A differential action of phenformin in normal and diabetic rat livers

Summary Phenformin inhibited gluconeogenesis by livers from both normal and diabetic rats. However, the concentration of phenformin which inhibited gluconeogenesis by the diabetic livers was not effective in normal livers. It is suggested that an action which is differentially effective in the diabetic state is likely to be clinically relevant.     

The Effects of Spectral Power Distribution and Illuminance Levels on Key Parameters in the Male Golden Hamster and Rat With Preliminary Observations on the Effects of Pinealectomy

Three different light sources were used to determine the effects of spectral power distribution (SPD) and illuminance levels on growth and organ weights of male golden hamsters and rats. SPD had little effect on organ weights or measurements of either rats or hamsters. However, responses to illuminance levels were quite apparent, provided they were equalized for the scotopic eye sensitivity curve characteristic of nocturnal animals. Under seven illuminance levels from 0 to 3.9 scotopic fc, hamsters demonstrated graded responses in gonadal weights and presumed function from 0 to 0.02 scotopic fc. Above this level, photopic saturation was apparent. The neuroendocrine system of pinealectomized animals failed to show sensitivity to illuminance levels. The suggestion is made that the pineal gland acts to monitor illuminance levels (below about 0.02 scotopic fc) as well as photic duration. While the latter appears to be an "all or none" effect, the former appears to be graded.     

云南省耿马县鼠疫疫源地及人间鼠疫调查报告

1990年12月11日～31日,对云南省耿马县首次鼠疫流行进行了现场调查。用血清学及细菌学方法在33个疫点(180km~2)检出了63例腺鼠疫患者和13例隐性感染者,并从人,鼠、蚤分离到49株鼠疫菌。造成鼠间鼠疫流行,主要是黄胸鼠数量及印鼠客蚤指数的急骤增高;人间鼠疫是由于鼠间鼠疫长期流行,地面游离蚤增加,人与蚤类接触频繁所致。结果表明:耿马县以勐撒镇为中心的鼠间及人间鼠疫大面积流行是一次典型的家鼠型鼠疫,其疫源地具有西南山地黄胸鼠鼠疫疫源地的特征。鼠疫在该县(至少在动物间)有可能长期存在。     

Induction and reversibility of thyroid proliferative changes in suckling rats given thiocyanate

Potassium thiocyanate given in the drinking water of pregnant rats led to decreased body weight in their 14-day-old offspring (27%) without altering thyroid weight. Reduction of the suckling rat's body weight could be explained be defective thyroxinemia (38). Plasma FT3 and TSH were unchanged after thiocyanate treatment. The biochemical changes were in agreement with the histological aspects of the hypothyroid animals. The typical pattern was hyperplastic goiter. Colloid volume was reduced compared with controls. Presence of resorbed peripheral vacuoles, a sign of thyroid hyperactivity, was disclosed by a three-fold increase in radioiodide (131I) uptake compared with controls. When the antithyroid drug was removed from the mother's milk, the pups'weight increased but did not reach control values. Plasma thyroid hormone levels returned to normal and even exceeded control values in spite of partial recovery of thyroid iodine content when thiocyanate treatment was stopped for ten days.     

Improvement of cyclosporin A-induced cholestasis by tauroursodeoxycholate in a long-term study in the rat

Cyclosporin A is an essential immunosuppressive drug, but it is potentially toxic to the kidney and liver. Ursodeoxycholic acid, a hydrophilic bile acid, has been reported to improve cholestasis in liver disease in man. The purpose of this work was to examine whether tauroursodeoxycholate could reduce cyclosporin A-induced hepatic or renal injuries in the rat. After randomization into three groups (N=8), rats received daily for 17 days: cyclosporin A intraperitoneally alone (30 mg/kg) or cyclosporin A intraperitoneally and tauroursodeoxycholate (60 mg/kg) by gavage; controls received the cyclosporin A excipient. Under tauroursodeoxycholate, cholestastic parameters (bile flow, bile salt secretion, serum bile salts, serum bilirubin) improved significantly without affecting cyclosporin A blood levels, and excretion of the drug and its metabolites in bile increased by 47%. Serum creatinine levels were better preserved, although not significantly. These results show that tauroursodeoxycholate prevents cyclosporin A-induced cholestasis in long-term treatment in rats, possibly by facilitating the drug elimination in bile.This work was supported by grants from the Caisse Régionale d'Assurance Maladie du Sud-Est and Houdé Laboratories.     

