Stress and morphine mediated changes in pituitary-adrenal axis in guinea-pigs.
1. Changes in plasma levels of B-END and cortisol were investigated in guinea-pigs receiving either stressful stimuli for various lengths of time or i.p. injections of morphine or saline. 2. A decrease in B-END levels occurred when animals were stressed, whereas cortisol was not affected. 3. Morphine (50 mg/kg i.p.) enhanced B-END and cortisol levels 5 min after injection, whereas a decrease in B-END was seen at 30 min. 4. Saline (i.p.) produced a decrease of B-END levels 30 min after injection and an increase in cortisol 5 and 10 min after injection. These findings suggest that in the guinea-pig the response of pituitary-adrenal axis to stress or morphine could change depending upon the time of sampling.
Milanés
M V
MV
Department of Physiology and Pharmacology, University School of Medicine, Murcia, Spain.
del Rio-García
J
J
Fuente
T
T
Martínez
J A
JA
Vargas
M L
ML
D000818:Animals; D005260:Female; D006168:Guinea Pigs; D006854:Hydrocortisone / Q000097:blood / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D010913:Pituitary-Adrenal System / Q000187:drug effects / Q000503:physiopathology*; D013315:Stress, Psychological / Q000503:physiopathology*; D001615:beta-Endorphin / Q000378:metabolism / Q000494:pharmacology
D001615:beta-Endorphin; D009020:Morphine; D006854:Hydrocortisone