Role of thromboxane in mediating the intrarenal vasoconstriction induced by unmodified stroma free hemoglobin in the isolated perfused rat kidney.
Unmodified stroma free hemoglobin (SFH) increased renal vascular resistance (RVR) from 4.0 +/- 0.2 to 6.9 +/- 0.9 mmHg/ml/min in control isolated kidneys. In kidneys obtained from rats pretreated with the thromboxane synthetase inhibitor OKY-046 RVR increased from 3.9 +/- 0.3 to 4.8 +/- 0.4 mmHg/ml/min. The percent increase in RVR was greater in response to SFH in control kidneys (67 +/- 14%) than in OKY-046 treated kidneys (23 +/- 7%)(p less than 0.05). SFH resulted in a fall in glomerular filtration rate (GFR) from 0.75 +/- 0.09 to 0.21 +/- 0.04 ml/min in control kidneys while in kidneys from OKY-046 treated rats GFR fell from 0.65 +/- 0.04 to 0.54 +/- 0.06 ml/min. The percent fall in GFR was greater in vehicle treated kidneys (69 +/- 8%) as opposed to OKY-046 treated kidneys (19 +/- 7%)(p less than 0.05). The rate of urinary thromboxane excretion measured before the addition of SFH to the perfusate was 52 pg/min in the control group and 7 pg/min in the OKY-046 treated group(p less than 0.05).
Lieberthal
W
W
Evans Memorial Department of Clinical Research, University Hospital, Boston, MA.
LaRaia
J
J
Valeri
C R
CR
D000818:Animals; D001802:Blood Substitutes / Q000633:toxicity*; D005919:Glomerular Filtration Rate / Q000187:drug effects; D006454:Hemoglobins / Q000633:toxicity*; D066298:In Vitro Techniques; D008297:Male; D010477:Perfusion; D051381:Rats; D017207:Rats, Sprague-Dawley; D012079:Renal Circulation / Q000187:drug effects* / Q000502:physiology; D013931:Thromboxanes / Q000502:physiology*; D014655:Vascular Resistance / Q000187:drug effects; D014661:Vasoconstriction / Q000187:drug effects
D001802:Blood Substitutes; D006454:Hemoglobins; D013931:Thromboxanes; C016484:hemoglobin, stroma free