title: Stimulation of adenylate cyclase of ciliary processes in response to decreased inflow of aqueous humour.
abstract: Intravitreal injection of ouabain was used to induce unilateral hypotony and to study the relationship of adenylate cyclase (AC) and sodium-potassium activated adenosine triphosphatase (NaK-ATPase) both of which are involved in the production of aqueous humour. After preliminary experiments, days 3 and 5 were chosen as representative times when IOP was maximally reduced and stable following ouabain injection. NaK-ATPase and adenylate cyclase activities were measured biochemically in the same homogenates of isolated ciliary processes (CP). Biochemical measurements showed that 46% of NaK-ATPase activity was inhibited after 3 days, and about 78% of NaK-ATPase was inhibited 5 days after ouabain injection. At the beginning of NaK-ATPase inhibition there was a significant stimulation of adenylate cyclase activity of the CP. The highest activities were seen 2 and 3 days after ouabain injection. The suggestion is made that these 2 enzymes are interdependent.
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D001082:Aqueous Humor / Q000187:drug effects* / Q000502:physiology; D002924:Ciliary Body / Q000201:enzymology*; D010042:Ouabain / Q000494:pharmacology; D011817:Rabbits; D012965:Sodium Chloride / Q000494:pharmacology; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
chemical_list: D012965:Sodium Chloride; D010042:Ouabain; D000262:Adenylyl Cyclases; D000254:Sodium-Potassium-Exchanging ATPase