Abstract
The streaming potential, defined as the transepithelial potential appearing in the presence of an osmotic water flow, was measured in rabbit kidney proximal convoluted tubules perfused in vitro. The S2 segments studied were dissected from mid-cortical and juxtamedullary portions of the kidney and the streaming potential induced by the addition of raffinose in bath was compared for each tubule with the diffusion potential corresponding to an imposed NaCl gradient in the absence of osmotic gradient. The amplitude of the measured streaming potential was found to vary from positive to negative values (+0.9 to -1.8 mV) according to the location of the dissected tubule: the more juxtamedullary the nephron, the more lumen negative was the streaming potential. This correlated well with the diffusion potentials recorded on the same tubules and the amplitude of the streaming potentials was a close function of the PNa/PCl ratios calculated from these diffusion potentials. This is in agreement with the hypothesis of solute polarization in an unstirred layer as the origin of the streaming potential; a calculation of hydraulic permeability (Pf) of the proximal tubule, taking the role of such an unstirred layer into consideration is proposed.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.