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פותח על ידי קלירמאש פתרונות בע"מ -
PLASMA AND INTESTINAL CONTENT OF 1, 25 DIHYDROXYVITAMIN D IN CALCIUM OR PHOSPHORUS RESTRICTED BIRDS
Year:
1993
Source of publication :
Endocrinology
Authors :
הורויץ, שמואל (בעלי חיים)
;
.
Volume :
132
Co-Authors:

J Russell - Department of Medicine, Albert Einstein College of Medicine, Bronx, New York 10461.

A Bar - Department of Medicine, Albert Einstein College of Medicine, Bronx, New York 10461.

L M Sherwood  - Department of Medicine, Albert Einstein College of Medicine, Bronx, New York 10461

Facilitators :
From page:
2639
To page:
2644
(
Total pages:
6
)
Abstract:

Regulation of prepro-PTH and vitamin D receptor (VDR) mRNAs in the parathyroid glands was studied in chickens in vivo. The birds were raised to 21 days of age on a vitamin D-deficient diet with 1% calcium and 0.65% phosphorous. At the end of this period, the chicks exhibited marked hypocalcemia and enlarged parathyroid glands. In three separate trials, the birds were repleted for 6 days with vitamin D and different dietary calcium and phosphate concentrations, with 2 micrograms/kg 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] and different dietary calcium concentrations (0.5%, 1.0%, or 1.8%), or with 2 or 10 micrograms/kg 1,25-(OH)2D3 and 0.6% or 1.9% calcium or were kept vitamin D3 deficient and fed 0.5%, 1.0%, or 1.8% dietary calcium. Vitamin D treatment when combined with a high level of dietary calcium resulted in an increase in plasma calcium from 6 mg/dl to greater than 10 mg/dl, a decrease in PTH mRNA of 65%, and a 6- to 8-fold increase in VDR mRNA. In another experiment in which no vitamin D source was given and the diets contained increasing levels of dietary calcium, plasma calcium increased significantly (5.5 vs. 7 mg/dl), while PTH mRNA decreased by 40% and VDR mRNA increased by 60%. Neither parathyroid gland weight nor total RNA was significantly affected. When chicks were repleted with 1,25-(OH)2D3, the increase in plasma calcium and VDR mRNA and the decrease in PTH mRNA were considerably more pronounced than those in the absence of the vitamin D source. Furthermore, in the presence of the hormone, parathyroid weight and total RNA decreased significantly with increasing concentrations of dietary calcium. When the chicks were repleted, respectively, with the two levels of 1,25-(OH)2D3, a marked positive interaction was evident between the hormone and dietary calcium in affecting levels of PTH and VDR mRNA. These results suggest that both 1,25-(OH)2D3 and calcium participate in the regulation of PTH and VDR gene transcription in the avian parathyroid gland. Whereas the action of 1,25-(OH)2D3 requires a minimal level of dietary calcium, calcium affects PTH and VDR gene transcription even in the absence of any vitamin D source.

Note:
Related Files :
Birds
calcium
Chickens
mRNA
Parathyroid Glands
Phosphorus
plasma
PTH/PTHrP receptor
Vitamin D
עוד תגיות
תוכן קשור
More details
DOI :
https://doi.org/10.1210/en.132.6.2639
Article number:
0
Affiliations:
Database:
גוגל סקולר
Publication Type:
תקציר
;
.
Language:
אנגלית
Editors' remarks:
ID:
37765
Last updated date:
21/08/2022 07:45
Creation date:
31/10/2018 10:08
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Scientific Publication
PLASMA AND INTESTINAL CONTENT OF 1, 25 DIHYDROXYVITAMIN D IN CALCIUM OR PHOSPHORUS RESTRICTED BIRDS
132

J Russell - Department of Medicine, Albert Einstein College of Medicine, Bronx, New York 10461.

A Bar - Department of Medicine, Albert Einstein College of Medicine, Bronx, New York 10461.

L M Sherwood  - Department of Medicine, Albert Einstein College of Medicine, Bronx, New York 10461

PLASMA AND INTESTINAL CONTENT OF 1, 25 DIHYDROXYVITAMIN D IN CALCIUM OR PHOSPHORUS RESTRICTED BIRDS .

Regulation of prepro-PTH and vitamin D receptor (VDR) mRNAs in the parathyroid glands was studied in chickens in vivo. The birds were raised to 21 days of age on a vitamin D-deficient diet with 1% calcium and 0.65% phosphorous. At the end of this period, the chicks exhibited marked hypocalcemia and enlarged parathyroid glands. In three separate trials, the birds were repleted for 6 days with vitamin D and different dietary calcium and phosphate concentrations, with 2 micrograms/kg 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] and different dietary calcium concentrations (0.5%, 1.0%, or 1.8%), or with 2 or 10 micrograms/kg 1,25-(OH)2D3 and 0.6% or 1.9% calcium or were kept vitamin D3 deficient and fed 0.5%, 1.0%, or 1.8% dietary calcium. Vitamin D treatment when combined with a high level of dietary calcium resulted in an increase in plasma calcium from 6 mg/dl to greater than 10 mg/dl, a decrease in PTH mRNA of 65%, and a 6- to 8-fold increase in VDR mRNA. In another experiment in which no vitamin D source was given and the diets contained increasing levels of dietary calcium, plasma calcium increased significantly (5.5 vs. 7 mg/dl), while PTH mRNA decreased by 40% and VDR mRNA increased by 60%. Neither parathyroid gland weight nor total RNA was significantly affected. When chicks were repleted with 1,25-(OH)2D3, the increase in plasma calcium and VDR mRNA and the decrease in PTH mRNA were considerably more pronounced than those in the absence of the vitamin D source. Furthermore, in the presence of the hormone, parathyroid weight and total RNA decreased significantly with increasing concentrations of dietary calcium. When the chicks were repleted, respectively, with the two levels of 1,25-(OH)2D3, a marked positive interaction was evident between the hormone and dietary calcium in affecting levels of PTH and VDR mRNA. These results suggest that both 1,25-(OH)2D3 and calcium participate in the regulation of PTH and VDR gene transcription in the avian parathyroid gland. Whereas the action of 1,25-(OH)2D3 requires a minimal level of dietary calcium, calcium affects PTH and VDR gene transcription even in the absence of any vitamin D source.

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