Autoregulation and non-homeostatic behaviour of renal blood flow in conscious dogs.

• Verfasst von: Persson, Pontus B. [VerfasserIn]
• Verfasst von: Ehmke, Heimo [VerfasserIn]
• Verfasst von: Kirchheim, Hartmut [VerfasserIn]
• Verfasst von: Janssen, B. [VerfasserIn]
• Verfasst von: Baumann, J. E. [VerfasserIn]
• Verfasst von: Just, Armin [VerfasserIn]
• Verfasst von: Nafz, Benno [VerfasserIn]
• Titel: Autoregulation and non-homeostatic behaviour of renal blood flow in conscious dogs.
• Verf.angabe: P. B. Persson, H. Ehmke, H. R. Kirchheim, B. Janssen, J. E. Baumann, A. Just, B. Nafz
• E-Jahr: 1993
• Jahr: 01 March 1993
• Umfang: 13 S.
• Fussnoten: Gesehen am 04.12.2024
• Titel Quelle: Enthalten in: The journal of physiology
• Ort Quelle: Hoboken, NJ : Wiley-Blackwell, 1878
• Jahr Quelle: 1993
• Band/Heft Quelle: 462(1993), 1, Seite 261-273
• ISSN Quelle: 1469-7793
• DOI: doi:10.1113/jphysiol.1993.sp019554
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1910824151

Abstract

1. Spontaneously occurring haemodynamic variations within 4 h affecting renal blood flow (RBF) were compared with externally induced short changes of renal artery pressure (RAP) in conscious resting dogs. 2. In all animals in which RAP was servo-controlled (n = 6), perfect autoregulation of RBF was observed. 3. In all 4 h recordings of spontaneous renal blood flow (n = 9), certain combinations of blood pressure and blood flow occurred remarkably frequently as indicated by three-dimensional frequency distributions. 4. Cluster analysis demonstrated significant differences between these areas of accumulation (P < 0.001). The average number of 'set points' per 4 h session was 3.1 +/- 0.3. 5. The shift from one set point to another is probably mediated by multiple control systems impinging on renal haemodynamics as suggested by 1/f fluctuations. 6. In seven dogs, an additional renal venous catheter allowed measurements of the arterial-venous (A-V) oxygen partial pressure (PO2) difference as an indicator of the renal metabolic demand. An inverse relationship between A-V PO2 difference and RBF (Y = X(-0.034) + 40.9, r = -0.9, P < 0.001) was found, indicating that the metabolic demands vary little (if at all) between the different set points. 7. The presented data suggest a modified view of renal homeostasis. There exist distinct combinations between RBF and RAP, which are very stable. Autoregulation merely buffers the fluctuations around these set points.