Hormonal replacement therapy in an animal model with chronic renal failure and ovariectomy:: Biochemical and densitometric study

Background. In spite of estrogen replacement therapy being extensively used in clinical and experimental studies without renal impairment, there are no long-term studies concerning estrogen replacement in chronic renal failure. Methods. In this experimental study, six groups of nephrectomized and ovariectomized animals were treated with different doses of 17beta-estradiol, alone or in combination with calcitriol, to evaluate the effect of these treatments on bone metabolism. Results. Biochemical results showed that estrogen alone did not have any effect neither on calcium nor on PTH serum levels. By contrast, in the groups treated with calcitriol, the levels of serum calcium were significantly higher, and the levels of iPTH were significantly lower than those observed in the control group. Animals receiving the combined treatment with estrogen and calcitriol showed the greater gain in uterus weight and a better bone mineral density at the lumbar site and the proximal and distal tibia sites. Conclusion. The combination of estrogen and calcitriol is the most effective therapy to prevent bone mass loss in animals with chronic renal failure and estrogen deprivation.