0 15

Cited 0 times in

The Activation of Na+-K+-2Cl- Cotransporter in Response to the Hypertonic Stress and Muscarinic Stimulation in Rat Parotid Acini

 Soo Yeon Lee  ;  Jeong Taeg Seo  ;  Syng-Ill Lee 
 International Journal of Oral Biology, Vol.22(3) : 199-204, 1997 
Journal Title
 International Journal of Oral Biology 
Issue Date
Na^(+)-K^(+)-2Cl^(-) cotransporter has been shown to be activated in response to volume shrinkage in a number of cell types. In this study, we investigated the role of cell shrinkage in the activation of Na^(+)-K^(+)-2Cl^(-) cotransporter in rat parotid acinar cells during hypertonic stress and muscarinic stimulation. We measured the recovery rate of the intracellular pH(pH_1) from NH_4^(+)-induced alkaline load in 2', 7'bis(2-carboxy-ethyl)-5(6')-carboxyfluorescein (BCECF)-loaded cells as an index of the activity of Na^(+)-K^(+)-2Cl^(-) contransporter. The rate of pH_1 recovery was enhanced by cell shrinkage caused by a 20% increase in perfusate osmolarity, This recovery was markedly inhibited by pretreatment with bumetanide, a blocker of Na^(+)-K^(+)-2Cl^(-) cotransporter. The rate of pHi recovery was also enhanced by 10μM carbachol stimulation which caused comparable shrinkage. Muscarinic stimulation induced an increase in [Ca^2+]_1, whereas hypertonic shrinkage failed to elevate [Ca2+]_1, Therefore, Ca^2+ does not seem to be the universal messenger for the activation of Na^(+)-K^(+)-2Cl^(-) cotransporter. In addition, the prevention of cell shrinkage during carbachol stimulation by reducing the perfusate osmolarity did not inhibit the activation of the Na^(+)-K^(+)-2Cl^(-) cotransporter. These results suggest that volume shrinkage alone is not sufficient to account for the marked activation of the Na^(+)-K^(+)-2Cl^(-) cotransporter observed during muscarinic stimulation. Other components of the intracellular signalling pathway are likely to be of great significance.
Appears in Collections:
2. College of Dentistry (치과대학) > Dept. of Oral Biology (구강생물학교실) > 1. Journal Papers
Yonsei Authors
Seo, Jeong Taeg(서정택) ORCID logo https://orcid.org/0000-0003-2697-0251
사서에게 알리기


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.