Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.3.1 (alkaline phosphatase)
 47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have used in situ hybridization to examine expression of collagen type I, II, and X mRNA and osteonectin mRNA in the chick epiphysis. Tissue samples from the proximal tibial growth cartilage were fixed in modified Carnoy's solution, dehydrated in ethanol, and embedded in paraffin. Longitudinal and transverse sections were demineralized with HCl and digested with hyaluronidase and proteinase K. In situ hybridization was carried out using biotinylated cDNA probes; the hybridized probe was detected using a streptavidin-biotinylated alkaline phosphatase conjugate. This procedure permitted detection of the corresponding mRNAs in cartilage with high sensitivity and low background. Osteonectin mRNA was detected in proliferating cartilage; lower levels of osteonectin mRNA were seen in the mid-hypertrophic region. This mRNA species was also expressed in cells that border the vascular canals in the premineralized region of the epiphysis. Collagen type X mRNA was detected throughout the hypertrophic zone. As localization of collagen type X mRNA corresponded to the site of maximal synthesis of the protein, reported in other studies, our results would further support the suggestion that this protein is associated with mineralization of cartilage. Collagen type II mRNA was seen in both the proliferating and the hypertrophic regions of the cartilage. Highest levels of expression were observed in the proliferative region. The results suggest that the transcriptional control of collagen type II and X by cells of the proliferating and hypertrophic regions of the growth cartilage may be related.
 ...
PMID:Developmental expression of genes in chick growth cartilage detected by in situ hybridization. 250 10

Sex hormones are closely related to the onset and progression of periodontal disease. The purpose of this study was to evaluate the effects of sex hormones on the metabolism of human periodontal ligament cells. Human periodontal ligament cells and gingival fibroblasts were prepared from 7 donors with normal gingiva. 17 beta-estradiol and progesterone were purchased from Sigma Chemical Company. The effects of sex hormones on cell morphology, alkaline phosphatase activity, cell proliferation, DNA synthesis, collagen synthesis and non-collagenous protein synthesis were investigated. The results were as follows: 1. Periodontal ligament cells showed osteoinductive-like cells in the cell morphology and alkaline phosphatase activity. 2. DNA synthesis was stimulated by 17 beta-estradiol and progesterone in the presence of 5% fetal calf serum. 3. Collagen synthesis was inhibited by 17 beta-estradiol and progesterone, while non-collagenous protein synthesis was inhibited by 17 beta-estradiol and low concentrations of progesterone. 4. The addition of serum into culture medium was necessary to induce the basic metabolism of human periodontal ligament cells. It was demonstrated that sex hormones are closely related to the metabolism of human periodontal ligament cells.
 ...
PMID:[Periodontal tissues and sex hormones. Effects of sex hormones on metabolism of fibroblasts derived from periodontal ligament]. 263 9

To investigate the effect of moderate alcohol consumption on blood constituents related to cardiovascular disease, 12 male volunteers consumed (instead of their usual alcoholic drinks) four different standardized amounts of red wine in addition to their habitual diet. Each dose was given to the subjects during a period of 5 weeks in a randomized order, all subjects receiving the four doses. They consisted of 0, 2, and 4 glasses/d, providing 0, 23, and 46 g alcohol/d as well as in "binge drinking" (14 glasses in the weekend, comparable to an average of 2 glasses/d). The results showed a clear dose-related response to the drinking for several blood constituents. Most marked was a decrease in the tissue-type plasminogen activator activity and to a lesser degree an increase in plasminogen levels. Collagen-induced platelet aggregation was reduced, affecting all parameters measured. Levels of HDL3-cholesterol, gammaglutamyltransferase, and urate showed a small but significant increase. No change was noted in the levels of alkaline phosphatase, alanine-aminotransferase, aspartate-aminotransferase, bile acids, folate, fibrinogen, the ADP-induced platelet aggregation, platelet secretion, or in hematologic values. The results are only partially in accordance with the presumed protective action of moderate drinking on the cardiovascular system and show a stronger response to the consumption of alcohol in coagulation and fibrinolysis factors than in blood lipids.
 ...
PMID:Effects of moderate alcohol consumption on platelet aggregation, fibrinolysis, and blood lipids. 288 51

Disaggregated chondrocytes from embryonic chick whole sterna proliferate in three-dimensional collagen gels forming mixtures of cartilage nodules (chondroids) and columns of cells. A typical matrix elaborated by the cells is composed of collagen type II and chondroitin and keratan sulphate proteoglycans. The cells of the chondroids are small and uniform whilst those in the columns are larger (hypertrophic) and have a vacuolated cytoplasm. Disaggregated cells from the caudal portion of the sternum (which in vivo contains small uniform cells and does not calcify) tend to form chondroids in culture whilst cells from the cephalic portion (which in vivo contains large hypertrophic cells and whose matrix calcifies) tend to form columns of hypertrophic cells. Only the cultures containing hypertrophic cells synthesise collagen type X and only the hypertrophic cells contain alkaline phosphatase. Collagen type X and alkaline phosphatase may therefore be coregulators of the calcification of hypertrophic cartilage matrix.
 ...
PMID:A comparison of the morphological, histochemical and biochemical features of embryonic chick sternal chondrocytes in vivo with chondrocytes cultured in three-dimensional collagen gels. 306 35

