ELECTROLYTE CONTENT OF MILK DIFFERS IN NORMOTENSIVE AND SPONTANEOUSLY HYPERTENSIVE RATS

Milk samples were collected from lactating spontaneously hyper-tensive (SHR) and Wistar-Kyoto (WKY) normotensive females 14 days postpartum and were later analyzed for content of calcium (Ca++), sodium (Na+), potassium (K+), chloride (Cl-), magnesium (Mg++), and total protein. Our findings revealed that milk samples from SHR females had significantly higher concentrations of Na+ and Cl- and significantly lower concentrations of Ca++, K+, and protein when compared with samples from WKY females. In addition, the Na+/K+ ratio for milk samples from SHR was significantly higher that that for samples from WKY. Milk levels of Mg++ were similar for females of the two strains. These results indicate that preweanling dietary content of several electrolytes implicated in the development of hypertension differs substantially between SHR and WKY pups. Such differences in milk electrolyte levels may constitute an important environmental trigger for age-related increases in arterial pressures of SHRs.