Figure 4. ROFA exposure impairs both NO-dependent and NO-independent arteriolar responsiveness to intraluminal A23187 in the spinotrapezius muscle. NO synthase was competitively inhibited by simultaneous superfusion with L-NMMA (10⁻⁴ M final superfusate concentration). Values are mean ± SE. For normal superfusate and with L-NMMA, n (number of arterioles studied) = 8; for 0.25 mg ROFA, n = 8. : *p < 0.05 vs. normal superfusate. **p < 0.05 vs. 5 psi response. ^#p < 0.05 vs. +L-NMMA. ^##p < 0.05 vs. 10 psi response. ^†p < 0.05 vs. 20 psi response.