Figure 4: Changes in the contractile responses of the main uterine artery following intravenous administration (IV) of MWCNTs. The changes in the contractile responses were assessed by wire myography of the main uterine artery segments from 17 - 19 days pregnant (A, B, C and D) Sprague Dawley rats, 24 hours following intravenous administration of 100 μg/kg of (D)-MWCNTs or DPPC/RSA. The stress generation in response to cumulative concentrations of phenylephrine (PE; A), angiotensin II (ANG II; B) and endothelin 1 (ET-1; C) are plotted. The percentage relaxation from a 30 μM phenylephrine pre-stimulation stress level in response to cumulative concentrations of acetylcholine is graphed (Ach: D). # indicates p < 0.05 compared to naïve using repeated measures ANOVA (n = 5 - 8). 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.