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Effect of Guanabenz on Rat AMD Models and Rabbit Choroidal Blood Flow.

Shen Y, Zhuang P, Chiou GC - Open Ophthalmol J (2011)

Bottom Line: There was a significant protection of the ERG c-wave by Guanabenz as compared to NaIO(3) group (P<0.01).The angiograms of FD70-FA showed decreased lesion size in the Guanabenz group.The choroidal blood flow was significantly increased at 30 and 60 minutes after Guanabenz instillation as compared to corresponding controls.

View Article: PubMed Central - PubMed

Affiliation: Institute of Ocular Pharmacology, College of Medicine, Texas A&M Health Science Center, College Station, TX 77843, USA.

ABSTRACT

Aim: The effects of Guanabenz, an agonist of α2-adrenergic receptors routinely used in human medicine as an antihypertensive drug, were studied on NaIO(3)-induced retinal pigment epithelium (RPE) degeneration, laser-induced choroidal neovascularization (CNV) and choroidal blood flow, in animal models.

Methods: The 35mg/kg NaIO(3)-induced RPE degeneration rat eyes were instilled with 1% Guanabenz eye drops 3 times a day for 7 days before NaIO(3) injection, and then 2 to 4 weeks thereafter. RPE function was measured with c-wave of electroretinogram (ERG). Male Brown Norway rats were anesthetized to receive Nd:YAG laser to break the Bruch's membrane. One percent Guanabenz eye drops were given likewise. The development of CNV was determined by fluorescein angiography performed on week 2 and week 4 using sodium fluorescein (FA) or fluorescein isothiocyanatedextran (FD70-FA). Colored microsphere technique was used for in vivo experiments to determine the choroidal blood flow in ocular hypertensive (40 mmHg) rabbit eyes.

Results: The RPE function was protected significantly by Guanabenz according to the c-wave of ERG. Four weeks after NaIO(3) injection, the amplitude of ERG c-wave was 0.422±0.092 millivolts in the control group, 0.103±0.04 millivolts in the NaIO(3) group, and 0.254±0.061 millivolts in the Guanabenz+NaIO(3) group. There was a significant protection of the ERG c-wave by Guanabenz as compared to NaIO(3) group (P<0.01). The angiograms of FD70-FA showed decreased lesion size in the Guanabenz group. Four weeks after laser treatment, the size of the CNV lesion was 2.99±0.18 mm(2) in the control group, and 1.24±0.16 mm(2) in the Guanabenz group (P<0.01). The choroidal blood flow was significantly increased at 30 and 60 minutes after Guanabenz instillation as compared to corresponding controls.

Conclusions: Guanabenz significantly protected RPE from NaIO(3)-induced degeneration, inhibited the development of CNV in laser-induced rat AMD model and increased choroidal blood flow markedly in vivo.

No MeSH data available.


Related in: MedlinePlus

Effect of guanabenz on ocular blood flow of ocular hypertensive rabbits. Data were expressed as means ± SEM. n=6 in each group; * was P < 0.05 and ** was P<0.01 as compared with the vehicle control group.
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Figure 5: Effect of guanabenz on ocular blood flow of ocular hypertensive rabbits. Data were expressed as means ± SEM. n=6 in each group; * was P < 0.05 and ** was P<0.01 as compared with the vehicle control group.


Effect of Guanabenz on Rat AMD Models and Rabbit Choroidal Blood Flow.

Shen Y, Zhuang P, Chiou GC - Open Ophthalmol J (2011)

Effect of guanabenz on ocular blood flow of ocular hypertensive rabbits. Data were expressed as means ± SEM. n=6 in each group; * was P < 0.05 and ** was P<0.01 as compared with the vehicle control group.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3104553&req=5

Figure 5: Effect of guanabenz on ocular blood flow of ocular hypertensive rabbits. Data were expressed as means ± SEM. n=6 in each group; * was P < 0.05 and ** was P<0.01 as compared with the vehicle control group.
Bottom Line: There was a significant protection of the ERG c-wave by Guanabenz as compared to NaIO(3) group (P<0.01).The angiograms of FD70-FA showed decreased lesion size in the Guanabenz group.The choroidal blood flow was significantly increased at 30 and 60 minutes after Guanabenz instillation as compared to corresponding controls.

View Article: PubMed Central - PubMed

Affiliation: Institute of Ocular Pharmacology, College of Medicine, Texas A&M Health Science Center, College Station, TX 77843, USA.

ABSTRACT

Aim: The effects of Guanabenz, an agonist of α2-adrenergic receptors routinely used in human medicine as an antihypertensive drug, were studied on NaIO(3)-induced retinal pigment epithelium (RPE) degeneration, laser-induced choroidal neovascularization (CNV) and choroidal blood flow, in animal models.

Methods: The 35mg/kg NaIO(3)-induced RPE degeneration rat eyes were instilled with 1% Guanabenz eye drops 3 times a day for 7 days before NaIO(3) injection, and then 2 to 4 weeks thereafter. RPE function was measured with c-wave of electroretinogram (ERG). Male Brown Norway rats were anesthetized to receive Nd:YAG laser to break the Bruch's membrane. One percent Guanabenz eye drops were given likewise. The development of CNV was determined by fluorescein angiography performed on week 2 and week 4 using sodium fluorescein (FA) or fluorescein isothiocyanatedextran (FD70-FA). Colored microsphere technique was used for in vivo experiments to determine the choroidal blood flow in ocular hypertensive (40 mmHg) rabbit eyes.

Results: The RPE function was protected significantly by Guanabenz according to the c-wave of ERG. Four weeks after NaIO(3) injection, the amplitude of ERG c-wave was 0.422±0.092 millivolts in the control group, 0.103±0.04 millivolts in the NaIO(3) group, and 0.254±0.061 millivolts in the Guanabenz+NaIO(3) group. There was a significant protection of the ERG c-wave by Guanabenz as compared to NaIO(3) group (P<0.01). The angiograms of FD70-FA showed decreased lesion size in the Guanabenz group. Four weeks after laser treatment, the size of the CNV lesion was 2.99±0.18 mm(2) in the control group, and 1.24±0.16 mm(2) in the Guanabenz group (P<0.01). The choroidal blood flow was significantly increased at 30 and 60 minutes after Guanabenz instillation as compared to corresponding controls.

Conclusions: Guanabenz significantly protected RPE from NaIO(3)-induced degeneration, inhibited the development of CNV in laser-induced rat AMD model and increased choroidal blood flow markedly in vivo.

No MeSH data available.


Related in: MedlinePlus