title: Influence of genetic background and gender on hypertension and renal failure in COX-2-deficient mice.
abstract: The present study was undertaken to determine whether the severity of renal failure or hypertension in homozygous cyclooxygenase (COX)-2-deficient (COX-2-/-) mice affected by genetic background or gender. COX-2 deletion was introduced into three congenic genetic backgrounds, 129/Sv (129/COX-2-/-), C57/BL6 (C57/COX-2-/-), and BALB/c (BALB/COX-2-/-), by backcrossing the original mixed-background knockout mice with the respective inbred strains for 9 or 10 generations. Evaluation of the severity of hypertension and renal failure was performed in knockout and wild-type mice at the age of 2.5-3.5 mo. Blood pressure measured by tail-cuff plethysmography was significantly elevated in the male 129/COX-2-/- mice (165.8 +/- 9.2 vs. 116 +/- 5.1 mmHg, P < 0.05), and to a much lesser extent in the female 129/COX-2-/- mice (127.4 +/- 3.3 vs. 102.4 +/- 3.3), whereas it was unchanged in the C57- or BALB/COX-2-/- mice regardless of gender. Urinary excretion of albumin, determined by EIA, was remarkably increased in the 129/COX-2-/- (16.4 +/- 4.1 vs. 0.16 +/- 0.043 mg albumin/mg creatinine, P < 0.001), and to a lesser extent in the male C57/COX-2-/- mice (0.595 +/- 0.416 vs. 0.068 +/- 0.019). Albumin excretion was not elevated in the male BALB/COX-2-/- or in female COX-2-/- mice on any of the three genetic backgrounds. Histological analysis showed abundant protein casts, dilated tubules, and infiltration of inflammatory cells in the male 129/COX-2-/- mice, but not in COX-2-/- mice in other strains or gender. However, the presence of small glomeruli in the nephrogenic zone was observed in all strains of COX-2 knockout mice, regardless of genetic background and gender. Therefore, we conclude that the severity of hypertension and renal failure in COX-2-deficient mice is influenced by genetic background and gender, whereas the incomplete maturation of outer cortical nephrons appears to be independent of genetic background effects.
authors.affiliation: National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA. tianxin.yang@hsc.utah.edu
authors.forename: Tianxin
authors.initials: T
authors.lastname: Yang
authors.forename: Yuning G
authors.initials: YG
authors.lastname: Huang
authors.forename: Wenling
authors.initials: W
authors.lastname: Ye
authors.forename: Pernille
authors.initials: P
authors.lastname: Hansen
authors.forename: Jurgen B
authors.initials: JB
authors.lastname: Schnermann
authors.forename: Josephine P
authors.initials: JP
authors.lastname: Briggs
mesh_terms: D000818:Animals; D001794:Blood Pressure; D001806:Blood Urea Nitrogen; D051546:Cyclooxygenase 2; D005260:Female; D006977:Hypertension, Renal / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology*; D007678:Kidney Glomerulus / Q000473:pathology / Q000502:physiology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics*; D051437:Renal Insufficiency / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology*; D012737:Sex Factors
chemical_list: D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases