The effects of adrenergic agonists on intraocular pressure and on adenylyl cyclase activity of ciliary processes in pigmented rabbits

Title:

The effects of adrenergic agonists on intraocular pressure and on adenylyl cyclase activity of ciliary processes in pigmented rabbits

Creator:

Čepelík, J., Dědina, M., and Hynie, S.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:ec54d396-4c66-4cd2-aa0b-aba7e3db9d55
uuid:ec54d396-4c66-4cd2-aa0b-aba7e3db9d55

Subject:

adenylyl cyclase, adrenergic agonists, ciliary processes, desensitization, and intraocular pressure

Type:

article, model:article, and TEXT

Description:

The effects of /¿-adrenergic agonists isoprenaline, fenoterol and clenbuterol on the activity of adenylyl cyclase from ciliary processes and on intraocular pressure were examined in pigmented rabbits. Isoprenaline, fenoterol and clenbuterol stimulated adenylyl cyclase activity in vitro, but clenbuterol behaved as a partial agonist. Preincubation of ciliary processes with any of these three drugs led to the heterologous desensitization of adenylyl cyclase to the stimulatory effects of beta-adrenergic agonists or vasoactive intestinal peptide (VIP). This desensitization was dose-dependent and was expressed mainly as a decrease of the highest effects of stimulatory drugs. The exact mechanism of this phenomenon is not yet known. After topical administration, all three tested /¿-adrenergic agonists decreased intraocular pressure with approximately the same intensity. The relationship between ocular hypotensive effects of /¿-adrenergic agonists and their effects on adenylyl cyclase of ciliary processes is discussed. It is concluded that ocular hypotensive effects of adrenergic agonists and other drugs stimulating adenylyl cyclase cannot be explained simply by stimulation or desensitization of adenylyl cyclase of ciliary processes.

Language:

English

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Source:

Physiological research | 1998 Volume:47 | Number:1

Harvested from:

CDK

Metadata only:

false