Abstract
Astrocytes exposed to hypoosmotic stress swell and subsequently reduce their size to almost their original volume, a phenomenon called regulatory volume decrease (RVD). We found that during hypoosmotic swelling there was a twofold increase in phosphatidylinositol (PI) hydrolysis. This increase was inhibited by the phospholipase C inhibitor, U-73122 (10 μM). Inhibition of PI hydrolysis resulted in blockage of RVD. We also examined whether agents that stimulate PI hydrolysis would enhance RVD. These agents significantly accelerated RVD. The rank order of potency was endothelin (20 nM) ≥ norepinephrine (100 μM) > endothelin-3 (7 n/M) > thrombin (1 U/ml) ≥ ATP (500 μM) > bradykinin (20 μM) ≥ carbachol (500 μM), as indicated by RVD rate constants. The extent of PI hydrolysis induced by these agents at the beginning of RVD exhibited a logarithmic relationship with the magnitude of RVD enhancement. Also, there was a linear relationship between the rate of PI hydrolysis and RVD rate constants. Our results suggest that stimulated PI hydrolysis is involved in the regulation of cell volume in astrocytes.
| Original language | English |
|---|---|
| Pages (from-to) | 1506-1514 |
| Number of pages | 9 |
| Journal | Journal of Neurochemistry |
| Volume | 61 |
| Issue number | 4 |
| State | Published - Oct 1 1993 |
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Keywords
- Astrocytes
- Cell volume
- Inositol phosphates
- Intracellular free Ca
- Phosphatidylinositol hydrolysis agonists
- Regulatory volume decrease
ASJC Scopus subject areas
- Biochemistry
- Cellular and Molecular Neuroscience
Cite this
Role of phosphoinositide hydrolysis in astrocyte volume regulation. / Bender, A. S.; Neary, J. T.; Norenberg, Michael D.
In: Journal of Neurochemistry, Vol. 61, No. 4, 01.10.1993, p. 1506-1514.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Role of phosphoinositide hydrolysis in astrocyte volume regulation
AU - Bender, A. S.
AU - Neary, J. T.
AU - Norenberg, Michael D
PY - 1993/10/1
Y1 - 1993/10/1
N2 - Astrocytes exposed to hypoosmotic stress swell and subsequently reduce their size to almost their original volume, a phenomenon called regulatory volume decrease (RVD). We found that during hypoosmotic swelling there was a twofold increase in phosphatidylinositol (PI) hydrolysis. This increase was inhibited by the phospholipase C inhibitor, U-73122 (10 μM). Inhibition of PI hydrolysis resulted in blockage of RVD. We also examined whether agents that stimulate PI hydrolysis would enhance RVD. These agents significantly accelerated RVD. The rank order of potency was endothelin (20 nM) ≥ norepinephrine (100 μM) > endothelin-3 (7 n/M) > thrombin (1 U/ml) ≥ ATP (500 μM) > bradykinin (20 μM) ≥ carbachol (500 μM), as indicated by RVD rate constants. The extent of PI hydrolysis induced by these agents at the beginning of RVD exhibited a logarithmic relationship with the magnitude of RVD enhancement. Also, there was a linear relationship between the rate of PI hydrolysis and RVD rate constants. Our results suggest that stimulated PI hydrolysis is involved in the regulation of cell volume in astrocytes.
AB - Astrocytes exposed to hypoosmotic stress swell and subsequently reduce their size to almost their original volume, a phenomenon called regulatory volume decrease (RVD). We found that during hypoosmotic swelling there was a twofold increase in phosphatidylinositol (PI) hydrolysis. This increase was inhibited by the phospholipase C inhibitor, U-73122 (10 μM). Inhibition of PI hydrolysis resulted in blockage of RVD. We also examined whether agents that stimulate PI hydrolysis would enhance RVD. These agents significantly accelerated RVD. The rank order of potency was endothelin (20 nM) ≥ norepinephrine (100 μM) > endothelin-3 (7 n/M) > thrombin (1 U/ml) ≥ ATP (500 μM) > bradykinin (20 μM) ≥ carbachol (500 μM), as indicated by RVD rate constants. The extent of PI hydrolysis induced by these agents at the beginning of RVD exhibited a logarithmic relationship with the magnitude of RVD enhancement. Also, there was a linear relationship between the rate of PI hydrolysis and RVD rate constants. Our results suggest that stimulated PI hydrolysis is involved in the regulation of cell volume in astrocytes.
KW - Astrocytes
KW - Cell volume
KW - Inositol phosphates
KW - Intracellular free Ca
KW - Phosphatidylinositol hydrolysis agonists
KW - Regulatory volume decrease
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UR - http://www.scopus.com/inward/citedby.url?scp=0027420761&partnerID=8YFLogxK
M3 - Article
C2 - 8397296
AN - SCOPUS:0027420761
VL - 61
SP - 1506
EP - 1514
JO - Journal of Neurochemistry
JF - Journal of Neurochemistry
SN - 0022-3042
IS - 4
ER -