Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20020 (adenosine triphosphatase)
 3,299 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The embryonic heart can pump blood in a single direction without one-way valves. With the development of molecular cell markers specific for contraction and relaxation, functional aspects of myocardial differentiation have been addressed through the use of in situ hybridization. In this study, we report how expression of the cardiac sarcoplasmic reticulum calcium-adenosine triphosphatase (SERCA2) and phospholamban (PLB) in the rat may partly explain why the embryonic atrium and ventricle function essentially as they do in the adult. SERCA2 is expressed in a craniocaudal gradient from as early as 10 embryonic days (ED) of development. PLB is first expressed at 12 ED but in a gradient essentially opposite to that seen for SERCA2. This spatial pattern of expression is maintained throughout much of fetal development. The spatial distribution of skeletal alpha-actin in the developing human heart indicates that alpha-actin isoform gradients or switching are not important in the establishment of unidirectional blood flow in the absence of valves, but it may serve as a marker for cardiac maturation.
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PMID:Molecular aspects of myocardial differentiation. 868 58

Beside its well-known role in bone development, vascularization plays a major role in bone cell migration for bone remodeling and metastatic tumor invasion. However, the various techniques used to identify vessels in bone have never been tested for trabecular bone vessel quantification, whereas bone remodeling quantitative parameters are commonly assessed. In this context, we developed and compared various histological techniques used to visualize blood vessels in rat bone in order to quantify them. First, several products were tested by intracardiac infusion to opacify the bone vascular network. The best results were obtained using either an India ink-1% agarose solution or an India ink-saturated barium sulfate solution followed by X-ray microradiography. Second, to identify the types of vessels, we also performed histoenzymology and immunohistochemistry stainings. Neither alkaline phosphatase (for endothelial cells) nor adenosine triphosphatase (ATPase) stainings (for smooth muscle cells) provided a low enough background to allow for vessel identification and quantification. For immunohistochemistry, various specific vessel constituents were analyzed: laminin, smooth muscle cell alpha-actin, factor VIII, and lectin Griffonia simplifolia. Anti-laminin and anti-smooth muscle cell alpha-actin antibodies gave the best results for quantification. Third, after optimization of these techniques, we performed quantitative bone and vessel histomorphometry on two groups of 12 rats each, for which bone remodeling and vessel number and area parameters were measured. No statistical differences were observed between the two groups, confirming the reproducibility of our measurements. A significant relationship was found between vessel number and histodynamic parameters; that is, bone formation rate correlated positively with India ink-positive vessel area (p < 0.009, r2 = 0.54) and alpha-actin-positive vessel number (p < 0.05, r2 = 0.66). Furthermore, we report reproducible techniques for visualization and quantification of vessels in bone that also allowed for simultaneous conventional bone histomorphometry. This methodology should help researchers to better understand the functional and anatomical relationship between trabecular bone and its vascularization during normal or pathological processes.
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PMID:Relationships between trabecular bone remodeling and bone vascularization: a quantitative study. 1193 53