The effect of sodium iothalamate on the vascular resistance of the isolated perfused rat kidney.
The direct effects of sodium iothalamate on renal vascular resistance (RVR) were examined using the isolated perfused rat kidney experimental model. A concentration-dependent biphasic change in RVR was produced with the hyperosmolar solution of sodium iothalamate [(Conray 420), 420 mgI/ml, 2500 mOsmol/kg/H2O]. The response characterized by an initial fall followed by a prolonged increase in RVR on discontinuation of the iothalamate infusion. No significant change in RVR was observed when iothalamate was infused as an iso-osmotic solution (60 mgI/ml, 280 mOsmol/kg/H2O) at a rate of 0.525 ml/min. to produce a concentration of 4.2 mgI/ml in the renal perfusate. We conclude that sodium iothalamate can exert direct biphasic effects on RVR which are mediated by its hyperosmolality rather than its chemical content.
Haylor
J L
JL
Department of Pharmacology and Therapeutics, Royal Hallamshire Hospital, Sheffield.
el Sayed
A A
AA
el Nahas
A M
AM
Morcos
S K
SK
D000818:Animals; D066298:In Vitro Techniques; D007483:Iothalamic Acid / Q000494:pharmacology*; D007668:Kidney / Q000098:blood supply* / Q000187:drug effects; D008297:Male; D009994:Osmolar Concentration; D010477:Perfusion; D051381:Rats; D011919:Rats, Inbred Strains; D014655:Vascular Resistance / Q000187:drug effects*
D007483:Iothalamic Acid