Antistressor effect of dalargin in rats with immobilization stress

Abstract

Long-term exposure to stress and, in particular, to surgical stress [7] may be accompanied by damage to target organs, namely the heart and mucosa of the gastrointestinal tract (GIT), due to the histotoxic action of hypercatecholaminemia, which develops during severe stress reactions [3]. An example of stress-induced damage to the myocardium and GIT in surgical practice is the low cardiac output syndrome in the earliest stages of various kinds of shock, and also the development of stress-induced ulcers of the gastric and duodenal mucosa [9]. Endogenous opioids and their synthetic analogs, as several research workers have shown, can considerably alleviate and even abolish pathological changes in the myocardium [6] and mucosa of GIT [2], induced by hypercatecholaminemia during exposure to different kinds of stress. The aim of this investigation was to study the antistressor effect of the synthetic Leu-enkephalin analog D-ala2-1euS-arg6-enkephalin (the preparation dalargin, synthesized in the Laboratory of Peptide Synthesis, All-Union Cardiologic Scientific Center, Academy of Medical Sciences of the USSR, under the direction of Professor M. I. Titov, and generously provided by him for research) in rats during long-term immobilization stress.