Short communicat ion ENHANCED RESPONSES TO OPIATES PRODUCED BY A SINGLE GENE SUBSTITUTION IN THE MOUSE

R.J. KATZ and R.L. DOYLE, Enhanced responses to opiates produced by a single gene substitution in the mouse, European J. Pharmacol. 67 (1980) 301--303. Adult male mice of the C57B1/6J strain, or mice differing at a single locus from the above, pallid mice (C57Bl! 6J-pa), were treated with morphine or vehicle and two responses associated with opiate receptor stimulation were examined. In comparison with vehicle treatment, morphine produced stereotyped running and reduced core temperature in the parent C57B1/6J line. These responses were significantly enhanced in the coisogenic pallid line. Thus, a single gene may enhance normal sensitivity to opiates. This suggests the existence of discrete and identified biochemical influences upon sensitivity to opiates through genetic means, and offers a novel model of naturally occurring permanently altered opiate sensitivity.