Microtubule disruption potentiates phenylephrine-induced vasoconstriction in rat mesenteric arterial bed.

The pressor response induced by phenylephrine in the rat isolated mesenteric arterial bed was significantly increased following treatment with nocodazole, a drug that disassembles microtubules (10 microM, 90 min). This increase was even greater in the presence of nitric oxide (NO) synthase inhibition, and completely reversed by paclitaxel (20 microM), a stabilizer of microtubules. These results demonstrate that disassembly of microtubules enhances vasoconstriction to receptor activation, suggesting that the microtubules modulate the transduction of intracellular signals in endothelium and vascular smooth muscle cells.