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Endogenous nitric oxide as a modulator of rabbit skeletal muscle microcirculation in vivo
Author(s) -
Persson M.G.,
Gustafsson L.E.,
Wikludn N.P.,
Hedqvist P.,
Moncada S.
Publication year - 1990
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1990.tb15829.x
Subject(s) - nitric oxide , omega n methylarginine , vasodilation , arginine , vasoconstriction , microcirculation , sodium nitroprusside , intravital microscopy , in vivo , skeletal muscle , endocrinology , chemistry , pharmacology , nitric oxide synthase , medicine , biology , biochemistry , microbiology and biotechnology , amino acid
1 Intravital microscopy of rabbit tenuissimus muscle microvasculature was used for in vivo studies of the role of endogenous nitric oxide (NO) in local vascular control. Derivatives of arginine were applied topically in order to modulate the formation of NO from l ‐arginine. 2 l ‐N G ‐monomethylarginine ( l ‐NMMA) (10–100 μ m ), but not d ‐N G ‐monomethylarginine ( d ‐NMMA), dose‐dependently reduced microvascular diameters. The vasoconstriction induced by l ‐NMMA (100 μ m ) was prevented by pretreatment with l ‐arginine (1 m m ) but not with d ‐arginine (1 m m ). Intravenous infusions of l ‐arginine (300 mg kg −1 ) reversed the effect of l ‐NMMA (100 μ m ). l ‐Arginine or d ‐arginine applied topically at 1 m m per se had no effect on microvascular diameters. 3 Vasodilatation by acetylcholine (0.03‐3 μ m ) was significantly inhibited by l ‐NMMA (100 μ m ), whereas vasodilatation by adenosine (0.1–100 μ m ) or sodium nitroprusside (100 n m ) was not affected. 4 The hyperaemic response after tenuissimus muscle contractions induced by motor nerve stimulation was unaffected by the presence of l ‐NMMA (100 μ m ). 5 Aggregates of platelets and white blood cells were seen in venules during superfusion with l ‐NMMA (100 μ m ), but not with d ‐NMMA (100 μ m ). 6 Our results suggest that endogenous NO formed from l ‐arginine is a modulator of microvascular tone and platelet and white cell‐vessel wall interaction in vivo . Nitric oxide does not, however, appear to play a role in the mediation of functional hyperaemia in this tissue.