S. J. Ritchey

Dietary boron supplementation enhanced the action of estrogen, but not that of parathyroid hormone, to improve trabecular bone quality in ovariectomized rats

This study investigated whether boron would enhance the ability of 17β-estradiol (E2) or parathyroid hormone (PTH) to improve bone quality in ovariectomized OVX rats. Adult OVX rats were treated for 5 wk with vehicle, boron (5 ppm as boric acid), E2 (30 µg/kg/d, sc), PTH (60 µg/kg/d, sc), or a combination of boron and E2 or PTH, respectively. The E2 treatment corrected many adverse effects of OVX on bone quality, increased bone Ca, P, and Mg contents, and decreased trabecular plate separation. Dietary boron supplementation had no effects on these bone parameters in OVX rats. When OVX rats were treated with boron and E2 together, trabecular bone volume (Tb.Bs/TV) and plate density were increased significantly more than that caused by E2 alone. The boron and E2 combination also increased trabecular bone surface (Tb.BV/TV) and decreased trabecular plate separation in OVX rats. In contrast, whereas daily PTH injection also increased bone Ca, Mg, and P contents, Tb.BV/TV, Tb.BS/TV, trabecular plate density and thickness, and decreased trabecular plate separation in OVX rats, the combination of boron and PTH had no additional improvement in bone quality over that achieved by PTH alone. In summary, this study shows for the first time that boron enhanced the action of E2, but not that of PTH, to improve trabecular bone quality in OVX rats.

Dietary Boron Supplementation Enhances the Effects of Estrogen on Bone Mineral Balance in Ovariectomized Rats

The present study investigated whether boron would enhance the action of 17β-estradiol (E2) or parathyroid hormone (PTH) on bone mineral balance in ovariectomized (OVX) rats. Forty-three days after OVX, the rats were treated for 5 wk with vehicle, boron (5 ppm as boric acid), E2 (30 µg/kg/d, sc), PTH (60 µg/kg/d, sc), or a combination of boron and E2 or PTH. Bone mineral balance was assessed by measuring apparent absorption, excretion, and retention of calcium (Ca), phosphorus (P), and magnesium (Mg). Serum Ca, P, Mg, and osteocalcin were also measured in this experiment. Boron alone had no effects on food consumption, weight gain, bone mineral balance, and serum levels of Ca, P, Mg, and osteocalcin. E2 alone increased serum P and Mg and decreased serum osteocalcin, but it had no effect on bone mineral balance. The combination of boron and E2 markedly improved apparent absorption of Ca, P, and Mg. In addition, the combination treatment increased the apparent retention of Ca and Mg (but not P) and also increased serum Ca and Mg but not serum P. On the other hand, boron cotreatment did not prevent the E2-induced reduction in serum osteocalcin in OVX rats. PTH alone significantly increased serum Ca, P, Mg, and osteocalcin concentrations, although it had no effect on bone mineral balance. Contrary to the boron-E2 combination treatment, the combination of boron and PTH did not enhance bone mineral balance. However, inasmuch as boron-PTH cotreatment did not enhance the stimulatory action of PTH on serum Ca, P, and osteocalcin, boron completely abolished the stimulatory effect of PTH on serum Mg. In conclusion, we have demonstrated for the first time that although boron by itself has no effect on bone mineral homeostasis, it appears to have synergistic enhancing effects on the action of E2 on Ca and Mg homeostasis in OVX rats.

Effects of exercise on iron status in mature female rats

Abstract Forty-eight female rats, age 6–8 months, were utilized in a six-week experiment to investigate the effect of exercise to exhaustion and iron intakes on several parameters of iron status. Animals were placed on diets of either 9 ppm or 40 ppm dietary iron and either subjected to exercise or remained sedentary to form the following experimental groups: 9-E, 9-S, 40-E, 40-S. Body weights and food intakes were not affected by iron intake or exercise. Animals that were exercised by swimming exhibited a training effect as measured by muscle citrate synthase activity. Weights of heart, liver, spleen and gastrocnemius muscle were not uniformly affected by exercise. Hemoglobin and hematocrit were significantly higher in the 40 ppm diet, but exercise did not affect either parameter. However, serum Fe and Total Iron Binding Capacity (TIBC) were significantly lowered (p

Effects of coarse wheat bran fiber and exercise on glucose and insulin levels in moderately overweight men

Abstract Nineteen moderately overweight males, aged 24–35, consumed high (0.5 g wheat bran/kg body weight) and low-fiber breads in a crossover design during 2 successive 6 week periods. Twelve of the subjects participated in a 4 mile walk-jog-run program 3 times weekly. No significant alteration in glucose tolerance and insulin levels, body weights, or % body fats as determined at 0, 6, and 12 weeks was due to the dietary treatment. Although glucose area under the curve was not altered by the exercise program, a significant (ϱ

Nutrition Camp—A Method for Human Nutrition Research

The nutrition camp has been a successful vehicle for balance studies with preadolescent children. This method requires a large staff for supervision of subjects, diet preparation, recreation, and laboratory analyses. The advantages, potential problems, and successful operating procedures are discussed. The method has general applicability for use with sev eral age groups. Though very expensive, the method can be justified as an approach to pro vide reliable data about the nutritional needs of normal human subjects.