자연발증 고혈압쥐에서 Atenolol이 대동맥 미세구조변화에 미치는 영향 = Influence of Atenolol on Microscopic Structural Changes of Aorta in Spontaneously Hypertensive Rats

다국어 초록 (Multilingual Abstract)

Hypertension has been known as a major risk factor for atherosclerosis, left ventricular hypertrophy, sudden death and other cardiovascular diseases. Hypertension-induced vascular changes are thought to be adaptive to the increased stress. Adaptation in the media includes incresed synthesis of the major connective tissue components, elastin and collagen, hypertrophy and hyperplasia of smooth muscle cells (SMC), which are due to wall thickening and increase in arterial cell mass. The present electronmicroscopic study was performed in normal Wistar-Kyoto rats(WKR), nontreated spontaneously hypertensive rats(SHR) and atenolol-treated SHR (2.5 ㎎/Kg/day) to define and compare the morphologic changes of aorta induced by hypertension as well as the restoration on its wall in normal WKR, SHR & atenolol treated SHR. Pretreatment with atenolol for 22 weeks thickness of media of the SHR aorta caused by hypertension was decreased and space between prominent elastic laminae was narrowed as compared to the control SHR. Irregularly arranged collagenous fibers among the abundant SMC in control SHR aorta are regularly distributed as shown in control WKR or atenolo-pretreated SHR. Cross bands of collagen fibrils are partly apparrent in atenolol-treated SHR. While were not clear and some fragemented in the media of the control SHR aorta. Ultrastructural study also revealed that nucleus with double membrane was well-developed, heterochromatin along with normally distributed, enchromatin and that various-sized vacuoles disappeared follow ing improvement of hypertension by chronic pretreatment with atenolol.
According to the from these experimental results, it is thought that atenolol a beta-adrenergic antagonist may improve vascular changes inducde by hypertension. Euchromatin are normally distributed and various-sized vacuoles disappeared following reversal of hypertension. From these experimental results, it is thought that atenolol, one of the beta-adrenergic blockades may improve vascular changes induced by hypertension.