[Effect of hypothalamic paraventricular beta-endorphin on burn shock in rats]

Dynamic changes of immunoreactive beta-endorphin (ir-beta-EP) in perfusates collected from hypothalamic paraventricular nuclei at different times after burn, and the effects of intrahypothalamic paraventricular microinjection of beta-endorphin or its antiserum on various cardiac indices (MAP, dP/dtmax, Lvsp and HR) and survival time, were observed in anesthetized SD rats after third degree burn of 20% total body surface area. The results showed a significant increase of ir-beta-endorphin contents in the perfusate with the appearance of two peaks. According to the cardiac indices and mean survival time, the condition of the burned animals were improved by injection of anti-beta-endorphin serum, while injection of beta-endorphin did the reverse. The above results suggest that massive accumulation of beta-endorphin in the paraventricular nucleus appears to be one of the important factors detrimental to burn shock.