Evaluation of beta-endorphin and naloxone on bovine uterine motility.
Effects of beta-endorphin and naloxone on bovine uterine motility were tested both in vivo and in vitro. Six cyclic Holstein cows were used to study in vivo effects of beta-endorphin and naloxone on uterine motility during estrus and diestrus. Intrauterine pressure changes were recorded by a microtip pressure transducer before and after treatment. Blood samples were taken every 10 min during the recording periods for beta-endorphin assay. The results revealed that beta-endorphin anc naloxone had no effect on intrauterine pressure in vivo. The effects of beta-endorphin and naloxone on myometrial contractility were also examined in vitro. Beta-endorphin and naloxone were added to tissue baths containing estrous and diestrous uterine strips. The results showed no significant effect of beta-endorphin and naloxone on bovine myometrial contractility. The role of beta-endorphin in bovine reproductive physiology is still not clearly understood, and additional studies are needed.
Ko
C H
CH
Department of Veterinary Clinical Medicine College of Veterinary Medicine University of Illinois Urbana, IL 61801 USA.
Wheaton
L G
LG
McKenna
D J
DJ
Whitmore
H L
HL
Gustafsson
B K
BK
Smith
R P
RP