Effect of a satiating meal on the concentrations of procolipase propeptide in the serum and urine of normal and morbidly obese subjects.

Abstract

The effect of a satiating meal on the serum and urinary concentrations of procolipase propeptide (Ala-Pro-Gly-Pro-Arg, APGPR) immunoreactivity, as measured by enzyme linked immunosorbent assay (ELISA) specific for free APGPR, has been studied in normal and morbidly obese human subjects. The normal subjects displayed a biphasic response with coordinate increases in both serum and urine APGPR immunoreactivity both occurring within the first two hours after the meal. In two of three of the morbidly obese subjects, this early rise in APGPR concentration in urine was not seen but was foliowed by a slow rise in urinary APGPR immunoreactivity at four to six hours. In both the normal and obese groups, the urinary immunoreactive signal was found to coelute with synthetic APGPR on gel chromatography. In rats, procolipase propeptide (Val-Pro-Asp-Pro-Arg, VPDPR) specifically inhibits fat intake early in the postprandial period when given peripherally or centrally. This study suggests that in humans APGPR reaches the circulation shortly after feeding and is excreted in the urine. These findings are consistent with the hypothesis that human procolipase propeptide may also act as a satiety signal. In addition the late appearance of the peptide in some of the morbidly obese patients could be associated with perturbation of appetite control in these subjects.

Inhibitory effect of enterostatin on the beta cell response to digestive insulinotropic peptides

“…Similar values (50 AE 4 nM) have been reported for the serum of normal rates. 26 Bowyer et al, 25 have shown that after consumption of a standard meal, circulating enterostatin rises to up to 100 nM. According to these data, the enterostatin concentrations employed in our perfusions (100 nM, 50nM and 10nM) would fall within the physiological range, thus supporting the concept of this peptide as an endogenous inhibitory agent of beta cell secretion.…”

“…In normal subjects, basal plasma enterostatin concentrations have been found to be 20 ± 40 nM (23,25) . Similar values (50 AE 4 nM) have been reported for the serum of normal rates.…”

5-HT1B receptors modulate the feeding inhibitory effects of enterostatin

“…Eating a high fat diet elevates the levels of enterostatin in the circulation and increases procolipase gene expression [4,38,40]. Procolipase gene is also expressed in the stomach and brain [25,34].…”

Obesity Pharmacotherapy: Current Perspectives and Future Directions

“…In a study performed in rats, chronic intracerebroventricular injections of enterostatin decreased intake of a high-fat diet and reduced body weight [146]. Previous experiments explored the hypothesis that an association exists between human obesity and enterostatin dysregulation [147,148]. However, in clinical trials, intravenous enterostatin failed to show any effect on feelings of hunger, satiety, or food preference [149].…”