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.

Kinetics of potassium transport across trout gills.

1. Kinetics of potassium transport across trout gills was studied, using an isolated-head preparation. 2.

Estimation of sodium uptake through the gill of the rainbow trout Salmo gairdneri.

Sodium exchanges through the gill epithelia were estimated in the rainbow trout, Salmo gairdneri, using the perfused head technique. The head tissues accumulate radioactivity. In addition there exists an extrabranchial entry of sodium, which is 20 times smaller than the branchial one.