Dopamine increases renal medullary blood flow without improving regional hypoxia.
The effects of dopamine (10 micrograms/kg/min i.v.) upon intrarenal microcirculation, total, superficial cortical and outer medullary blood flows and outer medullary pO2 were continuously determined in anesthetized rats with ultrasonic and laser-Doppler probes and oxygen microelectrodes. While total and cortical flows were unaffected, outer medullary flow increased by 35 +/- 5% (mean +/- SE, p < 0.01). Outer medullary pO2 was not significantly altered (from 16 +/- 4 to 18 +/- 4 mm Hg). In volume-expanded rats total and cortical flows rose as well. In rats pretreated with indomethacin, with or without N omega-nitro-L-arginine methyl ester HCl, dopamine restored renal microcirculation and ameliorated outer medullary hypoxia.
Department of Medicine, Hadassah University Hospital, Mount Scopus, Jerusalem, Israel.
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Heyman
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N
Kaminski
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M
Brezis
D000818:Animals; D001783:Blood Flow Velocity; D004298:Dopamine / Q000494:pharmacology*; D007213:Indomethacin / Q000494:pharmacology; D007679:Kidney Medulla / Q000098:blood supply* / Q000737:chemistry; D008839:Microelectrodes; D010100:Oxygen / Q000032:analysis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014655:Vascular Resistance / Q000187:drug effects
D010100:Oxygen; D004298:Dopamine; D007213:Indomethacin