Histological and ultrastructural development of the olfactory epithelium (OE) and vomeronasal organ (VNO) was investigated in the Japanese reddish frog, Rana japonica. Tadpoles, from hatching to the end of metamorphosis, and adult frogs were examined. In the adult, olfactory cells of the OE were equipped with olfactory vesicles with long cilia, but supporting cells with microvilli. The supporting cells of the OE contained secretory granules, PAS-positive by light microscopy, in their apical cytoplasm. On the contrary, sensory cells of the VNO were equipped with microvilli, and supporting cells of the VNO were equipped with cilia, but without secretory granules. Embryologically, the olfactory cells were indistinguishable from the supporting cells in the olfactory placode (primitive OE) lining the nasal pit, at hatch. The VNO appeared as a concave of the ventral part of the OE at 4 days after hatch. At the time, the olfactory and supporting cells of the OE became distinguishable from each other. Secretory granules were formed in the supporting cells of the OE at 36 days after hatch, and the OE was similar in fine structure to that in the adult. While, the VNO remained immature at 24-36 days after hatch, and did not complete its ultrastructural development at 60 days after hatch, the end of metamorphosis. These findings suggest that the OE may take part in the olfaction earlier than the VNO in ontogeny.

Male rats of the WBN/Kob strain, which are known to spontaneously develop diabetes with aging, were examined for histopathological changes in the retina. Five rats (10 eyes) each of WBN/Kob and Wistar/ST as a control were used, and the thickness of the retinal layers, both the central region and the peripheral region of the retina, were measured on weeks 1, 2, 3, 5, 9, 13, 17, 23, 27, 36, 45, 54, 67 and 80 after birth. The rod and cone cell layer in WBN/Kob rats was under-grown, and its thickness decreased 71.7% in the central zone and 59.3% in the peripheral zone of the retina compared with that of the control. In the central and peripheral retina, the rod and cone cell layer, outer nuclear layer and outer plexiform layer, as well as the inner plexiform layer in the central retina, gradually decreased in thickness from 5-45 weeks of age. In the central and peripheral parts of the retina, the number of nuclei decreased in accordance with the thinning of the nuclear layer. The thinned layers showed only cell loss. The rod and cone cell layer of the peripheral retina was thinner than that of the central retina. We obtained the following findings in the retina of male WBN/Kob rats. First, the rod and cone cell layer is undergrown compared with that of the control. Second, the first change occurred in the rod and cone cell layer. Third, the thinning of the rod and cone cell layer appeared at 5 weeks of age, and thinning with aging was slow. And finally, the thinning of the peripheral retina was more severe than that of the central retina. From the above findings, it seems that retinal changes in WBN/Kob rats are similar to the retinal degeneration of rds mice (retinal degeneration slow mice) and that WBN/Kob rats provide a useful animal model for human retinopathy.

The development of the musk gland in house musk shrews aged 0 to 21 days was studied lectin histochemically. On about 3 days of age, the musk gland could be discriminated from surrounding skin. This organ developed markedly on days 3 to 7, and its development continued to 21 days of age. Histologically, on day 1, the bulges that should develop into musk glands were identified in the vicinity of hair germs. On days 3 to 7, these bulges developed markedly, and on day 21 their structure revealed almost the same morphology with that in mature musk glands. We used 7 lectins; ConA, RCA I, PNA, SBA, UEA-I, DBA, and WGA. On day 1, 6 lectins except for WGA labelled the cell of the musk gland. WGA began to label it on day 3. Until 7 days of age, lectins bound to only the cytoplasm of the cell of musk glands. On days 12, however, PNA and UEA-1 labelled the cell membrane equally, and RCA I labeled it on day 21.

We have a big problem with the abuse of amphetamine and its close relative, methamphetamine (MAP) in Japan. As an animal model of people who abuse MAP, male and female rats were treated with MAP (0.1-10.0 mg/kg/day) for a long time. The results obtained in the present study were as follows. 1. Body weights in MAP-treated groups showed a dose-dependent decrease with loss of food intake. 2. Food intake in rats treated with MAP decreased, compared with the control, but when treatment with MAP was discontinued, food intake increased dramatically. 3. In a blood biochemistry assay, the turnover of protein and lipid was suppressed in rats after MAP. 4. The administration of MAP appeared to disturb the estrous cycle in female rats.

