The Effects of Phenoxybenzamine and Cold Stress On Tyrosine Hydroxylase Enzyme Activity and Expression of Tyrosine Hydroxylase Gene in the Rat Adrenal Medulla

Authors : Muhittin YÜREKLI

Pages : 197-204

View : 16 | Download : 7

Publication Date : 1998-12-01

Article Type : Research Paper

Abstract :The effects of cold exposure and cold plus phenoxybenzamine treatment on tyrosine hydrox-ylase insert ignore into journalissuearticles values(TH); activity and TH m RNA levels were investigated in the adrenal medulla of Sprague Dawley insert ignore into journalissuearticles values(SD); rats. SD rats were exposed to cold insert ignore into journalissuearticles values(4 °C); for 48 hours. Phenoxybenzamine was injected intra-peritoneally insert ignore into journalissuearticles values(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 3 H 2 O as a product of L-insert ignore into journalissuearticles values(3 H);-tyrosine hydroxylation, the formation of L-insert ignore into journalissuearticles values(3 H);-dopa from L-insert ignore into journalissuearticles values(3 H);-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 insert ignore into journalissuearticles values(P
Keywords : Cold exposure, adrenal medulla, phenoxybenzamine, tyrosine hydroxylase tyrosine hydroxylase mRNA