Sevoflurane Promotes Endothelium-Dependent Smooth Muscle Relaxation in Isolated Human Omental Arteries and Veins

Abstract

Anesthesia with sevoflurane is accompanied by vasodilatation. This could be due to the effects of sevoflurane on endothelium-dependent relaxation. We measured muscle tension of isolated human omental arteries and veins in response to substance P or glyceryl trinitrate in the presence of sevoflurane (0%, 1%, 2%, or 4%). Vascular levels of guanosine 3', 5'-cyclic monophosphate were measured with enzyme-linked immunosorbent assay. Substance P induced an endothelium- and concentration-dependent relaxation in omental vessels that was not affected by sevoflurane. In the presence of L-N(G)-nitroarginine methyl ester (nitric oxide synthase inhibitor), KCl (prevention of hyperpolarization), or both, sevoflurane at 4% enhanced the relaxation in the arteries (P < 0.05). In the vein segments, the relaxation was enhanced by sevoflurane at 4% in the presence of KCl and 2% and 4% in the presence of both L-N(G)-nitroarginine methyl ester and KCl (P < 0.05). The glyceryl trinitrate-induced endothelium-independent relaxation was enhanced by sevoflurane at 4% in both artery and vein segments (P < 0.05). Substance P increased the levels of guanosine 3', 5'-cyclic monophosphate similarly in the presence and absence of sevoflurane. These results show that sevoflurane, in contrast to its effect in animal models, promotes endothelium-dependent relaxation in human omental arteries and veins via an enhancement of the smooth muscle response to relaxing second messengers.

Venous Function and Central Venous Pressure

“…108 Such intervention is not always needed because of the activation of sympathetic and renin-angiotensin systems; this is associated with an increase of MCFP and maintenance of the needed MCFP-CVP gradient to preserve VR and CO. 103,109,110 Anesthetics, sedatives, and other interventions might minimize such a homeostatic response. 105,[111][112][113][114] Positions (Tilts) Different positions, e.g., head up versus head down, affect systemic hemodynamics including function of the venous system. A head-up position (e.g., standing up) could be associated with a gravity-induced shift of blood volume from the upper to the lower part of the body.…”

General Anesthetics and Vascular Smooth Muscle

“…The number of studies using isolated human vessels 122, 144,146,151,168,183,193,202,223,[302][303][304][305][306][307][308] is increasing, and they have reported both similarities and differences in vascular responsiveness to general anesthetics between humans and animals. However, as discussed above, the underlying mechanisms are not entirely clear.…”

“…However, as discussed above, the direct action of volatile anesthetics on arterial VSMCs may contribute to the prolonged systemic hypotension observed during the postanesthesia period. 157,158,294,303,305,307,308,[317][318][319] Again, on consideration of possible species differences, further studies using human capacitance vessels, as well as human systemic resistance vessels, would be essential to evaluate a possibility that the direct (i.e., nonneural) actions of general anesthetics on VSMCs contribute to systemic hypotension during their administration. 2 In previous studies with isolated mesenteric veins, 157,158,317 halothane, enflurane, and isoflurane inhibited the contractile response to norepi- nephrine.…”

Changes of dorsalis pedis artery flow pattern after caudal block in children: observational study using a duplex sonography

“…However, sevoflurane depresses sympathetic neuromuscular transmissions in human omental vessels by decreasing neuronal norepinephrine release and artery sensitivity, at least at concentrations above 2 vol% (19). In addition, Thorlacius and Bodelsson demonstrated that vasodilating effects of sevoflurane on human arteries were found to be significant only at the 4 vol% of concentration not at 1 vol% and 2 vol% (20).…”