Mutations in the Na-Cl cotransporter reduce blood pressure in humans.

The relationship between salt homeostasis and blood pressure has remained difficult to establish from epidemiological studies of the general population. Recently, mendelian forms of hypertension have demonstrated that mutations that increase renal salt balance lead to higher blood pressure, suggesting that mutations that decrease the net salt balance might have the converse effect. Gitelman's syndrome, caused by loss of function mutations in the Na-Cl cotransporter of the distal convoluted tubule (NCCT), features inherited hypokalemic alkalosis with so-called "normal" blood pressure. We hypothesized that the mild salt wasting of Gitelman's syndrome results in reduced blood pressure and protection from hypertension. We have formally addressed this question through the study of 199 members of a large Amish kindred with Gitelman's syndrome. Through genetic testing, family members were identified as inheriting 0 (n=60), 1 (n=113), or 2 (n=26) mutations in NCCT, permitting an unbiased assessment of the clinical consequences of inheriting these mutations by comparison of the phenotypes of relatives with contrasting genotypes. The results demonstrate high penetrance of hypokalemic alkalosis, hypomagnesemia, and hypocalciuria in patients inheriting 2 mutant NCCT alleles. In addition, the NCCT genotype was a significant predictor of blood pressure, with homozygous mutant family members having significantly lower age- and gender-adjusted systolic and diastolic blood pressures than those of their wild-type relatives. Moreover, both homozygote and heterozygote subjects had significantly higher 24-hour urinary Na(+) than did wild-type subjects, reflecting a self-selected higher salt intake. Finally, heterozygous children, but not adults, had significantly lower blood pressures than those of the wild-type relatives. These findings provide formal demonstration that inherited mutations that impair renal salt handling lower blood pressure in humans.

Effects of chronic kombucha ingestion on open-field behaviors, longevity, appetitive behaviors, and organs in c57-bl/6 mice: a pilot study.

Kombucha is a lightly fermented tea beverage popularly consumed as a self-prescribed folk-remedy for numerous ailments. Kombucha is claimed to enhance cognition, aid weight loss, and prolong life. This pilot study reports longevity, general health, and open-field exploratory behavioral outcomes from a 3-y longitudinal study of 64 C57-BL/6 mice (males and females), half of which chronically drank kombucha, and all of which experienced natural mortality. Compared by MANOVA to controls, mice that drank kombucha showed greater vertical exploration (P = 0.001) and a sex-interactive effect in novel object manipulation (P = 0.049). MANOVA of kombucha-drinking mice compared to controls detected differences in appetitive behaviors (food consumption, P < 0.001; beverage consumption, P = 0. 008), and gross body weight (P < 0.001). Appetitive behaviors changed with the addition of voluntary exercise on a running wheel, with differing patterns of change noted for males and females. Both male and female mice who drank kombucha lived longer than controls (P < 0.001), with the greatest variability among the male mice (sex interactive effect, P < 0.001). Comparable effects and mechanisms in humans remain uncertain, as do health safety issues, because serious health problems and fatalities have been reported and attributed to drinking kombucha.