Figure 4.

Comparison of 30 mM K⁺ and PGF_2α on rat middle meningeal arteries, and sample relaxation. A) Sample contraction induced by of 30 mM K⁺ or PGF_2α in rat meningeal artery. One can observe the slight positive drift for 30 mM K⁺ and slight the negative drift for PGF_2α. B) Sample relaxation in an artery precontracted with 30 mM K⁺ and the cumulative relaxation of added sodium nitroprusside (SNP). Small plateaus were allowed before next concentration was added.