외부에서 투여된 열자극, 알콜 및 생리적 염과 같은 환경 스트레스는 체내 각 부위에서 스트레스단백질(열자극단백질, HSP)을 생성하게 된다. 본 연구에서는 비소가 흰쥐 대동맥의 수축에 미치는 영향을 조사하기 위해 스트레스단백질의 발현과 대동맥의 수축력의 변화와 이들과의 관계를 알아보고자 실험을 실시하였다 적출한 혈관은 organ bath에 담가 0, 0.5, 1, 2,및 4 mM As를 처리한 후 1, 3, 및 8시간 뒤에 KCI(55 mM)에 대한 수
To examine whether salt stress would alter or not contractility of isolated rat aorta, under anesthesia with sodium pentobarbital(50 mg Kg-1 i.p.), male Sprague Dawley rats(300-330 g) were subjected to 0, 50, and 150 mM of sodium chloride at 37℃ for 60 min. where as the sham group was left at modified Krebs-bicarbonate solution.
To measure contractile response of vascular ring preparation isolated from rat was determined in organ bath and was recorded on physiograph connected to isometric transducer. And the strip was checked for expression of heat shock protein(Hsp) by Western blotting. One, three and eight hours later, we measured vascular contractility of isolated rat aorta treated with KCl, phenylephrine from organ bath study.
The dose-vascular responses of potassium chloride and phenylephrine showed a little augmentation by NaCl concentration in the strips exposed to NaCl for 8 hours. And the response of relaxation induced by nitroprusside and acetylcholine was not influenced by NaCl stress in isolated aorta ring for 8 hours, respectively.
Expression pattern of Hsp 70 of vascular muscle in isolated rat aorta showed a little increase in 150 mM NaCl group at 8 hours after NaCl treatment but not at 3 hours, and Hsp 60 expression of rat aorta was markedly increased in 50 mM NaCl group at 8 hours after NaCl treatment.
Taken together, NaCl induced dose- and time dependent accumulation of the Hsp but not affected contraction of rat aorta. These data suggest that short term high salt stress was not sufficient to induce hypertension of rat aorta..
In order to examine if arsenic, one of environmental stresses, contributes to hypertension as one of cardiovascular pathological factors, this study was performed in vivo and in vitro, using intacted or pithed rats and aorta ring preparation, respectively. And also the relationship between expression of heat shock protein (HSP) 90 and vasoactives-induced contractile response was elucidated.
To measure blood pressure, the carotid arterial pressure was recorded on physiograph(Grass Co. 79E) connected to strain gauge. On the other hand, contractile response of vascular ring preparation isolated from rat was determined in organ bath and was recorded on physiograph connected to isometric transducer. And HSP was detacted by Western blotting whole cell lysis.
Preganglionic nerve stimulation was increased by 26.0% in arterial pressure of rat treated with arsenic.
Vascular contractile response was monitored and HSP were measured by Western blotting of whole lysis prepared from samples exposed with 0, 0.5, 1, 2 and 4 mM of arsenic for 8 hours. The dose-vascular responses of potassium chloride were augmented by increasing dose of arsenic in the strips exposed to arsenic for 8 hours, and were not augmented for 1, 3, 5 hours. And the response of relaxation of rat aorta induced by histamine was not influenced by arsenic stress.
The increase of HSP 90 expression in rat aorta was pronounced at 8 hours after 4 mM of arsenic treatment, but HSP 60 expression was not.
Arsenic stress not only increased the expression of HSP 90 in the rat aorta, but also augmented contractions to potassium chloride.
These results indicated that arsenic stress was sufficient to induce heat shock protein 90, resulting in increased vascular contractility in rat aorta.