Proadrenomedullin N-terminal 20 peptide (PAMP) inhibits catecholamine secretion from adrenal medulla. This study investigates the effect of PAMP and its fragments on agonist-stimulated secretion from human adrenal slices and dispersed cells.
Adrenal glands were obtained from kidney donors. Slices and dispersed cells were prepared. Secretion of catecholamines, aldosterone, and cortisol was measured in response to various agonists with and without PAMP or its fragments.
The study used a controlled laboratory experiment design.
PAMP inhibited acetylcholine and high K+-stimulated catecholamine secretion. The inhibitory effect was concentration-dependent. The fragment PAMP(12–20) reproduced this effect, while PAMP(1–11) was ineffective.
PAMP also inhibited angiotensin II and ACTH-stimulated aldosterone and cortisol secretion from adrenal cortex.
The findings suggest PAMP acts via PAMP(12–20)-sensitive receptors to inhibit Ca2+-dependent secretion in human adrenal glands, indicating a paracrine regulatory role.
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