Artikel
Neonatal sympathectomy influences renal expression of arterial pressure regulating genes in spontaneously hypertensive rats (SHR)
Neonatale Sympathektomie ändert die renale Expression blutdruckregulierender Gene spontan hypertensiver Ratten (SHR)
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Veröffentlicht: | 11. November 2004 |
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Neonatal sympathectomy-induced chronic blood pressure reduction in SHR is largely due to renal mechanisms. The effect of neonatal sympathectomy on renal cortical and medullary mRNA expression of nine genes involved in blood pressure regulation was studied with real time RT-PCR. SHR controls received hydralazine 50 mg/kg*d to exclude blood pressure related effects. In 10-week-old animals (n = 9 per group) cortical gene expression patterns did not differ between sympathectomized and control rats. In sympathectomized SHR medullary expression was reduced for ETA-receptors, pre-pro-ET-1, nNOS (-25 %, p < 0.05), prorenin and p47phox NADPH oxidase subunit (-40 %, p < 0.01). A 10-day metabolism experiment (n = 7 per group) started with controls off hydralazine for 1 week did not reveal differential sodium sensitivity of arterial pressure between groups. Final 12h night time MAP on 1.8 % NaCl diet was 134 ± 5 mmHg in sympathectomized and 134 ± 7 mmHg in control rats (n.s.). By the end of this experiment cortical mRNA expression was 25 % less for prorenin (p < 0.05) and 25 % higher for COX2 (p < 0.01) in sympathectomized animals. Medullary expression of p47phox was 25 % less in sympathectomized animals (p < 0.01). Expression of AT1-receptor, ETB-receptor and eNOS mRNA showed no group differences under any condition. Neonatal sympathectomy is associated with a specific renal gene expression pattern independent of blood pressure reduction with a consistently decreased medullary p47phox mRNA abundance under varying conditions. This may relate to the chronic blood pressure lowering effect of neonatal sympathectomy in SHR.