Fig. 10. Agonist-induced desensitization of the WT and T347 mutant D₁ receptors.

Transiently transfected HEK293T cells were pretreated with 10 µm dopamine (DA) for 1 h, washed, and then rechallenged with the indicated doses of dopamine. The data are expressed as a percentage of the maximum cAMP response produced by the control group that was not pretreated with dopamine. A, a single experiment, representative of three, is shown for the WT receptor. B, a single experiment, representative of three, is shown for the T347 receptor. C, average data from three separate experiments performed as described in A and B are shown. The data represent the maximum cAMP response to 100 µm dopamine, after 1 h of dopamine pretreatment (10 µm), expressed a percentage of the control group in each experiment. Mean ± S.E. values are shown.