Mineral balance and bone histology in spontaneously hypertensive rats

SHRs (9 weeks old) were fed diets with or without extra NaCl (2%) and were given water or saline (1%) for 7 weeks. Food and liquid intakes were measured weekly. Blood pressure was determined at 9, 11, 13, 15, and 16 weeks of age. The values for body weight gain and food intake were not influenced by any treatment. Liquid intake greatly increased with the surplus of dietary NaCl. The blood pressure increased with age in all treatments. The increase in blood pressure was enhanced by the addition of NaCl to diet and water. Urinary potassium and calcium excretions were enhanced by added dietary NaCl and saline. Calcium content in the femoral bone was not changed by any treatment, although the number of osteoclast and the area of bone marrow were increased by saline supplementation.