A Study on Renal Arteriosclerosis in the Aged by the Percutaneous Renal Biopsy

It is the purpose of this paper to present the result of the renal arteriosclerosis in the aged. Special references have been made on interrelation between the arterial measurement of renal biopsy materials and age, blood pressure, minimal pressure of central retinal artery and groups of several diseases. Methods. Eleven cases of coronary sclerosis, nine cases of cerebrovascular sclerosis (group A and B, by classification of research group for arteriosclerosis in education ministry), twenty-three cases of essential hypertension (by WHO's criteria), fifteen cases of chronic glomerulonephritis, eleven cases of diabetes mellitus and eight aged patients without above mentioned disease as the control were studied by percutaneous renal biopsy. The areas of arterial branches of a given PAS stained kidney section were projected on the projection screen (Nicon) and measured directly by planimeter. Narrowing index of each vessel was calculated as quotient of area of arterial space by area of arterial wall. In this paper less than 0.5 of narrowing index represent definite narrowing of the vessel. The branches of renal artery were divided into two groups according to the diameter arterioles with the diameter below 50 microns, and small arteries with the diameter from 50 to 200 microns. Result. The narrowing indexes of arterioles were not correlated with the age. Those of small arteries were proportional to the age. In age group of from 40 to 49, from 50 to 59, from 60 to 69 and over 70, 80.6%, 81.6%, 83.6% and 91.8% of small arteries showed less than 0.5 of narrowing indexes respectively. There were no correlation finded between narrowing indexes of arterioles and systolic or diastolic blood pressure. In the systolic hypertensive group 90.5% and in the non hypertensive group 79.3% of small arteries showed less than 0.5 of narrowing index. In the diastolic hypertensive group 89.0% and in the non hypertensive group 74.5% of small arteries showed less than 0.5 of narrowing index. In the cases showing higher minimum pressure of central retinal artery the narrowing indexes of arterioles inclined to be less than 0.5. But no definite relation was found between minimum pressure of central retinal artery and narrowing index of small arteries.