Refined carbohydrate increases blood pressure and catecholamine excretion in SHR and WKY

Abstract

In spontaneously hypertensive (SHR) and normotensive (WKY) rats fed different diets, blood pressure (BP) increased significantly in both strains when the carbohydrate (CHO) source was from refined rather than from natural ingredients. This BP increase was observed whether sucrose, glucose, or starch was the principal CHO. Urinary excretion of norepinephrine, dopamine, and, to some extent, epinephrine also increased, while myocardial concentrations were unaffected. Despite a comparable elevation of catecholamine excretion in both SHR and WKY rats fed high amounts of refined CHO, the BP increases were greater in the former. The strain differences were explained by the known dissimilar response of their blood vessels to catecholamines. The results suggest that BP elevation after high CHO ingestion is mediated via increased catecholamine production and/or release, thus implying a neurogenic mechanism.

Metabolic and blood pressure response to feeding activity is enhanced in freely moving spontaneously hypertensive rats.

“…The slopes of the regression lines showing the relationship between BP and FA were greater in SHR than WKY (Table 2), which may be compatible with the results reported in the foregoing papers (PREUSS and PREUSS, 1980;YOUNG and LANDSBERG,1981;PREUSS and FOURNIER, 1982;FOURNIER et al, 1986). FOURNIER et al (1986) have reported that refined carbohydrate ingestion elevates BP in rats due to an increased catecholamine production and/or release. Despite a comparable elevation of catecholamine excretion in both SHR and WKY fed the same amount of refined carbohydrate, the increase in BP was greater in SHR than in WKY (FOURNIER et a!.,1986).…”

“…FOURNIER et al (1986) have reported that refined carbohydrate ingestion elevates BP in rats due to an increased catecholamine production and/or release. Despite a comparable elevation of catecholamine excretion in both SHR and WKY fed the same amount of refined carbohydrate, the increase in BP was greater in SHR than in WKY (FOURNIER et a!.,1986). Feeding sucrose-supplemented chow increased BP in SHR, but did not affect BP in WKY (PREUSS and PREUSS, 1980;YOUNG and LANDSBERG,1981).…”

“…The enhanced activity of the peripheral or central catecholaminergic system may play an important role in developing and maintaining hypertension in SHR (CHALMERS, 1975;JUDY et al, 1979;THOREN and RICKSTEN, 1979;HELLSTRAND and ENGEL,1980;TUCKER and JOHNSON, 1984). FOURNIER et al (1986) have shown that refined carbohydrate ingestion elevates blood pressure (BP) more in SHR than their normotensive counterparts (WKY). Feeding sucrosesupplemented chow elevated BP in SHR but not WKY (PREUSS and PREUSS, 1980;YOUNG and LANDSBERG, 1982).…”

Hyperinsulinemia produces both sympathetic neural activation and vasodilation in normal humans.

“…In rats, Edwards and Tipton (9) reported a dose-dependent relationship between increases in insulin (with euglycemia) and increases in arterial pressure. Hyperinsulinemia produced by feeding rats sucrose or fructose has been associated with elevated catecholamine secretion and arterial pressure (10,11).…”

Sympathoadrenal control by paraventricular hypothalamic beta-endorphin in hypertension.

“…22 " 25 Moreover, manipulation of food intake has been demonstrated to produce differential effects on systemic cardiovascular function between SHR and WKY rats. 26 - 27 Thus, in the present study, £-endorphin was microinjected into the PVH of SHR and WKY rats to elucidate a putative role for /3-endorphin as a neurotransmitter system integrating regulation of sympathoadrenal function by PVH neurons and a role of this system in the development of hypertension in SHR. Methods Male, 6-week-old SHR and WKY rats were purchased from Taconic Farms, Inc., German town, N.Y.…”