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Abstract #10106 Published in IGR 6-1
PD128,907 induces ocular hypotension in rabbits: involvement of D2/D3 dopamine receptors and brain natriuretic peptide
Chu E; Socci R; Chu TCJournal of Ocular Pharmacology and Therapeutics 2004; 20: 15-23
The purpose of this study was to determine the potential role of brain natriuretic peptide (BNP) in the PD128,907 (a dopamine D2/D3 receptor agonist)-induced ocular hypotension in rabbits. The effects of topical application of PD128,907 (75, 250, 750 μg) on intraocular pressure (IOP) were investigated. The lowest dose (75 μg) did not alter IOP; while the higher doses (250 and 750 μg) reduced IOP bilaterally. The PD128,907 (250 μg)-induced ocular hypotension, which lasted for three hours, could be blocked by raclopride (1000 μg), a dopamine D2/D3 receptor antagonist, as well as by sympathetic denervation. Aqueous humor inflow was reduced by intravitreal injection of PD128,907 (10 μg) by 67% at one and two hours, which then returned to baseline at three hours. Furthermore, topical application of PD128,907 (250 μg) elevated aqueous BNP levels three-fold at 30 minutes, six-fold at one hour, and five-fold at two hours, which could be blocked by pretreatment with raclopride (250 μg). Taken together, PD128,907-induced ocular hypotension by activation of dopamine D2/D3 receptors. This action was associated with reduced aqueous humor inflow and increased aqueous BNP levels.
Dr. T.-C. Chu, Department of Pharmacology and Toxicology, Morehouse School of Medicine, 720 Westview Drive Southwest, Atlanta, GA 30310-1495, USA
Classification:
11.14 Investigational drugs; pharmacological experiments (Part of: 11 Medical treatment)
