Short chain fatty acids dilate isolated human colonic resistance arteries.

Abstract

Colonic biopsy specimens were obtained from patients undergoing surgery for carcinoma of the rectum. Colonic resistance arteries (internal diameter 178-345 ,um) were dissected out under the microscope and mounted in a microvascular myograph capable ofmeasuring isometric tension development. Experiments were designed to test compounds trophic to the gastrointestinal tract -namely, glutamine and the three short chain fatty acids, acetic, propionic, and butyric acid, for effects on vascular tone. Glutamine in concentrations up to 30 mM neither constricted nor dilated the resistance arteries. The three short chain fatty acids alone and in combination, however, caused a concentration-dependent (range 0.1-30 mM) dilatation of resistance arteries preconstricted with 50 mM K+, and this relaxant effect was unaffected by removal of the endothelium, presence of indomethacin, and preconstriction with vasopressin. These data suggest that the trophic effect of glutamine on intestinal mucosa cannot be explained through actions of this compound on the resistance vasculature. In contrast, the relaxant effect of short chain fatty acids on resistance arteries in vitro suggests that these compounds may be able to improve the colonic microcirculation in vivo, thereby providing an explanation for their trophic effect on intestinal mucosa.

Mechanism of butyrate‐induced vasorelaxation of rat mesenteric resistance artery

“…The conclusion from this study was that hypercapnia caused relaxation through nitric oxide release. In the present study, removal of the endothelium was without effect on relaxation to butyrate and a role for nitric oxide release can therefore be excluded; similar observations have been made by Mortensen et al (1990) and Nutting et al (1991).…”

“…Butyrate has previously been shown to act as a vasodilator in a number of arteries, including the rat caudal artery (Nutting et al, 1991), the rat mesenteric artery (Austin & Wray, 1993;, and human colonic resistance artery (Mortensen et al, 1990). The concentration-dependency of the butyrate-induced relaxation of the NA contracture measured in the present study is similar to that observed for the relaxation of the phenylephrine-induced contracture in rat caudal artery (Nutting et al, 1991).…”

“…Exposure of blood vessels to short chain fatty acids (SCFA) such as lactate, acetate, and butyrate is known to induce vasodilatation (Mortensen et al, 1990;Nutting et al, 1991;Austin & Wray, 1993;. The mechanism underlying SCFA-mediated relaxation remains unclear.…”

Olfactory receptor responding to gut microbiota-derived signals plays a role in renin secretion and blood pressure regulation

“…These effects are mediated via SCFA signaling through the G protein-coupled receptors Gpr41 and 43, which are expressed in adipocytes, neutrophils, and sympathetic ganglia (13). Data from ex vivo studies indicate that SCFAs also induce vasodilation in both rodents and humans (14,15). Furthermore, the presence of acetate in hemodialysis solutions can induce hypotension (16,17).…”

Olfaction in the kidney: ‘smelling’ gut microbial metabolites

“…Several reports in the literature indicate that SCFAs induce vasorelaxation in ex vivo preparations (Mortensen et al . 1990; Nutting et al . 1991, 1992); therefore, we set out to determine whether there was an in vivo consequence to this ex vivo effect and, if so, the role of Olfr78.…”