This study was undertaken to evaluate the sedative effect of medetomidine, an alpha 2-adrenoceptor agonist, and the counteractive effect of atipamezole, an antagonist to medetomidine, in house musk shrews (Suncus murinus). Two hundred, 300, 400, or 600 micrograms/kg of medetomidine was intraperitoneal injected into 89 house musk shrews. A sedative effect was produced in one to two minutes after injection. The dose-dependent prolongation of the sedative duration and the dose-dependent appearance of a hypothermic effect were demonstrated. With 200 micrograms/kg of medetomidine, the sedative effect obtained was not adequate in some of the animals. With 300 micrograms/kg and above, a stable sedative state was induced in all the animals. The duration of sedation in the house musk shrews was much longer (p < 0.01) in males than in females. This suggested the higher susceptibility of male house musk shrews to this drug. The sedative effect and hypothermia obtained with 400 micrograms/kg of medetomidine were completely counteracted by more than 2.0 mg/kg of atipamezole. With 0.5 and 1.0 mg/kg of atipamezole, only a partial antagonistic action was produced. Transient vomiting appeared in 4.5% of the house musk shrews at approximately one minute after injection of medetomidine. This side-effect had occurred before the sedative effect was obtained, and was not serious enough to be a problem. None of the 89 house musk shrews died in this experiment. The above results show that the combination of medetomidine and atipamezole is a highly effective and safe anesthetic treatment which permits easy handling of house musk shrews.

Sexual dysfunction in diabetic men is thoroughly recognized, while not yet done in diabetic women. Recently, Streptozotocin (STZ)-induced male rats showed a significantly depressed copulatory behavior, compared with normal animals. We investigated whether STZ-induced diabetic female rats would produce observable deficits in sexual behavior. Results in the present study are the first to show that STZ-induced diabetic female rats have a depressed sexual behavior.

Fine structure of the vomeronasal organ (VNO) was examined in the chinchilla (Chinchilla laniger) from a viewpoint of comparative anatomy. The VNO of chinchilla was a pair of tubular structure, about 6mm in length, and situated bilaterally along the base of the nasal septum. The VNO was encircled rostrally by the vomeronasal cartilage, but caudally by a bony capsule. The VNO communicated with the nasal cavity via a small pore at its rostral end, while it ended blindly at its caudal end. Its lumen was crescent to elliptical in a transverse plane, and lined medially with the vomeronasal sensory epithelium (VSE), but laterally with the vomeronasal respiratory epithelium (VRE). Jacobson's glands were tubulo-alveolar in type and distributed from the dorsolateral to the ventrolateral region of the VNO and opened with the duct to the lumen in the transitional region from the VSE to the VRE. Their secretions were periodic acid-Schiff (PAS)-positive but alcian blue (AB)-negative. The VSE consisted of sensory, supporting and basal cells. Supporting cells were characteristic of a large number of huge dense bodies in the perinuclear cytoplasm. The other ultrastructural features in sensory, supporting and basal cells of the VSE were similar to those in the previous reports. The VRE consisted of ciliated, non-ciliated and basal cells. Acinar cells of Jacobson's gland possessed two types of secretory granules. Secretory granules of one type were homogeneous and electronlucent, about 1,700nm in diameter, while granules of the other type were about 2,200nm in diameter, and various in electron density. The present findings suggest that the VNO is functionally active in the chinchilla.

To increase the efficiency of Syrian hamster reproduction, individual males were caged with 2 or 4 estrous females. The fertility of the males caged with 2 or 4 females was lower than that of those caged with a single estrous female. To clarify the cause of this, we observed the copulating behavior of males for 30 minutes and examined their fertility. The median frequency of mounting, intromission and ejaculation was 27, 36 and 3, respectively, for the males caged with a single female, 37, 27 and 4, respectively, for the males caged with 2 females and 13, 2 and 0, respectively, for the males caged with 4 females. Thus, these parameters were markedly reduced in the 1:4 mating group as compared with the 1:1 and 1:2 mating groups. In the 1:2 mating group, spermatozoa were detected in the vaginas of 12 of the 14 females, but only 6 of these 12 females delivered litters. In the 1:4 mating group, complete sequences of copulating behaviors were rarely seen, and spermatozoa were detected in the vaginas of only 6 of the 28 females, and only one of these 6 females delivered. Thus, the efficiency of offspring production was not increased by raising the number of estrous females exposed to a male, probably due to a decrease in the frequency of male copulation in the presence of 2 females and due to inhibition of the male's copulating behavior in the presence of 4 females.

Adult male rats received pituitary transplantations to induce hyperprolactinemia. Some of those had bromocriptine (CB-154) treatment, and the other had vehicle (saline) as control. The grafted animals with vehicle exhibited significantly more suppression than sham operated animals. While the hyperprolactinemic rats treated with CB-154 showed no significantly more suppression of copulatory behavior than sham operated control. In the grafted animal without CB-154 treatment, the concentration of serum PRL was significantly higher than in sham operated controls. There were no significant differences in adrenal weight and serum levels of gonadotropin between grafted and control groups. These results may imply that PRL has direct actions on central nervous system (CNS) and inhibits copulatory behavior in hyperprolactinemic male rats.

