PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “ERGOCALCIFEROL”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 757 records · Page 42Linked to original sources
PubMed1981

Isolation and identification of 25-hydroxyvitamin D2 25-glucuronide: a biliary metabolite of vitamin D2 in the chick.

The biliary metabolites of vitamin D2 obtained from chickens dosed with 3H-labeled vitamin D2 were investigated. Most of the biliary radioactivity migrated as charged compounds on diethylaminoethyl-Sephadex chromatography, and the charged fraction could be resolved into several components by reversed-phase high pressure liquid chromatography. A major charged metabolite was further purified by reversed-phase high-pressure liquid chromatography. This compound was found to be beta-glucuronidase sensitive and to yield 25-hydroxyvitamin D2 upon mild acid hydrolysis. The metabolite was converted first to the methyl ester and then to silylated and acetylated derivatives, which were subjected to mass spectrometry. The structure of the original metabolite was established as 25-hydroxyvitamin D2 25-beta-D-glucuronic acid. This 25-hydroxyvitamin D2 25-beta-glucuronide is a major biliary metabolite of vitamin D2 in the chick and may play a role in the chick's discrimination against vitamin D2.

25-Hydroxyvitamin D 2↗
PubMed1976

Biological activity of 1,25-dihydroxyvitamin D2 in the chick.

1,25-Dihydroxyvitamin D2 has been prepared from 25-hydroxyvitamin D2 using rachitic chick kidney mitochondria. This metabolite was highly purified by Sephadex LH-20 chromatography and by preparative high-pressure liquid chromatography. Its purity was assessed by analytical high-pressure liquid chromatography which revealed no other 254-nm absorbing material and by mass spectrometry. The concentration of dilute solutions of 1,25-dihydroxyvitamin D2 was determined by high-pressure liquid chromatography and deflection of the 254-nm column monitor. The 1,25-dihydroxyvitamin D2 was then shown to be 1/5 to 1/10 as active as 1,25-dihydroxyvitamin D3 in the chick while it had previously been shown to be equal in activity in the rat. Thus, discrimination against the vitamin D2 side chain by the chick persists in the metabolically active 1,25-dihydroxyvitamin D compounds.

Animals↗
PubMed1975

Isolation and identification of 1,25-dihydroxyvitamin D2.

The chemical synthesis of [3alpha-3H]vitamin D2 of high specific activity has been described. With the use of this radioactive material, the existence of a polar metabolite believed to be the active form of vitamin D2 in the rat and chick has been demonstrated. It has been isolated in pure form from an in vitro chick kidney mitochondrial system and identified as 1,25-dihydroxyvitamin D2 by means of mass spectrometry, ultraviolet absorption spectrophotometry, and specific derivative synthesis. Its antirachitic activity equals that of 1,25-dihydroxyvitamin D3 in the rat.

Animals↗
PubMed1999

Comparative effects of vitamin K2 and vitamin E on experimental arteriosclerosis.

The comparative effects of vitamin K2 and vitamin E on aortic calcium (Ca) and inorganic phosphorus (P) levels in the aorta and the elastin fraction (fr.) were investigated in male rats after experimental arteriosclerosis was induced by vitamin D2 with atherogenic diet. Both vitamin K2 (100 mg/kg b.w.) and vitamin E (40 mg/kg b.w.) inhibited the increase of Ca and P in the aorta and the elastin fr. from the arteriosclerotic rats. Vitamin K2 (50 mg/kg b.w.) also suppressed the deposition of Ca and P in the aorta, but there was no change due to vitamin K3 or geranylgeraniol (side chain of vitamin K2) administration. Both vitamin K2 and vitamin E showed lipid radical scavenging activity in the in vitro experiment. However, neither vitamin K3 nor geranylgeraniol exhibited anti-arteriosclerotic or radical scavenging activity under the above experimental conditions. It is suggested that vitamin K2 and vitamin E promoted an antiarteriosclerotic effect by radical scavenging activity. These actions of vitamin K2 are required in the structure of 2-methylnaphtoquinone and its side chain (geranylgeraniol).

Animals↗
PubMed1981

Long-term anticonvulsant therapy and intestinal calcium absorption.

Twelve patients on anticonvulsant therapy were studied to determine whether or not the drugs induced alterations in gastrointestinal absorption of calcium, response to parathyroid hormone (PTH), or serum 25-hydroxy vitamin D (25-OHD) concentrations. Fractional calcium absorption (FCaA) was determined by giving 45Ca intravenously and orally. The short-term response to PTH was assessed by giving 200 U of parathyroid extract (PTE) intravenously over 15 min and measuring hourly urine cyclic adenosine monophosphate (cAMP) and tubular reabsorption of phosphate (TRP). Calcemic response to PTH was followed by giving intramuscular injections of PTE, 200 U every 6 hr. FCaA was 30.8 +/- 3.7% lower than the normal of 42.2 +/- 2.5% (P less than 0.025), and baseline 25-OHD levels were 30.5 +/- 3.4 ng/ml (normal 15 to 50 ng/ml). Anticonvulsant drugs did not alter renal response to PTE. There was a rise in urinary cAMP from 3.7 +/- 0.23 to 6.1 +/- 0.47 mumol/gm creatinine (P less than 0.005) with a fall in TRP from 87.8 +/- 1.2% to 78.8 +/- 1.6% (P less than 0.005). Serum calcium rose from 9.4 +/- 0.1 to 11.1 +/- 0.3 mg/dl (P less than 0.005). We conclude that FCaA is low in patients receiving anticonvulsant drugs, even when serum 25-OHD levels and the response of bone and kidney to PTH remain normal.

25-Hydroxyvitamin D 2↗
PubMed1987

Interactions between 1,25-dihydroxyvitamin D3 and vitamin D2: effects of pharmacologic doses in normal individuals.

To determine whether the administration of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) affects the conversion of a pharmacologic dose of vitamin D2 to 25-hydroxyvitamin D (25OHD), 20 normal subjects received two separate doses of vitamin D2--one with and the other without the concomitant administration of 1,25(OH)2D3. Serum 1,25(OH)2D rose in response to 1,25(OH)2D3 administration and fell when vitamin D2 was given alone. Serum osteocalcin rose in response to 1,25(OH)2D3 administration. Serum 25OHD rose in response to vitamin D2 administration regardless of whether the subjects also received 1,25(OH)2D3. The data from this study in humans support the suggestion that the effects of 1,25(OH)2D3 on serum 25OHD concentrations are mediated through mechanisms other than impairment of production.

25-Hydroxyvitamin D 2↗