大鼠自发性乳腺间变型腺癌对抗肿瘤药物敏感性的研究

研究了大鼠自发性乳腺间变型腺癌对抗肿瘤药物的敏感性，应用五类抗肿瘤药物对大鼠自发性乳腺间变型腺癌进行了敏感性试验．结果表明，大鼠自发性乳腺间变型腺癌对植物类药物、抗代谢类药物、烷化剂类药物和抗菌素类药物敏感（Ｐ＜０．００１），揭示了大鼠自发性乳腺间变型腺癌对抗肿瘤药物的敏感性比较广泛，是一株对抗肿瘤药物有广谱敏感性的瘤株．而对激素类药物不敏感（Ｐ＞０．０５），提示大鼠自发性乳腺间变型腺癌属于非激素依赖性瘤株     

Number of dopamine neurons predicts prolactin levels in two inbred mouse strains

Summary Mice of the BALB/cJ strain have more dopamine neurons than mice of the CBA/J strain. We now report that BALB/cJ mice have less circulating and pituitary prolactin than CBA/J mice, a relationship expected from the difference in tuberoinfundibular dopamine neuron number.     

Strain differences in the pattern and intensity of wheel running activity in laboratory rats

Summary Wheel running activity rhythms of three inbred rat strains, ACI/Ztm, BH/Ztm, and LEW/Ztm, were compared in order to evaluate the effect of genetic differences on circadian rhythm parameters. Significant strain differences were found in the general pattern of the activity rhythms and their characteristic periodicities as well as in the amount and duration of wheel running activity and the timing of activity onsets and offsets. The results suggest that genetic differences exist in the coupling of the multiple circadian oscillators that generate the overall pattern of wheel running activity.     

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.     

Effects of blood sampling,anesthesia and surgery on plasma vasopressin concentration in rats

The influence of blood sampling, anesthesia and surgery on plasma vasopressin concentration was assessed in rats. Mean plasma concentration in conscious, chronically catheterized rats was 1.4±0.1 pg/ml (n=6). This value remained constant over repeated plasma samplings in the same animals. On the other hand, decapitation increased the plasma vasopressin concentration to 6.0±2.4 (in pg/ml) (n=6), inactin anesthesia to 2.9±0.6 (n=6), anesthesia and femoral cannulation to 13.3±5.8 (n=6) and surgery for renal micropuncture to 81.3±35.0 (n=6). It is concluded that the level of circulating plasma vasopressin is highly dependent on the sampling technique and is closely related to the extent of surgery.     

Reduced tuberoinfundibular dopaminergic neuronal function in rats after long-term withdrawal of estrogen treatment

Summary Hypothalamic fragments from female rats treated repeatedly with estradiol valerate (EV) and bearing prolactin (PRL)-secreting tumors contained, seven months after the last EV injection, lower concentrations of dopamine (DA) than age-matched controls. Depolarizing concentrations of K⁺ (35 mM) and amphetamine (50 M) evoked in PRL-secreting tumor bearing rats an endogenous DA release significantly lower than in controls.     

模拟热浪期间突然强降温天气对高血压大鼠心血管系统影响的实验研究

通过模拟热浪期间突然强降温天气对高血压大鼠影响的实验研究,探讨热浪期间突然强降温对高血压大鼠心血管疾病的影响机理。应用TME1880气象环境模拟箱模拟了南京2006年6月19日5时至22日11时高温热浪期间突然强降温天气过程,将24只高血压大鼠随机分为实验组(包括热浪组、降温组和复温组)和对照组,每组各6只大鼠。把实验组放入模拟箱内,使其受热浪期间突然强降温天气过程影响,分别在模拟热浪期间突然强降温天气过程55、59和75 h时,先后取出热浪组、降温组和复温组监测基本生理指标;并采用断头采血和摘取心尖,测量各组高血压大鼠的热应激因子(HSP60、SOD、s ICSM-1、HIF-1α)、冷应激因子(NE、EPI、ANGⅡ)、血管收缩因子(ET-1、NO)以及心血管的危险因素(TC、TG、HDL-C、LDL-C和Tn-T)生化指标的含量。结果表明受高温热浪的影响,高血压大鼠的热应激因子除SOD含量明显下降以外其他热应激因子含量均明显增加,冷应激因子均明显下降,血管收缩因子ET-1下降而NO上升,心脑血管危险因素除TG上升以外其余因子均有不同程度的下降。热浪期间突然强降温可导致高血压大鼠热应激因子除SOD上升以外其余均下降,冷应激因子全部上升,血管收缩因子ET-1上升而NO下降,心血管危险因素均上升。通过分析可知,热浪可使得高血压大鼠动脉粥样硬化加剧,热浪期间突然强降温使得NE和ANGⅡ含量明显增加,加剧血压升高。受降温的影响Tn-T明显增多,说明突然的强降温冷刺激导致的血管收缩导致了心肌缺血,加上血脂四项的升高使得高血压大鼠心血管疾病进一步加重。初步探讨了热浪期间突然强降温天气对高血压大鼠心血管疾病的影响。     

湖北陆水湖局部地区鼠类的初步调查

湖北蒲圻陆水湖局部地区鼠类分布和活动情况的初步调查及结果分析。     

New eco-morphological-behavioural approach of the chinchilla rats in the pre-Andean foothills of the Monte Desert (Argentina)

This study characterizes the ecology, behaviour and morphology of populations of Abrocoma schistacea and A. uspallata in north-western Argentina. We carried out live-trapping, tagging and recapture during 2006–2008. Burrow structure and vegetation were described. Diet composition and the activity of chinchilla rats were defined. Both species inhabit rock crevices in the pre-Andean foothills of the Monte Desert. Some of their morphological specializations for saxicolous life, such as foot pads for better traction on rocky surfaces and reduced nails, are convergent with those of other saxicolous species. Both species appear to be diurnal, with activity peaking in the early morning. Dietary analyses suggest trophic specialization by both species. Density of A. schistacea was of 0.15 ± 0.06 individuals ha^?1; with individuals living in groups of 3–4 animals. Given their low abundance, restricted distribution and high level of habitat and food specialization, we urge that populations of this species be protected through effective management.