Hypothalamic gene expression in ω-3 PUFA-deficient male rats before, and following, development of hypertension

Dietary deficiency of omega-3 fatty acids (omega-3 DEF) produces hypertension in later life. This study examined the effect of omega-3 DEF on blood pressure and hypothalamic gene expression in young rats, before the development of hypertension, and in older rats following the onset of hypertension. Animals were fed experimental diets that were deficient in omega-3 fatty acids, sufficient in short-chain omega-3 fatty acids or sufficient in short-and long-chain omega-3 fatty acids, from the prenatal period until 10 or 36 weeks-of-age. There was no difference in blood pressure between groups at 10 weeks-of-age; however, at 36 weeks-of-age omega-3 DEF animals were hypertensive in relation to sufficient groups. At 10 weeks, expression of angiotensin-II1A receptors and dopamine D-3 receptors were significantly increased in the hypothalamic tissue of omega-3 DEF animals. In contrast, at 36 weeks, alpha(2a) and beta(1) adrenergic receptor expression was significantly reduced in the omega-3 DEF group. Brain docosahexaenoic acid was significantly lower in omega-3 DEF group compared with sufficient groups. This study demonstrates that dietary omega-3 DEF causes changes both in the expression of key genes involved in central blood pressure regulation and in blood pressure. The data may indicate that hypertension resulting from omega-3 DEF is mediated by the central adrenergic system. Hypertension Research (2012) 35, 381-387; doi: 10.1038/hr.2011.194; published online 10 November 2011