Innervation of XXXX epicardial coronary veins: immunohistochemistry and vasomotility.

@entity1 @entity3549 @entity2872 @entity10132 @entity5855 @entity2922 @entity4757 @entity1063 @entity669 @entity934
OBJECTIVE: The aim was to investigate the innervation and vasomotor responses to classical and putative transmitters of the coronary venous bed. METHODS: The innervation of @entity1 epicardial coronary veins was investigated using acetylcholinesterase histochemistry and immunofluorescence staining, together with antisera against the general neuronal marker protein gene product 9.5 ( @entity5855 ), the @entity2922 synthesising enzyme @entity669 hydroxylase, and neuropeptides [neuropeptide Y, vasoactive intestinal peptide ( @entity3549 ), @entity4757 , and @entity10132 ( @entity10132 )]. The vasomotor responses to @entity1063 , @entity934 , neuropeptide Y, @entity4757 , @entity1 alpha @entity10132 (alpha @entity10132 ), and @entity3549 were tested on isolated circular @entity1 epicardial coronary vein segments. RESULTS: A network of nerve fibres was shown in the major epicardial coronary veins by means of an antiserum to @entity5855 . The majority of the perivascular nerve fibres possessed neuropeptide Y and @entity669 hydroxylase immunoreactivity. Only a few nerve fibres displayed @entity4757 , @entity10132 , and @entity3549 immunoreactivity and acetylcholinesterase activity. @entity1063 and @entity934 induced powerful contractions of all the tested segments, whereas no contraction was induced by neuropeptide Y, alpha @entity10132 , @entity4757 , or @entity3549 . All segments precontracted with @entity2872 responded with potent relaxation to alpha @entity10132 , @entity4757 , and @entity3549 , whereas @entity1063 and @entity934 only in low concentrations induced weak relaxation of a few of the segments. No relaxation was induced by neuropeptide Y. CONCLUSIONS: This is the first study to demonstrate comprehensively the perivascular innervation of @entity1 coronary veins and corresponding vasomotor effects, suggesting a role in regulation of the coronary venous circulation.
