Effect of pineal treatment on rat HDL-cholesterol under basal conditions and under stimulation with HCG.

The effect of the pineal extract and that of two fractions, f1 and f2, one above, the other 10,000 daltons obtained by ultrafiltration of the extract, on HDL-cholesterol as well as on cholesterolemia and testosterone, under basal conditions and under exogenous HCG stimulation was followed up. Under basal conditions, the pineal extract induced a statistically significant decrease in the 3 biochemical indices, an effect which was also recorded with the two fractions, with the difference that the effect of f2 is more intense and significant as compared to f1, whereas the effect of the pineal extract appears more intense than that of the fractions. Under exogenous HCG stimulation, the pineal extract and less the fractions, partly inhibited the lowering effect of HCG on cholesterol and the rising effect of this hormone on testosterone. The role of the equilibrating agent of the pineal extract on HDL-cholesterol, cholesterolemia and testosterone, is discussed.