Investigation of the effect of physiological stress conditions on tyrosine hydroxylase enzyme activity and adrenomedullin levels in some rats tissues

In this study, the effect of cold stress on tyrosine hydroxylase (TH) activity was investigated in adrenal medulla, hypothalamus and heart. Adrenomedullin levels were also investigated in adrenal medulla, hypothalamus, heart, kidney, smooth muscle and striated muscle with under cold stress. Catecholamines, (dopamin, noradrenalin and adrenalin) are among the first molecules to show a response to stressors and are crucial in stimulating action in response to a percieved threat. Tyrosine hydroxylase (TH) is the rate-limiting enzyme in the synthesis of dopamin, noradrenalin and adrenalin. Adrenomedullin, is a novel potent vasorelaxing and hypotensive peptide recently isolated from human pheochromacytoma. It has been detected in adrenal medulla, heart, lung and kidney as well as in plasma and urine. The results indicated that adrenomedullin levels decreased depend on cold stress in hypothalamus, adrenal medulla, heart, kidney, striated muscle and smooth muscle. The results also demonstrated that TH activity increased in adrenal medulla, heart, hypothalamus with cold stress. KEYWORDS: Adrenomedullin (AdM), Tyrosine hydroxylase (TH), Cold Stress, Adrenal Medulla, Heart, Hypothalamus