AJP - Gastrointestinal and Liver Physiology, Vol 246, Issue 2 195-G203, Copyright © 1984 by American Physiological Society
Effects of nicotine on canine intestinal blood flow and oxygen consumption
R. H. Gallavan Jr, Y. Tsuchiya and E. D. Jacobson
The purpose of this study was to determine the effects of nicotine on
intestinal blood flow and oxygen consumption. The intravenous infusion of
nicotine at doses corresponding to those experienced by smokers produced a
transient increase in systemic arterial blood pressure and mesenteric blood
flow. Subsequently a steady-state response developed that consisted of a
reduction in mesenteric blood flow due to both a decrease in blood pressure
and an increase in intestinal vascular resistance. This increase in
resistance was probably due to increased levels of circulating
catecholamines. The intra-arterial infusion of nicotine into the intestinal
circulation at doses experienced by the average smoker had no effect on
either intestinal blood flow or oxygen consumption. Similarly, under in
vitro conditions nicotine had no direct effect on intestinal vascular
smooth muscle tension. Thus, nicotine appears to reduce intestinal blood
flow indirectly as a result of its systemic effects.
