Effect of Cytochalasin B and Colchicine on Α-amylase Release from Rat Parotid Tissue Slices

We have recently reported (3) that cytochalasin B, which disrupts microfilaments, and colchicine, which disrupts microtubules, interfered with the release of a-amylase from rat parotid tissue slices . Our observations on the effect of cytochalasin B on a-amylase release have been confirmed by Rifkin et al . (14) . Inhibitory actions of cytochalasin B or colchicine in several other systems have also been reported (5, 11, 18, 19, 22) . In contrast to the inhibitory action of either cytochalasin B or colchicine, these agents have also been shown to exert a stimulatory action in some systems . For example, Orci et al . (12) have shown that cytochalasin B enhanced the effect of glucose on insulin release from isolated pancreatic islets over the release observed with glucose alone . Similarly, Temple et al . (18) have observed that colchicine enhanced steroid production by an adrenal tumor cell line . Although the varied effects of cytochalasin B and colchicine might be a function of the system under study, they might also be a function of the compound, or the concentration of the compound used to alter the rate of a given process. In this paper we report the results from a study of this latter possibility .