REVERSE CHOLESTEROL TRANSPORT IN THE RAT - INFLUENCE OF SHORT-TERM D-MYO-INOSITOL-1,2,6 TRISPHOSPHATE (PP56) INFUSION

D-myo-inositol-1,2,6 trisphosphate (PP56) was infused in rats for 3 hr at a rate of 30.28 muM/hr/kg body weight. The cholesterol content in plasma, erythrocytes, the aorta, and the liver was monitored before an d at the end of the infusion and at 1 and 21 hr after the infusion. We found that the aortic total and free cholesterol content was reduced after the infusion and continuously until the end of the experiment (b y 27% each after 21 hr P < 0.05, P < 0.01, respectively). Erythrocyte cholesterol was increased by 6.6% (P < 0.05) at the end of the infusio n and 9.5% (P < 0.01) at the end of the experiment, while plasma and h igh-density lipoprotein cholesterol did not change significantly. Free cholesterol in the liver after infusion was decreased by 27% (P < 0.0 01) and cholesterol ester increased by 97% (P < 0.05) and did not retu rn to the preinfusion level. Short-term PP56 infusion in the rat appar ently infuences cholesterol transport in a way which would suggest a p romoted reverse cholesterol transport. Since the lipid values did not return to the preinfusion level, a long-term study is needed to elucid ate in more detail the influence of PP56 on cholesterol metabolism in vivo.