The effect of XXXX on the electrical properties of proximal tubule cells in the frog kidney.

@entity1372 @entity9592 @entity17894 @entity972 @entity815
The present study was designed to elucidate the effects of @entity1372 -coupled transport on the electrical properties of proximal tubule cells in the isolated perfused frog kidney. Cable analysis techniques have been employed to determine the resistance of the luminal and peritubular cell membranes in parallel (Rm) and the apparent ratio of the luminal over the peritubular cell membrane resistance ( @entity17894 ). Furthermore, the sensitivity of the potential difference across the peritubular cell membrane (PDpt) to 6-fold increases of peritubular @entity972 concentration (delta PDk) was taken as a measure of the relative @entity972 conductance of this membrane. In the absence of luminal @entity815 , PDpt amounts to -60 +/- 1 mV (n = 90), Rm to 36 +/- 3 k omega cm (n = 22), @entity17894 to 1.81 +/- 0.14 (n = 20), and delta PDk to 15.0 +/- 0.9 mV (n = 25). The application of 10 mmol/l @entity815 replacing 10 mmol/l @entity9592 leads to a rapid (within 30 s) depolarisation of PDpt to 50 +/- 5% of its control value and to a delayed (within 12 min) recovery to 95 +/- 5% of control. The rapid depolarisation is associated with a decline of Rm and @entity17894 , indicating a decrease mainly of the luminal cell membrane resistance. During recovery of PDpt there is a parallel increase of @entity17894 and a further decline of Rm pointing to a decline of the basolateral cell membrane resistance. Delta PDk is decreased during rapid depolarisation but increases again during the recovery phase. Thus, @entity815 initially decreases but then increases above control the apparent @entity972 conductance.(ABSTRACT TRUNCATED AT 250 WORDS)
