Figure 8. Representative effects of protein kinase C (PKC) activator and inhibitor on the basolateral membrane voltage (Vbl) and the input resistance (Rin, kΩ) of a principal cell in isolated Malpighian tubules of Aedes aegypti. The tubules were prepulsed with aedeskinin‑III (AK‑III, 10−6 M) to ascertain an active signaling pathway. (A) The PKC activator phorbol myristate acetate (PMA, 10−6M) had minor effects on Vbl and Rin. In the presence of PMA the tubule still responded to AK‑III. (B) The PKC inhibitor bisindolylmaleimide‑I (BIM‑I, 10−5 M) significantly depolarized Vbl and increased Rin. In the presence of BIM‑I the tubule did not respond to AK‑III. PMA and BIM‑I were dissolved in DMSO (final bath concentration of 0.1%). Arrows indicate the times Rin was determined.