Korean Circ J.  1996 Feb;26(1):78-87. 10.4070/kcj.1996.26.1.78.

Potentiating Effects of Bay K 8644 on the Relaxation Induced by Ultraviolet or Visible Light in Porcine Coronary Artery

• Kook H
• Baik YH
• Kang JC
• Chae SW

• KMID: 2093567
• DOI: http://doi.org/10.4070/kcj.1996.26.1.78

Abstract

BACKGROUND
This study was aimed at defining the varying responses of porcine coronary artery(PCA) to various wavelengths of ultraviolet irradiation, and at relating them to the changes in cyclic GMP contents.
METHODS
The ring preparations of PCA with intact or removed endothelium were irradiated with the ultraviolet or visible light of wavelengths(240-520mm) from xenon lamp of a spectrofluorometer, and the changes in vascular tension were recorder on polygraph. For cyclic GMP assay, rat thoracic aorta was frozen after irradiation and homogenated. The supernatant was extracted with water-saturated ether and the cyclic GMP contents were measured with radioimmunoassay.
RESULTS
Ultraviolet irradiation relaxed the preparations(UVR-relaxation) in resting state and those precontracted by prostaglandin F2alpha, the maximal relaxation occurring at 410nm, and the magnitude depending on the duration of irradiation. The UVR-relaxation was not affected by removing the endothelium, while it was markedly potentiated by pretreatment with Bay K 8644. The Bay K 8644-induced potentiation of UVR-relaxation was abolished by hemoglobin and slightly reduced by wrapping the rings with aluminum foil. Cyclic GMP contents in the increase was markedly potentiated by pretreatment with Bay K 8644.
CONCLUSION
The observations suggest that UVR-relaxation in procine coronary artery is caused by activating the nitric oxide-cyclic GMP system, which is most sensitively activated by UVR of 410nm and that its potentiation induced by Bay K 8644 may be related nitrous substance released from the agent upon UVR.

Keyword

Ultraviolet light; Porcine coronary artery; Vasodilatation; Bay K 8644

MeSH Terms

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester*
Aluminum
Animals
Aorta, Thoracic
Bays*
Coronary Vessels*
Cyclic GMP
Dinoprost
Endothelium
Ether
Light*
Passive Cutaneous Anaphylaxis
Radioimmunoassay
Rats
Relaxation*
Ultraviolet Rays
Vasodilation
Xenon
3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester
Aluminum
Cyclic GMP
Dinoprost
Ether
Xenon