Altered Dilator Responses to Heptanol andOctanol in Aorta from Renal Hypertensive Rats

다국어 초록 (Multilingual Abstract)

Background : Cells rely on gap junctions for intercellular communication, which is important for growth and contractility. The present study was conducted to test the hypothesis that contractile responses in aortic rings from two-kidney, one clip (2K1C) hypertensive rats are more dependent on gap junctional communication compared to those from normotensive rats.
Methods : 2K1C hypertension was induced by clipping the left renal artery and age-matched rats received a sham operation. Heptanol and octanol were used as inhibitors of gap junctional activity.
Results : The contraction induced by phenylephrine or KCl was completely reversed by either heptanol or octanol, and the relaxant response to inhibitors was more enhanced in 2K1C hypertensive rats compared to sham-operated rats. Vessels from hypertensive rats also relaxed more to nifedipine when precontracted with KCl, although it did not differ in aortic segments contracted with phenylephrine in between normotensive and hypertensive rats.
Conclusion : These results suggest that gap junctional communication and voltage-operated calcium channels are differentially regulated in 2K1C renal hypertension.

국문 초록 (Abstract)

배 경 : 세포막과 세포막 사이의 특수한 연결조직인 간극결합 gap junction의 활성이 혈관 평활근 수축에도 관여함이 알려져 있다. 이 연구는 신성고혈압 상태의 혈관수축에 있어 간극결합의 역할이 차이가 있는지 규명하고자 시행하였다.
방 법 : 체중 160-180 g 흰쥐 (Sprague-Dawley, ♂)의 일측 신동맥에 clip (직경 0.2 mm)을 장치하고 6 주 동안 사육하여 2-kidney, 1 clip (2K1C) 고혈압을 유발시켰다. 실험 당일 흉부 대동맥을 채취하여 등장성 장력변화를 생리기록기에 기록하였다.
결 과 : 적출 흉부 대동맥 표본에서 phenylephrine과 KCl에 의한 수축반응은 간극결합 활성 억제제인 heptanol과 octanol에 의해 완전히 이완되었다. Heptanol과 octanol 에 의한 이완반응은 2K1C 고혈압군에서 대조군에 비해 항진되었다. KCl로 수축시킨 후 nifedipine에 의한 이완반응은 고혈압군에서 대조군보다 더 강화되었으나 phenylephrine의 수축에는 양군에서 차이가 없었다.

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