Measurement of branchial vascular space of trout, Oncorhynchus mykiss: effects of adrenaline.
Using the isolated-perfused head preparation at a constant flow rate, hemodynamic effects of adrenaline were studied in trout gills. The calculation of the vascular spaces was performed with the isotopic pulse technique allowing measurement of the distribution space of the tracer. The results show that the branchial arterial circuit was cleared more quickly than the branchial venous and cephalic circuits. Adrenaline addition significantly increased the volume of the branchial arterial circuit at the expense of the venous circuit, illustrating the closing of arterio-venous sphincters under catecholamine control. The increase of the arterial volume could be explained by a vasodilation of the arterial circuit, rather than resulting from lamellar recruitment. Furthermore, the flow rate of the cephalic circuit represented 5% of the total branchial flow rate.
Laboratoire de Physiologie Cellulaire et Comparée, URA CNRS 651, Université de Nice, France.
E
E
Gardaire
M
M
Avella
J
J
Isaia
M
M
Bornancin
D000818:Animals; D001775:Blood Circulation / Q000187:drug effects / Q000502:physiology; D004837:Epinephrine / Q000494:pharmacology*; D006439:Hemodynamics / Q000187:drug effects* / Q000502:physiology; D066298:In Vitro Techniques; D007700:Kinetics; D010477:Perfusion; D012709:Serum Albumin / Q000493:pharmacokinetics; D014337:Trout / Q000502:physiology*
D012709:Serum Albumin; D004837:Epinephrine