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Query: UNIPROT:Q9UIJ5 (
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58,342
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The leaves of the plant Solanum malacoxylon contain 1,25 dihydroxycholecalciferol, the active form of
vitamin D
. The effect on egg-shell thickness of supplementing the diet of laying hens with a dry powdered preparation of the leaves (DLSM) has been studied. A significnat increase in shell thickness was evident for eggs laid on the second and subsequent days of the DLSM-regimen but nor for those laid during the first 24 hours. It is suggested that the provision of high doses of the
vitamin D
metabolite in the form of a DLSM supplement may restore calcium binding protein levels in birds approaching the end of the first laying year and hence improve dietary calcium absorption and consequently egg-shell quality.
Vet
Rec
1977 Dec 17
PMID:The effect on egg-shell thickness of the inclusion of the calcinogenic plant Solanum malacoxylon in the diet of laying hens. 60 86
The clinical, radiological and pathological findings in a natural outbreak of rickets affecting 82 pigs are described. An interesting feature was the presence of gross articular abnormalities including resorption of subchondral bone with folding and ulceration of the articular cartilage. The diet was deficient in calcium and
vitamin D
. A diagnosis of rickets complicated by nutritional secondary hyperparathyroidism was made. The results of treatment and the economics of the outbreak are discussed.
Vet
Rec
1978 Jul
PMID:Rickets in growing pigs and response to treatment. 67 16
A case of cervical deformity of lambs following dosage with
vitamin D
was investigated. The lesions of a scoliosis are described together with the kidney lesions. It is suggested that doses of
vitamin D
normally considered to be non-toxic to sheep may prove to be so under certain conditions.
Vet
Rec
1976 Feb 21
PMID:Cervical scoliosis and kidney lesions in sheep following dosage with vitamin D. 126 95
The morphology of the metaphyseal microvasculature at the epiphysis was examined at both the light and electron microscopic level in rickets and rachitic reversal. The animals studied were normal, rachitic, and rachitic reversed at 8, 24, and 96 hours post-
vitamin D
administration. The overall architecture of the metaphyseal vessels was significantly altered throughout the intervals examined. In the rachitic animal, arterioles, venules, and capillaries were found adjacent to the growth plate, either directly apposed to the hypertrophic chondrocytes or separated from them by bone-forming cells. These vessels are in many ways similar to the larger arterioles and venules that normally supply the metaphyseal capillary sprouts, but in the normal growing animal are usually located 350-500 microns from the epiphyseal cartilage. The rachitic capillaries appear relatively well differentiated with a partial basement membrane and a perivascular cell lining. In early rachitic reversal, small vascular projections are induced to grow from the large diameter venules that border upon the hypertrophic chondrocytes. These vascular sprouts that invade the epiphyseal cartilage are quite undifferentiated, with no basement membrane or pericyte lining at the sprout apex and occasional abluminal endothelial cell projections. Within 96 hours, the metaphyseal microvasculature has returned to an apparently normal state with only capillaries at the cartilage-vascular interface and larger vessels (arterioles and venules) located several hundred microns deeper into the metaphysis. The sequential processes of differentiation and cessation of capillary growth followed by dedifferentiation and reinitiation of microvascular growth make the rachitic system a unique one in which to study angiogenesis.
