Interaction of circadian rhythm and opiate-induced thermic and kinetic responses: a biotelemetric investigation.
The thermic and kinetic effects of a low dose of morphine sulphate (5mg/kg) were monitored using a remote biotelemetric procedure. Drug and control (saline) injections were administered at two times of day, during the high and low phases of the circadian temperature/activity cycle respectively. Standard measures of the responses revealed that the effect of a dose of morphine differs significantly according to the phase of the circadian rhythm in which it is administered. In contrast to previous studies employing standard stress-inducing rectal probing techniques of temperature measurement, the direction and time-course of thermic and kinetic responses were uncorrelated. The implications for research on physiological and behavioral drug effects and for theories of drug tolerance/dependence are considered.
Dafters
R I
RI
Department of Psychology, Glasgow University, Scotland.
Taggart
P
P
D000704:Analysis of Variance; D000818:Animals; D001831:Body Temperature / Q000187:drug effects; D002940:Circadian Rhythm / Q000502:physiology*; D007700:Kinetics; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D013686:Telemetry
D009020:Morphine