title: The effect of sodium iothalamate on the vascular resistance of the isolated perfused rat kidney.
abstract: 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.
authors.affiliation: Department of Pharmacology and Therapeutics, Royal Hallamshire Hospital, Sheffield.
authors.forename: J L
authors.initials: JL
authors.lastname: Haylor
authors.forename: A A
authors.initials: AA
authors.lastname: el Sayed
authors.forename: A M
authors.initials: AM
authors.lastname: el Nahas
authors.forename: S K
authors.initials: SK
authors.lastname: Morcos
mesh_terms: 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*
chemical_list: D007483:Iothalamic Acid