Changes in the visual organ with aging were investigated non-surgically in male WBN/Kob rats, in which spontaneous diabetic mellitus commonly occurs. Male Wistar/ST rats at the ages of 5, 9, 13, 17, 23, 27, 36, 45, 54, 67 and 80 weeks were examined for changes in the peri-orbital region, eyelid, lens, corpus vitreum and ocular fundus by macroscopic inspection and fundoscopy. The area around the eyelid was stained with reddish-brown excretions from the Harderian gland. This stain was frequently observed in rats of both strains aged 54 weeks or over, showing no difference in frequency between WBN/Kob rats and Wistar/ST rats. Lens opacity was observed in male WBN/Kob rats aged 67 weeks or over, and narrowing of the retinal artery and vein in those aged 36 weeks or over. The occurrence of lens opacity was consistent with that of visual dysfunction as determined by a test of the ability to differentiate light from dark using a Y-shaped apparatus (Kiyosawa et al., 1993).

Changes in the visual function of the male WBN/Kob rat known as diabetic strain with increasing age were studied electrophysiologically. The measurements of electroretinogram (ERG) and visual evoked potential (VEP) in male WBN/Kob rats were performed at 5, 9, 13, 17, 23, 27, 36, 45, 54, 67 and 80 weeks of age, and compared with those in male Wistar/ST rats used as control. The prolonged latencies and decreased amplitudes of a- and b- waves and oscillatory potentials of ERG in WBN/Kob rats aged over 17 or 27 weeks were recorded under the light or after 20 min dark adaptation. The visual abnormality as indicated by non-recordable ERG was obvious in WBN/Kob rats aged 67 and 80 weeks. No changes of N1, P and N2 peak latencies of VEP were recorded in WBN/Kob rats with increasing age. The amplitudes between N1 peaks and P peaks decreased remarkably in WBN/Kob rats aged 54 weeks. The amplitudes of VEP in 67 or 80 weeks old rats in which ERG disappeared showed 26 or 28% of those in 5 weeks old rats. From these results, recording of ERG and VEP suggested that the visual abnormality occurred in male WBN/Kob rats aged 67 or 80 weeks and the process of visual abnormality with increasing age was clarified.

The scent gland and ordinary sebaceous gland of Syrian hamsters and Mongolian gerbils were studied using lectin histochemistry. Male scent glands were larger in size than those of female in both species, but in histochemistry there was no distinct difference between both sexes. Histologically, the scent gland of Syrian hamsters had a strong resemblance to ordinary sebaceous glands, compared to that of Mongolian gerbils. Since the duct of Syrian hamsters was very short, it is difficult to distinguish the duct from the infundibulum. The duct and infundibulum of Mongolian gerbils were larger in diameter than those of Syrian hamsters. The duct widely opened to dermis. Seven lectins (ConA, RCA I, PNA, SBA, UEA-I, DBA and WGA) were used in this study. All of them labelled the differentiated cells of acinus in Syrian hamsters, although SBA did not label those cells in Mongolian gerbils. The cells of the duct in Syrian hamsters and Mongolian gerbils were not labelled with SBA. Ordinary sebaceous glands in both species were labelled with all seven lectins. Lectin-binding patterns of scent glands and sebaceous glands were similar in Syrian hamsters. While, in Mongolian gerbils, SBA-binding patterns were different between scent and sebaceous glands. Histologically, the scent gland of Syrian hamsters resembles the sebaceous gland. Therefore, there is a possibility that the scent gland of Syrian hamsters still provides some properties similar to sebaceous gland.

It is known that suppression of copulatory behavior observed in aged male animals is due to elevate prolactin levels, the so-called hyperprolactinemia, found in these animals. The present study was done to determine whether hyperprolactinemia can modify the copulatory behavior of young adult male rats. Hyperprolactinemia was induced by grafting one or two pituitary glands of adult males of the same strain under the kidney capsules of each sexually experienced male. Grafted animals exhibited suppressed copulatory behavior patterns when tested one month after pituitary transplantation. The animals given two pituitary grafts differed from the sham-operated controls in latency to intromit (P < 0.05), as well as in the numbers of intromission (P < 0.05) and ejaculation (P < 0.01). After tests of copulatory behavior, serum concentrations of LH, FSH, prolactin and testosterone were measured by radioimmunoassay. Serum levels of prolactin were significantly increased (P < 0.05) in the animals given 2 grafts, compared with sham-operated controls. From these results, suppression of copulatory behavior in the young adult animals grafted was similar to that in aged adults. The findings suggest that decline of copulatory behavior with increasing age results from chronic elevation of prolactin.

