Abstract
Background & Aims: Astrocyte swelling and brain edema associated with increased intracranial pressure are major complications of acute liver failure (ALF). The mechanism for such astrocyte swelling/brain edema, however, is not well understood. We recently found that ammonia, a key etiological factor in ALF, caused the activation of the Na-K-Cl cotransporter-1 (NKCC1) in cultured astrocytes, and that inhibition of such activation led to a reduction in astrocyte swelling, suggesting that NKCC1 activation may be an important factor in the mechanism of brain edema in ALF. To determine whether NKCC activation is also involved in brain edema in vivo, we examined whether NKCC activation occurs in the thioacetamide (TAA) rat model of ALF and determined whether treatment with the NKCC inhibitor bumetanide reduces the severity of brain edema in TAA-treated rats. Methods: Brain water content was measured using the gravimetric method. NKCC1 phosphorylation and protein expression were measured by Western blots. NKCC activity was measured in brain cortical slices. Results: NKCC activity was elevated in brain cortical slices of TAA-treated rats as compared to sham animals. Western blot analysis showed significant increases in total as well as phosphorylated (activated) NKCC1 protein expression in the cortical tissue. These findings were associated with a significant increase in brain water content which was attenuated by treatment with the NKCC inhibitor bumetanide. Conclusions: Our studies suggest the involvement of NKCC in the development of brain edema in experimental ALF, and that targeting NKCC may represent a useful therapeutic strategy in humans with ALF.
| Original language | English |
|---|---|
| Pages (from-to) | 272-278 |
| Number of pages | 7 |
| Journal | Journal of Hepatology |
| Volume | 54 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 1 2011 |
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Keywords
- Brain edema
- Liver failure
- NKCC
ASJC Scopus subject areas
- Hepatology
Cite this
The Na-K-Cl cotransporter in the brain edema of acute liver failure. / Jayakumar, Arumugam R.; Valdes, Vanessa; Norenberg, Michael D.
In: Journal of Hepatology, Vol. 54, No. 2, 01.02.2011, p. 272-278.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The Na-K-Cl cotransporter in the brain edema of acute liver failure
AU - Jayakumar, Arumugam R.
AU - Valdes, Vanessa
AU - Norenberg, Michael D
PY - 2011/2/1
Y1 - 2011/2/1
N2 - Background & Aims: Astrocyte swelling and brain edema associated with increased intracranial pressure are major complications of acute liver failure (ALF). The mechanism for such astrocyte swelling/brain edema, however, is not well understood. We recently found that ammonia, a key etiological factor in ALF, caused the activation of the Na-K-Cl cotransporter-1 (NKCC1) in cultured astrocytes, and that inhibition of such activation led to a reduction in astrocyte swelling, suggesting that NKCC1 activation may be an important factor in the mechanism of brain edema in ALF. To determine whether NKCC activation is also involved in brain edema in vivo, we examined whether NKCC activation occurs in the thioacetamide (TAA) rat model of ALF and determined whether treatment with the NKCC inhibitor bumetanide reduces the severity of brain edema in TAA-treated rats. Methods: Brain water content was measured using the gravimetric method. NKCC1 phosphorylation and protein expression were measured by Western blots. NKCC activity was measured in brain cortical slices. Results: NKCC activity was elevated in brain cortical slices of TAA-treated rats as compared to sham animals. Western blot analysis showed significant increases in total as well as phosphorylated (activated) NKCC1 protein expression in the cortical tissue. These findings were associated with a significant increase in brain water content which was attenuated by treatment with the NKCC inhibitor bumetanide. Conclusions: Our studies suggest the involvement of NKCC in the development of brain edema in experimental ALF, and that targeting NKCC may represent a useful therapeutic strategy in humans with ALF.
AB - Background & Aims: Astrocyte swelling and brain edema associated with increased intracranial pressure are major complications of acute liver failure (ALF). The mechanism for such astrocyte swelling/brain edema, however, is not well understood. We recently found that ammonia, a key etiological factor in ALF, caused the activation of the Na-K-Cl cotransporter-1 (NKCC1) in cultured astrocytes, and that inhibition of such activation led to a reduction in astrocyte swelling, suggesting that NKCC1 activation may be an important factor in the mechanism of brain edema in ALF. To determine whether NKCC activation is also involved in brain edema in vivo, we examined whether NKCC activation occurs in the thioacetamide (TAA) rat model of ALF and determined whether treatment with the NKCC inhibitor bumetanide reduces the severity of brain edema in TAA-treated rats. Methods: Brain water content was measured using the gravimetric method. NKCC1 phosphorylation and protein expression were measured by Western blots. NKCC activity was measured in brain cortical slices. Results: NKCC activity was elevated in brain cortical slices of TAA-treated rats as compared to sham animals. Western blot analysis showed significant increases in total as well as phosphorylated (activated) NKCC1 protein expression in the cortical tissue. These findings were associated with a significant increase in brain water content which was attenuated by treatment with the NKCC inhibitor bumetanide. Conclusions: Our studies suggest the involvement of NKCC in the development of brain edema in experimental ALF, and that targeting NKCC may represent a useful therapeutic strategy in humans with ALF.
KW - Brain edema
KW - Liver failure
KW - NKCC
UR - http://www.scopus.com/inward/record.url?scp=78751570908&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=78751570908&partnerID=8YFLogxK
U2 - 10.1016/j.jhep.2010.06.041
DO - 10.1016/j.jhep.2010.06.041
M3 - Article
C2 - 21056502
AN - SCOPUS:78751570908
VL - 54
SP - 272
EP - 278
JO - Journal of Hepatology
JF - Journal of Hepatology
SN - 0168-8278
IS - 2
ER -