title: Iris arteriolar diameters in hypoxia and hyperoxia: a photographic study in albino guinea pigs.
abstract: The irides of albino guinea pigs were photographed, and the iris arteriolar diameters were measured with the animal breathing room air, 10% O2/90% N2, or 100% O2. The iris arterioles constrict significantly in hyperoxia and dilate in hypoxia. The average constriction in 100% O2 was 27% +/- 8%, and the average dilatation in 10% oxygen was 34% +/- 20%.
mesh_terms: D000818:Animals; D001160:Arterioles / Q000502:physiology; D006168:Guinea Pigs; D007498:Iris / Q000098:blood supply*; D010100:Oxygen / Q000097:blood*; D014661:Vasoconstriction; D014664:Vasodilation
chemical_list: D010100:Oxygen