增产菊胺酯对雄性小鼠生殖激素的影响

为了探讨增产菊胺酯引起小鼠精了生成障碍的可能机理，本文研究了增产菊胺酯对雄性小鼠卵泡刺激素（ＦＳＨ）、黄体生成素（ＬＨ）及睾酮（Ｔ）的影响。小鼠经口染毒，隔天一次，连续１０次，第３５天处死。检验因清ＦＳＨ、ＬＨ没有明显变化，而睾丸组织睾酮含量出现剂理依赖性降低，高剂量组与对照组比较有显著性差异（Ｐ〈０．０５），结果表明，增产菊胺酯不影响ＦＳＨ、ＬＨ，而影响Ｔ的合成和分泌。这可能是增产菊胺酯对小鼠精     

赛赓啶对 KBV200细胞多药抗性的逆转作用

研究赛赓啶对KB_V200细胞多药抗性的逆转作用及逆转机制。在KB_V200细胞,采用MTT法,测出赛赓啶对长春新碱、阿霉素和鬼臼乙叉甙耐药的逆转系数分别为5.5,2.0和1.9,而对5-氟尿嘧啶、美法仑的细胞毒性作用无明显影响,表明赛赓啶为多药抗性逆转剂。荧光分光光度法测定表明,赛赓啶可使KB_V200细胞内阿霉素蓄积量增加。流式细胞荧光测定显示赛赓啶可增加罗丹明123的蓄积并减慢其外排。免疫细胞化学及狭缝杂交表明赛赓啶不影响KB_V200细胞的P-糖蛋白染色深度和 mdr1 RNA 表达水平。以上结果提示赛赓啶的多药抗性逆转机制是抑制P-糖蛋白泵的功能。     

Central circulation in rats with different tolerance to acute blood loss

Study of the dynamics of cardiac output in rats with different tolerance to acute massive blood loss showed that the pumping ability of the heart remains intact during the entire posthemorrhagic period in all high-resistant and in 65% low-resistant rats. In 35% rats that were low-resistant to blood loss, the cardiac output deficiency syndrome developed after cessation of bleeding against the background fall in arterial pressure and a decrease in the hepatic blood flow, which are the signs of rapid variant of the dysfunction produced by acute blood loss. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 10, pp. 384–388, October, 1998     

The effects of running and meditation on beta-endorphin, corticotropin-releasing hormone and cortisol in plasma, and on mood

The relations between three hormones of the hypothalamic-pituitary-adrenocortical (HPA) axis, beta-endorphin (β-EP), corticotropin-releasing hormone (CRH) and cortisol, and mood change were examined in 11 elite runners and 12 highly trained meditators matched in age, sex, and personality. Despite metabolic differences between running and meditation, we predicted that mood change after these activities would be similar when associated with similar hormonal change. Compared to pre-test and control values, mood was elevated after both activities but not significantly different between the two groups at post-test. There were significant elevations of β-EP and CRH after running and of CRH after meditation, but no significant differences in CRH increases between groups. CRH was correlated with positive mood changes after running and meditation. Cortisol levels were generally high but erratic in both groups. We conclude that positive affect is associated with plasma CRH immunoreactivity which itself is significantly associated with circulating β-EP supporting a role for CRH in the release of β-EP. Increased CRH immunoreactivity following meditation indicates, however, that physical exercise is not an essential requirement for CRH release.     

眼镜蛇人蛰前、蛰眠期和出蛰后血清激素与能量物质代谢的关系

本文研究眼镜蛇入蛰前、蛰眠期及出蛰后血清 T_3,T_4和皮质醇水平与体内能量物质的含量变化关系,探讨其与蛰眠行为的关系。结果表明入蛰前眼镜蛇大量摄食储能过冬,由于血清激素水平降低,控制了体内组织器官的氧化代谢系统,使新陈代谢逐渐下降。蛰眠期血糖血脂明显下降,耗氧量显著减少,呈节能低代谢状态。此期血清激素水平已升高,但低温抑制了体内代谢。出蛰后血清激素水平明显升高且在春暖升温季节使眼镜蛇代谢率升高。     

Benign intracranial hypertension and recombinant growth hormone therapy in Australia and New Zealand

Benign intracranial hypertension (BIH) is reported in three children from Australia and one from New Zealand, who were being treated with recombinant human growth hormone (rhGH). Three males and one female, aged between 10.5 and 14.2 y, developed intracranial hypertension within 2 weeks to 3 months of starting treatment. A national database, OZGROW, has been prospectively collecting data on all 3332 children treated with rhGH in Australia and New Zealand from January 1986 to 1996. The incidence of BIH in children treated with growth hormone (GH) is small, 1.2 per 1000 cases overall, but appears to be greater with biochemical GHD (<10IUml ^-1), i.e. 6.5/1000 (3 in 465 cases), relative risk 18.4, 95% confidence interval 1.9-176.1, than in all other children on the database. The incidence in patients with Turner's syndrome was 2.3/1000 (1 in 428 cases). No cases in patients with partial GHD (10–20 IUml ^-1) or chronic renal failure were identified. Possible causative mechanisms are discussed. The authors'practice is now to start GH replacement at less than the usual recommended dose of 14IUm-² week^-1 in those children considered to be at high risk of developing BIH. Ophthalmological evaluation is recommended for children before and during the first few months following commencement of rhGH therapy and is mandatory in the event of peripheral or facial oedema, persistent headaches, vomiting or visual symptoms. The absence of papilledema does not exclude the diagnosis.     

Effect of pindolol on endocrine and temperature responses to buspirone in healthy volunteers

Ten healthy subjects received buspirone (30 mg orally) with and without pre-treatment with the 5-HT1A receptor antagonist, pindolol (80 mg over 3 days). Following pindolol treatment the growth hormone and hypothermic responses to buspirone were significantly decreased. There was also a delay in the onset of the prolactin response to buspirone but the total amount of prolactin secretion, calculated as area under the curve, was not significantly reduced. The data suggest that the growth hormone and hypothermic responses to buspirone in humans are mediated by 5-HT1A receptors, but an explanation founded on pharmacokinetic factors cannot presently be excluded. Both this latter possibility and the lack of selectivity of pindolol for 5-HT receptors indicate the need for the further neuroendocrine studies of the mode of action of buspirone, preferably with more selective 5-HT1A receptor antagonists.     

Human Y-79 retinoblastoma cells express functional corticotropin-releasing hormone receptors

In human Y-79 retinoblastoma cells corticotropin-releasing hormone (CRH) produces a marked and rapid increase of adenylate cyclase activity. The concentration of the peptide producing half-maximal stimulation is 60 nM. The effect of CRH is significantly antagonized by the specific CRH receptor antagonist alpha-helical CHR 9-41 and is mimicked by sauvagine and urotensin I, two peptides displaying sequence homology with CRH. These results demonstrate the presence of functional CRH receptors in human Y-79 retinoblastoma cells and suggest that this cell line may be a suitable model in which to study the action of CRH on human retinal cell function.