Anat
Rec
1991 Apr
PMID:Rearrangement of the metaphyseal vasculature of the rat growth plate in rickets and rachitic reversal: a model of vascular arrest and angiogenesis renewed. 171 Aug 78
New methods of tissue preparation were developed to study the morphology and distribution of calcium ions in duodenal enterocytes from normal, rachitic, and
vitamin D
-replete (either cholecalciferol [CC] or 1,25-dihydroxycholecalciferol [1,25-DHCC] treated) chicks. Frozen hydrated sections were prepared from cryofixed tissues by ultracryomicrotomy at -125 degrees C. Sections were subsequently freeze-dried by increasing the temperature to -100 degrees C. The latter temperature was maintained throughout both the structural and elemental analyses. In cells from normal, rachitic, and
vitamin D
-treated [CC] animals the brush border from lanthanum-infused tissues was electron dense and calcium-lanthanum positive by x-ray analysis. In the absence of lanthanum, i.e., sucrose-infused duodena, the microvilli were still calcium positive. In the terminal web region of normal and CC-treated enterocytes, numerous, apparently interconnected, tubules and vesicles were seen. Vacuole-like structures were also seen. Such structures were especially prominent in the enterocytes from the vitamin-treated [CC] animals. Except for the vacuoles, the tubules and vesicles were electron dense in the lanthanum-infused duodena, and clear in sucrose-infused tissues. In both instances, the structures were calcium positive. Similar, but even larger structures were seen below the terminal web. Here however, the tubules and vesicles seemed to be organized into multiple complex interconnecting networks, i.e., tubulo-vesicular complexes. Both the tubules and the vesicles seemed to be interconnected via smaller channel-like entities. The extensiveness of this structure was better appreciated in the enterocytes from lanthanum-infused tissues, where it appeared similar in structure and complexity to an en face view of the sarcoplasmic reticulum of skeletal muscle. These intestinal complexes were less well developed, decreased in number, and quite often absent, in the apical cytoplasm of absorptive cells from rachitic chicks. In the enterocytes from animals treated for 24 hours with 1,25-DHCC, the same highly developed tubulo-vesicular networks were again seen in the enterocyte apical cytoplasm. They were even more developed in the 1,25-DHCC-treated animals. All structures were intensely calcium positive in enterocytes from both the lanthanum- and the sucrose-infused preparations. Numerous endocytotic (pinocytotic) vesicles were seen at the lumenal plasmalemma. Similar structures were also apparent in the terminal web region of the 1,25-DHCC-treated enterocytes. Exocytotic vesicles were seen at the apical aspect of the lateral cell membrane, below the level of the junctional complex. All components of this unique system contained high concentrations of calcium.(ABSTRACT TRUNCATED AT 400 WORDS)
Anat
Rec
1991 Feb
PMID:Cryofixation, ultracryomicrotomy, and X-ray microanalysis of enterocytes from chick duodenum: vitamin-D-induced formation of an apical tubulovesicular system. 201 10
The calcification of cartilage matrix in endochondral bone formation occurs in an extracellular matrix composed of fibrils of type II collagen with which type X collagen is closely associated. Also present within this matrix are the large proteoglycans containing chondroitin sulfate which aggregate with hyaluronic acid. In addition, the matrix contains matrix vesicles containing alkaline phosphatase. There is probably a concentration of calcium as a result of its binding to the many chondroitin sulfate chains. At the time of calcification, these proteoglycans become focally concentrated in sites where mineral is deposited. This would result in an even greater focal concentration of calcium. Release of inorganic phosphate, as a result of the activity of alkaline phosphatase, can lead to the displacement of proteoglycan bound calcium and its precipitation. The C-propeptide of type II collagen becomes concentrated in the mineralizing sites, prior to which it is mainly associated with type II collagen fibrils and is present in dilated cisternae of the enlarged hypertrophic chondrocytes. The synthesis of type II collagen and the C-propeptide, together with alkaline phosphatase, are regulated by the
vitamin D
metabolites 24,25(OH)2 cholecalciferol and 1,25 (OH)2 cholecalciferol. At the time of calcification, type X collagen remains associated with type II collagen fibrils. It may play a role in preventing the initial calcification of these fibrils focusing mineral formation in focal interfibrillar sites. This process of calcification is clearly very complex, and involves different interacting matrix molecules and is carefully regulated at the cellular level.
Anat
Rec
1989 Jun
PMID:Cartilage macromolecules and the calcification of cartilage matrix. 267 83
A cytochemical technique for the electron microscopic localization of calcium adenosine triphosphatase (Ca-ATPase) was utilized to localize this enzyme in the enterocytes of rachitic and
vitamin D
-replete chicks. In animals treated with cholecalciferol (CC, vitamin D3), an electron-dense reaction product was located along the basolateral membranes of the absorptive cells within 72 hr after injection. Similarly, a reaction product was identified in association with the basolateral membranes within 24 hr after injection of 1,25-dihydroxycholecalciferol, the active metabolite of
vitamin D
. A microvillar reaction product was not seen in either of these two groups. Electron-dense reaction products were also seen in association with mitochondria and scattered throughout the cytoplasm of these enterocytes. The Ca-ATPase reaction product was dependent upon the presence of medium calcium and substrate (ATP), was inhibited by vanadate, and was heat labile. In the rachitic animals, a reaction product indicative of Ca-ATPase activity was not seen in association with either the basolateral membranes or the mitochondria. These data appear to indicate that an energy-requiring calcium-activated membrane pump plays a role in the flux of calcium across the enterocytes of the small intestine.
