Kartifuzova Z. The role of opioid peptides in regulation of liver activites under normal condition and under (experimental) alcohol-induced hepatitis

The Thesis for obtaining the Scientific Degree of PhD in Medical on speciality 14.03.04 - pathophysiology. - O.O.Bogomoletz Physiology Institute of NAS of Ukraine, Kyiv, 2010. The aim of the investigation was to determine influence of the opioid peptides leu- enkephaline and met-enkephaline and synthetic leu-enkephaline analogue dalargin on a liver during experimental alcohol-induced liver damage. It has been established that both opioid peptide and opioid receptor antagonist naloxone significantly decrease or even prevent alterations of the morphostructure of liver under experimental alcoholic hepatitis. The investigated morphometric characteristics are: capillary diameters and cross-sectional area of nuclei of hepatocytes, and small-center necroses in liver tissue. Enkephalines are reported to diminish ?-glutamiltransferase raise, caused by ethanol introduction. Leu-enkephaline has also been shown to reduce the activity of alaninaminotransferase in the presence of alcoholic hepatitis. According to the data obtained, naloxone introduction promotes reduction of aspartataminotransferase activity under the influence of ethanol. The stated reduction of bile acids' and bile lipids' concentration is indicative of the biliary excretion decrease under the experimental alcoholic hepatitis. It has been shown that enkephaline decreases effectively the oppressing action of ethanol on secretion of both conjugated and free bile acids and bile lipids. Obtained data enable us to suggest that opioid peptides modulate bile qualitative properties and the function of bile secretion under the influence of alcohol. Thus, effects of opioid peptides in the presence of alcohol-induced liver damage denote their hepatoprotective characteristics under alcoholic intoxication.