<基礎的研究発生病理>M-SHRSPの網膜細動脈狭細・口径不同所見の器質的変化 <Fundamental researches Pathogenesis>Organic changes of narrowing and irregularity in caliber of retinal arterioles in malignant or precocious stroke-prone spontaneously hypertensive rat (M-SHRSP)

Stroke-prone spontaneously hypertensive rats of M-strain (M-SHRSP) showed severe hypertension with an abrupt rise in blood pressure. Changes in retinal arterioles such as arteriolar narrowing or caliber irregularity were studied by electron microscopy. In the preparations of serial sections of M-SHRSP of more than 15 weeks of age, irreversible angiosclerotic changes in retinal arterioles were observed and they were recognized as caliber irreguality or narrowing in fundus color photographs. Electron microscopy showed that, through histological rupture of internal elastic lamina of the retinal arteriole, smooth muscle cells invaded underneath the endothelium of the arteriolar wall where intraluminal stenosis of the retinal arteriole was suspected on color fundus photographs. Severe hypertension seems to induce irreversible angiosclerotic changes in the retinal arterioles which are observed as narrowing or irregurality of retinal arterioles in the fundus of M-SHRSP of the late stage.