Pressure-induced depolymerization of brain microtubules in vitro.

Microtubules, assembled in vitro from tubulin extracted from rabbit brain, were subjected to changes in hydrostatic pressure (200 to 10,000 pounds per square inch) and temperature (37 degrees to 0 degrees C). Increased pressure, like cooling, reversibly depolymerizes microtubules, as measured by changes in either turbidity, birefringence, or the number of microtubules seen in electron micrographs. The characteristic response of brain microtubules in vitro to pressure is similar to that of mitotic spindle microtubules in vivo.