Figure 5. The effect of intrathecal l-arginine (l-Arg, middle three bars; 10, 100, 1000 μm, 10 μl injection volume) and vehicle (PBS, leftmost bar; 10 μl volume).

l-Arginine elicits an increase in MAP at all doses (P < 0.05), denoted by an asterisk (*). No changes (ns, P > 0.05), were observed when PBS was given or when l-Arg was injected in ODQ-pretreated rats (rightmost bar; 10 μl of 100 mm ODQ followed by 10 μl of 1 mm l-Arg).