Effects of ethanol on contractile response of gall bladder isolated from guinea pig

The effect of acute intragastric vs. intravenous alcohol administration on inflammation markers, blood lipids and gallbladder motility in healthy men

Ethanol intake increases plasma concentrations of triglycerides and chronic ethanol use impairs lipid metabolism and causes chronic inflammation. The gut plays an important role in metabolic handling of nutrients, including lipids, and a leaky gut associated with alcohol intake, allowing inflammatory signals to the portal vein, has been proposed to constitute a mechanism by which ethanol induces hepatic inflammation. We compared the effects of enteral and parenteral administration of ethanol on a range of circulating inflammation markers (including soluble CD163, a marker of liver macrophage activation), lipids, cholecystokinin (CCK) and fibroblast growth factor 19 (FGF19) as well as gallbladder volume. On two separate and randomized study days, we subjected healthy men (n = 12) to double-blinded intragastric ethanol infusion (IGEI) and isoethanolemic intravenous ethanol infusion (IVEI). Blood was sampled and ultrasonographic evaluation of gallbladder volume was performed at frequent intervals for 4 h after initiation of ethanol administration on both days. Little or no effects were observed on plasma levels of inflammation markers during IGEI and IVEI, respectively. Circulating levels of total, low-density lipoprotein and high-density lipoprotein cholesterol decreased after ethanol administration independently of the administration form. Triglyceride and very low-density lipoprotein (VLDL) cholesterol concentrations increased more after IGEI compared to IVEI. IVEI had no effect on plasma CCK and caused an increased gallbladder volume whereas IGEI elicited a CCK response (P < 0.0001) without affecting gallbladder volume. Circulating FGF19 concentrations decreased equally in response to both ethanol administration forms. In conclusion, by evaluating a range of circulating inflammation markers during IGEI and IVEI we were not able to detect signs of systemic low-grade inflammation originating from the presence of ethanol in the gut. IVEI increased gallbladder volume whereas IGEI increased plasma CCK (with neutral effect on gallbladder volume), increased plasma VLDL cholesterol and triglyceride concentrations; indicating that the enteral route of administration may influence ethanol's effects on lipid metabolism.

The effect of moderate alcohol intake on gallblader motility a milk ultrasonographic study

OBJECTIVES

To assess the effect of periodic and moderate alcohol intake on gallbladder motility.

METHODS

The ultrasonographic ellipsoid method was used in 21 healthy male subjects: 12 non-alcohol and 9 alcohol drinkers. The stimulus for gallbladder contraction was 165 ml of half cream milk. Gallbladder dynamics were studied for 20 minutes following the ingestion of the milk. The mean percentage change in gallbladder volume after 10 and 20 minutes gave indications of gallbladder motility.

RESULTS

Moderate and periodic alcohol intake did not stimulate rapid postprandial gallbladder emptying.

CONCLUSION

The protective effect of alcohol against biliary cholesterol cholelithiasis could not be due to stimulation of gallbladder emptying.

Preferential inhibition by ethanol of phorbol ester-induced smooth muscle contraction of guinea pig gallbladder

In order to investigate how ethanol inhibits the contractility of gallbladder smooth muscle, the effects of different ethanol concentrations were examined on gallbladder contractile responses to stimulants which act on the smooth muscle by different mechanisms. A low concentration (25 mM) of ethanol significantly inhibited the contractile response to phorbol-12,13-dibutyrate (PDBu), but not that to KCl. It also did not significantly affect contractile response to Ca2+ ionophore A23187 in the presence of verapamil or that to Ba2+ in a medium without Ca2+. On the other hand, a higher concentration (200 mM) of ethanol significantly inhibited the contractile responses to PDBu, KCl, Ca2+ ionophore A23187 and BaCl2. These results together with our recent finding that PDBu-induced contraction of guinea pig gallbladder is completely dependent on activation of the voltage-dependent Ca2+ channel suggest that low concentrations of ethanol selectively inhibit the signal transduction of gallbladder smooth muscle cells in the pathway from activation of protein kinase C to that of the voltage-dependent Ca2+ channel, while high concentrations of ethanol inhibit the intracellular common pathway (probably in the cytoskeletal apparatus).