It is well known that the lighting conditions affect many physiological phenomenon of laboratory animals. However, lighting conditions are frequently disturbed by investigators themselves. In this study, behavioral (ambulation and drinking) rhythmicities of rats were investigated after irregular lighting; i. e. presentation of short time lightings at 21: 00, 24: 00 and 3: 00 for 12 min during dark period (18: 00-6: 00) . Vaginal smear was taken and sexual cycle was observed everyday. Ambulatory and drinking activities were measured by Gundai type Ambulo-drinkometer. The irregular lightings produced the following changes in the rhythmicities: 1) increase in the ambulatory activity during 15: 00-18: 00 immediately before dark period 2) decrease in ambulatory activity before ovulation 3) disappearance of inhibitory phenomenon of drinking activity which was usually observed before ovulation 4) increase in the drinking activity during 6: 00-9: 00 immediately after dark period 5) the changes in rhythmicities of the behavioral activities lasted for more than 1 month after replacement to the regular lighting condition.

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The amylases were studied in the yolk of fertilized eggs and in the pancreases of the embryos of domestic fowls. The amylase activity in the yolk increased markedly from 13 days of incubation until hatching, but the activity decreased when the embryos were taken out of the eggs. The isoamylases in the yolk and in the pancreas of the embryo were identical electrophoretically. The amylase occurs mainly in the pancreas of the embryo. We think that the increase in amylase activity in the yolk of fertilized eggs during incubation depends upon the accumulation of pancreatic amylase synthesized by the developing embryo in the egg.

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A plumage color mutant, dotted white (DTW), of Japanese quail is described in this paper. The adult DTW mutant shows white plumage with a small colored spot on the head and/or back. The pigmented spots invariably appear on the dorsal region and never on the ventral region of the body. Some birds lack colored spots and show pure white plumage. The chick of the DTW mutant shows cream yellow plumules similar to those of the White Leghorn chick. Colored spots also exist as in adults, and its coloration is diluted light brown. The feathers on colored spots of the adult show diluted pigmentation as compared with wild-type feathers. In addition, the wheat-straw colored shaft streak is extremely narrow and the transversal bars are missing. The DTW mutant is thought to be genetically different from previously reported similar mutants, brown-splashed white, panda, and recessive white. Genetic analyses revealed that the DTW mutant plumage is controlled by an autosomal recessive gene. The gene symbol dtw is provisionally proposed, since there remains a possibility that the DTW character may be allelic to some of the similar mutant characters mentioned above.

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The present study is concerned with the effect of radiation to the testis on fertilizing ability in vitro using golden hamster spermatozoa. Male hamsters at 6 and 8 weeks of age were given acute testicular X-irradiation (200 kVp, 20 mA, 0.47-0.48 Gy/min) . Spermatozoa were collected from the cauda epididymides at different times after irradiation and then they were suspended in fertilization medium. After preincubation for 4-5 hr, the spermatozoa were cultured with the eggs collected from mature hamsters treated with PMSG-hCG. Fertilized eggs were examined for incidence of sperm penetration and formation of pronuclei at 4-5 hr after insemination. The fertilization rate (47.7%) at the 6th week after irradiation with a dose of 2 Gy was much lower in comparison with the control value (92.6%) . However, the fertilization rates at the 3rd and 9th weeks after irradiation were 97.7 and 90.6%, respectively. In these period, no difference was found between the irradiated groups and the control groups. From the changes in sperm concentration after irradiation with a dose of 2 Gy, it was found that the fertilization rate was the lowest at the 6th week. The sensitive stage to radiation during spermatogenesis with reference to the reduction of fertilizing ability after irradiation coincides with that of decrease in the sperm concentration and sperm motility. The results of fertilization rate at the 6th week after different doses of X-irradiation (0.25-6 Gy) indicated that the reduction of fertilization rate is nearly expressed as a dose-response relationship. These results suggest that X-irradiation of the testis affects the decrease in sperm concentration and sperm motility, and finally brings forth the reduction of fertilizing ability of spermatozoa.

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A new method to eliminate odors from air recirculating in an animal house is described. The new system consists of an ozonizer and titania silica ozone decomposition catalyst in the terminal of a recirulating ventilation system. The principle underlying the elimination of odors is the oxydative reaction of malodorous components on the surface of the catalyst caused by coupling with ozonolysis. This method appeared superior in terms of its durability, efficiency and lack of resistance to air flow.

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Two surges of prolactin (PRL) are observed daily during pseudopregnancy (PSP) in the rat: the nocturnal (N) surge at dawn and the diurnal (D) surge in the evening. In order to clarify differences in the controlling mechanisms of the two types of PRL surges, we attempted to examine the turnover rates of dopamine (DA) and norepinephrine (NE) in the preoptic-anterior hypothalamus (PAH) and mid-posterior hypothalamus (MPH) on day 5-6 of PSP. The turnover rates of DA in the hypothalamus were inversely correlated with the serum PRL levels at the D surge when a significant increase in serum PRL was accompanied by not only a marked decrease in turnover rates of DA in the PAH, but also a slight decrease in turnover rates of the amine in the MPH. Contrarily, no significant decrease occurred in the turnover rates of DA in the hypothalamus at the N surge. There was no obvious correlation between the turnover rates of NE in the hypothalamus and the serum PRL levels at either PRL surge. These findings suggest that decreased turnover rates of DA in the hypothalamus are involved in the D surge, and it is most probable that the N PRL surge occurs under the control of another factor such as the hypothalamic PRL-releasing factor.

