TY - JOUR

T1 - The effect of L-NAME on intra- and inter-nephron synchronization

AU - Sosnovtseva, O V

AU - Pavlov, A N

AU - Pavlova, O N

AU - Mosekilde, E

AU - Holstein-Rathlou, Niels-Henrik

N1 - Keywords: Algorithms; Animals; Arterioles; Enzyme Inhibitors; Homeostasis; Hypertension, Renal; Kidney Glomerulus; Kidney Tubules; Kinetics; Male; NG-Nitroarginine Methyl Ester; Nephrons; Nitric Oxide Synthase; Rats; Rats, Sprague-Dawley; Renal Artery; Renal Circulation

PY - 2009

Y1 - 2009

N2 - Kidney autoregulation involves complicated intra- and inter-nephron synchronization phenomena among oscillatory modes produced, respectively, by the tubuloglomerular feedback (TGF) mechanism and by the myogenic regulation of the afferent arteriolar blood flow. The present study aims at examining to what extent these phenomena are reflected in the overall blood flow to the kidney and how they are affected by intravenous administration of nitro-l-arginine-methyl-ester (L-NAME), a potent NO synthesis inhibitor. Wavelet analysis is applied to detect rhythmic activity at the level of the renal artery and compare the observed fluctuations with blood flow variations recorded from efferent arterioles of individual nephrons. We show that administration of L-NAME increases the gain in both the TGF and the myogenic oscillations, and that both normotensive and hypertensive rats demonstrate reduced stability of the various rhythms. This implies that L-NAME, besides strengthening the gain in the individual feedback mechanisms, also causes more frequent transitions among the various synchronization states. In a broader perspective the purpose of the study is to demonstrate the significance of complex dynamic phenomena in the normal regulation of physiological systems as well as in their response to drugs.

AB - Kidney autoregulation involves complicated intra- and inter-nephron synchronization phenomena among oscillatory modes produced, respectively, by the tubuloglomerular feedback (TGF) mechanism and by the myogenic regulation of the afferent arteriolar blood flow. The present study aims at examining to what extent these phenomena are reflected in the overall blood flow to the kidney and how they are affected by intravenous administration of nitro-l-arginine-methyl-ester (L-NAME), a potent NO synthesis inhibitor. Wavelet analysis is applied to detect rhythmic activity at the level of the renal artery and compare the observed fluctuations with blood flow variations recorded from efferent arterioles of individual nephrons. We show that administration of L-NAME increases the gain in both the TGF and the myogenic oscillations, and that both normotensive and hypertensive rats demonstrate reduced stability of the various rhythms. This implies that L-NAME, besides strengthening the gain in the individual feedback mechanisms, also causes more frequent transitions among the various synchronization states. In a broader perspective the purpose of the study is to demonstrate the significance of complex dynamic phenomena in the normal regulation of physiological systems as well as in their response to drugs.

U2 - 10.1016/j.ejps.2008.10.019

DO - 10.1016/j.ejps.2008.10.019

M3 - Journal article

C2 - 19028576

VL - 36

SP - 39

EP - 50

JO - Norvegica Pharmaceutica Acta

JF - Norvegica Pharmaceutica Acta

SN - 0928-0987

IS - 1

ER -