Chronic methionine load-induced hyperhomocysteinemia enhances rat carotid responsiveness for angiotensin II

The purpose of the present study was to investigate the effects of chronic methionine treatment on vascular smooth muscle contractility for angiotensin II (Ang II). Methionine at 0.1, 1 and 2 g/ kg body weight was administered daily in the drinking water for 2, 4, 8 and 16 weeks. Rat carotid rings from control and treated animals were placed in an organ chamber containing Krebs solution. Concentration-response curves for Ang II and potassium chloride (KCl) were determined. Methionine-rich diet enhanced the plasmatic homocysteine concentration, and the magnitude of the contractile response to Ang II was increased in carotid rings from treated animals after 8 and 16 weeks. However, the treatment did not alter KCl-induced contraction. In another set of experiments, the rings were incubated with indomethacin and curves for Ang II were obtained. Exposure of the rings to indomethacin inhibited the enhancement in the contractile response to Ang II. The present findings show that chronic methionine treatment enhances homocysteine plasmatic concentration leading to an enhanced Ang-II-induced contraction, which appears to be related to the release of vasoconstrictor prostanoid(s). Copyright (C) 2004 S. Karger AG, Basel.702919

Interaction of Maternal Separation on the UCh Rat Cerebellum

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Maternal care is the main source of signals and stimuli for proper development, growth, and production of adjustment responses to stressful factors. Adverse experiences in childhood are associated with a vulnerability to developing abusive ethanol ingestion via alterations of the response of the hypothalamic-pituitary-adrenal axis. Alcoholism causes global brain abnormalities, with the cerebellum being one of the most susceptible areas. We evaluated the effect of maternal separation on the cerebellum structure of male UCh rats. Adult male UChA (low 10% ethanol consumption) and UChB (high 10% ethanol consumption) rats were divided in to four experimental groups: (1) UChA, (2) UChA maternal separation (MS), (3) UChB, and (4) UChB MS. The MS occurred between the 4th and 14th days of age, for 240 min day(-1). Euthanasia was performed at 120 days of age. An image analysis system was used to measure cerebellar cortical height and Purkinje cellular area and height in five rats from each group. The cerebellar sections were stained with antibodies against IGFR-I. MS did not alter the ethanol consumption of UChA and UChB rats. Corticosterone level was significantly higher in UChA MS and UChB MS rats than in UChA and UChB rats. The Purkinje cellular area and height were higher in UChA MS rats. IGFR-I expression was observed in the cortical glomerular area of UChA MS and UChB MS rats. MS altered the Purkinje cells in the cerebella of male UCh rats. Microsc. Res. Tech. 77:44-51, 2014. (c) 2013 Wiley Periodicals, Inc.7714451Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [06/60569-3