Journal of Applied Physiology, Vol 55, Issue 5 1634-1636, Copyright © 1983 by American Physiological Society
Adrenal hormones and liver cAMP in exercising rats--different modes of anesthesia
W. W. Winder, E. O. Fuller and R. K. Conlee
We have compared five different modes of anesthesia (iv and ip
pentobarbital sodium, ether, CO2, and cervical dislocation) with respect to
their effects on liver glycogen, liver adenosine 3',5'-cyclic monophosphate
(cAMP), blood glucose and lactate, plasma corticosterone, norepinephrine,
and epinephrine in resting rats and in rats run on a treadmill at 26 m/min
for 30 min. Ether, CO2, and cervical dislocation were found to be
unsuitable due to the marked elevation in plasma catecholamines seen in
both resting and exercising rats. Injection of pentobarbital sodium ip
required an average of 8 min before onset of surgical anesthesia as opposed
to less than 5 s for iv pentobarbital. Exercising rats anesthetized with ip
pentobarbital showed markedly lower plasma catecholamines compared with
rats given iv pentobarbital. Hepatic cAMP increased in response to exercise
in all groups except the ip pentobarbital group. This is most likely due to
the long delay between the end of the exercise and freezing of the liver in
the ip pentobarbital-anesthetized animals. We conclude that iv injection of
pentobarbital is the most suitable method of anesthesia for obtaining
accurate measurements of plasma stress hormones, substrates, and
metabolites and of hepatic cAMP and glycogen in resting and exercising
rats.