Bone mass loss associated with aging can lead to osteoporosis and multiple bone fractures with impaired healing requiring prolonged hospitalization and costly medical care. We have used an experimental implantation model to test the ability of old animals to form new bone. Bone repair inducers, consisting of demineralized bone matrix (DBM), bone marrow, and collagen, were implanted in the abdominal wall muscles of 1-month and 16-month old rabbits. DBM contains a bone morphogenetic protein (BMP) that induces the differentiation of primitive mesenchymal cells into bone producing cells. The stromal cells of bone marrow can differentiate into osteoblasts after implantation, while collagen could serve as a calcification nucleus or framework for new tissue formation. Animals were killed 4 to 6 weeks after implantation. Implants were X-rayed, examined histologically, and analyzed for water content, calcium, and alkaline phosphatase. Only the implants of bone marrow enclosed in filter chambers (0.45 micron pore diameter) were associated with bone formation. Intramuscular implants of DBM and bone marrow in the old animals induced the formation of new bone but contained less calcium and lower levels of alkaline phosphatase than implants in the young animals. Collagen implants were resorbed and failed to induce bone formation or calcify. The results indicate that formation of new bone, under the conditions of this study, is reduced with aging.
 ...
PMID:Skeletal repair in the aged: a preliminary study in rabbits. 319 21

The vascular extracellular matrix (ECM) plays an important role in the histopathology of cerebral microcirculation, but its characterization is still incomplete. For that reason we investigated paraffin-embedded and cryostat sections of intracerebral and meningeal vessels from eight normotensive and six hypertensive humans using monospecific affinity-purified polyclonal antibodies against human/monkey amino-terminal procollagen I + III peptide (P I P, P III P), collagen IV (7-S and NC1 domains), VI, and laminin (P 1 fragment) by applying peroxidase-antiperoxidase- and alkaline phosphatase-antialkaline phosphatase techniques. In normotensives, laminin and collagen IV were codistributed in the basal lamina of meningeal and intraparenchymal vessels. Collagen VI was only present in the adventitia of meningeal vessels and larger intraparenchymal arteries and veins, whereas it was absent from cortical vessels including capillaries. Intensive staining for collagen VI was observed in the choroid plexus, the superficial glia and sheath of cranial nerves. In hypertensives, the basement membrane constituents laminin and collagen IV appeared ubiquitously increased. Here, collagen VI was also deposited in the broadened vascular intima and media of larger arteries and in cortical vessels. In both groups collagen VI and P III P appeared to be codistributed. Our results indicate that significant qualitative change sin ECM of cerebral blood vessels are taking place during the development of hypertension, such as (1) an atypical deposition or an increase of collagen VI which by interconnecting collagen fibrils (I and III) might exert a stabilizing (sclerosing) function in the ECM, and (2) a thickening of vascular basement membranes caused by an accumulation of its major components laminin and collagen IV.
 ...
PMID:Altered expression of collagen type VI in brain vessels of patients with chronic hypertension. A comparison with the distribution of collagen IV and procollagen III. 323 76

Primary bone cell cultures are used widely to examine the regulation of bone metabolism by growth factors and hormones. Characterization of this model system is now being conducted at the molecular level to define modulation of gene expression. Cells were obtained from rat parietal bone by sequential collagenase digestions. Cell populations were evaluated for bone-related products, including collagen isoform expression and mRNA levels, alkaline phosphatase activity, and osteocalcin production. Serum-deprived, confluent cultures of the first and second collagenase-released populations produced a lower percentage of total protein as collagen than the third, fourth, and fifth populations, while co-culturing the third through fifth populations resulted in the highest level. Collagen typing on SDS-polyacrylamide gels revealed an abundance of mature type I collagen in all cell populations; type III collagen synthesis was undetectable by this method. This is in contrast to the presence of cytoplasmic mRNA for both type I and type III collagen in all cell populations, suggesting post-transcriptional modulation of type III collagen synthesis. The expression of alkaline phosphatase and osteocalcin was highest in cultures of later released cells, indicating that these cell populations display phenotypic characteristics associated with cells of the osteoblast lineage.
 ...
PMID:Further biochemical and molecular characterization of primary rat parietal bone cell cultures. 326 77

