西酞普兰对戊四氮点燃癫痫大鼠行为学及海马5-HT能递质系统影响的在体微透析研究

为研究5-羟色胺(5-HT)能神经递质在癫痫形成过程中的变化及西酞普兰(CTP)对其的影响,本研究用CTP(1mg/kg.d灌胃)预干预1周后,对戊四氮(PTZ,30mg/kg.d,腹腔注射)点燃癫痫过程中的行为学及在不同时间点对大鼠海马进行微透析取样,经高效液相电化学检测技术在活体观察了30只自由活动大鼠5-HT及其代谢产物5-羟吲哚乙酸(5-HIAA)水平和5-HT转化率(5-HIAA/5-HT)的动态变化。结果显示:PTZ注射后在CTP组发作潜伏期延长,发作程度轻和点燃时间延长,发作死亡率降低。点燃早期,CTP组大鼠的海马5-HT水平升高,5-HT转化率降低,与对照组和PTZ组比较,有显著性差异(P<0.05);点燃晚期CTP组和PTZ组与对照组比较5-HT水平和5-HT转化率均显著降低(P<0.05)。本研究结果提示PTZ点燃过程中,早期CTP升高脑内5-HT水平,可能直接抑制了引起爆发放电的动作电位,而抑制发作;晚期脑内5-HT神经元丢失和受体减少,功能减退,而导致CTP的作用减退。     

Formation of Morphine Tolerance in Offspring of Morphine-Tolerant Animals: Neurochemical and Neuroimmune Correlates

We carried out a complex physiological, neurochemical, and neuroimmunologic study of the formation of tolerance to analgetic effect of morphine and analyzed enkephalinase A activity in different brain structures and serotonin antibodies in the serum. More early development of morphine tolerance and a sharp increase in serum antibody titer was found in the offspring of morphine-tolerant rats. This points to an imbalance in the neurotransmitter system and can serve as a diagnostic marker of endogenous opioid system pathology.     

Serotonin-depleting midbrain lesions fail to mitigate hyperphagia and obesity in the Zucker fatty rat

Previous research has shown that damage to the dorsal and median raphe nuclei of rats can impede the subsequent development of hypothalamic hyperphagia and obesity as well as impair the defense of established hypothalamic obesity in response to food deprivation. The present study sought to determine if raphe injury might alter the development of another form of obesity, namely that which occurs spontaneously in the Zucker fatty rat. Subjects were 20 obese females (fafa; mean weight of 200 g) and 20 lean littermate controls (FaFa females; mean weight of 150 g). Following 10 days of baseline intake and weight recordings, half of each group received radio-frequency heat lesions of the dorsal and median raphe nuclei while the other half received sham surgery. Except for a mild suppression of food intake and weight gain during the first few days after lesioning, raphe injury did not alter the hyperphagia or obesity shown by fatties over the 7 week ad lib feeding period studied. Additional 24-hr intake tests of varying sucrose and quinine solutions revealed reduced sucrose acceptance and enhanced quinine rejection by fatties much as has been seen in previous studies of hypothalamic obese rats. Terminal assays of forebrain monoamine levels confirmed that raphe lesions were effective in depleting serotonin (-71% compared to controls) without producing major changes in norepinephrine or dopamine (-14% and +2%, respectively). The inability of raphe lesions to mitigate this form of hyperphagia and obesity suggests that earlier observations of their attenuating effects on hypothalamic obesity were not due to non-specific impairments of behavioral or metabolic factors necessary to permit overeating and weight gain.     

Functional characterization of the human atrial essential myosin light chain (hALC-1) in a transgenic rat model

Most patients with hypertrophic cardiomyopathy and congenital heart diseases express the atrial essential myosin light chains (ALC-1) in their ventricles, partially replacing the ventricular essential light chains (VLC-1). This VLC-1/ALC-1 isoform shift is correlated with an increase in cross-bridge cycling kinetics as measured using skinned fibers from the hypertrophied ventricles of human hearts.To study the functional importance of hALC-1 in the intact perfused heart, we generated a transgenic rat model (TGR) overexpressing hALC-1 in the heart. Twelve-week-old TGR rats expressed 17±4 g hALC-1 per mg of whole SDS-soluble protein. Their perfused heart contractility parameters were evaluated using the Langendorff preparation. Expression of hALC-1 was accompanied by statistically significant improvements (P<0.001) in the contractile parameters of the hearts of the TGR compared to the age matched control (WKY) animals, represented by increases from 20.8±2.3 to 45.1±3.6 mmHg/g heart weight in the developed left ventricular pressure, 1,035.7±89.8 to 2,181±135.4 mmHg/s in the contraction rate, and 713±60.2 to 1,364±137.4 mmHg/s in the relaxation rate in the WKY and the TGR groups respectively. Characterizing the functional effects of hALC-1 at the whole organ level represents a step towards gene therapy of heart failure.     

