An atypical vasopermeability response to leukotrienes in the iris-ciliary body.

The effects of leukotrienes (LTs) on the blood-aqueous barrier in the guinea pig were investigated. Leukotriene B4 (LTB4) and D4 (LTD4) were administered in doses of 1 to 1000 ng into the anterior chamber. Plasma extravasation was determined as extravascular 125I-albumin levels in the iris-ciliary body using 125I-albumin and 51Cr-erythrocytes as an intravascular marker. LTB4 and LTD4 alone did not cause significant plasma extravasation. Although combinations of 100 ng and more of each LT raised extravascular albumin levels in the ocular anterior uvea. These studies suggest a synergistic interaction of LTB4 and LTD4 with respect to plasma extravasation in the iris-ciliary body. These results further support a possible involvement of LTs in uveal inflammatory diseases.