Effect of cyclic guanosine monophosphate (cGMP) inhibition via 1H-[1,2,4]oxadiazolo[4,3-α-]quinoxalin-1-one (ODQ) on venous smooth muscle response to DETA/NO in nonpregnant (NP, n = 6) and late pregnant animals (LP, n = 6). Solid bars denote response in the absence of ODQ, and open bars show response after administration of a maximal concentration of ODQ (10 mmol/L). Although there was a significant (P < .05) decrease in dilation in both groups in the presence of ODQ, the extent of residual dilation was similar (P > .05).