The changes in the contractile responses as assessed by wire myography of the main uterine artery from 17 - 19 days pregnant (A, C, E and G) and non-pregnant female (B, D, F and H) Sprague Dawley rats, 24 hours following intratracheal instillation of 100 μg/kg of (S)-MWCNTs or 10% surfactant. The stress generation in response to cumulative concentrations of phenylephrine (PE; A and B), angiotensin II (ANG II; C and D) and endothelin 1 (ET-1; E and F) are plotted. The percentage relaxation from a 30 μM phenylephrine pre-stimulation stress level in response to cumulative concentrations of acetylcholine (Ach; G and H) is graphed. * indicates p < 0.05 compared to 10% surfactant while # indicates p < 0.05 compared to naïve using repeated measures ANOVA (n = 5 - 7). The p values were derived following the comparison of each concentration response curve across treatment groups using a regression analysis by examining the best-fit values.
