Experimental steroid glaucoma 6. the relation between intra ocular pressure and aqueous levels of cyclic amp in steroid treated young rabbit eyes
Ogino, T.; Masuda, S.; Shiokawa, K.; Yoshikawa, T.; Sato, T.
Nippon Ganka Gakkai Zasshi 84(10): 1738-1745
ISSN/ISBN: 0029-0203 Accession: 005425571
The relationship between intraocular pressure and tissue levels of cAMP in rabbits' eyes receiving treatment with steroid or instillation of theophylline (a phosphodiesterase inhibitor) or bupuranolol (a .beta.-blocker) was studied. An indirect relationship between intraocular pressure and aqueous levels of cAMP was found. A rise in intraocular pressure caused by glucocorticoids was explained by an increase in cellular content of cAMP. cAMP increase resulted from decreased phosphodiesterase activity with a consequent increase in the activity of protein kinase and carbonic anhydrase, and a failure of the feedback mechanism. Increased intraocular pressure following instillation of dibutyryl cAMP seemed due to an increase in cellular content of cAMP. Bupranolol administration, which inhibits the activity of adenylate cyclase, resulted in a reduction of intraocular pressure and aqueous cAMP level, supporting the relation between intraocular pressure and cAMP. An increased cellular content of cAMP generally apparently is related to elevation of intraocular pressure and specifically is a cause of increased intraocular pressure following the administration of glucocorticoids.