Fig. 6. Plasma lipoprotein lipase activity before and 1 h after administration of 600 U heparin kg^–1 body mass in resting (control) and swimming rainbow trout (4 days at 1.5 BL s^–1). Heparin increased LPL activity in both groups (P<0.001), but this effect was not different between resting and swimming fish (P>0.05). Values are means ± s.e.m. (N=9).