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Research Article| Volume 1, ISSUE 2, P151-157, August 1978

The high yield of prostacyclin biosynthesis by the iris and its effects on the intraocular muscles

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      Abstract

      Iris, and to a lesser extent ciliary body , from cat and rabbit produce considerable amounts of prostacyclin (PGI2) after incubation of the tissue with 1-14C arachidonic acid. These tissues also generate PGI2-like material after gentle squeezing. It is likely that major metabolites found previously in iris and aqueous humor actually were 6-keto-PGF. It is concluded that PGH2 and PGI2 are synthetized at the same location. PGI2 induces a contraction of the sphincter and dilator and a relaxation of the ciliary muscle if the tissues had been previously exposed to indomethacin. Thromboxane A2 (TXA2) has either no effect or may cause a slight relaxation of the sphincter.
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