The Effect of Perfusion Flow Rate and Adrenergic Stimulation on Oxygen Transfer in the Isolated, Saline-perfused Head of Rainbow Trout (Salmo Gairdneri)

摘要: An isolated, saline-perfused trout head preparation, irrigated with hyperoxic water (PWoλ = 250 Torr), was used to assess diffusion/perfusion limitations gill oxygen transfer. In the absence of catecholamines, increasing perfusion flow rate caused a reduction partial pressure in dorsal aortic perfusate, indicating diffusion uptake. Physiological concentrations epinephrine stimulated uptake dose-dependent fashion. Moreover, elicited greater effect during increased as result larger initial limitations, by flow. By using variety adrenergic agonists and antagonists, it demonstrated that beta-receptor stimulation enhanced whereas alpha-receptor had no effect. These results are discussed reference changes epithelial permeability and/or surface area changes.