Effect of 6-hydroxydopamine on heart lipoprotein lipase activity in mice

The effect of 6-hydroxydopamine (6-OHDA) on heart lipoprotein lipase (LPL) activity in mice was investigated in vivo and in vitro. Intraperitoneal administration of 6-OHDA (30 mg/kg b. w.) provoked a statistically significant (p less than 0.05) increase in heart LPL activity and a significant fall (p less than 0.05) in post-heparin lipolytic activity (PHLA) in blood serum, compared with controls. However, injection of heparin (10 IU/100 g b.w. i.p.) and 6-OHDA provoked a fall in heart LPL activity to values similar to those found in controls and an increase in serum PHLA, although not so high as in animals injected with heparin alone. Adrenalectomized mice to which 6-OHDA was administered showed values of heart LPL activity similar to control animals, while heart LPL activity in the 6-OHDA group was significantly higher compared with controls (p less than 0.01). Administration of 6-OHDA in vitro to heart homogenate significantly increased LPL activity, whether or not heparin was present in the incubation medium (p less than 0.0005).