A Sensitive Radioimmunoassay for 1,25-Dihydroxyvitamin D3 (Calcitriol) after High-Performance Liquid Chromatography of Plasma or Serum Extracts

The aim of this study was to determine the changes in serum calcium concentration and in the concentrations of calcium regulating hormones after a single oral or intravenous calcium administration. Standard dosages of calcium, as used in routine patient care, were employed.Intact para thy rin, calci tonin, calcitriol, calcidiol, total calcium, ionized calcium, total protein and phosphate were determined in 12 healthy young men before and up to 8 h after oral and intravenous administration of calcium.During a fortnight there were four study days with 1000 mg calcium orally (p. o.) 5 2000mg orally, 180mg calcium intravenous (i.v.) and a control day without calcium. During the study the men were on a low calcium diet.

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“…Calcitriol was determined with a radioimmunoassay after high performance liquid chromatography of serum extracts according to Scharla et al (29).…”

Section: Calcitriolmentioning

confidence: 99%

Calcium Regulating Hormones after Oral and Intravenous Calcium Administration

Herfarth¹,

Drechsler²,

Imhoff³

et al. 1992

Clinical Chemistry and Laboratory Medicine

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Effect of ovariectomy on bone histology and plasma parameters of bone metabolism in nulliparous and multiparous sows

Scholz-Ahrens

Delling

Jungblut³

et al. 1996

Z Ernährungswiss

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To investigate the suitability of the pig as animal model for postmenopausal osteoporosis, effects of ovariectomy (OVX) on bone metabolism and histology were studied in two groups of sows (9 months, nulliparous or 35 months, multiparous). A standard diet of about 1.5% calcium (Ca) was fed till sacrifice at either 12 or 20 months post OVX when mineral content and histology were studied in representative bone specimens of proximal tibia, iliac crest and lumbar vertebrae. At 4, 8, 12, and 18 months post OVX, total and bone-specific alkaline phosphatase (APt, APb) calcidiol, calcitriol and parathyroid hormone (PTH) were measured in plasma. In young sows OVX did not significantly affect plasma variables except for calcitriol, which was higher at 4 months post OVX. No significant differences between OVX or control animals were observed in the variables of bone chemical and histological analyses, neither 12 nor 20 months post OVX. In multiparous sows OVX significantly increased PTH plasma concentrations at 8 months post OVX and plasma calcitriol, APt and APb at 12 months post OVX. All effects were moderate and transient. OVX did not significantly affect the variables of bone chemical and histological analyses neither 12 nor 20 months post OVX. Although undoubtedly the clinical-chemical changes observed were not accompanied by any histomorphometric signs of osteopenia/osteoporosis, it must be left to future experiments as to whether this resulted from the ample calcium supply provided. This possibility is supported by recent observations showing that porcine osteopenia could be induced by OVX in animals maintained on only 0.75% dietary calcium but not on higher (0.9%) Ca regimens.

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Advances and challenges in the measurement of 1,25-dihydroxyvitamin D: a comprehensive review

Jin

Bertholf

2023

Critical Reviews in Clinical Laboratory Sciences

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A Sensitive Radioimmunoassay for 1,25-Dihydroxyvitamin D3 (Calcitriol) after High-Performance Liquid Chromatography of Plasma or Serum Extracts

Cited by 3 publications

References 41 publications

Calcium Regulating Hormones after Oral and Intravenous Calcium Administration

Calcium Regulating Hormones after Oral and Intravenous Calcium Administration

Effect of ovariectomy on bone histology and plasma parameters of bone metabolism in nulliparous and multiparous sows

Advances and challenges in the measurement of 1,25-dihydroxyvitamin D: a comprehensive review

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