[Mechanism of nitric oxide's effect on the sensitivity of smooth muscle contractions to calcium].
It was investigated whether the SH-groups of contractile proteins are involved in NO-induced relaxation of saponin-skinned smooth muscle strips. Both, the thiol-specific alkylating agent N-ethylmaleamide (NEM), and thiol-reducing agent dithiotreitol (DTT) induced relaxation of maximally activated skinned rat portal vein preparations. The relaxing effects of DTT and nitric oxide donor sodium nitroprusside were not additive. After the relaxation, induced by one of this agent, the effect of the other one was negligible. We suggest that NO-induced smooth muscle relaxation be due to decreasing of force sensitivity to Ca2+. This effect of nitric oxide is realized by its interaction with critical thiol groups of smooth muscle contractile proteins.
Andrukhov
O Ia
OIa
A.A. Bogomoletz Institute Physiology, Ukrainian Academy of Sciences, Kiev.
Sahach
V F
VF
D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D003285:Contractile Proteins / Q000737:chemistry / Q000502:physiology; D004229:Dithiothreitol / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology*; D009569:Nitric Oxide / Q000494:pharmacology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D011169:Portal Vein / Q000187:drug effects; D051381:Rats; D013438:Sulfhydryl Compounds / Q000737:chemistry
D003285:Contractile Proteins; D020030:Nitric Oxide Donors; D013438:Sulfhydryl Compounds; D009599:Nitroprusside; D009569:Nitric Oxide; D002118:Calcium; D004229:Dithiothreitol
Mekhanizm vplyvu oksydu azotu na chutlyvist' skorochuval'noho aparatu hladen'kykh m'iaziv do Ca2+.