TY - JOUR T1 - CROSS-CELLULAR ADAPTATION TO METHADONE AND MEPERIDINE IN CEREBRAL CORTICAL SLICES FROM MORPHINIZED RATS JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 252 LP - 255 VL - 135 IS - 2 AU - A. E. Takemori Y1 - 1962/02/01 UR - http://jpet.aspetjournals.org/content/135/2/252.abstract N2 - Meperidine did not alter the respiratory rate of unstimulated cortical slices at concentrations between 5 x 10-4 and 1 x 10-3 M, but these concentrations had a depressive effect on the respiratory rate of KCl-stimulated cortical slices. Methadone had a diphasic action on the respiratory rate of unstimulated cortical slices, stimulating at 2 x 10-4 and 5 x 10-4 M and depressing at concentrations above 1 x 10-3 M. Methadone depressed the KCl-stimulated respiratory rate of cortical slices at a concentration (1 x 10-4 M) which did not affect the unstimulated rate. Complete cross-cellular adaptation was seen with methadone in cortical slices adapted to the depressive effect of morphine. There was only a partial cross-adaptation to meperidine. The adaptation to morphine, methadone and meperidine was acutely reversed by an injection of nalorphine to the morphinized rats prior to sacrifice. ER -