Possible Interaction: Glycerol and Leptin

“The … leptin at concentrations of 10(-12) to 10(-6) M … incubation medium of isolated fat cells significantly increased glycerol release when compared with basal levels, being always higher (8-15%) in female adipocytes when … male specimens for all tested concentrations when expressed on a fat content relative basis.”

“We investigated the effects of leptin on placental lipid catabolism and found that in both term human placental explants and primary cultures of trophoblastic cells, leptin increased glycerol release, an index of the hydrolysis of esterified lipids, in a dose-dependent manner.”

“There was a statistically significant negative correlation (r=−0.812, p<0.01) between the values of leptin and glycerol just after the termination of swimming.”

“Conclusions/interpretationThe findings of this study suggest that the diminution of circulating glycerol reduces endogenous glucose production, contributing to severe fasting-induced hypoglycaemia in leptin-treated rodent models of type 1 diabetes, and support that depletion of glycerol contributes to the glucose-lowering action of leptin.”

“ Leptin release from adipocyte of SRD-fed rats negatively correlated with glycerol release.”

“The … of leptin at concentrations of 10−12 to 10−7 M in the incubation medium of isolated fat cells significantly increased (p<0.0001) glycerol release, except at the concentration of 10−11 M, where the increase was (p<0.01) as compared to the basal lipolytic activity.”

“At the same time, leptin promoted the glycerol release in a dose dependent manner (P<0.01), but had no effect on the FFA release (P>0.05).”

“However, leptin suppressed the insulin- or IGF-I-stimulated lipid accumulation and enhanced the release of glycerol , a measure of lipolysis, in a dose-dependent manner during and after the maturation of the cell.”

“Moreover, intraperitoneal administration of leptin (130 microg/kg) elevated the levels of plasma glycerol and free fatty acid (FFA).”

“In keeping with the increase in serum NEFA concentrations in vivo, leptin stimulated lipolysis in vitro, increasing glycerol concentrations in the medium to about 219% of that in basal (non-treated) culture medium after 8 hr of incubation.”