Fig. 3.
Signaling pathways (i.e., NO and PGI2) involved in ACh-mediated, endothelium-dependent vasodilation in young (A) and old (B) rats following intermittent parathyroid hormone (PTH) administration and/or exposure to marrow. NG-nitro-l-arginine methyl ester (l-NAME) denotes that the ACh dose-response experiment was conducted in the presence of the NO synthase (NOS) inhibitor. l-NAME + indomethacin (INDO) denotes that the ACh dose-response experiment was conducted in the presence of the NOS and cyclooxygenase (COX) inhibitors. Data were analyzed by one-way ANOVAs. Values are means ± SE. The sample size n represents the number of rats per group. CON, control. aP < 0.050 between groups; bP < 0.050 between groups; cP < 0.050 between groups.