Mechanisms for pituitary adenylate cyclase-activating polypeptide-induced increase in excitability in guinea-pig and mouse adrenal medullary cells.

Mechanisms for pituitary adenylate cyclase-activating polypeptide-induced increase in excitability in guinea-pig and mouse adrenal medullary cells. Eur J Pharmacol. 2020 Jan 27;:172956 Authors: Inoue M, Harada K, Matsuoka H Abstract Pituitary adenylate cyclase-activating polypeptide (PACAP) acts on adrenal medullary (AM) cells as a neurotransmitter of the sympathetic preganglionic nerve. In guinea-pig AM cells, PACAP induces little catecholamine secretion, but enhances secretion evoked by stimulants, whereas in other animals, such as mouse, PACAP itself induces depolarization and/or catecholamine secretion. The present studies aim to explore the physiological implication of these species differences in PACAP actions, the ion channel mechanism for PACAP-induced depolarization, and the mechanism for facilitation of muscarinic receptor-mediated cation currents in mouse and guinea-pig AM cells. The perforated patch clamp technique was used to record the whole-cell current in isolated AM cells. The amplitudes of 3 nM PACAP-induced inward currents were significantly larger in mouse AM cells than guinea-pig, whereas 1 μM muscarine-induced currents were larger in guinea-pig AM cells than mouse. Exposure to PACAP consistently resulted in enhancement of muscarine-induced currents in guinea-pig AM cells and facilitation of cell membrane insertion of heteromeric TRPC1-TRPC4 channels in response to muscarine in PC12 cells. The PACAP-induce...
Source: European Journal of Pharmacology - Category: Drugs & Pharmacology Authors: Tags: Eur J Pharmacol Source Type: research