PMID- 8946000
OWN - NLM
STAT- MEDLINE
DCOM- 19970103
LR  - 20181130
IS  - 0002-9513 (Print)
IS  - 0002-9513 (Linking)
VI  - 271
IP  - 5 Pt 2
DP  - 1996 Nov
TI  - Functional evidence for a Ca2+/polyvalent cation sensor in the mouse thick 
      ascending limb.
PG  - F1052-60
AB  - The effects of extracellular polyvalent cations on the cytosolic free Ca2+ 
      concentration ([Ca2+]i) of isolated segments of the mouse nephron were 
      investigated using fura 2 microfluorometry. Extracellular Ca2+ concentration 
      ([Ca2+]o), gadolinium (Gd3+), and neomycin (Neo) increased the [Ca2+]i in 
      cortical thick ascending limb (CTAL) tubules with effective doses (ED50) of 
      approximately 3.5 mM for Ca2+, 20 microM for Gd3+, and 40 microM for Neo. This 
      effect was reproduced by Ba2+ but not by Mg2+. High [Ca2+]o inhibited the 
      responses to Gd3+, Neo, and Ba2+. The Gd(3+)- and Neo-evoked [Ca2+]i transients 
      persisted in the absence of external Ca2+ and were abolished by the depletion of 
      internal Ca2+ stores with thapsigargin (TG). The responses to rises in [Ca2+]o 
      were similarly inhibited by TG and slightly reduced by 20 microM La3+ but not by 
      10 microM nifedipine. Mn2+ also mobilized a TG-sensitive internal Ca2+ store and 
      stimulated its own entry. External Ca2+, Gd3+, and Neo induced small but 
      significant increases in [Ca2+]i in distal convoluted tubule, cortical collecting 
      duct, and outer medullary collecting duct segments, transiently increased [Ca2+]i 
      in some medullary TAL (MTAL) tubules, but had no effect on descending thin limb. 
      We conclude that a Ca(2+)-mobilizing Ca2+/polyvalent cation sensor resembling 
      that of the parathyroid gland cells is predominantly located in the mouse CTAL 
      but also in the MTAL and, to a lesser extent, in more distal segments.
FAU - Paulais, M
AU  - Paulais M
AD  - Institut National de la Sante et de la Recherche Medicale Unite 323, Faculte de 
      Medecine Necker, Paris, France.
FAU - Baudouin-Legros, M
AU  - Baudouin-Legros M
FAU - Teulon, J
AU  - Teulon J
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Am J Physiol
JT  - The American journal of physiology
JID - 0370511
RN  - 0 (Cations)
RN  - AU0V1LM3JT (Gadolinium)
RN  - I16QD7X297 (Neomycin)
RN  - SY7Q814VUP (Calcium)
RN  - TSN3DL106G (Fura-2)
SB  - IM
MH  - Animals
MH  - Calcium/*metabolism/pharmacology
MH  - Cations/*metabolism
MH  - Cytosol/metabolism
MH  - Extracellular Space/metabolism
MH  - Fura-2
MH  - Gadolinium/pharmacology
MH  - Kidney Tubules/metabolism
MH  - Loop of Henle/*metabolism
MH  - Male
MH  - Mice
MH  - Mice, Inbred Strains
MH  - Neomycin/pharmacology
MH  - Nephrons/drug effects/metabolism
MH  - Osmolar Concentration
EDAT- 1996/11/01 00:00
MHDA- 1996/11/01 00:01
CRDT- 1996/11/01 00:00
PHST- 1996/11/01 00:00 [pubmed]
PHST- 1996/11/01 00:01 [medline]
PHST- 1996/11/01 00:00 [entrez]
AID - 10.1152/ajprenal.1996.271.5.F1052 [doi]
PST - ppublish
SO  - Am J Physiol. 1996 Nov;271(5 Pt 2):F1052-60. doi: 
      10.1152/ajprenal.1996.271.5.F1052.