Pituitary Peptides other than ACTH may not be Aldosterone Secretagogue in Primary Aldosteronism

Summary

In order to elucidate whether pituitary peptides other than ACTH which are derived from the proopiomelanocortin (POMC) are involved for aldosterone secretion in primary aldosteronism, we administered ovine corticotropin releasing factor (CRF), β-endorphin and naloxone to seven patients with aldosterone producing adenoma. One hundred μg of CRF produced an augmented aldosterone response in patients with aldosteronism, while 500 μg of β-endorphin infusion failed to cause any significant changes in neither normal subjects nor patients. An opioid antagonist, naloxone (10 mg, iv) produced no noticeable change in plasma aldosterone in normal subjects, while it caused a slight increase in patients with primary aldosteronism. Plasma cortisol increased to a similar degree in response to CRF and naloxone in normal subjects and patients.

In three patients with isolated ACTH deficiency, neither aldosterone nor cortisol responded to these stimuli. The present results indicate that POMC-derived pituitary peptides other than ACTH are unlikely to participate in the aldosterone secretion in normal subjects or in patients with primary aldosteronism.

Key words

Primary aldosteronism - Naloxone - β-endorphin - ACTH - CRF