PMC

Cross tolerance between amphetamine and pseudoephedrine. Western blot analysis was used to measure the level of cross-tolerance between pseudoephedrine and amphetamine to drug induced c-Fos expression in striatum (n = 3) and nucleus accumbens (n = 3) in chronically treated rats. A: acute response to amphetamine in rats chronically treated with saline, amphetamine and pseudoephedrine (8 day treatment of drug twice a day with an increasing dose schedule; rats were killed 1.5 h after 40 mg/kg, i.p pseudoephedrine injection). There was no significant difference in the acute response to amphetamine between rats chronically treated with amphetamine or pseudoephedrine. B: acute response to pseudoephedrine in rats chronically treated with saline, pseudoephedrine and amphetamine (8 day treatment of drug twice a day with an increasing dose schedule, rats were killed 1.5 h after 40 mg/kg, i.p pseudoephedrine injection). There was no significant difference in the acute response to pseudoephedrine between rats treated with amphetamine or pseudoephedrine. The data are expressed as percentage of c-Fos value of control animals injected with saline. Values are mean ± S.E.M. a indicates significantly different from control and chronic; b indicates significantly different from acute, p < 0.05.

Data were from an oriented immobilised β ₂-AR column at 37 °C. The equations of the best fit lines were y = (2.58±0.02)×10³x+(0.43±0.01) for ephedrine with a coefficient of 0.9962 and y = (1.76±0.07)×10³x+(0.29±0.01) for pseudoephedrine with a coefficient of 0.9915. The value of X used for the plot of pseudoephedrine was set at (2.49±0.26). A, Ephedrine at different concentrations was added in the mobile phase. The injection solute was 5.0 nmol of ephedrine; B, Ephedrine at different concentrations was added in the mobile phase while 5.0 nmol of pseudoephedrine was injected as analytes.

Pseudoephedrine induced c-Fos expression. Western blot analysis was used to measure the acute pseudoephedrine (40 mg/kg, i.p) induced c-Fos expression in striatum and nucleus accumbens. c-Fos protein was detected 1.5 h after saline and pseudoephedrine injection.

Chromatogram of pseudoephedrine hydrochloride and loratadine. Retention time: Pseudoephedrine hydrochloride = 1.31 min; Loratadine = 3.45 min