The presence of the scent glands were examined macroscopically and histologically in the Japanese vole, Microtus montebelli and the Hungarian vole, Microtus arvalis. A pair of scent glands were observed on the buttocks of the Japanese vole as the oval nodules with yellowish colored skin. The size of the glands was larger in males than in females. Histologically, the glands were composed of the aggregation of many acini of sebaceous glands. The epidermis above the scent glands were thicker than that in the other areas. In the Hungarian vole, no such gland could be detected with macroscopical and histological examinations.

Changes in visual function with increasing age were studied in male WBN/Kob rats, a new diabetic strain. In order to detect visual abnormalities in WBN/Kob rats, 5 WBN/Kob and 5 Wistar/ST (control) rats from each group were examined at 5, 9, 13, 17, 23, 27, 36, 45, 54, 67 and 80 weeks of age using dark and light distinction and open-field tests. The rates at which WBN/Kob rats selected the dark area were 85.0 to 100%, 58.8% and 52.6% at 5 to 54, 67 and 80 weeks of age, respectively, while those for Wistar/ST rats were 85.0 to 100% in each age group. Visual abnormality was obvious in WBN/Kob rats aged 67 and 80 weeks, compared with Wistar/ST rats (P < 0.05). There were no significant signs of visual abnormality in the open-field test. Detection of visual abnormality seems to be possible from 67 weeks of age.

Female mice of the IVCS strain (ddN origin), aged 90, 180, 240, 270 and 300 days, were used in this experiment. The percentages of fertilized ova per ova collected from the oviducts, on Day 1 of pregnancy, of mice aged 90 and 180 days were 100% and 91.1%, respectively. Significantly decreased rates of fertilized ova were observed in mice aged 240 to 300 days as compared to 90-day-old controls (P < 0.05). Almost all two-cell embryos collected from 90- to 270-day-old mice developed into blastocysts or expanded blastocysts, and the developmental rate from 2-cell embryo to hatched blastocyst then decreased significantly (P < 0.05). The developmental rate from 2-cell embryo to hatched blastocyst also decreased significantly in 300-day-old mice (P < 0.05). These results demonstrate differences in the viability of mouse embryos collected from mice of different ages.

Differences in susceptibility of female mice among 10 strains to Corynebacterium kutscheri infection were studied pathologically and bacteriologically. Twenty mice of each strain were inoculated orally with 4 x 10(5.0) CFU of the bacteria. The gross lesions were observed in 60.0% of BALB/c-nu/nu mice, 25.0% of CBA/N mice, 10.0% of MPS mice, and 5.0% of A/J and C3H/He mice, while BALB/cCr, C57BL/6Cr, B10.BR/SgSn, ddY and ICR mice showed neither clinical signs nor gross lesions. Six BALB/c-nu/nu, two CBA/N and one MPS mice died within 15 days after inoculation. C. kutscheri was recovered from 95.0% of BALB/c-nu/nu mice, followed by 75.0% of A/J mice, 65.0% of CBA/N mice, 55.0% of MPS and BALB/cCr mice, and 30% of C3H/He mice. On the other hand, from C57BL/6Cr, B10.BR/SgSn and ddY mice, the bacteria were recovered at less than 15.0% of the mice. No bacteria were recovered from ICR mice. C. kutscheri colonized most frequently in the cecum, colon and rectum. Number of mice having agglutinating antibodies were less than 20% and their antibody titers ranged from 1:10 to 1:80. These results indicated that there were differences in susceptibility of mice among the strains to oral infection of C. kutscheri. Namely, BALB/c-nu/nu, A/J, CBA/N, MPS and BALB/cCr mice appeared to be susceptible, and C3H/He mice intermediate, while C57BL/6Cr, B10.BR/SgSn, ddY and ICR resistant. BALB/c-nu/nu mice were most susceptible and exhibited markedly severe disease by the infection.

Visual evoked potentials (VEPs) were recorded from 8 different points (from points A and B near the bregma to points G and H near the occipital bone) of the dura under parietal bone in rats. The study was performed with 68 adult male Slc: Wistar/ST rats weighing 259.9-298.0g. VEPs recorded from the dura had a large negative component with a peak around 45 msec (N1), a large positive component with a peak around 75 msec and a large negative component with a peak around 120 msec (N2). Points A and B were not suitable for recording of the VEPs because some rats showed no N2 peak. The amplitude of peaks N1 to P at point E, upper the left optic layer of the superior colliculus, was higher than those from other points. Point E was the best position for recording of the VEP from dura in Slc: Wistar/ST rats.

