C-type natriuretic peptide and atrial natriuretic peptide have been reported to bind to distinct receptors and to exert opposing effects on different systems. Although it is known that atrial natriuretic peptide inhibits the corticotropin-releasing hormone-stimulated hormone release in man, the corresponding action of C-type natriuretic peptide has so far not been characterized. We investigated the effects of 30-min infusions of 150 and 300 micrograms C-type natriuretic peptide on adrenocorticotropin, cortisol, and prolactin release stimulated by 100 micrograms corticotropin-releasing hormone and on cardiovascular parameters in 8 healthy male volunteers. Compared with placebo, 300 micrograms C-type natriuretic peptide significantly (P <0.05) enhanced the stimulation of cortisol (area under curve (arbitrary units): 520 +/- 35 vs 651 +/- 55) and prolactin (area under curve: 29 +/- 3 vs 37 +/- 5). Adrenocorticotropin levels were increased, but the differences did not reach statistical significance (maximum increment: 27 +/- 4 vs 36 +/- 2 pg/ml). C-type natriuretic peptide at a dose of 150 micrograms had no clear effect on these hormones and C-type natriuretic peptide also produced no cardiovascular or subjective effects. Our data suggest stimulatory effects of C-type natriuretic peptide on corticotropin-releasing hormone-induced hormone release and offer further evidence for a complex role of different natriuretic peptides in endocrine regulation.
