On the site of discrimination of chicks against vitamin D2

Drescher, Dennis G.; DeLuca, Hector F.; Imrie, M.H.

doi:10.1016/0003-9861(69)90084-8

Cited by 37 publications

(15 citation statements)

References 10 publications

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“…If liver catabolizes ergocalciferol faster than cholecalciferol, then our results could be explained by more rapid clearance of ergocalciferol from the circulation. This phenomenon was not apparent in the previous work of Drescher et al (1969), Imrie et al (1967) or Jones et al (1975). All of these previous experiments suggested that the point of discrimination against ergocalciferol by the chick was at the 25(OH)D level.…”

Section: Concentrationsmentioning

confidence: 68%

Discrimination in the metabolism of orally dosed ergocalciferol and cholecalciferol by the pig, rat and chick

Horst¹,

Napoli²,

Littledike³

1982

Biochemical Journal

108

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Vitamin D-deficient pigs, rats and chicks were repleted with four daily oral doses of crystalline ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3) containing equal concentrations of each. At 24 h after the last dose, the plasma of each species was analysed for vitamin D and 25-hydroxyvitamin D by standard methods. The mean (+/- S.D.) ratios of plasma cholecalciferol to ergocalciferol concentration were 1.5 +/- 0.1 (pig). 1.7 +/- 0.1 (rat) and 6.3 +/- 1.2 (chick). The mean ratios of plasma 25-hydroxycholecalciferol to 25-hydroxyergocalciferol concentration were 4.0 +/- 0.1 (pig), 0.4 +/- 0.02 (rat) and 10.7 +/- 3.4 (chick). The mean plasma cholecalciferol/ergocalciferol ratios for the 24,25-dihydroxy-, 25,26-dihydroxy- and 1,25-dihydroxy-derivatives in the pig were 2.6 +/- 0.6, 5.8 +/- 1.3 and 5.8 +/- 0.8 respectively. This is the first evidence that mammals other than the New World monkey, like birds, discriminate between ergocalciferol and cholecalciferol. These data, therefore, suggest that species discrimination between the different forms of vitamin D is probably a general phenomenon in mammals. Moreover, this is the first indication of a species (rat) that discriminates against a cholecalciferol metabolite in favour of an ergocalciferol metabolite. Species discrimination against particular forms of vitamin D may be important to the choice of experimental animal models for studying the regulation of vitamin D metabolism and may also be an important consideration in dietary vitamin supplementation.

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Section: Concentrationsmentioning

confidence: 68%

Discrimination in the metabolism of orally dosed ergocalciferol and cholecalciferol by the pig, rat and chick

Horst¹,

Napoli²,

Littledike³

1982

Biochemical Journal

108

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“…This metabolite was described in man (DeLuca et al, 1967;Avioli et al, 1967). chicks (Drescher et al, 1969), and hogs (Blunt et al, 1968a), proved to possess all the biological activities of the parent vitamin, and acted more rapidly (Lund and DeLuca, 1966;Morii et al. 1967).…”

mentioning

confidence: 90%

Isolation and identification of 25-hydroxyergocalciferol

Suda¹,

DeLuca²,

Schnoes³

et al. 1969

Biochemistry

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“…Experiments with 3H-labeled 1,25-(OH)2D2 are now planned to test this possibility. Inasmuch as the D2 compounds are rapidly excreted (Imrie et al, 1967) and only small amounts of 25-OH-D2 (Drescher et al, 1969) or 1,25-(OH)zD~ (Jones et al, 1975) are found even though the enzymatic machinery can metabolize vitamin D2 normally (Jones et al, 1976), it is likely that discrimination is at the metabolic level in which all vitamin D compounds with a c 2 4 substitution are rapidly eliminated. However, the full elucidation of such a mechanism must await identification of the site of such discriminatory metabolism.…”

Section: Discussionmentioning

confidence: 99%

“…In support of this theory are the extremely low levels of 25-hydroxyvitamin D2 (25-OH-Dz)' (Drescher et al, 1969) and 1,25-dihydroxyvitamin D2 (1,25-(OH)*D2) (Jones et al, 1975) that are observed in the rachitic chick after the in vivo administration of physiological doses of radioactive vitamin D2. Using in vitro techniques we were able to show that these reduced levels of hydroxylated vitamin D2 metabolites are not due to a failure of the enzymic machinery to carry out the reactions (Jones et al, 1976).…”

mentioning

confidence: 97%

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

Jones¹,

Baxter²,

DeLuca³

et al. 1976

Biochemistry

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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.

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On the site of discrimination of chicks against vitamin D2

Cited by 37 publications

References 10 publications

Discrimination in the metabolism of orally dosed ergocalciferol and cholecalciferol by the pig, rat and chick

Discrimination in the metabolism of orally dosed ergocalciferol and cholecalciferol by the pig, rat and chick

Isolation and identification of 25-hydroxyergocalciferol

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

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On the site of discrimination of chicks against vitamin D2

Cited by 37 publications

References 10 publications

Discrimination in the metabolism of orally dosed ergocalciferol and cholecalciferol by the pig, rat and chick

Discrimination in the metabolism of orally dosed ergocalciferol and cholecalciferol by the pig, rat and chick

Isolation and identification of 25-hydroxyergocalciferol

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

Contact Info

Product

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