肥胖抑制素/胃饥饿素系统作为虹膜肌肉收缩的一种新型调节机制。

The obestatin/ghrelin system as a novel regulatory mechanism of iris muscle contraction.

作者信息

Rocha-Sousa A, Falcão-Reis F, Leite-Moreira A F

机构信息

Laboratory of Physiology, Faculty of Medicine, University of Porto, Portugal.

出版信息

Curr Eye Res. 2008 Jan;33(1):73-9. doi: 10.1080/02713680701791058.

DOI:10.1080/02713680701791058

PMID:18214744

Abstract

PURPOSE

To evaluate obestatin and ghrelin effects on iris muscle contraction.

MATERIALS AND METHODS

Obestatin (10(-5) M) or ghrelin (10(-5) M) were tested on two consecutive carbachol-or epinephrine-elicited contractions of iris rabbit sphincter or dilator muscles. Ghrelin and obestatin effects on iris muscles basal tension were also tested, and their effects on iris sphincter EFS-elicited contraction were evaluated.

RESULTS

Compared with the first, tension of the second carbachol-induced contraction of the iris sphincter decreased 11.5+/-5.5% in the vehicle group, increased 19.0+/-10.2% in presence of obestatin, and remained unchanged by ghrelin. Epinephrine-induced contractions were not affected by obestatin or ghrelin. EFS-elicited contractions were decreased 9.3+/-3.2% by ghrelin. Basal tension of the iris sphincter decreased 21.7+/-3.7% in presence of ghrelin (10(-5) M), while that of the dilator decreased 14.1+/-5.0% in presence of obestatin (10(-5) M).

CONCLUSION

This study suggests that obestatin potentiates the cholinergic contraction of the iris sphincter and relaxes the iris dilator muscles.

摘要

目的

评估胃饥饿素和肥胖抑制素对虹膜肌肉收缩的影响。

材料与方法

分别用胃饥饿素（10⁻⁵ M）或肥胖抑制素（10⁻⁵ M）对兔虹膜括约肌或开大肌由卡巴胆碱或肾上腺素引发的连续两次收缩进行测试。还测试了胃饥饿素和肥胖抑制素对虹膜肌肉基础张力的影响，并评估了它们对虹膜括约肌电场刺激（EFS）引发收缩的影响。

结果

与第一次相比，在对照组中，虹膜括约肌由卡巴胆碱诱导的第二次收缩张力降低了11.5±5.5%，在存在肥胖抑制素的情况下增加了19.0±10.2%，而胃饥饿素使其保持不变。肾上腺素诱导的收缩不受肥胖抑制素或胃饥饿素的影响。胃饥饿素使EFS引发的收缩降低了9.3±3.2%。在存在胃饥饿素（10⁻⁵ M）的情况下，虹膜括约肌的基础张力降低了21.7±3.7%，而在存在肥胖抑制素（10⁻⁵ M）的情况下，虹膜开大肌的基础张力降低了14.1±5.0%。