Figure 6.

A, changes in arteriole diameter following sequential intravitreal injections of the gliotoxin FC (150 μm), Et-1 (7–12 nm), a vasoconstricting peptide, and NF023 (50 μm), a P2X1 receptor antagonist. Et-1 restored the tone of the vessel, which was decreased following FC treatment. NF023 injection evoked a small dilatation. B, summary data showing arteriole diameter changes evoked by application of NF023 without pretreatment (data from Fig. 2) and following pretreatment with FC and Et-1. Numbers in parentheses indicate number of rats. ^**P < 0.01 relative to NF023 alone. Et-1, endothelin-1; FC, fluorocitrate; NF023, 8,8′-[carbonylbis(imino-3,1-phenylenecarbonylimino)]bis-1,3,5-naphthalene-trisulphonic.