Male Japanese white rabbits were given
tributyltin fluoride (TBTF) by gastric intubation with a single dose of 100 mg/kg
body weight and their
lipid and
glucose metabolisms were investigated. After administration of TBTF, a reversible, but remarkable increase of
lipids in plasma, particularly of
triglycerides and total
cholesterol, was observed. Ultracentrifugation of plasma
lipoproteins revealed a marked increase in chylomicron+VLDL (
very low density lipoprotein) fraction.
Lipoprotein lipase (LPL) activity in postheparin plasma reduced significantly (p less than 0.02) to the levels of about 50% of the control. Fasting
blood glucose level was elevated and a significant inhibition of
insulin (IRI) release in response to the intravenous
glucose infusion was observed in TBTF treated rabbits, but the level of
blood glucose and the degree of inhibition of IRI release were low compared with those of
triphenyltin fluoride treated rabbits, in which much greater fasting
hyperglycemia was observed. Microscopic examination of pancreas, kidneys and thyroid gland did not reveal histological alterations contributing to the
hyperlipidemia. These results suggest that
hyperlipidemia induced in rabbits by
tributyltin fluoride is due to decreased LPL activity. The decrease in LPL activity seems to be related to the inhibition of
insulin release from islets by TBTF.