Role of endogenous PACAP in catecholamine secretion from the rat adrenal gland

• Published in: American journal of physiology. Regulatory, integrative and comparative physiology integrative and comparative physiology, 2001-11, Vol.281 (5), p.1562-R1567
• Main Authors: Fukushima, Yasuo, Hikichi, Hirohiko, Mizukami, Kazuhiko, Nagayama, Takahiro, Yoshida, Makoto, Suzuki-Kusaba, Mizue, Hisa, Hiroaki, Kimura, Tomohiko, Satoh, Susumu
• Format: Article
• Language: English
• Subjects: Adrenal Glands - drug effects; Adrenal Glands - secretion; Animals; Electric Stimulation; Epinephrine - secretion; Male; Neuropeptides - pharmacology; Neuropeptides - physiology; Neurotransmitter Agents - pharmacology; Norepinephrine - secretion; Peptide Fragments - pharmacology; Perfusion; Pituitary Adenylate Cyclase-Activating Polypeptide; Rats; Rats, Wistar; Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide; Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I; Receptors, Pituitary Hormone - agonists; Receptors, Pituitary Hormone - antagonists & inhibitors; Receptors, Vasoactive Intestinal Polypeptide, Type I
• ISSN: 0363-6119; 1522-1490
• DOI: 10.1152/ajpregu.2001.281.5.r1562

1  Laboratory of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Aobayama, Sendai 980-8578; and 2  Department of Dental Pharmacology, The Nippon Dental University School of Dentistry at Niigata, Hamaura-cho, Niigata 951-8580, Japan We elucidated the contribution of endogenous pituitary adenylate cyclase-activating polypeptide (PACAP) to neurally evoked catecholamine secretion from the isolated perfused rat adrenal gland. Infusion of PACAP (100 nM) increased adrenal epinephrine and norepinephrine output. The PACAP-induced catecholamine output responses were inhibited by the PACAP type I receptor antagonist PACAP- (6-38) (30-3,000 nM) but were resistant to the PACAP type II receptor antagonist [Lys 1 ,Pro 2,5 ,Ara 3,4 ,Tyr 6 ]-vasoactive intestinal peptide (LPAT-VIP; 30-3,000 nM). Transmural electrical stimulation (ES; 1-10 Hz) or infusion of ACh (6-200 nM) increased adrenal epinephrine and norepinephrine output. PACAP-(6-38) (3,000 nM), but not LPAT-VIP, also inhibited the ES-induced catecholamine output responses. However, PACAP-(6-38) did not affect the ACh-induced catecholamine output responses. PACAP at low concentrations (0.3-3 nM), which had no influence on catecholamine output, enhanced the ACh-induced catecholamine output responses, but not the ES-induced catecholamine output responses. These results suggest that PACAP is released from the nerve endings to facilitate the neurally evoked catecholamine secretion through PACAP type I receptors in the rat adrenal gland. transmural electrical stimulation; acetylcholine; pituitary adenylate cyclase-activating polypeptide receptor antagonists; pituitary adenylate cyclase-activating polypeptide -(6-38); adrenal chromaffin cells