Dysregulation of Renal Cyclooxygenase-2 in Rats with Lithium-induced Nephrogenic Diabetes Insipidus
Electrolytes & Blood Pressure
;
: 68-74, 2007.
Article
in English
| WPRIM
| ID: wpr-62077
ABSTRACT
This study aimed to examine whether the expression of major prostaglandin E2 (PGE2) synthesis enzyme, cyclooxygenase-2 (COX-2), is changed in the kidneys of the rats with lithium-induced nephrogenic diabetes insipidus (Li-NDI). Sprague- Dawley rats treated with lithium for 4 weeks were used as the NDI model and expression of renal COX-2 was determined by immunoblotting and immunohistochemistry. In Li-NDI where urine output was markedly increased and urine osmolality was significantly decreased, COX-2 expression in the inner medulla was decreased (28% of control), while it increased 18-fold in the cortex and outer medulla. Consistent with this, labeling intensity of COX-2 in macula densa region was increased, whereas it was decreased in the interstitial cells in the inner medulla, indicating a differential regulation of COX-2 between the cortex and inner medulla in Li-NDI. Accordingly, urinary PGE2 excretion was significantly increased in Li-NDI. In conclusion, there is a differential regulation of COX-2 between cortex and inner medulla in Li- NDI and urinary PGE2 excretion is increased in Li-NDI, possibly due to an increased renal production. This may suggest that increased renal production of PGE2 could play a role in modulating water reabsorption in the renal collecting duct in Li-NDI.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Osmolar Concentration
/
Immunohistochemistry
/
Dinoprostone
/
Immunoblotting
/
Prostaglandins
/
Diabetes Insipidus, Nephrogenic
/
Aquaporins
/
Cyclooxygenase 2
/
Kidney
/
Lithium
Limits:
Animals
Language:
English
Journal:
Electrolytes & Blood Pressure
Year:
2007
Type:
Article
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