Figure 1

Representative polygraph tracings of longitudinal muscle strips. Uterine strips were isolated from uteri of gestation day 20 rats and exposed in muscle baths to 0.2% DMSO (solvent control) or 1, 10 or 100 μM lindane for 1 h. After exposure, the strips were rinsed 3 times and monitored in fresh physiological salt solution without test chemicals for an additional 5 h. A) Five minutes prior to exposure and 30 min after initiating a 1-h exposure (arrows mark addition of test chemical). B) 4.5 hours after rinsing (10 min shown).