Complete complementary DNA of rat tyrosine aminotransferase messenger RNA. Deduction of the primary structure of the enzyme

The primary structure of rat tyrosine aminotransferase (L-tyrosine:2-oxoglutarate aminotransferase; EC 2.6.1.5), a liver-specific enzyme involved in gluconeogenesis, has been deduced from the nucleotide sequence of a cloned full-length cDNA. The mRNA is 2362 nucleotides long (excluding the poly(A) tail) and codes for a polypeptide of 454 amino acids with a molecular weight of 50634. Unambiguous identification was obtained by comparison of this sequence with the amino acid sequences of several peptides obtained from the purified enzyme.     

Opposite effects of two ligands for peripheral type benzodiazepine binding sites, PK 11195 and RO5-4864, in a conflict situation in the rat

The effects of two drugs acting at the peripheral type benzodiazepine binding sites, PK 11195 and RO5-4864, were examined in shock-induced suppression of drinking in rats. These two compounds have opposite effects : RO5-4864 (3.1-1205 mg/kg i.p.) enhanced whereas PK 11195 (25-50 mg/kg i.p.) decreased the punished responding, and PK 11195 (6.25 mg/kg, a dose which did not alter the punished responding) blocked the proconflict action of RO5-4864 (6.25 and 12.5 mg/kg). The effects of RO5-4864 and PK 11195 were not antagonized by RO15-1788, a selective antagonist of the central benzodiazepine site. In addition, PK 11195 (6.25 mg/kg) did not reverse the proconflict effect of two beta-carbolines : beta-CEE and FG 7142. AS picrotoxin did not change the punished responding, these data imply that the effects of RO5-4864 and PK 11195 on the one hand and those of chlordiazepoxide and beta-carbolines on the other hand are differentially mediated and suggest that the peripheral type benzodiazepine binding sites are involved in this conflict model.     

Effect of 6-hydroxydopamine on neuropeptides in the rat female genitourinary tract

The occurrence and distribution of neuropeptide Y has been determined in the rat female genitourinary tract by radioimmunoassay and chromatographic analysis. Within the bladder, higher concentrations of neuropeptide Y were found in the trigone (48.8±5.2 pmol/g) than in the dome (36.0±2.1 pmol/g). In the genital tract, highest concentrations were identified in the vagina (41.4±2.1 pmol/g). Treatment of rats with 6-hydroxydopamine resulted in significant depletion of neuropeptide Y concentrations in both parts of the bladder, together with vagina, uterine horn and fallopian tube. No change was observed in the cervix, uterine body and ovary. Concentrations of vasoactive intestinal polypeptide were unaffected by treatment with 6-hydroxydopamine except in the area of the cervix where concentrations rose from 64.1±5.7 pmol/g to 133.6±15.1 pmol/g (p<0.05). There was a generalised, but statistically insignificant rise in substance P concentrations.     

褐稻虱饲料稻株中数种氨基酸的营养效应

本研究初步证实饲料稻株中甘氨酸、赖氨酸和酪氨酸含量的高低,同褐稻虱(Nilaparvata lugens Stal)的发育进度、存活率、短翅型出现率和单雌产卵量关系极为密切,它们是褐稻虱赖以正常生长发育和繁殖的重要氨基酸。     

从乙型肝炎病毒表面抗原阳性母亲流产的胎儿查出乙型肝炎病毒标志

应用Southern blot杂交试验检测HBsAg及HBeAg均阳性母亲流产的9例胎儿肝细胞中HBV DNA的存在状态,并与其HBV血清学、免疫电镜及肝脏免疫组织化学的结果相比较。结果在3例胎肝高分子DNA中检出了整合的HBV DNA顺序,且此3例HBV DNA整合到胎肝细胞基因组并无特定部位,提示为随机整合。3例中2例的血清及肝匀浆都检出HBsAg颗粒,其胎肝细胞胞浆HBsAg也阳性;另1例受HBV感染的唯一标志是在胎肝细胞中存在着整合的HBVDNA。此外,另1例则仅胎肝细胞中HBsAg阳性而无整合的HBV DNA。在胎肝细胞中检出整合的HBV DNA进一步证实HBV子宫内传播途径的存在。     

