Tobacco cigarette smoke attenuates duodenal ulcer margin hyperemia in the rat. Comparison of IAP clearance and hydrogen gas clearance techniques for measurements of gastrointestinal blood flow.

The hyperemia at the duodenal ulcer margin is important for ulcer healing. We studied the effect of tobacco cigarette smoke on the hyperemia at the margin of mepirizole-induced duodenal ulcer. Duodenal mucosal blood flow values measured by iodo[14C]antipyrine (IAP) autoradiography and hydrogen gas clearance (HGC) were compared. Twenty-four hours after rats were injected with an ulcerogenic dose of mepirizole, they were exposed to tobacco cigarette smoke and duodenal mucosal blood flow was measured by IAP autoradiography. There is a significant correlation between the blood flow measurements by HGC and IAP autoradiography. The hyperemia at the ulcer margin previously demonstrated in our laboratory is absent after exposure of the rats to tobacco cigarette smoke. We speculate that the inhibition of ulcer margin hyperemia could explain the aggravation of duodenal ulcer by tobacco cigarette smoke.