Blood content of tyrosine is an index of glucocorticoid action on metabolism.
Glucocorticoid hormones directly or indirectly control virtually all metabolic and physiological processes. Glucocorticoids are also shown to act on a multitude of genes, enzyme systems, and proinflammatory factors, but for these hormones there is no representative index of action on metabolism similar to glucose content in blood for insulin. The absence of such an index prevents the assessment of tissue provision with these hormones under various conditions and seems to be an essential cause of complications associated with the clinical use of glucocorticoid preparations. Considering specific features of tyrosine metabolism and data obtained experimentally and on a clinical model (adrenalectomy in rats and substitution therapy in endocrine disease), blood content of this amino acid seems promising as such an index. Based on comparing results of glucocorticoid treatment in patients with systemic lupus erythematosus with changes in their blood tyrosine contents, the pharmacological effect of glucocorticoid preparations is suggested to be mainly due to compensating a relative shortage of these hormones.
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Center of Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russia. irma2@kmail.ru
D005938:Glucocorticoids / Q000502:physiology*; D006801:Humans; D014443:Tyrosine / Q000097:blood*
D005938:Glucocorticoids; D014443:Tyrosine