Box 4.39Biosynthesis and control of catecholamines secreted by the adrenal medulla

Image ch4fb39.jpg

Stimuli from the hypothalamus, medulla and pons activate preganglionic cholinergic nerves that stimulate the release of epinephrine and smaller amounts of norepinephrine from the chromaffin cells of the adrenal medulla. All synthetic steps take place in the cytoplasm except the conversion of dopamine to norepinephrine which occurs in the secretory granules. Epinephrine is taken up into the secretory granules for storage and release.

Abbreviations: TH, tyrosine hydroxylase; AAD, amino acid decarboxylase; DβH, dopamine β-hydroxylase; PNMT, phenylethanolamine-N-methyltransferase.

From: Chapter 4, The adrenal gland

Cover of Endocrinology
Endocrinology: An Integrated Approach.
Nussey S, Whitehead S.
Copyright © 2001, BIOS Scientific Publishers Limited.

NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.