AJP - Heart and Circulatory Physiology, Vol 249, Issue 1 155-H163, Copyright © 1985 by American Physiological Society
Effect of prostaglandins on bradykinin-induced visceral-cardiac reflexes
C. L. Stebbins, R. C. Smith and J. C. Longhurst
We examined the effect of prostaglandins on the reflex cardiovascular
response to bradykinin applied to the abdominal organs of anesthetized
cats. Bradykinin (10 micrograms/ml) was applied to the serosal surface of
the stomach, gallbladder, or jejunum before and after injection of
indomethacin (2-10 micrograms/ml iv) and after application of 1
microgram/ml of prostaglandins E1, E2, or F2 alpha (PGE1, PGE2, PGF2 alpha)
or prostacyclin (PGI2). In six cats, stimulation of the stomach with
bradykinin significantly increased mean arterial pressure (MAP) by 37 +/- 5
(SE) mmHg and maximal dP/dt by 633 +/- 101 mmHg/s. Following indomethacin
the bradykinin-induced increases in MAP and dP/dt were significantly
reduced to 19 +/- 4 mmHg and 191 +/- 58 mmHg/s, respectively. Treatment
with PGE1, PGE2, or PGI2, but not PGF2 alpha, restored the initial
bradykinin response. The gallbladder and jejunum responded similarly. Also
application of exogenous prostaglandins, PGE2 or PGI2, to the stomach,
gallbladder, or jejunum significantly augmented the cardiovascular response
to bradykinin. Finally, PGE2 restored a portion of the cardiovascular
response to bradykinin following the development of tachyphylaxis. We
conclude that prostaglandins are necessary for the full manifestation of
the cardiovascular response to bradykinin.
