Adipocyte lipolysis, hormonal and metabolic changes in ethanol‐drinking rats

Abstract

The effect of ethanol drinking on some hormonal and metabolic changes in the rat and on lipolysis in isolated adipocytes was tested. Male growing Wistar rats divided into two groups were used in the experiment. Ten percent ethanol solution as the only drinking fluid for 2 weeks depressed body weight gain. The diminution of blood insulin with simultaneous increase in leptin concentration found in these rats suggest that the physiological regulation of leptin secretion is disturbed by ethanol. Liver triglycerides content was substantially augmented due to ethanol ingestion. Adipocytes were isolated from both groups of rats by collagenase digestion and the lipolytic activity of these cells was compared. Isolated cells (10(6)/ml) were incubated for 90 min in Krebs-Ringer buffer (pH 7.4, 37 degrees C) containing 3 mm glucose and different lipolytic modulators: adrenaline (1 microm), insulin (1 nm), dibutyryl-cAMP (1 mm) and DPCPX (a selective antagonist of adenosine A1 receptor, 1 microM). To determine basal lipolysis cells were incubated without lipolytic agents. Lipolysis was determined by the amount of glycerol released from cells to the incubation medium. Basal and adrenaline-induced lipolysis was depressed in adipocytes of ethanol-drinking rats. The antilipolytic activity of insulin was the same in both groups of isolated cells. Lipolysis induced by dibutyryl-cAMP was only slightly reduced due to ethanol consumption, whereas triglycerides breakdown evoked by adenosine A1 receptor antagonism was unchanged. Results obtained in vitro indicate that subchronic ethanol drinking attenuates basal and stimulated lipolysis in adipocytes, however, the antilipolytic effect of insulin and the adenosine pathway are unchanged.

Resveratrol Alleviates Ethanol-Induced Hormonal and Metabolic Disturbances in the Rat

“…It was demonstrated that blood insulin levels were significantly reduced by ethanol. Similar effect was previously found in rats ingesting 10 % ethanol solution for ten days (Szkudelski and Kandulska 1999) or for two weeks (Szkudelski et al 2004, Szkudelska et al 2007. Importantly, our present study revealed for the first time that the unfavourable effect of ethanol on blood insulin levels is markedly alleviated by resveratrol.…”

“…Moreover, Pravdova et al (2008) demonstrated that ethanol intake (6 %, for 28 days) reduced body weight gain and adiposity in the rat, however, adiponectin expression and blood adiponectin levels were increased. Similarly to adiponectin, it was also demonstrated that ethanol ingestion may increase blood leptin levels in the rat in spite of reduced body weight gain (Pravdova et al 2009, Szkudelski et al 2004.…”

Alcohol, Adipose Tissue and Lipid Dysregulation

“…Unlike adiponectin, the effects of alcohol on circulating leptin are less consistent and may be related to changes in fat mass instead of the alcohol per se. Leptin has been reported to be increased [24,91,92], decreased [10,93,94], and unchanged [24] across a range of rodent models of chronic alcohol intake. Further, administration of leptin in combination with alcohol decreased body weight and eWAT mass suggesting that increased leptin may decrease appetite or increase energy expenditure [10].…”

DNA Methylation of the Leptin Gene Promoter is Altered by Chronic Alcohol Exposure in an Animal Model for Alcohol Dependence

“…A possible explanation for our results might be the effect of ethanol on lipid metabolism and leptin protein regulation. Since ethanol ingestion dampens beta 3 adrenoceptor and basal mediated lipolysis [26][27][28][29], an increase of leptin expression can be observed [30].…”