Fine structure of the vomeronasal organ (VNO) was examined in an insectivore, house musk shrew (Suncus murinus), from a viewpoint of comparative anatomy. The VNO was a pair of tubular structure, about 6mm in length, and situated at the base of the nasal septum. The medial wall of the lumen of the VNO was lined with the sensory epithelium (SE) consisting of sensory, supporting and basal cells, while the respiratory epithelium (RE) lining the lateral wall was pseudostratified and covered with microvilli. Jacobson's glands were distributed on the dorsolateral to ventrolateral side of the VNO and opened to the lumen in the transitional region from the RE to the SE. Their secretion was PAS-positive bu talcian blue-negative. Ultrastructurally, sensory cells of the SE were bipolar neurons and covered on their free surface with conspicuously long microvilli. The other ultrastructural features in sensory, supporting and basal cells were similar to those in previously reported species. The ultrastructural features of the RE were also similar to those in previous reports except that the free surface was covered with microvilli instead of cilia. In addition, a few kinds of migrating cells were often observed in both the SE and the RE. Acinar cells of Jacobson's glands possessed a round to elliptical nucleus and many large secretory granules, about 1,000 nm in diameter. Rough endoplasmic reticulum and Golgi apparatus were well developed in their cytoplasm.(ABSTRACT TRUNCATED AT 250 WORDS)

It is known that in the reproductive systems, aged-related changes are prominent. Similarly, in normal nonhuman primates and other mammals such as rats, various sexual activities of male and female decline with aging. The purpose of the present study was to clarify the pattern of sexual behavior in matured mice, voles, Syrian hamsters, rats, guinea pigs, rabbits and house musk shrews of both sexes, and to select the appropriate animals for studies of aged-related changes in sexual behavior. There were species differences among laboratory animals in the pattern of sexual behavior. In summary, hamsters and rats ejaculated about three times during 30 min, while mice did once during 10 hrs. The former animals showed the intromission and ejaculation within a few min and 10 min, respectively, the latter did the ejaculation a few hrs after introduction of a heat female. In female animals, rats displayed receptive and proceptive behaviors, while hamsters and guinea pigs did only receptive behavior. From the above results, rats of both sexes may be recommended for studies of aged-related changes in sexual behavior.

The musk gland of the adult house musk shrews (Suncus murinus) of both sexes was studied lectin histochemically. The musk gland was a kind of scent gland, consisted of congregation of branched or unbranched simple tubuloalveolar gland holocrine in nature and was attached by an apocrine gland-like structure (sweat gland) in the deeper layer of its periphery. Acinar cells of the musk gland were distinguishable into three type from basal to luminal parts of the acinus; immature cells, mature cells and degenerating cells. There was no histological difference between both sexes. Lectin-binding pattern of the musk gland was examined in comparison with that of the sweat gland and ordinary sebaceous gland by histochemical staining techniques using seven lectins: ConA, RCA I, PNA, SBA, UEA-I, DBA, WGA, WGA and PNA labelled the duct of the musk gland more intense than the acinus. Several lectins showed a tendency to label the cells situated near the luminal surface more intense than those near the basement membrane in both the acinus and duct of the musk gland. In the sweat gland and ordinary sebaceous gland, the lectin-binding pattern was different with each other and from that in the musk gland. These findings suggest that the musk gland, sweat gland, and ordinary sebaceous gland are different to each other in nature of cells and the secretion.

In order to determine whether visual disturbance in small rodents is detectable by means of the open-field test, the ambulation scores of enucleated and intact rats in an open-field were measured. In a 30-min test of Slc:Wistar/ST rats, there were significant differences in ambulation scores between enucleated and intact rats in the first 10-min. In addition, the effects of observation times (09:00-11:00, 13:00-15:00 and 17:00-19:00 hr) and strains on the open-field test were studied using a 10-min test. Regardless of observation times, ambulation scores of enucleated rats of the Slc:Wistar/ST and F344/N Slc strains were significantly elevated as compared with those of intact rats from both strains. When tested during the 13:00-15:00 hr period, there were significant differences in the Slc:SD rats. These findings indicate that the changes in ambulation are due to visual disturbance. However, significant ambulatory changes in F344/N Slc rats were documented at the three different observation times. Based on these results, Slc:Wistar/ST rats appear to be suitable for detecting visual disturbance by the open-field test.