Figure 3.

Effects of agonist type on channel kinetics and desensitization. (Aa) Representative traces recorded from HKIR3.1/3.2/A1 cells voltage-clamped at −60 mV in response to 20-s applications of NECA, adenosine, and R-PIA (all at 1 μM). Mean data are summarized in the bar chart shown (Ab), where each agonist caused a significant and reversible potentiation of currents (P < 0.001). (B) Channel activation kinetics were not significantly different between the agonists. NS, not significant. (C) Channel-deactivation time constants were markedly affected by the type of agonist used. Deactivation was accelerated with adenosine but slowed with R-PIA when compared with NECA.