ISSN:
1432-2013
Schlagwort(e):
Microperfusion
;
Glomerular Filtration Rate
;
Feedback Mechanism
;
Loop of Henle Function
;
Mikroperfusion
;
Glomerulumfiltrat
;
Rückkoppelungsmechanismus
;
Funktion der Henleschen Schleife
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Medizin
Notizen:
Summary Possible regulation of glomerular filtration rate by tubulo-glomerular feedback from a late tubular site was studied in microperfusion experiments on rats. During perfusion of loops of Henle with varying flow rates and different perfusion solutions, filtration rate of the perfused nephrons was measured by total proximal fluid collection and inulin determination. During perfusion with isotonic Ringer's solution nephron filtration rate decreased significantly with increasing perfusion rates. Since proximal intratubular pressure was experimentally kept constant, this response must reflect decreased glomerular capillary pressure. Increasing the flow rate during perfusion with isotonic sodium sulfate or mannitol solutions was not associated with significant changes of filtration rate. Thus some correlate of the flow rate of normal loop of Henle fluid can affect filtrate formation. Such an effect may be mediated by the juxtaglomerular apparatus. Our results are consistent with the concept that the triggering signal is a function of the amount of distal sodium that is able to permeate the cell membrane at the receptor site rather than of distal intratubular sodium concentration.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00586493
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