85Sr uptake by the chick embryonic heart: Effect of high doses of isoproterenol

1992 ◽  
Vol 70 (7) ◽  
pp. 959-962 ◽  
Author(s):  
I. Oštádalová ◽  
B. Oštádal
Keyword(s):  
Chick Embryo ◽  
Intracellular Calcium ◽  
Embryonic Heart ◽  
Developmental Changes ◽  
Chick Embryos ◽  
Embryonic Tissues ◽  
High Doses

The aim of the present study was to establish whether intraamnial administration of toxic doses of isoproterenol to chick embryos increases cardiac accumulation of strontium, the homologue element of calcium. It has been shown that the ability of embryonic tissues (blood, heart, and liver) to accumulate 85Sr decreases significantly during ontogeny. Administration of isoproterenol to chick embryos did not elevate the concentration of 85Sr in the heart. It seems, therefore, that isoproterenol-induced developmental changes in the chick embryonic myocardium are not necessarily due to intracellular calcium (as measured by 85Sr) overload.Key words: heart, isoproterenol, radiostrontium, chick embryo.

Protein Accumulation in Early Chick Embryos Grown under Different Conditions of Explantation

Development ◽  
1959 ◽  
Vol 7 (1) ◽  
pp. 66-72
Author(s):  
L. Gwen Britt ◽  
Heinz Herrmann
Keyword(s):  
Chick Embryo ◽  
Slow Rate ◽  
The Other ◽  
Protein Accumulation ◽  
Chick Embryos ◽  
Developmental Processes ◽  
Embryonic Tissues ◽  
Somite Formation ◽  
Explanted Chick Embryo

The recent development of techniques originally devised by Waddington (1932) for the maintenance of the explanted chick embryo (Spratt, 1947; New, 1955; Wolff & Simon, 1955) has opened the possibility of determining quantitatively some parameters of the developmental processes occurring in embryonic tissues under these conditions. As a result of such measurements, protein accumulation in explanted embryos was found to be much smaller than in embryos developing in the egg. On the other hand, the progress of somite formation was found to take place at similar rates in embryos developing as explants or in situ (Herrmann & Schultz, 1958). The slow rate of protein accumulation in the explanted embryos made it seem desirable to investigate whether under some other conditions of explantation protein accumulation would approach more closely the rate of protein formation observed in the naturally developing embryo.

Embryonic development of the heart

Development ◽  
1969 ◽  
Vol 22 (3) ◽  
pp. 333-348
Author(s):  
Francis J. Manasek
Keyword(s):  
Cell Layer ◽  
Embryonic Heart ◽  
Outer Cell ◽  
Chick Embryos ◽  
Myocardial Wall ◽  
Undifferentiated Cells ◽  
Epicardial Layer ◽  
Outer Cell Layer ◽  
Heart Wall

The mature heart may be thought of as consisting of three layers, endocardium, myocardium, and an outer investing tissue called the epicardium. During early formation of the tubular heart of chick embryos, at about the 8-somite stage, two tissue layers become clearly discernible with the light microscope: the endocardium and the developing myocardial wall. The outer epicardial layer does not appear until later in development. It is generally accepted that embryonic heart wall or ‘epimyocardium’ is composed of muscle and undifferentiated cells. As its name implies, the epimyocardium is thought to give rise to myocardium and epicardium. Kurkiewicz (1909) suggested that the epicardium was not an epimyocardial derivative but rather is formed from cells originating in the sinus venosus region, which migrate over the surface of the heart. Nevertheless, it has become generally accepted that the outer cell layer of the embryonic heart wall differentiates in situ to give rise to the definitive visceral epicardium (Patten, 1953).

scholarly journals Developmental changes in the type I procollagen processing pathway in chick-embryo cornea

1991 ◽  
Vol 276 (3) ◽  
pp. 777-784 ◽  
Author(s):  
S J Mellor ◽  
G L Atkins ◽  
D J S Hulmes
Keyword(s):  
Chick Embryo ◽  
Kinetic Model ◽  
Rate Constants ◽  
Collagen Fibril ◽  
Electrophoretic Analysis ◽  
Developmental Changes ◽  
Type I ◽  
Electron Microscopic ◽  
Type I Procollagen ◽  
Stage Of Development

Type I procollagen processing in chick-embryo corneas was studied at days 12, 14 and 17 of development. Pulse-chase experiments and electrophoretic analysis of salt-soluble extracts showed developmental changes in the processing pathway. A kinetic model was fitted to the data to determine rate constants for processing of both N- and C-propeptides. Data for pro alpha 1(I)-chain processing and pro alpha 2(I)-chain processing were fitted separately (where pro means procollagen). Between days 12 and 17 the relative flux through the pC-collagen (procollagen chain lacking the N-propeptide) and pN-collagen (procollagen chain lacking the C-propeptide) pathways increased approx. 4-fold. Pro alpha 1(I) chains and pro alpha 2(I) chains were processed by slightly different routes. Variations in the rate constants were compared with electron-microscopic measurements of collagen fibril diameters at each stage of development. Diameters increased by less than 10% over the period from 12 to 17 days. It was concluded that fibril diameters are relatively insensitive to the pathway of procollagen processing in the salt-soluble pool.

scholarly journals Effect of cortisol acetate on collagen biosynthesis and on the activities of prolyl hydroxylase, lysyl hydroxylase, collagen galactosyltransferase and collagen glucosyltransferase in chick-embryo tendon cells

