The inhibitory action of corticotropin-releasing hormone on gonadotropin secretion in the ovariectomized rhesus monkey is not mediated by adrenocorticotropic hormone

Earlier observations in our laboratory indicated that i.v. infusion of human/rat corticotropin-releasing hormone (hCRH) suppresses pulsatile luteinizing hormone (LH) and follicle-stimulating hormone (FSH) release in ovariectomized rhesus monkeys. Since cortisol secretion increased significantly as well, it was not possible to exclude the possibility that this inhibitory effect of hCRH on gonadotropins was related to the activation of the pituitary/adrenal axis. The purpose of the present study was to determine the role of pituitary/adrenal activation in the effect of hCRH on LH and FSH secretion. We compared the effects of 5-h i.v. infusions of hCRH (100 micrograms/h, n = 7) and of human adrenocorticotropic hormone (ACTH) (1-24) (5 micrograms/h, n = 3; 10 micrograms/h, n = 3, 20 micrograms/h, n = 3) to ovariectomized monkeys on LH, FSH, and cortisol secretion. As expected, during the 5-h ACTH infusions, cortisol levels increased by 176-215% of baseline control, an increase similar to that observed after CRH infusion (184%). However, in contrast to the inhibitory effect observed during the CRH infusion, LH and FSH continued to be released in a pulsatile fashion during the ACTH infusions, and no decreases in gonadotropin secretion were observed. The results indicated that increases in ACTH and cortisol did not affect LH and FSH secretion and allowed us to conclude that the rapid inhibitory effect of CRH on LH and FSH pulsatile release was not mediated by activation of the pituitary/adrenal axis.     

湖南土家族的体质特征

以20至69岁的湖南土家族人为观察测量对象,根据1392人(男896,女496)的身高,1038人(男668,女370)的头部测量,364人(男235,女129)的五官测量和观察结果,分析该民族的体质特征,并与国内其他民族相比较。     

担子菌多糖及羊脾RNA对肿瘤的抑制与有关组织中cAMP含量关系的探讨

本文讨论了对带瘤小鼠注射香菇多糖、松口蘑多糖和羊脾RNA后,活体内有关组织中cAMP含量与抑瘤率之间的关系。 结果表明,上述活性物质不仅增强了机体免疫活性,同时亦促使机体内脾、瘤等组织的cAMP增高,此种增高,与抑瘤率成正相关。     

杂交水稻及三系在发育过程中的酯酶同工酶比较研究

本文报道了利用聚丙烯酰胺凝胶电泳技术,测定杂交水稻及三系亲本共50个组合的萌动胚、芽,不同发育时期的叶片、根、雄蕊等12个组织或器官的酯酶同工酶的结果。根据所测结果,可把杂交水稻的酯酶同工酶酶谱分为5种类型:互补型、偏父型、偏母型、同型和“杂种”酶谱。强优势组合以互补型酶谱居多,弱优势组合都是同型酶谱,“杂种”酶谱仅见于V优64的幼穗分化期叶片和V优63、汕优63的三叶期叶片中。不同器官的互补酶谱都可作为预测杂种比势,鉴定杂交稻种子的纯度和真实性以及选配新杂交组合的一个手段或依据,但以对萌动胚或幼芽的测定更有实践意义。     

Stimulation of arachidonic acid metabolism: differences in potencies of recombinant human interleukin-1 alpha and interleukin-1 beta on two cell types

Recombinant human interleukin-l (rIL-1) alpha and beta, which have 26% homology in their amino acid sequence, stimulated arachidonic acid metabolism by squirrel monkey smooth muscle cells and rat liver cells; their relative effectiveness, however, varied with the two cells. Recombinant IL-1 alpha was 3 times more effective than rIL-1 beta at stimulating arachidonic acid metabolism by the primate smooth muscle cells. Recombinant IL-1 alpha was 3 times less effective than rIL-1 beta when measured by their capacity to synergistically stimulate arachidonic acid metabolism of rat liver cells in the presence of palytoxin and anti-diuretic hormone (ADH). The rIL-1 alpha and rIL-1 beta also stimulated the release of radiolabelled arachidonic acid from the smooth muscle cells prelabelled with [3H]arachidonic acid. The two recombinant IL-1s have different heat stabilities, again when measured by their capacity to stimulate arachidonic acid metabolism; IL-1 alpha was more heat stable than IL-1 beta.     

