Steroid-induced concentric membrane whorls in dog liver

When daily doses of 10 mg/kg of the androgenic steroids fluoxymesterone, methyltestosterone, testosterone propionate, oxymetholone and mepitiostane were administered to adult male and female beagle dogs for 6 months, concentric membrane whorls were produced in the hepatocytes of all groups. The whorls frequently had a central core mainly composed of lipids or mitochondria and the membranes of the whorls, consisting of paired membranes, continued to the smooth or granular endoplasmic reticulum at the periphery of the structures.

Effect of castration on the appearance of diabetes in NOD mouse

To examine the influence of sex hormones on the appearance of overt diabetes in NOD mice, oophorectomy and orchiectomy were performed. Castrated males showed a high incidence of diabetes. The time course of onset was similar to that of the intact females. On the other hand, castrated females showed a intact-male pattern of onset with a low incidence. Clinical determinations demonstrated a close similarity between spontaneous and castration-induced diabetes. These data suggest that sex hormones modulate the expression of overt diabetes in NOD mouse, i. e. androgens have at least a suppressive effect.

Sex difference of mercuric chloride-induced renal tubular necrosis in rats--from the aspect of sex differences in renal mercury concentration and sulfhydryl levels--

When doses of 0.3 to 2 mg/kg of mercuric chloride were intravenously administered to rats of the JCL-SD strain, acute renal tubular necrosis was produced in the straight portion of the proximal tubules with a pronounced sex difference, the male being more susceptible. Necrosis was inhibited by castration of male rats and promoted by testosterone pretreatment. When 0.15 mg of mercury per rat was injected to adult rats, females showed higher levels of mercury in the whole kidney, outer cortex and inner cortex. Castration of male rats caused elevated renal levels of mercury and pretreatment with testosterone of females lowered the levels. Renal levels of sulfhydryl groups were higher than male rats and castrated male rats showed elevated renal levels. The sex difference in the levels of sulfhydryl groups seems to be one factor which causes different susceptibility to mercury between males and females.

Breeding of a non-obese, diabetic strain of mice

A female mouse spontaneously exhibiting polyuria and glucosuria accompanied by rapid weight loss waa found in one of two sublines derived from the CTS mice. Eight mating pairs were made using its offspring and selection was performed for both spontaneous diabetes and reproductive ability. After six generations of the selective breeding the diabetic (nod) and the control (non) lines were established. A marked sex difference was observed in the incidence of diabetic symptoms in the nod mouse. The cumulative incidence of the onset up to 30 weeks of age was 80% in females and less than 20% in males. The onset of diabetes was abrupt in both sexes, and spontaneous remission was not observed. However, daily administration of insulin induced an increase of body weight and a prolongation of life span. Diabetic symptoms are biochemically characterized by polyuria, polydipsia, hyperglycemia, glucosuria and hypercholesteremia. Pathological examination revealed a high frequency of lymphocyte infiltration around and/or into the Langerhans' islet. It was observed even at the prediabetic stage over five weeks of both sexes. The number and size of the islets were markedly reduced in the overt diabetic mice. Although the mechanism of the pathogenesis is not clear yet, the nod mouse may be a useful animal model for investigating the human juvenile type diabetes.

Chemistry of bleomycin. XVIII. carbon-13 NMR studies

During chemical studies of bleomycin, many fragments and derivatives have been isolated and characterized. The 13C-NMR spectra of these compounds were taken and analyzed for structural information, and the complete assignment of the spectra was achieved. The 13C-chemical shift map thus obtained contains information about the structure and conformation and will be useful for studies on the chemistry and biology of bleomycin and related compounds.

[Histological changes of various organs in aged SD-JCL rats (author's transl)]

Age-related histological changes were studied in various organs from SD-JCL rats reared throughout their lifespan. In aged-male rats examined at 5 to 36 months of age were frequently observed nephropathy, periarteritis, skeletal muscle degeneration, pigmentation of the follicular epithelium in the thyroid, fibrosis of the pancreatic islets, hyperplasia of the parathyroid epithelium, and changes of the acini in the extraorbital lacrymal gland. In aged-female rats sinusoid dilatation of the adrenal, and atrophy of the ovary were also noted. Perilobular fat deposition of the liver, dilatation of the gastric gland and severe hemosiderosis of the spleen were observed similar frequency in the both sexes. The nephropathy and cardiovasculopathy were major factors to cause death for males, while the main cause of death for females was tumors, especially of the mammary and pituitary glands. Enlargement of the parathyroid gland, bone resorption and metastatic calcification in the solf tissues were found in rats with severe nephropathy.

[Spontaneous tumors in aged SD-JCL rats (author's transl)]

Incidence of spontaneous tumors was examined in 77 male and 73 female SD-JCL rats reared throughout their lifespan of 5 to 36 months. Total tumor incidences were 60% and 95% for males and females, respectively. The sex difference was mostly attributable to a high incidence of mammary tumor in females. The pituitary tumor was found in 30% of males and 66% of females aged 5 to 36 months while islet cell tumor of the pancreas and thyroid tumor occurred later and the incidence of latter was particularly high in rats lived more than 2 years. Myeloid leukemia appeared to occur as early as 5 months of age.

[Effects of the population density on growth of SD-JCL rats (author's transl)]

The effects of the population density on growth and life span of 21 to 26 months in SD-JCL-rats were investigated. The mean life spans of males and females were 23 and 24 months, respectively. The population density had no definite influence on increase in body weight of females, whereas a most accelerated growth of males was seen with 2 rats per cage. The total amounts of food intake of each animal throughout its life were about 15 and 11 kg for males and females, respectively, and those of water intake were about twice the food. No correlation was observed between the population density and the weights of the liver, kidney, heart and femur, though mals reared at 5 animals per cage had lightest adrenals among all the animals.