Anat
Rec
1987 Dec
PMID:Electron microscopic cytochemical localization of a basolateral calcium adenosine triphosphatase in vitamin D replete chick enterocytes. 283 84
Pregnant ewes were injected intramuscularly with 300,000 iu of vitamin D3 in a water miscible vehicle either 10, seven or four weeks before the expected lambing date and the effects on plasma concentrations of 25-hydroxyvitamin D3 were monitored. The concentrations increased quickly and remained high at parturition but at no time were they outside the normal physiological range. The concentrations in the plasma of the newborn lambs were higher than in uninjected controls and were well correlated with the concentrations in their mothers. Dosing pregnant ewes with 300,000 iu of vitamin D3 in a rapidly available form, approximately two months before lambing, provided a safe means of increasing the
vitamin D
status of the ewe and the newborn lamb by preventing the seasonally low concentrations of 25-hydroxyvitamin D3.
Vet
Rec
1987 Feb 28
PMID:Effect of vitamin D supplementation during pregnancy on the vitamin D status of ewes and their lambs. 303 71
To examine whether either of the two known active
vitamin D
metabolites 1,25(OH)2D3 or 24,25(OH)2D3 could reverse the mineralization defect induced by 1-hydroxyethylidene-1,1-bis phosphonate (EHDP), a model of EHDP-induced rickets was used. Rats at the age of 31 days were injected for 10 consecutive days with EHDP (10 mg/kg). Other littermates were treated with a combination of EHDP and either 1,25(OH)2D3 or 24,25(OH)2D3 or were treated following 10 days of EHDP, with either of the
vitamin D
metabolites for an additional 72 hr. Samples of cartilage fluid (Cfl) and of blood were removed prior to sacrifice for biochemical studies of some parameters of calcification. These parameters were correlated with the results of light and electron microscope studies of growth plate cartilage and bone. EHDP-treated rats revealed signs of typical rickets, manifested by widened growth plates and impaired bone mineralization. Transmission electron microscope (TEM) examination revealed matrix vesicles distributed throughout the growth plate; however, there appeared to be an arrest of the spread of the crystals at the provisional zone of calcification. Treatment with either 1,25(OH)2D3 or 24,25(OH)2D3 failed to reverse the rachitic condition of the animals. Serum calcium blood levels were elevated in the 1,25(OH)2D3 and EHDP-treated group. 1,25(OH)2D3 and 24,25(OH)2/D3 further increased the already elevated serum alkaline phosphatase levels observed in EHDP rats, although the increase observed with 1,25(OH)2D3 was not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)
Anat
Rec
1988 Jan
PMID:EHDP-induced rachitic syndrome in rats is not reversed by vitamin D metabolites. 312 78
Specific antisera raised against calbindin-D28K (CaBP), the vitamin D-dependent calcium-binding protein from chick intestine, was used to localize the protein in chick ultimobranchial glands (UB glands) by the peroxidase-antiperoxidase technique. CaBP was localized in secretory cells in the cell cords and in a few cells of the epithelium lining the follicles. It was not found in the fibroblastlike cells in the cell cords nor in islands of parathyroid tissue present in the UB gland. The immunomarker for CaBP was distributed throughout the cytoplasm and nucleus of the secretory cells. The same cells demonstrated a positive reaction in their cytoplasm when reacted with an antiserum specific for salmon calcitonin (CT), thus confirming the presence of CaBP and CT in the same UB-gland secretory cells. In other tissues, the presence of CaBP is regarded as an end-organ marker for actions of the
vitamin D
endocrine system. This novel demonstration of CaBP in UB-gland cells responsible for secretion of calcitonin suggests a direct effect of the
vitamin D
endocrine system on those cells in addition to an indirect effect through the stimulation produced by elevated circulating calcium levels.
Anat
Rec
1987 Sep
PMID:Localization of calbindin-D28K in calcitonin containing cells of chick ultimobranchial glands. 368 64
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