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Characterization of intraocular pressure responses of the Tibetan monkey (Macaca thibetana).

Liu G, Zeng T, Yu W, Yan N, Wang H, Cai SP, Pang IH, Liu X - Mol. Vis. (2011)

Bottom Line: Three hours after topical ocular administration, travoprost reduced IOP by 5.2±0.6 mmHg (n=6, p<0.001), and timolol reduced IOP by 2.8±0.7 mmHg (p<0.05).The circadian IOP fluctuation in conscious Tibetan monkeys and their responses to travoprost, timolol, and other experimental conditions are similar to other primates.These monkeys appear to be a suitable model for glaucoma research.

View Article: PubMed Central - PubMed

Affiliation: Ophthalmic Laboratories & Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan, PR China.

ABSTRACT

Purpose: To characterize the effects of circadian rhythm, feeding time, age, general anesthesia, and ocular hypotensive compounds on intraocular pressure (IOP) of the Tibetan monkey (Macaca thibetana).

Methods: Tibetan monkeys were trained for IOP measurement with the TonoVet® rebound tonometer without sedation or anesthesia. Their circadian IOP fluctuation was monitored every 3 h. Effects of changing the feeding time, general anesthesia, age (2-3 year-old versus 8-15 year-old animals), and various pharmacological agents, such as travoprost, timolol, naphazoline and spiradoline, on IOP were also evaluated.

Results: After behavioral training, conscious Tibetan monkeys were receptive to IOP measurement. The lowest and highest IOP values in a circadian cycle were recorded at 3:00 AM (19.8±0.4 mmHg, mean±SEM, n=12) and noon (29.3±0.9 mmHg), respectively. Changing the feeding time from 11:30 AM to 12:30 PM lowered the noon IOP to 25.1±1.2 mmHg. General anesthesia lowered IOP in these monkeys, while IOP of young and mature animals were similar. Three hours after topical ocular administration, travoprost reduced IOP by 5.2±0.6 mmHg (n=6, p<0.001), and timolol reduced IOP by 2.8±0.7 mmHg (p<0.05). Naphazoline and spiradoline lowered IOP by 4.8 mmHg and 2.5 mmHg (both p<0.001), respectively, 2 h after drug administration.

Conclusions: The circadian IOP fluctuation in conscious Tibetan monkeys and their responses to travoprost, timolol, and other experimental conditions are similar to other primates. These monkeys appear to be a suitable model for glaucoma research.

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Related in: MedlinePlus

Effect of travoprost (0.004%, 30 μl) on IOP of conscious Tibetan monkeys. The drug was administered topically at 9 AM (Time 0) onto a randomly assigned eye of each animal, while the contralateral eye received vehicle as control. IOP was monitored at 3, 6, 24, and 48 h later. Error bars represent SEM (n=6). Top Panel: IOP values of both groups. ***p<0.001 between the two treatment groups by two-tailed paired Student's t-test. Bottom panel: % IOP change of the travoprost group relative to the vehicle control group.
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f4: Effect of travoprost (0.004%, 30 μl) on IOP of conscious Tibetan monkeys. The drug was administered topically at 9 AM (Time 0) onto a randomly assigned eye of each animal, while the contralateral eye received vehicle as control. IOP was monitored at 3, 6, 24, and 48 h later. Error bars represent SEM (n=6). Top Panel: IOP values of both groups. ***p<0.001 between the two treatment groups by two-tailed paired Student's t-test. Bottom panel: % IOP change of the travoprost group relative to the vehicle control group.

Mentions: To determine the Tibetan monkey’s IOP responses to pharmacologically active compounds, travoprost (0.004%; 30 µl) and timolol (0.5%; 30 µl), both of which are widely used ocular hypotensive drugs approved for human use, were tested in these animals. Topical ocular administration of either travoprost or timolol reduced IOP in conscious Tibetan monkeys. After drug treatment, travoprost reduced IOP by 17.2% (5.2 mmHg; p<0.001) from the vehicle group at 3 h, by 20.4% (5.0 mmHg; p<0.001) at 6 h, and by 20.0% (4.6 mmHg; p<0.001) at 24 h. No statistical difference was found between thses two group at 48 h, indicating that the IOP lowering effects of travaprost lasting less than 48 h (Figure 4). Timolol was also effective in lowering IOP in these monkeys, though much less efficacious and shorter acting than travoprost. Compared to the vehicle-treated group, timolol reduced IOP by 8.7% (2.8 mmHg; p<0.05) at 3 h after drug administration. At 6 h and 24 h, no significant IOP effect was observed (Figure 5).


