Generation second messengers by prostanoids in the iris-sphincter and ciliary muscles of cows, cats and humans.
We have examined the generation of second messengers after stimulation of feline, bovine, human iris-sphincter and ciliary muscles by selected prostaglandins (PGs). The tissues, labeled or unlabeled with 3H-myo-inositol, were stimulated by a range of concentrations of 16,16-dimethyl PGE2, 11-deoxy PGE1, 17-phenyl trinor PGE2 and PGF2alpha. In both tissues of all three species, 16,16-dimethyl PGE2 and 11-deoxy PGE1 stimulated the formation of cyclic AMP. Butaprost, an EP2 receptor agonist, which was tested only in feline ciliary muscle, generated cyclic AMP. In the feline iris-sphincter and in bovine and feline ciliary muscles, 17-phenyl trinor PGE2, an EP1 receptor agonist, significantly increased inositol phosphate turnover. The FP receptor agonist, PGF2alpha stimulated inositol phosphate turnover in the bovine, feline, and human iris-sphincter muscles and in human ciliary muscles. Feline and bovine ciliary muscles did not respond to PGF2alpha. These results suggest that EP1 receptors are present in feline iris-sphincter muscle and in bovine and feline ciliary muscles. The EP2 receptors exist in both tissue. These results also suggest the presence FP receptors in bovine, feline, and human iris-sphincter and in human ciliary muscles. Bovine and feline ciliary muscles do not appear to express FP receptors.
Bhattacherjee
P
P
Department of Ophthalmology & Visual Sciences, University of Louisville, KY, USA.
Smithson
M
M
Paterson
C A
CA
D000818:Animals; D002415:Cats; D002417:Cattle; D002924:Ciliary Body / Q000187:drug effects* / Q000378:metabolism*; D000242:Cyclic AMP / Q000096:biosynthesis; D006801:Humans; D066298:In Vitro Techniques; D007295:Inositol Phosphates / Q000096:biosynthesis; D007498:Iris / Q000187:drug effects* / Q000378:metabolism*; D011453:Prostaglandins / Q000494:pharmacology*; D011982:Receptors, Prostaglandin / Q000145:classification / Q000187:drug effects / Q000378:metabolism; D015290:Second Messenger Systems / Q000187:drug effects*; D013045:Species Specificity
D007295:Inositol Phosphates; D011453:Prostaglandins; D011982:Receptors, Prostaglandin; D000242:Cyclic AMP