This report documents osteoblast differentiation in vitro, as demonstrated by the 50-100X increase of proteins which are known markers of the osteoblast phenotype. Collagen type I and osteocalcin synthesis and accumulation, alkaline phosphatase activity, and matrix calcification show similar temporal relationships that are analogous to those seen during in vivo bone development. Chicken embryonic osteoblast progenitor cells were selected by initial growth at low densities in minimal medium. Upon subcultivation into nutrient-enriched medium at higher cell densities, near homogeneous populations of osteoblasts were obtained as demonstrated by the greater than 80% enrichment of cells positive for alkaline phosphatase activity. A comparison was made between cells grown in the presence or absence of 10 mM beta-glycerolphosphate (beta-GPO4), a chemical stimulant of matrix calcification, as a function of time. Cultures treated with beta-GPO4 showed visible calcification at Day 12 when culture monolayers became confluent. By Day 30, numerous large foci of calcification were visible and a 20-fold increase in calcium (Ca) content was observed. In contrast, untreated cultures had only a 3-fold increase in Ca content with many smaller diffuse areas of calcification. DNA, RNA, and total protein levels were nearly identical between the two cultures, indicating that beta-GPO4 had no marked effect on either cell proliferation or transcriptional activity. The major collagen type produced by either culture was type I, with no detectable type III as determined by CNBr peptide mapping and delayed reduction analysis. Alkaline phosphatase activity showed a rapid approximately 50-fold induction by Day 18 and remained elevated in control cultures. However, cultures treated with beta-GPO4 demonstrated a rapid 80% decline of enzyme activity after 18 days. In contrast, total osteocalcin levels showed a 100-fold induction by Day 18 and remained elevated in both control and beta-GPO4-treated cultures throughout the time period examined. While the overall levels of osteocalcin were the same in beta-GPO4-treated and untreated cultures, 2- to 5-fold more osteocalcin was associated with the more mineralized matrices of the beta-GPO4-treated cultures. In order to confirm the association of osteocalcin with areas of mineralization, co-localization of mineral to osteocalcin and collagen was carried out by combining vital labeling with tetracycline and immunofluorescent staining with anti-osteocalcin and anti-collagen antibodies. Both collagen and osteocalcin showed strong localization with areas of mineralization.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Expression of differentiated function by mineralizing cultures of chicken osteoblasts. 349 52

The aim of this study was to determine the effect of blood coagulation and platelet aggregation on the perfusability of arterioles (19-50 micron) and capillaries in subepicardial and subendocardial ischemic and nonischemic myocardium of anesthetized open-chest rabbits. Fluorescein isothiocynate-dextran (MW 150,000) was injected intravenously to label perfusable myocardial microvessels of rabbits that were subjected to 60 min of coronary artery occlusion. Fluorescent microscopy was used to identify the perfusable vessels and an alkaline phosphatase stain was employed to locate the total microvasculature of the heart. Stereological principles were utilized to determine various morphometric parameters. About 25% of the capillaries were incapable of being perfused but virtually all arterioles were perfusable in occluded myocardium of the control group. Essentially all capillaries and arterioles were perfusable in nonoccluded myocardium. Collagen infusion produced a perfusion defect in 14% of the capillaries and arterioles in nonoccluded myocardium and in 33% of the capillaries and arterioles in occluded myocardium. Heparin, prostaglandin E1 (PGE1), or PGE1 + heparin did not prevent the perfusion defect in capillaries of occluded myocardium. It is concluded that while promotion of blood coagulation and platelet aggregation was able to produce microvessel obstruction, these hemostatic mechanisms were not primarily responsible for the capillary obstruction observed during myocardial ischemia in the rabbit heart.
 ...
PMID:Effect of blood coagulation and platelet aggregation on perfusable capillaries and arterioles in ischemic and nonischemic myocardium. 365 5

The upper molars of adult Wistar rats were moved lingually by a wire spring for 5 and 9 days. Collagen-containing fibroblasts in the pressure zone caused by the tooth movement were investigated morphologically (forms characterized by type A and type B compartments) and cytochemically (location of acid and alkaline phosphatase activity). The following results were obtained: The distribution of collagen-containing fibroblasts with type A or type B compartments could not be distinguished clearly in either 5-day or 9-day specimens; Acid phosphatase activity was recognized in the Golgi apparatus, lysosomes, and elliptical bodies associated with type B compartments; Alkaline phosphatase activity was positive in the plasma membrane of collagen-containing profiles and in both intracellular and extracellular collagen fibrils. These results suggest that fibroblasts are capable of phagocytosing collagen fibrils in all areas of the cytoplasmic membrane and that digestion of collagen fibrils in fibroblasts may be associated with acid and alkaline phosphatase.
 ...
PMID:Phagocytosis of collagen by fibroblasts incident to experimental tooth movement. 403 1


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>