1977 ◽  
Vol 164 (3) ◽  
pp. 533-539 ◽  
Author(s):  
A Oikarinen
Keyword(s):  
Chick Embryo ◽  
Enzyme Activities ◽  
Collagen Synthesis ◽  
Enzyme Synthesis ◽  
Prolyl Hydroxylase ◽  
Chick Embryos ◽  
Isolated Cells ◽  
Lysyl Hydroxylase ◽  
Tendon Cells

Collagen synthesis and the activities of prolyl hydroxylase, lysyl hydroxylase, collagen galactosyltransferase and collagen glucosyltransferase were studied in isolated chick-embryo tendon cells after the administration of cortisol acetate to the chick embryos. When the steroid was injected 1 day before isolation of the tendon cells, collagen synthesis was decreased, even though the enzyme activities were not changed. When cortisol acetate was given as repeated injections over a period of 4 days, both collagen synthesis and the enzyme activities decreased. The hydroxylase activities decreased even more than the two collagen glycosyltransferase activities, both in isolated cells and in whole chick embryos. The amount of prolyl hydroxylase protein diminished to the same extent as the enzyme activity, indicating that cortisol acetate inhibits enzyme synthesis. The inhibitory effect of cortisol acetate on collagen synthesis and on the enzyme activities was partially reversible in 3 days. Total protein synthesis was completely restored within this time. Only massive doses of cortisol acetate inhibited collagen synthesis in vitro. Additional experiments indicated that cortisol acetate did not decrease the rate of the enzyme reactions when added directly to the enzyme incubation mixtures. The results suggest that cortisol acetate decreases collagen synthesis both by its direct effect on collagen polypeptide-chain synthesis and by decreasing the activities of enzymes involved in post-translational modifications.

The changes in lectin activity during the development of embryonic chick skin

Development ◽  
1980 ◽  
Vol 59 (1) ◽  
pp. 59-69
Author(s):  
Kunio Kitamura
Keyword(s):  
Chick Embryo ◽  
Developmental Changes ◽  
Embryonic Chick ◽  
Dorsal Skin ◽  
Lectin Activity ◽  
Embryonic Skin ◽  
Mesenchymal Condensation ◽  
The Relationship

Changes in lectin activity during development of embryonic chick skin were studied. In the dorsal skin of the chick embryo in which feathers were formed, lectin activity first increased, during the period of dermal condensation, and then it decreased during the development of feathers. A similar change in lectin activity was also found in the anterior shank skin, the prospective scale region of the chick embryo. The embryonic cornea, in which no mesenchymal condensation took place, had lectin activity and did not show any developmental changes in lectin activity. Apteria regions of the dorsal skin, experimentally formed by treatment with hydrocortisone, gave low lectin activity. The lectin found in the embryonic skin showed specificity for lactose. The relationship found between lectin activity and dermal condensation in the embryonic chick skin is discussed.

Effect of a Leucine Analogue on Incorporation of Glycine into the Proteins of Explanted Chick Embryos

Development ◽  
1958 ◽  
Vol 6 (2) ◽  
pp. 262-269
Author(s):  
Phyllis W. Schultz ◽  
Heinz Herrmann
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Chick Embryo ◽  
Total Protein ◽  
Nutrient Medium ◽  
Chick Embryos ◽  
Agar Gel ◽  
Egg Extract ◽  
Amino Acid Analogues

Amino acid analogues have been observed to give rise to abnormal forms of development of chick and amphibian embryos (Herrmann, 1953; Rothfels, 1954; Waddington & Sirlin, 1954; Feldman & Waddington, 1955; Herrmann, Rothfels-Konigsberg, & Curry, 1955). Assuming that these disturbances may be due to interference with the utilization of amino acids for protein formation, we have attempted an analysis of this effect by comparison of the protein contents and of the uptake of glycine into the proteins of chick embryo explants in the presence and absence of amino acid analogues. The results of such experiments are reported in this paper. The chick embryos used for explanation, the explantation technique, and the determination of total protein glycine and of tracer glycine were essentially the same as described previously (Herrmann & Schultz, 1958). The embryos were explanted at the 11–13 somite stage on to the surface of an agar gel containing egg extract as nutrient medium following the procedure given by Spratt (1947) as modified by Rothfels (1954).

Impaired energy metabolism as an initial step in the mechanism for 6-aminonicotinamide-induced limb malformation

Development ◽  
1980 ◽  
Vol 59 (1) ◽  
pp. 217-222
Author(s):  
Yal C. Sheffield ◽  
Robert E. Seegmiller
Keyword(s):  
Amino Acid ◽  
Energy Metabolism ◽  
Chick Embryo ◽  
Chondroitin Sulfate ◽  
Atp Synthesis ◽  
Initial Step ◽  
Chick Embryos ◽  
Impaired Energy Metabolism ◽  
All Treatment

The analogue and antagonist of nicotinamide, 6-aminonicotinamide (6-AN), impairs cartilage formation and results in shortening of the limbs when administered to chick embryos. Studies have shown that 6-AN forms an abnormal NAD analogue which inhibits the activity of NAD-dependent enzymes associated with production of ATP. To determine if an effect on ATP synthesis might be associated with the mechanism of teratogenesis in the chick embryo, ATP levels of cartilage from day-8 chick embryos treated in vitro were assayed in relation to biosynthesis of protein, DNA and chondroitin sulfate. Incorporation of 35SO4− was inhibited by 6 h of treatment with 10 µg/ml of 6-AN, whereas incorporation of [3H]thymidine and [3H]amino acid was not inhibited until 12 h. Incorporation of [3H]- glucosamine was increased at all treatment times. A decrease in the level of ATP preceded any detectable inhibition of precursor incorporation. These results are consistent with the hypothesis that 6-AN inhibits chondroitin sulfate synthesis through a reduction in the level of ATP in chondrocytes.

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