Renal arteriovenous shunting in rejecting allograft, hydronephrosis, or haemorrhagic hypotension in the rat.
We studied the occurrence of arteriovenous (A-V) shunting in three experimental rat models, namely in rejecting allograft kidney, in uni- or bilateral ureteral obstruction, and in haemorrhagic hypotension. Isografted or sham-operated rats served as controls. Radiolabelled microspheres were injected into the renal artery and the increase in the amount of radioactivity in the lungs was considered to reflect A-V shunting in the kidney. In animals exposed to haemorrhage, with a blood pressure not less than 70% of the initial blood pressure, practically no shunting was seen. When animals were bled to a hypotension beyond the autoregulation, A-V shunting occurred inversely correlated to the degree of hypotension. In ureteral obstruction, a less marked but significant increase in shunting of microspheres to the lungs was found after 24 h of unilateral obstruction, irrespective of whether the spheres were injected into the obstructed or the contralateral kidney. Significant A-V shunting during the allograft rejection process was also demonstrated. Histologically, microspheres were found in afferent arterioles less frequently in kidneys with A-V shunting than in controls. These results indicate that A-V shunting is involved in haemorrhagic hypotension, renal graft rejection, and hydronephrosis. In the latter situation A-V shunting is probably regulated by a humoral factor.
Nilsson
L
L
Department of Medicine, Lund University, Malmö General Hospital, Sweden.
Ekberg
H
H
Fält
K
K
Löfberg
H
H
Sterner
G
G
D000818:Animals; D001163:Arteriovenous Anastomosis / Q000503:physiopathology*; D005260:Female; D006084:Graft Rejection / Q000276:immunology / Q000503:physiopathology*; D006869:Hydronephrosis / Q000150:complications / Q000503:physiopathology*; D007022:Hypotension / Q000150:complications / Q000503:physiopathology; D007668:Kidney / Q000098:blood supply*; D016030:Kidney Transplantation / Q000276:immunology; D008297:Male; D051381:Rats; D011914:Rats, Inbred BN; D011920:Rats, Inbred WF; D012079:Renal Circulation / Q000502:physiology; D012771:Shock, Hemorrhagic / Q000150:complications / Q000503:physiopathology*; D014184:Transplantation, Homologous