Fig. 1. Effect of glibenclamide on fluid secretion by tubules of Tenebrio. Glibenclamide was tested at 0.1 mmol l^-1 (triangles) and 0.5 mmol l^-1 (circles) in control Ringer (50 mmol l^-1 K⁺). Secretion rates recovered after stimulation with Tenmo-DH₃₇ (100 nmol l^-1). The horizontal bars indicate the time of exposure to glibenclamide (broken bar) and to Tenmo-DH₃₇ (solid bar). Data are presented as means ± 1 S.E.M. for 7-8 tubules.