Genetic mapping of genes regulating the thymus size in back-cross rats between the laboratory BUF/Mna strain and the MITE strain derived from the wild rat, Rattus norvegicus

The thymoma prone BUF/Mna (B) rat is a useful model for Studying the genes responsible for thymus enlargement during the stage of young growth. Among the strains of rats, B rats have the largest thymuses at al stages of life. A locus, Ten-1 , which contributes to thymus enlargement in back-cross (BC) rats between the B and WKY/NCrj (W) strains, was mapped on chromosome 1. To determine the precise location of the bus, (B×(B×MITE)F1) BC rats were generated by crossing the B strain with the Inbred MITE (M) strain, which was established from captured, Japanese wild rats, and were examined by linkage study using polymerase chain reaction with 67 microsatellite markers. Linkages with thymus enlargements were found In genotypes of seven markers, BSIS, LSN, MYL2, IGF2, PBPC2, D1Mgh11 , and D1Mit6 , by X^2-test and Student's t -test, which confirmed the presence of the genetic locus associated with thymus enlargement, Ten-1 , in this region. Paradoxically, a suppressive locus, Tsu-1 , to thymus enlargement was also found on chromosome 3, showing linkages of phenotype of the small thymus with genotypes of SCN2A, CAT D3Mit16 , and D3Mit13 . By analyses of mapmaker/exp and mapmaker/qtl, Ten-1 was mapped at 4.6 cM proximal from IGF2 locus on chromosome 1 and Tsu-1 at 4.0 cM proximal from CAT locus on chromosome 3, respectively.     

Latent inhibition of conditioned odor potentiation of startle: a developmental analysis

We conducted a two-part study of age and latent inhibition in the rat. In the first part of the study, rats given odor-shock pairings at 23 or 75 days of age exhibited a potentiated startle response in the presence of the odor the following day. This effect did not occur in rats trained at 16 or 20 days of age. Odor pre-exposure on the day prior to conditioning markedly reduced the odor potentiation of startle effect in 23- and 75-day-old rats but had no effect in 16 and 20-day-olds. In the second part of the study, rats were pre-exposed to the odor at 16 or 20 days of age and then conditioned at 23 days of age. When tested the day after conditioning, these pre-exposed rats exhibited a disruption in the odor potentiation of startle effect. We compare our results with other studies of latent inhibition, and with recent studies on whether conditioned responses are appropriate to the animal's age at training or their age at test.     

银杏叶提取物联合盐酸文拉法辛对抑郁大鼠海马nNOS蛋白表达及NO水平的影响

目的 :探讨抑郁症脑损伤的机制 ,研究银杏叶提取物 (EGb)及合成抗抑郁药盐酸文拉法辛(Venlafaxine)对抑郁大鼠的抗脑损伤及神经元保护作用。方法 :慢性应激建立大鼠抑郁模型。将 84只雄性大鼠分为正常对照组、抑郁模型组和不同治疗组。快速断头法处死 ,取海马后一侧进行免疫组化反应 ,观察海马CA3区nNOS蛋白的表达 ;另一侧检测NO含量 ;同时测定血清中NO含量。结果 :抑郁模型组海马nNOS表达增加 ,海马及血清中NO含量增加 ,P <0 0 1;联合用药组海马nNOS表达下降 ,海马及血清中NO含量减少 ,P <0 0 1。结论 :慢性应激增加海马nNOS表达 ;EGb有减轻神经元损伤 ,保护神经元的作用 ,其与Venlafaxine合用可能会达到对抑郁进行多靶点、多层次的治疗 ,弥补单一用药的不足。     

Effect of adenosine and β-endorphin on contractions of the vas deferens of rats differing in predisposition to ethanol

Laboratory for the Search for and Study of Agents for Prevention and Treatment of Drug Addictions, Research Institute of Pharmacology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. V. Val'dman.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 108, No. 12, pp. 700–702, December, 1989.     

Adoptive Transfer of Suppression of Autoimmune Response to Rat Male Accessory Glands With Spleen Mononuclear Cells From Antigen-Pretreated Rats

ABSTRACT: The injection of the spleen mononuclear (SpM) cells, obtained from rats rendered unresponsive to autoantigen of rat male accessory glands (RAG) by pretreatment with low doses of purified fraction of RAG (containing the autoantigen), into normal syngeneic recipients markedly prevented the development of delayed type hypersensitivity (DTH) reaction to the autoantigen (suppression of the induction) (p < 0.001). The humoral response was not altered. The control animals were rat receptors of spleen mononuclear cells from donor rats pretreated with rat lung saline extract or 0.15 M NaCl. In contrast, the transference of SpM cells from donor rats pretreated with low doses of autoantigen prior to the immunization to rats previously immunized, did not modify the expression of the immune response against the autoantigen when compared with control rats. The suppression of the induction of DTH response was also obtained when prior to the immunization, the recipients received T-cell-enriched SpM cell population from unresponsive animals (p < 0.001), but not when they were injected with B-cell-enriched SpM cells. These results suggest that suppressor T cells capable of controlling induction of the autoimmune response against RAG autoantigen might be one of the immunoregulatory mechanisms that are activated when soluble autoantigen of RAG enter into circulation.     

Effect of chronic elevation of plasma calcium concentration by PTH or vitamin D3 on blood pressure and hypotensive activity of nifedipine in rats

The influence of a chronically elevated total plasma calcium concentration on blood pressure and heart rate was investigated in conscious normotensive rats. The plasma calcium concentration was elevated by continuous subcutaneous infusion with parathormone (PTH) after parathyreoidectomy, and by oral treatment with vitamin D₃. In both groups an elevated blood pressure was observed at the 1st day of treatment only. Blood pressure was returned to pretreatment values from the second day of treatments onaards. No significant changes in heart rate, due to hypercalcaemia, were observed. In hypercalcaemic rats, the calcium entry inhibitor nifedipine proved more potent in reducing blood pressure than in normocalcaemic control animals. Hydralazine was equipotent in reducing blood pressure in both groups. It is suggested, that the vasoconstrictor effects of a chronically elevated total plasma calcium concentration in conscious rats does not obviously result in a chronically elevated blood pressure, but rather in an enhanced sensitivity of the blood pressure towards calcium entry blockade.