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L‐NAME effects over ovariectomized rats: role of ECaC and ENaC nephron transporters
Author(s) -
Lirani Ana Paula Rebucci,
Abreu Nayda Parisio,
Boim Mirian Aparecida,
Schor Nestor,
Castro Marise Lazaretti,
Bergamaschi Cassia Toledo
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.a1064-b
Subject(s) - endocrinology , medicine , ovariectomized rat , nitric oxide , estrogen , epithelial sodium channel , reabsorption , chemistry , calcium channel , calcium , kidney , sodium , organic chemistry
Osteoporosis is a great medical problem, mainly in post‐menopausal women. Nitric Oxide (NO) is involved in atheroprotection and bone metabolism regulation, as well as in the mediation of estrogen effects in females. The aim of this study was to evaluate the role of nitric oxide over the epithelial renal calcium (ECaC) and sodium (ENaC) channels expression in ovariectomized rats. Age matched virgin Wistar rats served as control (C, n=5) and the others rats were divided in ovariectomy (OV, n=5) and ovariectomy + L‐NAME (OVN, n=6) groups. The L‐NAME (50 mg/Kg/day) was administred by gavage during 14 days, in OVN group, starting on the 30th day after surgery. The mRNA expression levels of ECaC and ENaC were analyzed in the renal tissue by cDNA synthesys and Real Time PCR techniques. The OV group showed an increase in ECaC channel expression when compared with C group (C 0,82±0,02 vs OV 1,1±0,1 arbitrary units, p<0,05) and the OVN group had an overexpression in this channel compared with both other groups (OVN 1,8±0,2 vs OV 1,1±0,1 vs C 0,82±0,02 arbitrary units, p<0,05). The ENaC channel did not show diferences in studied groups. The ovariectomized rats presented an upregulation on ECaC nephron channel showing that the absence of estrogen is followed by an increase in calcium reabsorption. When ovariectomy was combined with L‐NAME treatment, there was an overexpression of ECaC channel, suggesting that NO blocking exacerbates the effect of ovariectomy over this nephron transporter. The ENaC expression was not changed by neither ovariectomy nor NO blocking. Financial support: CNPq, FAPESP, CAPES, Pronex.