Effects of acute and chronic desipramine treatment on somatostatin receptors in brain

The effects of acute (5 mg/kg, IP twice daily for 2 days) and chronic (5 mg/kg IP twice daily for 21 days) administration of desipramine (DMI) on [¹²⁵I]-Tyr¹¹-somatostatin binding sites in brain were examined. There was no change in [¹²⁵I]Tyr¹¹-somatostatin binding in membranes prepared from the frontal cortex, striatum, and hippocampus of rats acutely or chronically treated with DMI as compared to non treated animals. [¹²⁵I]Tyr¹¹-Somatostatin binding was increased in membranes prepared from the rat nucleus accumbens only after chronic DMI administration. Scatchard analysis of the binding data from the nucleus accumbens showed that [¹²⁵I]Tyr¹¹-somatostatin labels a single population of somatostatin binding sites with an affinity constant, K_d, of 1.8±0.60 nM and a B_max of 330±90 fmol/mg protein. Chronic treatment with DMI increased the B_max (500±140 fmol/mg protein) but had no effect on the K_d. This finding shows a regional effect of DMI on [¹²⁵I]Tyr¹¹-somatostatin binding sites in rat brain and suggests that somatostatin may play a role in the pathophysiology of depression.     

Ontogenetic Development of 5-HT1D Receptors in Human Brain: An Autoradiographic Study

The pattern of pre- and postnatal appearance of 5-HT_1D receptors throughout the different areas of the human brain was studied by quantitative in vitro autoradiography, using [¹²⁵I]GTI (serotonin O -carboxymethyl-glycyl-[¹²⁵I]tyrosinamide) as a ligand. The anatomical distribution of 5-HT_1D receptors in neonatal, infant and children's brain was in good agreement with that observed in the adult, the basal ganglia and substantia nigra being the most intensely labelled areas. The development of these receptors throughout the human brain was mainly postnatal: low densities of [¹²⁵I]GTI binding sites were observed at the fetal/neonatal stage in most regions analyzed, in contrast with the high levels of labelling found in infant and children's brains. Indeed, in a number of regions, including the globus pallidus, substantia nigra and visual cortex, a peak of overexpression of 5-HT_1D receptors was observed in the first decade of life. Such overexpression could support a regulatory role for 5-HT_1D receptors in advanced periods of the CNS developmental process. Our results also indicate that the administration of drugs acting on 5-HT_1D receptors during the early postnatal period of life could result in modifications of their properties, as these receptors are already functional in this period.     

DNA damage by the glycation products of glyceraldehyde 3-phosphate and lysine

Summary In order to evaluate whether base modifications, apurinic/apyrimidinic site formation, strand breaks, or a combination of these lesions results from the interaction of glycation products with DNA, plasmid DNA was first reacted with these products, and then subjected to digestion with endonuclease III and endonuclease IV of Escherichia coli. Analysis of the differential effects of digestions with these enzymes by electrophoresis on agarose gels demonstrated that reactive glycation products produce both base modification and apurinic/apyrimidinic sites in DNA, in addition to the strand breaks observed after incubation with glycation products alone. These types of DNA damage may occur in specific diabetic cells where elevated levels of glycating sugars are associated with pathologic dysfunction. [Diabetologia (1994) 37: 145–149] Received: 28 May 1993 and in revised form: 30 August 1993     

糖皮质激素受体高、低亲和力位点在急性淋巴细胞性白血病治疗中的意义

研究了１０例正常人和２９例急性淋巴细胞性白血病（急淋）患者外周血糖皮质激素受体高、低亲和力结合位，或（ＧＣＲＨ、ＧＣＲＬ），利用Ｒｕ３８４８６对ＧＣＲＬ进行封闭，对部分患者ＧＣＲＨ、ＧＣＲＬ在激素联合化疗前后水平的变化进行了动态观察。结果表明，正常对照组ＧＣＲＨ、ＧＣＲＬ分别为４６０８±１８８９位点／细胞和１３５２３８±８８５０９位点／细胞，两者相关良好。急淋患者ＧＣＲＨ、ＧＣＲＬ分别为６０５２±３８８８位点／细胞和１２６４０５±１０２１３３位点／细胞，经过糖皮质激素药物联合化疗后，其水平分别为３６１６±１９６２位点／细胞和１４３５９７±１１２２８９位点／细胞，ＧＣＲＨ下降明显（Ｐ＜０．０１），下降率为４０．３％；而ＧＣＲＬ化疗前后差异不显著（Ｐ＞０．０５）。提示ＧＣＲＬ在介导糖皮质激素联合化疗疗效的维持中起重要的作用。     

固体废物处理和处置设施的选址

新建废物处理和处置设施的选址是一项综合性很强的工作，涉及自然环境，社会政治和经济、安全和技术等诸多方面，选址的主要目标通过一系列的选址技术的步骤来具体体现。     

Localization of MPP+ binding sites in the brain of various mammalian species

Summary The distribution and density of³H-MPP⁺ binding sites were studied by in vitro quantitative autoradiography in the brain of the mouse, rat and monkey. The highest levels of³H-MPP⁺ specific binding were observed in rat brain. The substantia nigra in rat and monkey, and the anterior caudate-putamen formation in mouse and monkey showed the lowest density of autoradiographic grains. The presence of a relatively high density of MPP⁺ sites in the hippocampus of all species studied could be of interest to explain some effects of MPTP administration on convulsions caused by chemoconvulsants.The finding of a 60–70% reduction of³H-MPP⁺ binding sites in the rat caudate-putamen, on the side of quinolinic acid infusion and no changes after 6-hydroxydopamine lesion of dopaminergic nigrostriatal neurons suggests the presence of these sites mainly on striatal cells.The results suggest that the distribution of MPP⁺ binding sites in brain would not seem to be related to MPTP toxicity.