衰老对兔虹膜平滑肌对激动剂和场刺激反应的影响。

Effects of ageing on responses of rabbit iris smooth muscles to agonists and field stimulation.

Takayanagi I, Shiraishi K, Satoh M

Department of Chemical Pharmacology, Toho University School of Pharmaceutical Sciences, Chiba, Japan.

Gen Pharmacol. 1992 May;23(3):463-9. doi: 10.1016/0306-3623(92)90112-w.

Abstract

The pharmacological properties of contractile responses of sphincter and dilator to field stimulation did not change with age, so that innervation of both these muscles does not change apparently with age. 2. In the sphincter, no age-related change was observed in muscarinic cholinoceptor mechanisms. Tension induced by field stimulation increased with age from 5 to 13 weeks, decreased from 40 to 125 weeks and did not change thereafter. Age-related change in tension is due to change in the amount of acetylcholine released by stimulation. 3. In the dilator, the pD2 value of norepinephrine increased with age from 5 to 13 weeks, decreased from 13 to 125 weeks and did not change thereafter. The pD2 value of norepinephrine was proportional to the receptor reserve, suggesting that changes in alpha 1-adrenoceptor mechanisms are due to changes in receptor reserve. No age-related change was observed in affinity of alpha 1-adrenoceptors. 4. The tension of the dilator induced by field stimulation increased with age from 5 to 13 weeks did not change from 13 to 180 weeks. The age-related change in tension is due to change in the amount of norepinephrine released by stimulation.

摘要

括约肌和扩张肌对场刺激的收缩反应的药理学特性不会随年龄而改变，因此这两块肌肉的神经支配显然不会随年龄而变化。2. 在括约肌中，毒蕈碱型胆碱能受体机制未观察到与年龄相关的变化。场刺激诱导的张力在5至13周龄时随年龄增加，在40至125周龄时降低，此后无变化。张力的年龄相关变化是由于刺激释放的乙酰胆碱量的变化。3. 在扩张肌中，去甲肾上腺素的pD2值在5至13周龄时随年龄增加，在13至125周龄时降低，此后无变化。去甲肾上腺素的pD2值与受体储备成正比，表明α1-肾上腺素能受体机制的变化是由于受体储备的变化。未观察到α1-肾上腺素能受体亲和力与年龄相关的变化。4. 场刺激诱导的扩张肌张力在5至13周龄时随年龄增加，在13至180周龄时无变化。张力的年龄相关变化是由于刺激释放的去甲肾上腺素量的变化。