A substantial contribution of 5-hydroxytryptamine (5-HT) in the contractile response of bovine digital artery (BDA), as well as short- and longer-term changes in basal reactivity to the amine induced by endothelium removal, have been recently described. The present work investigated the vasomotor reactivity to 5-HT in bovine digital vein (BDV) in order to evaluate possible differential control by this amine in the two sides of vascular bed. Three main differences in BDA and BDV vascular reactivity to 5-HT were observed. (i) 5-HT induces more effective and potent contractile effects in BDV than in BDA; (ii) the endothelium removal induces short-term increased reactivity to 5-HT in BDA but not in BDV; (iii) significant but opposite long-term changes in contractile reactivity to 5-HT were recorded in incubated BDV (hyper-reactivity) and BDA (hypo-reactivity) that had been deprived of the endothelium before incubation. The disclosed differential arterial/venous vasomotor control of 5-HT may contribute to the physiological haemodynamic regulation of the bovine foot as well as to the establishment of poor blood flow leading to laminitis.
5-HT-mediated vasoconstriction in bovine digital vein
BELLOLI, Chiara
2012-01-01
Abstract
A substantial contribution of 5-hydroxytryptamine (5-HT) in the contractile response of bovine digital artery (BDA), as well as short- and longer-term changes in basal reactivity to the amine induced by endothelium removal, have been recently described. The present work investigated the vasomotor reactivity to 5-HT in bovine digital vein (BDV) in order to evaluate possible differential control by this amine in the two sides of vascular bed. Three main differences in BDA and BDV vascular reactivity to 5-HT were observed. (i) 5-HT induces more effective and potent contractile effects in BDV than in BDA; (ii) the endothelium removal induces short-term increased reactivity to 5-HT in BDA but not in BDV; (iii) significant but opposite long-term changes in contractile reactivity to 5-HT were recorded in incubated BDV (hyper-reactivity) and BDA (hypo-reactivity) that had been deprived of the endothelium before incubation. The disclosed differential arterial/venous vasomotor control of 5-HT may contribute to the physiological haemodynamic regulation of the bovine foot as well as to the establishment of poor blood flow leading to laminitis.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.