水蒸汽蒸馏巴柑檬叶和果皮精油化学成分的研究

巴柑檬是我们第一次从国外引种成功的一种名贵香料植物。用色谱-质谱-计算机联用技术、毛细管气相色谱保留指数法和标准品叠加法分析了水蒸汽蒸馏巴柑檬叶和果皮精油的化学成分。从叶和果皮精油分离出来的220个和200个成分中,分别鉴定出48个和57个成分。鉴定组分的含量分别占叶和果皮精油的99.80％和98.54％。叶精油与果皮精油在化学成分方面的主要区别是叶油中萜烃化合物含量较低,而萜醇类化合物含量较高。     

三乙醇胺基强碱性聚苯乙烯树脂共价固定胰酶的研究

用多孔强碱型三乙醇胺基聚苯乙烯阴离子交换树脂做为载体,用CNBr与载体上的多羟基作用共价偶联了胰酶。红外光谱表明:其共价偶联反应机理与用CNBr活化多糖类载体并接酶的机理相类似。最适偶联条件研究表明:CNBr用量增多,酶蛋白载量增加。但比活下降。偶联pH为10时,固定化酶有适宜的载量和较高的比活。由于胰酶水解蛋白反应释放出H~+质子,这些质子在载体内积累,使微环境内H~+质子浓度增加,进而使得固定化胰酶的pH—活性曲线在pH9～11范围内未出现下降。在变温和60℃恒温下对固定化酶的热稳定性测试表明:固相酶的热稳定性比天然酶的热稳定性有所提高。     

Acetylcholine in the posterior hypothalamic nucleus is involved in the elevated blood pressure in the spontaneously hypertensive rat

Intravenous injection of physostigmine, 40 and 80 ug/kg, in unanesthetized normotensive rats increased systolic blood pressure (SBP) by 21 +/- 3 and 42 +/- 7 mmHg. This pressor response was 80% inhibited by intracerebroventricular (icv) injection of hemicholinium-3 (HC-3), 20 ug. Simultaneous icv injection of HC-3 and choline (365 ug) prevented the inhibition of the pressor response by HC-3. In spontaneously hypertensive rats, injection of HC-3 either icv (20 ug) or bilaterally into the posterior hypothalamic nuclei (1 ug) decreased SBP by about 40 mmHg. The effect of intrahypothalamic HC-3 was completely blocked by simultaneous injection of choline (24.3 ug) into the same site. The hypotensive effect of icv HC-3 was completely blocked by icv choline (243 ug) and was inhibited up to 60% by injections of choline (24.3 ug) into the posterior hypothalamic nuclei.     

Intervention trial with selenium for the prevention of lung cancer among tin miners in Yunnan,China

This pilot study evaluated the feasibility and effectiveness of conducting a double-blind clinical trial for the prevention of lung cancer with selenium (Se) in Yunnan Tin Corporation, the People's Republic of China, where the incidence rates of lung cancer are extraordinarily high among the miners. Forty healthy miners were randomized to either 300 μg of Se in high Se malt cakes or an identical placebo of malt cakes daily for one year. Subjects consumed their usual daily diet. The low Se concentrations in plasma (0.05±0.008 μg/mL) and hair (0.442±0.085 μg/g) reflected their low dietary Se intake in the control subjects. In Se-supplemented group, the Se status was increased by 178% for serum and 194.8% for hair. The serum GSHpx activity was increased by 155.7%, whereas the lipid peroxide level was reduced by 74.5% compared to the placebo. The results of UDS assay indicated that the lymphocyte DNA damage induced by ultraviolet irradiation and carcinogen 3,4-benzpyrene could be protected by Se supplementation. Se-supplementation did not affect the liver function test (SGPT), as well as the concentrations of hemoglobin, albumin, and cholesterol. Thus, daily intake of 300 μg Se in form of Se-malt as a chemopreventive measure is safe and effective to humans with low Se status.