Inference of the existence of high blood pressure as a cause of renal disease in the mid-19th century: Observations on vascular structures in the kidney

Histological examination of the kidney was well under way by the mid-19th c entury. Pathological changes noted to be present in Bright's disease gave r ise to considerable debate in the literature of the time. Toynbee was perha ps the first to note medial hypertrophy and intimal narrowing of blood vess els in the kidney, while Johnson, around the same time, thought that kidney disease was the cause of compressed vessels. Although he later proposed a causal relationship between contraction of vessels a nd hypertrophy, Johnso n never went beyond the insights articulated by Bright himself and failed t o make the link between hypertrophy of vessels and persistently raised bloo d pressure. Traube considered the possibility that cardiac and renal diseas e could be the consequences of the same unknown disease, but rejected hyper trophy per se as a causal factor. Gull and Sutton disagreed strongly with J ohnson and proposed the presence of a general disease which leads to both c ardiac hypertrophy and renal disease. But it was Ewald, writing in Germany, who was able to ascribe both cardiac and vascular hypertrophy to increasin g tension in the arterial system and he was the first to articulate the eff ect of hypertension on the kidney.