Calcium Excretion and Serum Calcium Concentration in Adult Intact and Gonadectomized Rats

Rice, Bernard F.; Ponthier, Roy L.; Miller, Max

doi:10.1210/endo-83-6-1375

Cited by 5 publications

(3 citation statements)

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“…Serum immunoreactive parathyroid hormone (PTH) was not measured, but it is unlikely that values were altered in castrated rats since these animals were either normocalcemic following ovariectomy or had mild hypercalcemia following orchiectomy and showed no changes in mean serum 1,25-(OH),D. Orchiectomy was previously shown to increase urine calcium. (20) Vitamin D deficiency and parathyroidectomy alter bone histomorphometry in the rat model, but the skeletal changes are accompanied by much more pronounced changes in serum mineral homeostasis. Thus, the evidence is unconvincing that the skeletal effects of castration are mediated by changes in either calciumregulating hormones or mineral metabolism.…”

Section: Discussionmentioning

confidence: 99%

Differential effects of gonadal function on bone histomorphometry in male and female rats

Turner

Hannon

Demers

et al. 1989

Journal of Bone and Mineral Research

175

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The effects of castration on bone histomorphometry and mineral homeostasis were compared in male and female rats. Measurements were performed 4 weeks after sham operation or gonadectomy. Orchiectomy produced increases in serum calcium and decreases in serum testosterone and androstenedione, whereas ovariectomy produced decreases in serum estradiol and testosterone. Orchiectomy did not alter static bone histomorphometric measurements of the tibial diaphysis, whereas ovariectomy increased cross-sectional and medullary areas, lowered endosteal tetracycline-labeled surface length, and markedly increased endosteal nonlabeled surface length. Orchiectomy decreased mean periosteal bone formation rate and mean periosteal bone apposition rate, whereas ovariectomy increased both measurements. Orchiectomy and ovariectomy markedly diminished trabecular area and trabecular surface length at the tibial metaphysis. Orchiectomy did not alter the number of osteoclasts per mm trabecular surface or the percentage of trabecular surface covered by osteoclasts, whereas ovariectomy increased both measurements. These findings indicate that gonadal hormones produce separate and distinct effects on bone metabolism as determined by histomorphometry in male and female rats.

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Section: Discussionmentioning

confidence: 99%

Differential effects of gonadal function on bone histomorphometry in male and female rats

Turner

Hannon

Demers

et al. 1989

Journal of Bone and Mineral Research

175

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“…Throughout the study, all rats were maintained on Purina Lab chow and tap water ad libitum. Serum calcium was measured by atomic absorption spectroscopy using a modification of the method of Zettner and Seligson previously described (Rice et al 1968). All bloods were collected by cardiac puncture and scrum separated after centrifugation.…”

Section: Methodsmentioning

confidence: 99%

Hypercalcaemia of Neoplasia, Parathyroid Hormone and Vitamin D: Studies in Parabiosis

Ponthier

Rice

1974

Acta Endocrinologica

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A localized transplantable Leydig cell tumour of the Fischer rat regularly produces lethal hypercalcaemia in thyroparathyroidectomized and intact hosts. The parabiosis model was used to explore and compare the hypercalcaemia producing action of this tumour, parathyroid hormone, and vitamin D. Administration of exogenous parathyroid hormone (10 and 20 units) to one thyroparathyroidectomized parabiont rat increased the serum calcium in both parabionts within 24 hours. Endogenous parathyroid hormone, studied by producing parabiosis between thyroparathyroidectomized rats and intact rats, raised the serum calcium of the thyroparathyroidectomized parabiont within 7 days in parabiosis, suggesting that endogenous parathyroid hormone is effective across the parabiotic union. Vitamin D3 (100 000 and 150 000 units) given to one parabiont of a thyroparathyroidectomized pair produced hypercalcaemia only in the injected parabionts. When the hypercalcaemia producing tumour was grown in thyroparathyroidectomized pairs for 3\p=n-\6 weeks, severe hypercalcaemia and death occurred only in the tumour bearing parabiont. The serum calcium of the non-tumour parabiont did rise over a period of 3\p=n-\6weeks and was compatible with an approach to calcium

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“…Thus Orimo, Fujita and Yoshikawa (1972) demonstrated increased sensitivity of bone to parathyroid hormone in oophorectomized rats and a similarly increased sensitivity has been demonstrated more recently in castrated mice (Broulik, Stepan and Pacovsky 1978). Castrated male rats have also been shown to excrete more calcium in their urine than intact animals of the same sex (Rice, Ponthier and Miller 1968).…”

Section: Discussionmentioning

confidence: 99%

Effects of Calcium Deprivation and Orchidectomy on Bone Composition in the Rat

Hodgkinson

1979

Horm Metab Res

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The effects of calcium deprivation and of orchidectomy, separately and combined, on body growth and bone composition have been examined in mature male rats. Calcium deprivation had no significant effect on the rate of body growth but femoral bone weight, bone ash weight and total calcium and phosphorus contents of the femora were reduced while the water content increased. However, there were no significant changes in the ratio of bone weight to body weight, in the amounts of calcium or phosphorus per unit weight of bone, or in the ratio of calcium to phosphorus in the bone. Orchidectomy reduced the rate of body growth, the mean weight of the femora and the ratio of bone weight to body weight. There was a 60% decrease in bone water and a 30--35% reduction in the calcium and phosphorus content of the femora but the amounts of ash, calcium and phosphorus per unit weight of bone fell by only 6--10%. The combination of orchidectomy and calcium deprivation had no greater effect on body weight, bone weight or bone composition than had orchidectomy alone. It is concluded that calcium deprivation and orchidectomy both cause osteoporosis in mature rats but the effects of orchidectomy are more severe than those of calcium deprivation and there appears to be some demineralization of the bone remaining after orchidectomy.

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Calcium Excretion and Serum Calcium Concentration in Adult Intact and Gonadectomized Rats

Cited by 5 publications

References 0 publications

Differential effects of gonadal function on bone histomorphometry in male and female rats

Differential effects of gonadal function on bone histomorphometry in male and female rats

Hypercalcaemia of Neoplasia, Parathyroid Hormone and Vitamin D: Studies in Parabiosis

Effects of Calcium Deprivation and Orchidectomy on Bone Composition in the Rat

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