Developmental changes in cyclo-oxygenase mRNA induction by hypoxia in rat kidney.
BACKGROUND
Prostaglandins, synthesized by cyclo-oxygenase (COX), regulate renal hemodynamics and also epithelial water and solute transport. Developmental changes occur in COX-2 mRNA expression and its response to lipopolysaccharide stimulation in rats. We examined age-related changes in COX mRNA expression induced by hypoxia in the renal cortex and medulla of developing rats.


METHODS
Total RNA was extracted from 1- and 4-week-old male Wistar rats exposed to one or 4 h of hypoxia (8% O2). Cyclo-oxygenase mRNA was quantitatively analyzed using a real-time polymerase chain reaction with dual-labeled fluorogenic probes.


RESULTS
Expression of COX-1 mRNA did not change in response to hypoxia in the cortex or medulla in either infantile or adult rats. In infantile rats, COX-2 mRNA expression was not induced by one or 4 h of hypoxia. In adults, 1- and 4-h exposures to hypoxia induced COX-2 mRNA in the renal cortex, and 1-h of exposure induced COX-2 mRNA in the medulla.


CONCLUSIONS
Response of expression of COX-2 mRNA in rats exposed to acute hypoxia show age-related variability treated by acute hypoxia. Cyclo-oxygenase-2 might not play a major role in the hypoxic infantile rat kidney.
Ogawa
Tetsushi
T
Department of Pediatrics, Gunma University School of Medicine, Maebashi, Japan. mat-1@mve.biglobe.ne.jp
Tomomasa
Takeshi
T
Morikawa
Akihiro
A
D000818:Animals; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D000860:Hypoxia / Q000378:metabolism*; D007527:Isoenzymes / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins; D016133:Polymerase Chain Reaction; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*; D011453:Prostaglandins / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
D007527:Isoenzymes; D008565:Membrane Proteins; D011453:Prostaglandins; D012333:RNA, Messenger; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; C496513:Ptgs1 protein, rat