Fluid secretion by isolated tick salivary glands dependent on an intact cytoskeleton

Isolated salivary glands from female Dermacentor variabilis (Say) were pre-treated with either cytochalasin D or nocodazol, followed by stimulation with dopamine. Glands pre-treated with 1 microM-cytochalasin D did not secrete fluid; pre-treatment with 1 nM-cytochalasin D did not significantly reduce fluid secretion. Glands pre-treated with 1 microM-nocodazol had a significant reduction in fluid secretion (P = 0.003); 1 nM-nocodazol did not significantly affect fluid secretion. Ligation of the main salivary duct and pre-treatment with 1 microM-cytochalasin D significantly increased gland weight compared to the dopamine stimulated controls (P = 0.0412). Cytochalasin D-treated type III acini had a significantly larger mean diameter compared to the dopamine control (P = 0.0047). Glands treated with 1 mM-verapamil plus 10 microM-dopamine exhibited a significant decrease in fluid secretion (P = 0.017), and when ligated, had a significantly decreased weight compared to the controls (P = 0.0028).