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To clarify the effects of age on bacterial translocation from the gastrointestinal tract, mice at the age of 1, 2, 4, 6, 12, and 15 months were antibiotic-decontaminated for 4 days and then inoculated orally with streptomycin-resistant Escherichia coli C25. Mice treated with cyclophosphamide and untreated controls were tested for bacterial translocation to the mesenteric lymph nodes (MLN) 2 days later. The population levels of E. coli C25 in cyclophosphamide-treated and untreated mice were approximately 10^9.3 and 10^9.5 per gram of cecum, respectively, at each tested age. There were no significant differences in the incidence of translocation of E. coli C25 to MLN at any of the tested ages, whereas the number of E. coli C25 detected in MLN was higher in young mice than in aged mice in both the cyclophosphamide-treated and untreated groups. These findings suggest that bacterial translocation from the GI tract may be a more important problem in young animals than in aged animals.

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Urogenital organ system induced by idiopathic hemorrhage in sudden died male El mice were investigated macro-and histopathologically and angiographically. The mortality of the male El mice with brief life span was 85% during observation period for 33 weeks, and about half of the male El mice died between 10-week-old and 20-week-old. In all dead mice, urine retention was prominent, and the seminal vesicle or the coagulating gland, especially the bulbocavernosus muscle had severe hemorrhage. There was coagulated blood mass in the urethral lumen and the lumen of the seminal vesicle and the coagulating gland. Further, in pans spongiosa, coagulated blood mass occupied the most area of the corpus spongiosum penis and corpus cavernosum penis with severe hemorrhage. Angiographically, the penile artery in not affected male El mice was thinner than that in control mice.

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Observation and recording methods of the ocular-f undus in small laboratory animals were studied using the industrial endoscope and VTR systems, respectively. The ocular-fundus was observed widely, brightly and clearly in the usual animal facility. In addition, the ocular-fundus was recorded easily and it was possible to examine the ocular-fundus recorded by the VTR systems.

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This study was designed to assess the usefulness of young farm pigs as an experimental model for hypercholesterolemia. In order to test this, we investigated both serologic and electrocardiographic effects of atherogenic diet. Four-week-old pigs were fed an atherogenic diet for 8 weeks. No arrhythmia was observed on ECG in all animals. There were no significant difference between control and atherogenic diet group on the values of ECG parameters. However, plasma lipids values of atherogenic diet group were significantly (p<0.05) higher than those of control diet group. Thus, hypercholesterolemia was induced in young farm pigs by feeding atherogenic diet in a relatively short time. This fact suggests that young farm pigs may be an useful model for further studies of the effect of hypercholesterolemia on cardiovascular function and the early pathogenesis of atherosclerosis.

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The sexual receptive and proceptive behaviors induced by opiate antagonists, naloxone and naltrexone in estrogen-primed ovariectomized rats were observed under the presence of sexually active males. The females were treated intraperitoneally with naloxone or naltrexone at doses ranging from 0.5 to 4.0mg/kg and the sexual behavior of females was tested before and after the injection of drug. The results obtained suggest that the opiate antagonists play a role in the regulation of lordosis behavior, but not proceptive behavior in female rats.

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Factor H is a plasma glycoprotein with M. W of 160 KDa which serves as one of the regulatory proteins for C3 convertases. We have previously reported three serologically defined mouse factor H allotypes by surveying many laboratory and wild mice. In the present work, we established a congenic strain with factor H allotype, H. 2, on BALB/c (H.1 allotype) background and named this strain BALB-H. 2. Alloantiserum against each allotype has been easily prepared using two congenic strains by immunization with a small amount of whole mouse serum. BALB-H. 2 is valuable for the genetic studies on the genes in the vicinity of factor H gene (cfh) derived from Mus. m. molossinus.

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We found a spontaneous cleft palate in a mouse of CF#1/Ohu (Ohu University, Japan) . Further, the frequency of the spontaneous cleft palate in strains of CF#1 / Jms (Institute of Medical Scince, University of Tokyo, Japan) and CF#1/Jah (National Institute of Amimal Health, Japan) were about 3%, respectively. The frequency and the types of spontaneous cleft palate in CF#1 were cleary different from those in A/J and CL/Fr strains which were used as model animals of lip and cleft palate. We think that CF#1 is the new animal models to analyze a cleft palate genetically and biochemically.

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The model of hyperprolactinemia induced by pituitary homografts under the kidney capsule has been used mainly in the field of reproductive physiology. The authors report an improved method for pituitary grafting in mice. The procedure was as follows : 1. The male pituitary glands with normal saline were aspirated into a polyethylene tube. 2. Two incisions were made in the kidney capsule. 3. The polyethylene tube with pituitary glands was inserted via a large incision. 4. Blow-ing air into the tube, the pituitary glands were left under the kidney capsule and normal saline streamed out of a small incision. Using this method, all pituitary grafted mice became pseudopregnant.

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Effects of hypophysectomy on circadian rhythms of ambulatory and drinking activities in adult male rats were automatically recorded and investigated with a Gundai-type ambulodrinkometer. The rats were maintained under LL conditions following an LD condition. When free-running rhythms had stabilized, the rats were hypophysectomized. The rhythmicities of both activities became indistinct over the 2-4 weeks following surgery, and then gradually recovered. At this time, phase shifts (phase advance) were observed in the hypophysectomized rats, while these changes were not observed in sham-operated rats. All rats entrained to light-ing when kept under LD conditions again. These results suggest that the pituitary does not play an essential role in maintaining circadian rhythms, but does function as an important subordinal oscillator.

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A survey on the number of animals used in experiments including bioassay, diagnosis, education and preparation of biological agents such as vaccine between April 1990 and March 1991 was conducted. Out of 849 universities, institutes, testing laboratories and companies, 607 replies were received. The distribution of the number of animals is shown in the following tables.

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