肿瘤坏死因子受体超家族成员在免疫系统和疾病中的研究

肿瘤坏死因子受体超家族 (tumor necrosis factor receptor superfamily, TNFRSF) 是细胞因子受体的一个蛋白质超家族,其显著特征是通过细胞外富含半胱氨酸结构域结合肿瘤坏死因子(tumor necrosis factor,TNF)。肿瘤坏死因子受体(tumor necrosis factor receptors,TNFRs)是古老的细胞因子,TNFRs同源基因最早可追溯到节肢动物果蝇中。TNFRs在炎症反应、细胞凋亡、淋巴细胞稳态和组织发育中发挥重要的作用,TNFRs最主要的功能是与免疫系统相关。鉴于其在免疫系统中发挥重要的作用,肿瘤坏死因子受体家族成员已成为治疗糖尿病、动脉粥样硬化、骨质疏松、自身免疫性疾病、移植排斥反应和癌症等人类疾病的靶点。随着科学技术发展,关于TNFRs的功能有了新的进展,在无脊椎动物和低等脊椎动物中已经有大量报道。在本篇综述中,主要总结了在高等哺乳动物中发现的29种TNFR成员的相关报道,包括8种死亡受体和21种非死亡受体,主要涉及在免疫系统以及与疾病相关领域的研究。大多数研究处于基础实验阶段,少数走向临床研究的案例取得的临床效果并不理想,靶向设计针对自身免疫性疾病、炎症和肿瘤疾病的治疗方案需要更深入的理解TNFRs功能。本文旨在对TNFRs成员发挥的功能有进一步的认识。     

Effect of gossypol on testicular blood flow and testosterone production in rats

Rats were treated with highly purified gossypol acetic acid at doses of 15 or 30 mg/kg day-1 for 6 weeks to produce an effect on spermatogenesis as shown by reduced sperm motility and increased sperm malformation rates. The treated rats did not differ from the controls in the body weight growth curves and reproductive organ weights. When stimulated with hCG, testicular blood flow was increased in the low dose group; the testosterone concentrations in peripheral and testicular venous blood were also increased to a greater extent than those of the control group. No difference was found between the high dose and control groups in testicular blood flow or testosterone concentrations. The morphology of the Leydig cells was apparently normal, although some degenerative changes in the germinal epithelium were observed in the high dose group. Therefore, there is no evidence in our experiment to show any anti-androgenic effect following 6-week treatment of gossypol in rats, even at the dose of 30 mg/kg day-1.     

High concentrations of a novel peptide, neuropeptide Y, in the innervation of mouse and rat heart

A newly discovered bioactive peptide, neuropeptide Y (NPY), has been found in the innervation of the mouse and rat heart by immunocytochemistry, NPY-immuno-reactive nerves were very dense around the nodal tissues. They also surrounded the coronary arteries and arterioles and were found in close association with the cardiac muscle. The distribution of NPY-containing nerves paralleled that of noradrenergic fibers, demonstrated by the use of antibodies to the catecholamine-converting enzymes tyrosine hydroxylase and dopamine beta-hydroxylase. Furthermore, NPY was seen to be present in a proportion of intrinsic neurons mostly found in the atria and in close proximity to the nodal tissue. The concentrations of extractable NPY-immunoreactive material (about 150 pmol/g in whole mouse heart) by far surpasses those of the other peptides so far reported in the cardiac tissue. High performance liquid chromatography demonstrated the NPY immunoreactivity to elute in a single sharp peak, in an identical position to brain NPY.     

龙葵抗阿特拉津生物型叶绿体基因文库的建立

用对阿特拉津(Atrazine)除草剂抗性的龙葵生物型B_(12)株系作材料,制备叶绿体DNA。B_(12)株ctDNA(叶绿体DNA)经BamHI酶解,在0.7％琼脂糖凝胶电泳上呈现24条带,其中最大的片段为18.6kb,最小的片段为1kb。用pBR322作为载体,构建B_(12)株ctDNA BamHI片段文库。通过与探针的分子杂交,从中筛选出含有编码叶绿体32kd蛋白质的阿特拉津抗性基因的克隆pSB135和含有ATP合酶α亚单位基因的克隆pSB132。     

贵州宽叶缬草油的化学成分

贵州产宽叶缬草(Valeriana officinalis L.var.latifolia Miq.)油,用Finnigan4510型毛细管气相色谱/质谱/计算机联用方法进行了化学成分分析,共检出了29个成分鉴定了其中21个成分,占全精油的92.33%,主要成分为乙酸龙脑酯,α-蒎烯,莰烯,β-蒎烯,柠檬烯,乙酸葛缕酯,二氢乙酸葛缕酯等。该油芬芳,适于调配烟用香精,亦用于调节器配食用香精和化妆品香精。