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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 naphazoline (0.3%, 30 µl) on IOP of conscious Tibetan monkeys. The drug was administered topically at 10 AM (Time 0) onto a randomly assigned eye of each animal, while the contralateral eye received vehicle as control Error bars represent SEM (n=6). Top Panel: IOP values of both groups. *p<0.05, ***p<0.001 between the two treatment groups by two-tailed paired Student's t-test. Bottom panel: % IOP change of the naphazoline group relative to the vehicle control group.
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f6: Effect of naphazoline (0.3%, 30 µl) on IOP of conscious Tibetan monkeys. The drug was administered topically at 10 AM (Time 0) onto a randomly assigned eye of each animal, while the contralateral eye received vehicle as control Error bars represent SEM (n=6). Top Panel: IOP values of both groups. *p<0.05, ***p<0.001 between the two treatment groups by two-tailed paired Student's t-test. Bottom panel: % IOP change of the naphazoline group relative to the vehicle control group.

Mentions: Recently, compounds that increase aqueous concentrations of natriuretic peptides, such as naphazoline, an adrenergic α2 and imidazoline I1 receptor agonist, and spiradoline, a kappa opioid receptor agonist, were shown to reduce IOP in the rabbit [19,20]. We also evaluated them in the Tibetan monkeys. Both compounds significantly lowered monkey IOP, although naphazoline was clearly more efficacious. Topical ocular administration of naphazoline (100 μg; 0.33%, 30 µl) reduced monkey IOP maximally by 17.4% (4.8 mmHg; p<0.001) at 2 h after treatment. When compared to the contralateral vehicle-treated eye, a statistical significant IOP lowering lasted for at least 5 h (Figure 6). Spiradoline (100 µg; 0.33%, 30 µl) induced a maximum IOP reduction of 8.7% (2.5 mmHg; p<0.001) 2 h after drug administration (Figure 7).


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 naphazoline (0.3%, 30 µl) on IOP of conscious Tibetan monkeys. The drug was administered topically at 10 AM (Time 0) onto a randomly assigned eye of each animal, while the contralateral eye received vehicle as control Error bars represent SEM (n=6). Top Panel: IOP values of both groups. *p<0.05, ***p<0.001 between the two treatment groups by two-tailed paired Student's t-test. Bottom panel: % IOP change of the naphazoline 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

f6: Effect of naphazoline (0.3%, 30 µl) on IOP of conscious Tibetan monkeys. The drug was administered topically at 10 AM (Time 0) onto a randomly assigned eye of each animal, while the contralateral eye received vehicle as control Error bars represent SEM (n=6). Top Panel: IOP values of both groups. *p<0.05, ***p<0.001 between the two treatment groups by two-tailed paired Student's t-test. Bottom panel: % IOP change of the naphazoline group relative to the vehicle control group.
Mentions: Recently, compounds that increase aqueous concentrations of natriuretic peptides, such as naphazoline, an adrenergic α2 and imidazoline I1 receptor agonist, and spiradoline, a kappa opioid receptor agonist, were shown to reduce IOP in the rabbit [19,20]. We also evaluated them in the Tibetan monkeys. Both compounds significantly lowered monkey IOP, although naphazoline was clearly more efficacious. Topical ocular administration of naphazoline (100 μg; 0.33%, 30 µl) reduced monkey IOP maximally by 17.4% (4.8 mmHg; p<0.001) at 2 h after treatment. When compared to the contralateral vehicle-treated eye, a statistical significant IOP lowering lasted for at least 5 h (Figure 6). Spiradoline (100 µg; 0.33%, 30 µl) induced a maximum IOP reduction of 8.7% (2.5 mmHg; p<0.001) 2 h after drug administration (Figure 7).

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