대한약리학회지 (The Korean Journal of Pharmacology)
- 제31권3호
- /
- Pages.285-290
- /
- 1995
- /
- 0377-9459(pISSN)
돼지 관상동맥 및 흰쥐 흉부대동맥에서 자외선 및 가시광선 조사시 파장에 따른 기계적 반응과 Cyclic GMP의 농도변화
Biphasic Mechanical Responses of Rat Thoracic Aorta to Irradiation with $250{\sim}500\;nm$ Light
- 국현 (전남대학교 의과대학 약리학교실)
- Kook, Hyun (Department of Pharmacology, Chonnam University Medical School)
- 발행 : 1995.12.30
초록
이 실험은 여러 파장
This study was undertaken to define the varying responses of vascular smooth muscle to different wavelengths of ultraviolet radiation and to relate them to the changes in cyclic GMP contents. The ring preparations of rat thoracic aorta with intact or removed endothelium were irradiated with the ultraviolet or visible light (UVR) of wavelengths in step of 10 nm between 250 and 500 nm from xenon lamp of a spectrofluorometer, and the changes in vascular tension were recorded. For cyclic GMP assay, the preparations, pretreated with phenylephrine as in the tension experinents, were frozen after irradiation and homogenated in trichloroacetic acid. The supernatant was extracted with ether and the cyclic GMP contents were measured with radioimmunoassay. In the endothelium-intact preparations, biphasic responses, vasoconstriction (UVR-contraction) followed by vasodilatation (UVR-dilatation), were observed. The maximal UVR-contraction was observed at 320 nm, while the maximal vasodilatation was elicited at 420 nm. In the endothelium-removed rings, however, only vasodilatation was observed, with the maximal vasodilatation taking place at 370 nm. The cyclic GMP contents were not affected by the Irradiation with 320 nm for 30 sec or 1 min in the endothelium-intact preparations, while it was significantly increased by 380 and 420 nm. In the endothelium-removed preparations, UVR of 370 nm markedly increased the cyclic GMP contents. The present study indicates that the increase in cyclic GMP is closely related to vasodilatation induced by UVR of 420 nm in the endothelium-intact or 370 nm in the denuded preparations, whereas it is not involved in the vasoconstriction induced by UVR of 320 nm in the intact rings, and the mechanism leading to UVR-contraction remains to be clarified. These observations suggest that nitric oxide-cyclic GMP system is closely related to the UVR-dilatation in rat aortic preparation, while it is not involved in the UVR contraction.