AJP - Regulatory, Integrative and Comparative Physiology, Vol 247, Issue 4 701-R708, Copyright © 1984 by American Physiological Society
Effects of vasoactive intestinal peptide on canine prostatic contraction and secretion
E. R. Smith, T. B. Miller, M. M. Wilson and M. C. Appel
Vasoactive intestinal peptide (VIP)-like immunoreactivity was found in
intrinsic autonomic ganglion cells and nerve fibers located at the surface
and within the canine prostate. In anesthetized dogs, porcine VIP
(100-3,000 ng/kg iv) decreased arterial pressure and increased heart rate
but did not result in the release of fluid from the prostate, indicating
that VIP neither contracted glandular smooth muscle to expel fluid nor
provoked secretion. Intravenous infusions of VIP at 10, 50, 100, and/or 200
ng X kg-1 X min-1 produced dose-related decreases in arterial pressure,
increases in heart rate, and potentiation of the secretory response to the
intravenous administration of pilocarpine and to electrical stimulation of
the hypogastric nerves at 2 but not at 20 Hz. VIP at 1 microgram/ml neither
contracted isolated strips of prostate nor modified their contraction by
norepinephrine. It is unlikely that VIP mediates hypogastric nerve-induced
prostatic contraction or secretion in the dog, but VIP may serve as a
neuromodulator of nerve-induced secretion.
