PMID- 9064643
OWN - NLM
STAT- MEDLINE
DCOM- 19970314
LR  - 20190726
IS  - 0031-6768 (Print)
IS  - 0031-6768 (Linking)
VI  - 433
IP  - 3
DP  - 1997 Jan
TI  - Characterization of swelling-induced ion transport in HT-29Cl.19A cells. Role of 
      inorganic and organic osmolytes during regulatory volume decrease.
PG  - 276-86
AB  - Combined intracellular and transepithelial potential and resistance measurements 
      were performed to localize the ion conductances activated by hypo-osmotic shock 
      of cultured human colonic carcinoma cells (HT-29Cl.19A). Furthermore, the effect 
      of cell swelling induced by a hypo-osmotic solution on the intracellular Ca2+ 
      activity [Ca2+]i and release of amino acids into the extracellular solution was 
      examined. Application of a 40% hypo-osmotic solution on both sides of confluent 
      monolayers induced a hyperpolarization of the intracellular potential caused by 
      increased K+ conductance of the basolateral membrane, followed by a sustained 
      depolarization due to increased Cl- conductance in the apical and basolateral 
      membranes. Usually no transepithelial current occurred, presumably because of 
      random distribution of Cl- channels. However, in some monolayers cell swelling 
      induced a transepithelial Cl- current because of a more pronounced expression of 
      volume-sensitive Cl- channels in the apical membrane. Exposure to hypo-osmotic 
      solution increased [Ca2+]i transiently. The increase of [Ca2+]i was also observed 
      to occur in the presence of the muscarinic receptor agonist carbachol or the 
      inhibitor of the microsomal Ca2+-ATPase thapsigargin (TG), which prevented 
      carbachol-induced Ca2+ release, suggesting that cell swelling recruits Ca2+ from 
      a different source compared to carbachol or TG. Following incubations with 
      hypo-osmotic solutions, about 60% of the intracellular free amino acids including 
      aspartate, glutamate, glycine and taurine was released. It is concluded that the 
      regulatory volume decrease (RVD) in HT-29Cl.19A colonocytes is achieved by 
      activation of K+ and Cl- conductances, resulting in net loss of salt, as well by 
      extrusion of amino acids.
FAU - Bajnath, R B
AU  - Bajnath RB
AD  - Institute of Neurobiology, Faculty of Biology, University of Amsterdam, Kruislaan 
      320, NL-1098 SM Amsterdam, The Netherlands.
FAU - de Jonge, H R
AU  - de Jonge HR
FAU - Borgdorff, A J
AU  - Borgdorff AJ
FAU - Zuiderwijk, M
AU  - Zuiderwijk M
FAU - Groot, J A
AU  - Groot JA
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Germany
TA  - Pflugers Arch
JT  - Pflugers Archiv : European journal of physiology
JID - 0154720
RN  - 0 (Amino Acids)
RN  - 67526-95-8 (Thapsigargin)
SB  - IM
MH  - Amino Acids/metabolism
MH  - Colon/*drug effects
MH  - Humans
MH  - Ion Transport/*drug effects/*physiology
MH  - Membrane Potentials/*drug effects
MH  - Thapsigargin/*pharmacology
MH  - Tumor Cells, Cultured
MH  - Water-Electrolyte Balance/*drug effects
EDAT- 1997/01/01 00:00
MHDA- 1997/01/01 00:01
CRDT- 1997/01/01 00:00
PHST- 1997/01/01 00:00 [pubmed]
PHST- 1997/01/01 00:01 [medline]
PHST- 1997/01/01 00:00 [entrez]
AID - 10.1007/s004240050278 [doi]
PST - ppublish
SO  - Pflugers Arch. 1997 Jan;433(3):276-86. doi: 10.1007/s004240050278.