Fig. 2. Effects of exogenous glucose on resting tension. In females, resting tension was maintained in media containing 5 or 10 mmol l^-1 glucose but increased in glucose-free (0), 1 and 2 mmol l^-1 glucose conditions (dissimilar letters denote significant differences between treatments, ^*P<0.05). There were no significant differences in resting tension for males at all concentrations tested. Immature females also showed higher resting tension compared with immature and sexually maturing males at 0, 1 and 2 mmol l^-1 glucose. Values are means ± s.e.m. (N=8-26 strips per group).