Alteration of rat splenic lymphocyte migration in vitro by the state of microtubule integrity

Rat splenic lymphocytes exhibit a positive chemokinetic response to colchicine and vinblastine. Both agents elicit a dose-dependent increase in chemokinesis with their peak effect at 2 to 4 × 10^?7M being 3.5 times baseline random migration. The distance traveled by the leading front and the total movement of rat splenic lymphocytes is maximal in the absence of a gradient at all effective concentrations of colchicine or vinblastine. Checkerboard analysis established this response as entirely chemokinetic without any chemotactic component. That this chemokinetic response was due to a shift in the dynamic state of microtubules toward disassembly was supported by the inactivity of lumicolchicine and the capacity of heavy water to reverse the effect in a dose-response fashion. Cytochalasin B suppressed baseline random migration and reversed the chemokinetic response of the rat splenic lymphocytes to 4 × 10^?7M colchicine. The chemokinetic motility of rat splenic lymphocytes may depend not only on microtubule disassembly but also on the contractile activity of microfilaments.