Endothelium-dependent transfer of ethanol tolerance in the aorta.
Recent studies have suggested that the endothelium-dependent tolerance to the direct vasoconstrictor effect of ethanol in the rat aorta is mediated by endothelium-derived relaxing factor (EDRF). This hypothesis was tested directly by employing a sandwich technique which has been used to demonstrate the release and action of EDRF. These experiments measured the ethanol-induced contraction of a spirally-cut aortic strip without endothelium obtained from an ethanol naive control rat. The response of the spiral strip was measured before and after it was sandwiched with a longitudinally-cut aortic strip with or without endothelium obtained from either control or ethanol tolerant rats. There was no significant difference in the ethanol-induced contraction of the spiral strip after beginning sandwiched with a longitudinal strip with or without endothelium obtained from a control rat or with a longitudinal strip without endothelium from a tolerant rat. In contrast, when a longitudinal strip with endothelium from a tolerant rat was sandwiched with the spiral strip the ethanol-induced contraction was significantly reduced. This effect was inhibited by methylene blue but not by indomethacin. Further, the magnitude of the carbachol-induced relaxation of the sandwiched preparation was significantly greater when the longitudinal strip with endothelium was obtained from a tolerant rat than from control rat. These data demonstrate the involvement of EDRF in the endothelium-dependent tolerance to ethanol in the rat aorta.
D000818:Animals; D001011:Aorta / Q000187:drug effects* / Q000502:physiology; D002217:Carbachol / Q000494:pharmacology; D004361:Drug Tolerance; D004727:Endothelium / Q000187:drug effects / Q000502:physiology*; D000431:Ethanol / Q000633:toxicity*; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D008751:Methylene Blue / Q000494:pharmacology; D009569:Nitric Oxide; D051381:Rats; D011919:Rats, Inbred Strains; D014661:Vasoconstriction / Q000187:drug effects; D014665:Vasodilator Agents / Q000502:physiology*
D014665:Vasodilator Agents; D009569:Nitric Oxide; D000431:Ethanol; D002217:Carbachol; D008751:Methylene Blue; D007213:Indomethacin