Taurine supplementation in spontaneously hypertensive rats: Advantages and limitations for human applications.

Taurine (2-aminoethanesulfonic acid) is a ß-amino acid found in many tissues particularly brain, myocardium, and kidney. It plays several physiological roles including cardiac contraction, antioxidation, and blunting of hypertension. Though several lines of evidence indicate that dietary taurine can reduce hypertension in humans and in animal models, evidence that taurine supplementation reduces hypertension in humans has not been conclusive. One reason for the inconclusive nature of past studies may be that taurine having both positive and negative effects on cardiovascular system depending on when it is assessed, some effects may occur early, while others only appear later. Further, other consideration may play a role, e.g., taurine supplementation improves hypertension in spontaneously hypertensive rats on a low salt diet but fails to attenuate hypertension on a high salt diet. In humans, some epidemiologic studies indicate that people with high taurine and low salt diets display lower arterial pressure than those with low taurine and high salt diets. Differences in techniques for measuring arterial pressure, duration of treatment, and animal models likely affect the response in different studies. This review considers both the positive and negative effects of taurine on blood pressure in animal models and their applications for human interventions.

Perinatal taurine depletion increases susceptibility to adult sugar-induced hypertension in rats.

This study tests the hypothesis that perinatal taurine depletion produces autonomic nervous system dysregulation and increases arterial pressure in young male rats maintained on a high sugar diet. Sprague-Dawley dams were either taurine depleted (beta-alanine 3% in water) or left untreated from conception to weaning. Their male offspring were fed normal rat chow with or without 5% glucose. At 7-8 weeks of age, the male offspring were either tested in a conscious, unrestrained state or after anesthetia. Body weight was slightly lower in the taurine-depleted rats although their heart or kidneys to body weight ratios were similar. Plasma potassium, blood urea nitrogen, plasma creatinine, hematocrit, fasting blood glucose concentrations and glucose tolerance were all similar. In the taurine-depleted, high glucose group, mean arterial pressure and sympathetic nervous system activity were increased while baroreflex function was impaired. These findings suggest that in this model perinatal taurine depletion causes autonomic nervous system dysfunction that may contribute to dietary high sugar-induced hypertension.

Sex dependent effects of perinatal taurine exposure on the arterial pressure control in adult offspring.

The present study tests the sex-dependent effect of perinatal taurine exposure on arterial pressure control in adults. Female Sprague-Dawley rats were fed normal rat chow with 3% beta-alanine (taurine depletion,TD), 3% taurine (taurine supplementation,TS) or water alone (C) from conception to weaning. Their male and female offspring were then fed normal rat chow and tap water with 5% glucose (C with glucose, CG; TD with glucose, TDG; TS with glucose, TSG) or water alone (CW, TDW or TSW). At 7-8 weeks of age, they were studied in a conscious condition. Body weights were lower in male and female TDG and male TDW rats. Kidney to body weights increased in female TSW but not TSG. Plasma sodium and potassium were not significantly different among males. Among females, plasma sodium levels were lower in all glucose treated groups while plasma potassium levels were lower only in TDG. Hematocrit, fasting blood glucose, and glucose tolerance were not significantly different between the sexes. Mean arterial pressure increased in male TDG, TSW, and TSG while in the females, mean arterial pressure increased in TabstractDW, TDG, and TSG. Heart rates were not significantly different between the sexes. The present data indicate that perinatal taurine exposure alters arterial pressure control of adult rats and this effect is gender specific.