A method for measuring oxygen consumption in isolated perfused gills

A method is described for measuring respiration in isolated perfused flounder gills experiencing pressures and flows similar to those seen in vivo. Mean oxygen consumption of 13 preparations bathed and perfused in identical saline was 5.00 +/- 0.75 (S.E.) umol h-1 g wet-1, whilst that of five preparations perfused with saline but bathed in sea water (32 mg l-1) was 12.06 +/- 2.39 (S.E.) umol h-1 g wet-1. The oxygen consumption of the seawater bathed gills was significantly higher 9P < 0.05) than the saline bathed gills. These results provide direct evidence both of the high metabolic activity of the gillunder normal perfusion conditions and of the increased energy expenditure of the gill in hyperosmotic, compared to isosmotic, environments.