title: Renal hemodynamic responses to dynamic exercise in rabbits.
abstract: Cardiovascular hemodynamics, including renal blood flow, were measured in rabbits with one intact and one denervated kidney during various intensities of treadmill exercise. Within the first 10 s of exercise, there was rapid vasoconstriction in the innervated kidney associated with decreases in renal blood flow (range -10 to -17%). The vasoconstriction in the innervated kidney was evident at all workloads and was intensity dependent. There was no significant vasoconstriction or change in renal blood flow (range 0.5 to -3.1%) in the denervated kidney at the onset of exercise. However, a slowly developing vasoconstriction occurred in the denervated kidney as exercise progressed to 2 min at all workloads. Examination of responses to exercise performed under alpha-adrenergic blockade with phentolamine (5 mg/kg iv) revealed that the vasoconstriction in the innervated kidney at the onset of exercise and the delayed vasoconstriction in the denervated kidney were due primarily to activation of alpha-adrenergic receptors. In addition, a residual vasoconstriction was also present in the innervated kidney after alpha-adrenergic blockade, suggesting that, during exercise, activation of other renal vasoconstrictor mechanisms occurs which is dependent on the presence of renal nerves.
authors.affiliation: Departments of Anesthesiology and Physiology, Medical College of Wisconsin and Veterans Affairs Medical Center, Milwaukee, Wisconsin 53295, USA.
authors.forename: P J
authors.initials: PJ
authors.lastname: Mueller
authors.forename: K P
authors.initials: KP
authors.lastname: O'Hagan
authors.forename: K A
authors.initials: KA
authors.lastname: Skogg
authors.forename: J B
authors.initials: JB
authors.lastname: Buckwalter
authors.forename: P S
authors.initials: PS
authors.lastname: Clifford
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D003714:Denervation; D005260:Female; D005557:Formaldehyde / Q000494:pharmacology; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D007668:Kidney / Q000294:innervation; D009638:Norepinephrine / Q000378:metabolism; D010656:Phenylephrine / Q000494:pharmacology; D005082:Physical Exertion / Q000502:physiology*; D011817:Rabbits; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000502:physiology; D012018:Reflex / Q000502:physiology; D012079:Renal Circulation / Q000187:drug effects / Q000502:physiology*; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology
chemical_list: D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D011942:Receptors, Adrenergic, alpha; D005557:Formaldehyde; D010656:Phenylephrine; D009638:Norepinephrine