PROSTAGLANDIN AND THROMBOXANE SYNTHESIS BY MICROSOMES OF RABBIT OCULAR TISSUES

  • 1 January 1979
    • journal article
    • research article
    • Vol. 18  (2) , 166-171
Abstract
Microsomes of albino rabbit ocular tissues were incubated with (1-14C)-arachidonic acid for 15 min at 37.degree. C. TLC revealed that ciliary body-iris microsomes were capable of synthesizing prostaglandin F2.alpha.(PGF2.alpha.), PGE2, PGD2, thromboxane B2(TXB2), and 6-keto-PGF1.alpha.. Indomethacin 14 .mu.M in the incubation medium essentially abolished all prostaglandin synthesis detectable by this method. Imidazole 10 mM in the incubation medium inhibited only TXB2 synthesis. Ciliary body-iris microsomes were incubated for 2 min at 0.degree. C with PGH2. The products of this reaction were superfused over spiral strips of rabbit aorta and produced the strong contractions typical of TXA2. Addition of imidazole to the incubation medium blocked the formation of the contracting substance. Incubation of ciliary body-iris microsomes with (1-14C)-8,11,14-eicosatrienoic acid produced PGF1.alpha., PGD1 and PGE1, but no evidence of any thromboxane product or 6-keto-PGF1.alpha.. Conjunctival and corneal microsomes synthesized prostaglandins, although less effectively than ciliary body-iris microsomes, when incubated with (1-14C)-arachidonic acid. Microsomes of sclera, retina-choroid, and lens synthesized little, if any, prostaglandins.