Renal hemodynamics and arterial pressure during chronic intrarenal adenosine infusion in conscious dogs.

The major aim of this study was to examine the chronic effects of increased intrarenal adenosine (ADO) levels on control of renal hemodynamics and mean arterial pressure (MAP). In six uninephrectomized conscious dogs, intrarenal ADO infusion (2 micrograms . kg-1 . min-1) for 6 days caused no significant changes in MAP, which averaged 94 +/- 3 mmHg during the control period and 91 +/- 2 mmHg during ADO infusion. ADO infusion for 6 days decreased glomerular filtration rate (GFR) and filtration fraction while causing no significant changes in effective renal plasma flow (ERPF) or sodium and water balance. To examine the role of angiotensin II (ANG II) in altering the blood pressure and renal effects of ADO, we also studied the effects of intrarenal ADO infusion in five uninephrectomized conscious dogs during continuous intrarenal infusion of ANG II (1 ng . kg-1 . min-1) to prevent renal levels of ANG II from decreasing. However, even when renal ANG II levels were maintained constant, ADO infusion at 2 micrograms . kg-1 . min-1 for 4 days and 10 micrograms . kg-1 . min-1 for 5 days failed to alter MAP, which averaged 104 +/- 6 mmHg during the control period, 106 +/- 5 mmHg during infusion of 2 micrograms . kg-1 . min-1, and 105 +/- 5 mmHg during infusion of 10 micrograms. . kg-1 . min-1 ADO. Intrarenal ANG II infusion did not prevent decreases in GFR and filtration fraction during ADO infusion.(ABSTRACT TRUNCATED AT 250 WORDS)