Abstract
N1-methylnicotinamide (NMN) transport was studied in isolated perfused snake (Thamnophis spp.) proximal renal tubules. Unidirectional lumen-to-bath (Jl----bNMN) and bath-to-lumen (Jb----lNMN) fluxes saturated. Although Jl----bNMN and Jb----lNMN were similar, mean Jl----bNMN tended to exceed mean Jb----lNMN at all concentrations studied. Direct measurements confirmed a net reabsorptive flux equal to the difference between the unidirectional fluxes. This transport, opposite in direction to tetraethylammonium (TEA) transport, was not inhibited by TEA. Transport into the cells across both the luminal and peritubular membranes during flux measurements was apparently down an electrochemical gradient by a mediated process that was sodium dependent. Inhibition with NMN analogues suggested that transport into the cells across the luminal membrane during Jl----bNMN was more specific than transport into the cells across the peritubular membrane during Jb----lNMN. Transport out of the cells across both the luminal and peritubular membranes during flux measurements was apparently against an electrochemical gradient.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: 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.
