Interaction of salicylate and noise results in mortality of rats

Summary Survival as a function of salicylate dose and the intensity of environmental noise was investigated in 150 adult female pigmented rats. Rats were assigned to groups (n=6/group) defined by combinations of salicylate levels from 0- (saline) to 300 mg/kg, injected subcutaneously, and noise levels from ambient noise to 98 dB SPL, presented daily for 10-h periods for up to 17 days. Mortality occurred in groups exposed to the higher combinations of salicylate and noise.     

Blood pressure and impairment of endothelium-dependent relaxation in spontaneously hypertensive rats

Summary Correlation between hypertension and impairment of endothelium-dependent relaxation was demonstrated using aortae from certain strains of rats with various levels of spontaneous hypertension. It was also observed that the impairment of endothelium-dependent relaxation is the secondary change due to hypertension, and the level and duration of hypertension is the determinant factor of the impairment.     

Similarity between the effects of suprachiasmatic nuclei lesions and of pinealectomy on gonadotropin release in ovariectomized,sulpiride-treated and melatonin-replaced rats

The aim of this study was to compare the effects of pineal indole treatments on LH and FSH release in pinealectomized and suprachiasmatic lesioned and ovariectomized rats rendered hyperprolactinemic by acute sulpiride treatment. pinealectomy or suprachiasmatic nuclei lesions in female rats both decreased plasma LH and FHS at 10, but not at 20 d after surgery, whereas the daily afternoon administration of melatonin effectively restored levels of both gonadotropins to control values. In ovariectomized rats, pinealectomy or suprachiasmatic nuclei lesions were ineffective in counteracting the high plasma levels of LH and FSH. However, sulpiride treatment in both pinealectomized and suprachiasmatic nuclei lesioned and castrated female rats significantly decreased the levels of LH and FSH, an effect which was counteracted by daily afternoon melatonin administration. Other pineal indoles tested, i.e., 5-hydroxy- and 5-methoxytryptophol, were ineffective in regulating gonadotropin levels. The results suggest that the pineal gland, through its hormone melatonin, can modulate gonadotropin secretion by acting on a dopamine mechanism independent of hypothalamic suprachiasmatic areas.     

Distal axonopathy in streptozotocin diabetes in rats

Summary We noted the earliest morphological changes in the motor endplates 8 weeks after the induction of streptozotocin diabetes in rats. Morphometric measurements showed reduced axonal areas of the lateral plantar and the sicatic nerves in the diabetic rats 28 but not 2 and 8 weeks after the experiment. These findings suggested distal axonopathy.     

The AA and ANA rat lines,selected for differences in voluntary alcohol consumption

Summary The offspring of rats that voluntarily select larger quantities of alcohol are heavier consumers of alcohol than the offspring of rats that tend to avoid it. Such selective breeding, repeated over many generations, was used to develop the AA (Alko, Alcohol) line of rats which prefer 10% alcohol to water, and the ANA (Alko, Non-Alcohol) line of rats which choose water to the virtual exclusion of alcohol. In addition to demonstrating the likely role of genetic factors in alcohol consumption, these lines have been used to find behavioral, metabolic, and neurochemical correlates of differential alcohol intake. Some of the line differences that have been found involve the reinforcing effects of ethanol, the changes in consumption produced by alcohol deprivation and nutritional factors, the behavioral and adrenal monoamine reactions to mild stress, the development of tolerance, the accumulation of acetaldehyde during ethanol metabolism, and the brain levels of serotonin. It is hoped that these studies will lead to a better understanding of the genetically-determined mechanisms that influence the selection of alcohol.     

Platelet insulin receptor determination in non-insulin dependent diabetes mellitus

Summary The platelet membrane insulin receptors of healthy and non-insulin dependent (type 2) diabetic patients were studied. Receptor number and affinity proved to be decreased in type 2 diabetes mellitus. The changes in platelet insulin receptor characteristics are in good correlation with the alterations reported in other tissues or cells. The possible role of these phenomena in the pathogenesis of disturbed platelet function in diabetics needs further investigation.     

改良肾大部切除大鼠诱发慢性肾衰模型的建立

对5/6切除大鼠肾脏诱发其慢性肾功能衰竭的动物模型进行改良，该方法省时省力，可以减少麻药用量不当造成的大鼠死亡，随差血肌酐(Scr)、尿素氮(BUN)的增加，肾衰逐渐加重，为药理研究及筛选治疗慢性肾衰的有效药物提供了一种实验对象。     

Difference of the inhibitory action of verapamil on the positive inotropic effect of Ca2+ between spontaneously hypertensive and normotensive rat myocardium

Summary Verapamil, a calcium entry blocker, had a greater inhibitory effect on the positive inotropic effect of excess Ca²⁺ in SHR than in NWR, suggesting that the cardiac responsiveness to verapamil was enhanced in SHR.     

盐酸阿扑吗啡片剂对去势大鼠的壮阳作用和生殖器官质量的影响

制备雄性去势大鼠模型,测定给药各组去势大鼠阴茎勃起潜伏期和生殖器官质量.结果表明:与单纯模型组相比,盐酸阿扑吗啡在外部刺激下能提高雄性去势大鼠阴茎的兴奋性,阴茎勃起潜伏期缩短,而给药各组生殖器官的质量和脏器指数与去势大鼠模型组比较均无明显差异.盐酸阿扑吗啡对雄性去势大鼠具有壮阳作用,对生殖器官组织无明显影响.     

MNNG诱发WISTAR大鼠胃癌癌变早期的研究

本实验用Wistar雄性大鼠作为实验动物，用MNNG作为诱变剂，以灌胃方法给大鼠用药，然后辅以高浓度食盐水和二期口服MNNG，以促使胃癌的发生，在其胃癌癌变早期的不同时期处死大鼠，结果发现癌变过程中胃粘膜出现糜烂、溃疡，组织细胞出现单纯性增生，不典型增生高分化腺癌。