The effects of phenoxybenzamine and cold stress on tyrosine hydroxylase enzyme activity and expression of tyrosine hydroxylase gene in the rat adrenal medulla

Abstract

Abstract:Soguk uygulaması ve soguga ek olarak phenoxybenzamine uygulamasının, tirozin hidroksilaz (TH) ve TH mRNA seviyesi üzerindeki etkileri Sprague Dawley (SD) sıçanlarının adrenal medullasında araştırıldı. SD sıçanları 48 saat 4 °C’de soguga maruz bırakıldı. Phenoxybenzamine uygulaması % 0.9 NaCl içeren % 5 etanol içinde hazırlanarak 20 mg/kg olacak sekilde periton içine (i.p) yapıldı. TH aktivitesi,

Abstract:The effects of cold exposure and cold plus phenoxybenzamine treatment on tyrosine hydroxylase (TH) activity and TH m RNA levels were investigated in the adrenal medulla of Sprague Dawley (SD) rats. SD rats were exposed to cold (4 °C) for 48 hours. Phenoxybenzamine was injected intraperitoneally (i.p) at 20 mg/kg, which was prepared in 5% ethanol containing 0.9 % NaCL TH activity was measured by monitoring the formation of 3H2O as a product of L−(3H) -tyrosine hydroxylation, the formation of L−(3H) -dopa from L−(3H) -tyrosine. Total adrenal RNA was isolated and blotted onto a nylon membrane and the immobilized RNA was then hybridized from TH cDNA probe. TH mRNA was assayed by densitometric scanning of the autoradiograms with a videodensitometer. TH activity and mRNA levels were found to be significantly increased in the adrenal medulla of SD rats exposed to cold for 48 hours and treated with cold plus phenoxybenzamine (P<0.01).