PP005. Vitamin D depletion aggravates hypertension in transgenic rats

Abstract

Vitamin D may ameliorate hypertension and kidney disease through genomic and extra-genomic pathways. To investigate the impact of vitamin D in a transgenic rat model of angiotensin II-mediated hypertensive organ failure. In 4-week-old age-matched rats overexpressing the human renin and angiotensinogen genes, group 1 (n=18) received vitamin D depleted chow; group 2 (n=15) standard chow and intraperitoneal paricalcitol at 800ng/kg thrice weekly; and group 3 (n=15) standard chow and vehicle injections. Blood pressure (tail cuff) and 24-h albuminuria were determined once weekly. After three weeks, animals were sacrificed. Heart tissue was examined for atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) by RT-PCR. The vitamin D depleted group had higher blood pressure at week 1 (mean difference 23.4mmHg, 95% CI 9.1-37.7) and tended to have higher blood pressure in weeks 2 and 3 (mean difference 14.3mmHg 95% CI -0.02-28.7 and 15.2mmHg 95% CI -1.5-33). The depletion group had higher heart-to-body weight ratio, and a trend towards higher ANP and BNP levels. The group receiving paricalcitol did not perform better. No differences were found between groups in mortality or proteinuria. Short-term vitamin D depletion aggravated hypertension and end-organ damage in a rat model of angiotensin II-induced hypertension. Short-term interventions with high-dose vitamin D analogues had no protective effect.