ISSN:
1432-2013
Keywords:
Parathyroid hormone
;
Human calcitonin
;
Transepithelial ion net fluxes
;
Na+, Cl−, K+, Mg2+, Ca2+ transport
;
Electron microprobe analysis-Mouse kidney
;
In vitro microperfusion
;
Cortical and medullary thick ascending limb of Henle's loop
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract The effect of parathyroid hormone (PTH) on transepithelial Na+, Cl−, K+, Ca2+ and Mg2+ transport was investigated in isolated perfused cortical thick ascending limbs (cTAL) and that of human calcitonin (hCT) was tested in both cortical and medullary thick ascending limbs (mTAL) of the mouse nephron. The transepithelial ion net fluxes (J x) were determined by electron probe analysis of the perfused and collected fluids. Simultaneously, the transepithelial voltage (PDte) and resistance (R te) were recorded. In cTAL segments, PTH and hCT significantly stimulated the reabsorption of Na+, Cl−, Ca2+ and Mg2+. hCT generated a net K+ secretion towards the lumen and PTH tended to exert the same effect. Neither PDte nor R te were significantly altered by either PTH or hCT. However, in the post-experimental period a significant decrease in PDte was noted. Time control experiments carried out under similar conditions revealed a significant decrease in PDte with time, which could have masked the hormonal response. In mTAL segments, Mg2+ and Ca2+ transport was close to zero. hCT did not exert any detectable effect on either PDte or J Cl −, J Na + J K +, J Mg 2+ and J Ca 2+ in these segments. In conclusion, our data demonstrate that PTH and hCT stimulate NaCl reabsorption as well as Mg2+ and Ca2+ reabsorption in the cTAL segment of the mouse. These data are in agreement with and extend data obtained in vivo in the rat.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00370694