Characterization of intraocular pressure responses of the Tibetan monkey (Macaca thibetana).

Liu G, Zeng T, Yu W, Yan N, Wang H, Cai SP, Pang IH, Liu X - Mol. Vis. (2011)

Effect of travoprost (0.004%, 30 μl) on IOP of conscious Tibetan monkeys. The drug was administered topically at 9 AM (Time 0) onto a randomly assigned eye of each animal, while the contralateral eye received vehicle as control. IOP was monitored at 3, 6, 24, and 48 h later. Error bars represent SEM (n=6). Top Panel: IOP values of both groups. ***p<0.001 between the two treatment groups by two-tailed paired Student's t-test. Bottom panel: % IOP change of the travoprost group relative to the vehicle control group.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3108893&req=5

f4: Effect of travoprost (0.004%, 30 μl) on IOP of conscious Tibetan monkeys. The drug was administered topically at 9 AM (Time 0) onto a randomly assigned eye of each animal, while the contralateral eye received vehicle as control. IOP was monitored at 3, 6, 24, and 48 h later. Error bars represent SEM (n=6). Top Panel: IOP values of both groups. ***p<0.001 between the two treatment groups by two-tailed paired Student's t-test. Bottom panel: % IOP change of the travoprost group relative to the vehicle control group.
Mentions: To determine the Tibetan monkey’s IOP responses to pharmacologically active compounds, travoprost (0.004%; 30 µl) and timolol (0.5%; 30 µl), both of which are widely used ocular hypotensive drugs approved for human use, were tested in these animals. Topical ocular administration of either travoprost or timolol reduced IOP in conscious Tibetan monkeys. After drug treatment, travoprost reduced IOP by 17.2% (5.2 mmHg; p<0.001) from the vehicle group at 3 h, by 20.4% (5.0 mmHg; p<0.001) at 6 h, and by 20.0% (4.6 mmHg; p<0.001) at 24 h. No statistical difference was found between thses two group at 48 h, indicating that the IOP lowering effects of travaprost lasting less than 48 h (Figure 4). Timolol was also effective in lowering IOP in these monkeys, though much less efficacious and shorter acting than travoprost. Compared to the vehicle-treated group, timolol reduced IOP by 8.7% (2.8 mmHg; p<0.05) at 3 h after drug administration. At 6 h and 24 h, no significant IOP effect was observed (Figure 5).

Bottom Line: Three hours after topical ocular administration, travoprost reduced IOP by 5.2±0.6 mmHg (n=6, p<0.001), and timolol reduced IOP by 2.8±0.7 mmHg (p<0.05).The circadian IOP fluctuation in conscious Tibetan monkeys and their responses to travoprost, timolol, and other experimental conditions are similar to other primates.These monkeys appear to be a suitable model for glaucoma research.

View Article: PubMed Central - PubMed

Affiliation: Ophthalmic Laboratories & Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan, PR China.

ABSTRACT

Purpose: To characterize the effects of circadian rhythm, feeding time, age, general anesthesia, and ocular hypotensive compounds on intraocular pressure (IOP) of the Tibetan monkey (Macaca thibetana).

Methods: Tibetan monkeys were trained for IOP measurement with the TonoVet® rebound tonometer without sedation or anesthesia. Their circadian IOP fluctuation was monitored every 3 h. Effects of changing the feeding time, general anesthesia, age (2-3 year-old versus 8-15 year-old animals), and various pharmacological agents, such as travoprost, timolol, naphazoline and spiradoline, on IOP were also evaluated.

Results: After behavioral training, conscious Tibetan monkeys were receptive to IOP measurement. The lowest and highest IOP values in a circadian cycle were recorded at 3:00 AM (19.8±0.4 mmHg, mean±SEM, n=12) and noon (29.3±0.9 mmHg), respectively. Changing the feeding time from 11:30 AM to 12:30 PM lowered the noon IOP to 25.1±1.2 mmHg. General anesthesia lowered IOP in these monkeys, while IOP of young and mature animals were similar. Three hours after topical ocular administration, travoprost reduced IOP by 5.2±0.6 mmHg (n=6, p<0.001), and timolol reduced IOP by 2.8±0.7 mmHg (p<0.05). Naphazoline and spiradoline lowered IOP by 4.8 mmHg and 2.5 mmHg (both p<0.001), respectively, 2 h after drug administration.

Conclusions: The circadian IOP fluctuation in conscious Tibetan monkeys and their responses to travoprost, timolol, and other experimental conditions are similar to other primates. These monkeys appear to be a suitable model for glaucoma research.

Show MeSH
Related in: MedlinePlus