低硒大鼠心肌细胞的钾通道

以含硒量低于０．０１２μｇ／ｇ的饲料喂养Ｗｉｓｔａｒ大鼠，形成低硒动物模型，用膜片箝技术记录动物模型心肌细胞的钾通道活动。用丹酚酸Ａ或亚硒酸钠可激活钾通道开放。用黄嘌呤／黄嘌呤氧化酶产生氧自由基作用于细胞膜可明显抑制钾通道开放。     

Determination of peritoneal glucose kinetics in rats: implications for the peritoneal implantation of closed-loop insulin delivery systems

Summary Peritoneal glucose kinetics were evaluated in the anaesthetized rat, to assess whether the peritoneal cavity would be a suitable site for the implantation of membrane-protected islets of Langerhans (bioartificial pancreas) or the glucose sensor of an artificial B cell. Glucose was measured in peritoneal fluid samples aspirated by needle puncture. Basal peritoneal and blood glucose concentrations were identical in 16 h fasted (n=4) and non fasted (n=3) animals. After 10 min of an i.v. glucose infusion (n=15) the increment in peritoneal glucose concentration was 63±3% of the increment in blood glucose concentration and both values were significantly correlated (r=0.92; p<0.001). After 10 min of glucose clamping (12.6±0.8 mmol/l), the increment in peritoneal glucose concentration was 69±3% (n=5; p<0.05) of the increment in blood glucose concentration. In three additional experiments it was 93±3% of the increment in blood glucose concentration (NS), after 30 min of glucose clamping (8.0±0.5 mmol/l). Peritoneal glucose concentration monitored by a glucose sensor: (a) followed blood glucose sluggishly during a glucose clamp (n=5), confirming the data shown above, (b) followed blood glucose with a 5 min delay and reached the same plateau after the intravenous injection of 1U insulin (n=3; NS). We conclude that peritoneal glucose reflects blood glucose at basal state and during variations of glycaemia, nevertheless, presenting heterogeneous kinetics. These kinetics might be appropriate for a bioartificial pancreas but not for an in vivo calibration procedure, of a peritoneally implanted glucose sensor.     

3,4-Bis(3′-hydroxyphenyl)hexane — A new mammary tumor-inhibiting compound

Summary The syntheses of the hexestrol derivatives 3,4-bis-(3-hydroxyphenyl)hexane (4a), 3,4-bis(4-fluoro-3-hydroxyphenyl)hexane (4b), 3,4-bis(3, 4dihydroxyphenyl)hexane (4c), and 3,4-bis(3,4-diacetoxyphenyl)hexane (4d) are described. All compounds showed a marked, competitive inhibition of the estradiol receptor interaction (K _a4c>K_a4a>K_a4d>K_a4b). Evaluated in the mouse uterine weight test compounds 4c and 4d almost reached the estrone effect, whereas 4a and 4b did not produce full uterotrophic response. Compounds 4a-d antagonized the estrone stimulated uterine growth of the immature mouse. Compound 4a (NSC-297170) exhibited a specific, dose-related growth inhibition of the estrogen responsive MCF-7 human breast tumor cell line. Tested on the 9,10-dimethyl-1,2-benzanthracene-induced hormonedependent mammary adenocarcinoma of the Sprague-Dawley rat all compounds showed marked inhibition of tumor growth. As in all experiments compounds 4a and 4b, which is resistant to hydroxylation in 4position exhibited an identical pattern of action, which is different from that shown by compound 4c, the effect of compound 4a cannot be explained by its possible catechol metabolite 4c.Supported by grants from the Deutsche Forschungsgemeinschaft and the Verband der Chemischen Industrie-Fonds der Chemischen Industrie     

雷公藤对大鼠肾移植急性排异反应治疗作用的免疫机理探讨

利用大鼠肾移植模型,以血、尿及移植肾组织免疫活性细胞、白细胞介素为研究指标,探讨GTW抗大鼠急性排异作用机理。结果量示,GTW可抑制移植肾组织排异反应。可减少肾移植大鼠外周血MRC OX-8阳性细胞(Tc/s,NK细胞)数量,抑制W3/2S(Th,单核细胞)、MRCOX-8(Ts/c,NK细胞)、MRCOX-19(T细胞)和IL-2R阳性细胞在移植肾组织内的浸润,减少尿IL-6的产生.斑点杂交未证实GTW可抑制移植肾组织IL-1α,βmRNA的表达.