Anesteziol Reanimatol. 1989 Nov-Dec; (6): 27-30.

[Changes in the concentration of endogenous opiates in the blood and cerebrospinal fluid during acute painful stimuli and protective electroacupuncture analgesia]

Gimmel'farb GN, Shumilova IIu, Khalmuratova RA.

The concentrations of endogenous opiates (beta-endorphin, methionine-enkephalin, leucine-enkephalin) in the spinal fluid and arterial blood plasma has been studied in 16 dogs, using the model of acute pain stimulation under electroacupuncture analgesia (EAA). It has been shown that pain stimulation under EAA is accompanied by a significant increase in methionine-enkephalin++ and leucine-enkephalin concentrations (by 244 and 69.4%, respectively) in the spinal fluid. beta-endorphin level tends to increase. There is also a trend towards the reduction in beta-endorphin and methionine-enkephalin concentrations in the arterial blood plasma, which is indicative of effective antinociceptive stimulation of the endogenous opiate system. However, by the end of the first hour a decrease of methionine-enkephalin and leucine-enkephalin levels in the spinal fluid was paralleled by a trend towards beta-endorphin and methionine-enkephalin increase and a significant leucine-enkephalin increase in arterial blood plasma, which can account for the exhaustion of the opiate system.