Thomas Sherwood

Intravenous Urography in Experimental Acute Renal Failure in the Rat

Intravenous urography using large doses of diatrizoate has been carried out in rats suffering from acute renal failure states induced either by temporary renal ischaemia or by intraperitoneal injection of mercuric chloride. All the animals were azotaemic, all had some degree of histological tubular necrosis but urine output ranged from anuria to marked polyuria. A dense nephrogram was always obtained even in animals with complete anuria. It is concluded that considerable glomerular filtration probably occurs in acute renal failure whatever the urine output.

Mercury-induced renal vascular shut-down: observations in experimental acute renal failure.

Abstract. Mercuric chloride introduced into the systemic circulation or directly into the renal artery in dogs leads to an immediate and lasting fall in renal blood flow. On arteriography severe cortical ischaemia is seen. These findings were studied in 32 animals. Renal vascular shut‐down induced by mercuric chloride appears concentration dependent, and is not mediated by glomerular filtration. It is possible to protect the kidney from shut‐down by an infusion of hyperosmolar mannitol given before mercuric chloride. This suggests that the ‘no‐reflow phenomenon’, already documented in the ischaemic kidney and brain, has a counterpart in mercury induced acute renal failure. Endothelial cell swelling may be an important primary vascular disorder underlying many acute renal failure states.

Preservation of Normal Cortical Vasculature in Ischaemic Renal Failure in the Dog

Ischaemic renal failure in the dog was studied by clamping one renal artery for 2 hr in 18 animals. Total renal blood flow was measured for 3 hr after this and only reduced by about 30%. Fine detail renal angiography showed a normal cortical perfusion pattern. Urine flow rates and creatinine clearances from these kidneys, however, were found to be grossly impaired over this period. Seven days later the angiogram of the oliguric kidney remained normal. Two-hour unilateral renal ischaemia in the dog leads to a form of acute renal failure with a striking disparity between glomerular perfusion and clearance, arguing agains a primary circulatory defect.

In vivo renal micro-angiography. An experimental technique to study renal cortical perfusion during haemorrhagic shock

Abstract An experimental technique of in vivo microangiography in dogs is described. This uses a fine focal spot tube (Siemens Biangulix 0·27 mm) and industrial film which is placed in contact with the kidney. The resulting angiograms allow ready visualisation of glomerular tufts. The technique has been used in a preliminary study of changes in renal cortical perfusion occurring in haemorrhagic shock. The angiograms show a progressive shut-down of glomerular perfusion roughly in parallel with perfusing pressure, renal blood flow and urine flow rate. These changes can be largely reversed by retransfusion.

Intravenous Urography in Experimental Acute Renal Failure

We studied renal opacification during intravenous urography in 20 rats subjected to glycerol-induced acute renal failure, with and without prior saline loading. Animals drinking saline suffered less s

Renal Medulla Perfusion

The left kidney of dogs anaesthetised with intravenous pentobarbitone was explanted to the flank, in close contact with a hand film changer loaded with industrial X-ray film. Renal angiography using Thorotrast was performed before and during bleeding to an aortic pressure of 60 mm Hg. The kidneys of normal and hypotensive animals were also clamped after Thorotrast injection, fixed, and sectioned to obtain detailed radiographs of the renal circulation arrested at various stages. Patterns of normal cortical and medullary perfusion were studied, with angiographic demonstration of at least three rates of renal blood flow, and double filling of the renal veins. In haemorrhagic hypotension, there was marked slowing of the medullary circulation, which continued in the presence of severe cortical ischaemia. The anatomical boundaries of renal perfusion compartments can be precisely delineated by these methods.