The synthesis of cyclooxygenase products in ocular tissues of various species

In the present study we compared the synthesis of various cyclooxygenase products in albino rabbit, dog (puppy and adult), cat, cow and human ocular tissues from 14C-arachidonic acid (AA). Albino rabbit conjunctiva synthesized a substantial amount (47%) of cyclooxygenase products, while cat and dog (puppy as well as adult) conjunctival tissues synthesized lesser but significant amounts of cyclooxygenase products from 14C-AA. Cyclooxygenase activity in the anterior uvea of different species tested was in the following order of potency: cat greater than albino rabbit greater than dog greater than human greater than cow. Furthermore, human and cow anterior uvea synthesized significantly lesser amount of cyclooxygenase products from 14C-AA than amounts from an intermediate substrate, 14C-PGH2. Interestingly, cow anterior uvea synthesized PGF2 alpha and 6-keto-PGF1 alpha (a stable metabolite of PGI2) while human anterior uvea synthesized all cyclooxygenase products from 14-C-PGH2.