scholarly journals Regulation of production of δ-aminolaevulinate synthase in tissues of chick embryos. Effects of porphyrogenic agents and of haem precursors

1989 ◽  
Vol 262 (3) ◽  
pp. 815-821 ◽  
Author(s):  
P D Drew ◽  
I Z Ades
Keyword(s):  
Chick Embryo ◽  
Molecular Mass ◽  
Northern Blot ◽  
Chick Embryos ◽  
In Ovo ◽  
Synthetic Oligonucleotide ◽  
Embryo Liver ◽  
Rna Concentration

Studies conducted by several groups have established that porphyrogenic agents which caused elevations in chick-embryo liver delta-aminolaevulinate (ALA) synthase activity also increased the concentrations of the enzyme's RNA, and that haemin inhibited these elevations. We have determined in this study, using immune-blot analyses, that administration in ovo of allylisopropylacetamide (AIA) in combination with diethyl 1,4-dihydro-2,4,6-trimethyl,3,5-pyridinedicarboxylate (DDC) increased the mass of ALA synthase in intestine and kidney of chick embryos. Furthermore, the molecular mass of the subunit of the enzyme in those tissues appeared identical with that of liver ALA synthase. Using a synthetic oligonucleotide complementary to ALA synthase mRNA, we determined by solution hybridization and Northern-blot analyses that AIA and DDC also increased the concentrations of ALA synthase mRNA in intestine and kidney and that testosterone elevated the concentration of the RNA in kidney. In analyses of RNA obtained from chick-embryo liver, intestine, kidney, heart, brain and lung, the probe bound primarily in each case to a single 2.3 kb RNA. Finally, the haem precursors ALA and FeCl3, when injected together into the fluid surrounding embryos, inhibited both the elevations in ALA synthase mass and RNA concentration brought about by porphyrogenic agents in liver, kidney and intestine. Thus the results indicated that: (1) certain porphyrogenic agents increased ALA synthase mass and RNA in chick-embryo intestine and kidney, in addition to liver; (2) ALA and FeCl3 inhibited the elevations; and (3) the sizes of ALA synthase's subunit as well as the enzyme's mRNA appeared identical, in each case, in all tissues examined.

scholarly journals Evidence that in chick embryos destruction of hepatic microsomal cytochrome P-450 haem is a general mechanism of induction of δ-aminolaevulinate synthase by porphyria-causing drugs

1980 ◽  
Vol 190 (3) ◽  
pp. 519-526 ◽  
Author(s):  
L K Lim ◽  
G Srivastava ◽  
J D Brooker ◽  
B K May ◽  
W H Elliott
Keyword(s):  
Chick Embryo ◽  
Enzyme Induction ◽  
General Mechanism ◽  
Chick Embryos ◽  
In Ovo ◽  
Microsomal Cytochrome ◽  
Primary Mechanism ◽  
Embryo Liver ◽  
The Relationship ◽  
Cytochrome P 450

A variety of prophyrinogenic compounds were tested for their effect in ovo on chick-embryo liver microsomal cytochrome P-450 haem concentration and mitochondrial delta-aminolaevulinate synthase activity. With all drugs tested, there was a 30—50% decrease in cytochrome P-450 haem concentration within 1 h of treatment, and this was closely followed by an increase in delta-aminolaevulinate synthase activity. The relationship was independent of the extent of enzyme induction and is consistent with the proposal that drug-mediated destruction of cytochrome P-450 haem is the primary mechanism of induction of delta-aminolaevulinate synthase. After induction, synthesis of delta-aminolaevulinate synthase could be maintained by inhibiting further haem synthesis. These studies suggest that induction of porphyria is a combination of two distinct processes: (a) induction of delta-aminolaevulinate synthase synthesis by destruction of cytochrome P-450 haem and consequent depletion of cellular free haem; (b) maintenance of continued delta-aminolaevulinate synthase synthesis by preventing replenishment of cellular haem either by inhibiting haem synthesis and/or by promoting continuous removal of newly synthesized haem.

scholarly journals Studies of tRNAVal isolated from chick embryo liver irradiated in ovo

1975 ◽  
Vol 32 (6) ◽  
pp. 766-767
Author(s):  
L Gyenge ◽  
E Bölöni ◽  
A Benkó ◽  
L D Szabó ◽  
F Joliot-Curie
Keyword(s):  
Chick Embryo ◽  
In Ovo ◽  
Embryo Liver

Drug-Induced Porphyrin Biosynthesis. X. Potentiation of Propanidid-Induced Elevation of δ-Aminolevulinic Acid Synthetase and Porphyrins in Chick Embryo Liver by the Carboxylesterase Inhibitor Bis-[p-nitrophenyl] Phosphate

1973 ◽  
Vol 51 (9) ◽  
pp. 700-704 ◽  
Author(s):  
Hillel Taub ◽  
G. S. Marks
Keyword(s):  
Chick Embryo ◽  
Aminolevulinic Acid ◽  
Ester Group ◽  
Synthetase Activity ◽  
Chick Embryos ◽  
Drug Induced ◽  
Duration Of Action ◽  
Nitrophenyl Phosphate ◽  
Embryo Liver ◽  
Ala Synthetase

Propanidid, an ultra short-acting non-barbiturate anesthetic containing an ester group, induces δ-aminolevulinic acid (ALA)-synthetase and porphyrin accumulation in 17-day-old chick embryo liver. The potency and duration of action of propanidid in inducing ALA-synthetase activity and porphyrin accumulation was markedly increased when administered to chick embryos which had been pretreated with bis-[p-nitrophenyl] phosphate, an inhibitor of liver carboxylesterase.

scholarly journals Drug-induced accumulation of uroporphyrin in chicken hepatocyte cultures. Structural requirements for the effect and role of exogenous iron

1984 ◽  
Vol 224 (3) ◽  
pp. 769-777 ◽  
Author(s):  
A Ferioli ◽  
C Harvey ◽  
F De Matteis
Keyword(s):  
Chick Embryo ◽  
Molecular Target ◽  
Chick Embryos ◽  
In Ovo ◽  
Drug Induced ◽  
Structural Requirements ◽  
Binding Characteristics ◽  
Alternative Hypotheses ◽  
Do So

The ability of drugs to cause uroporphyria in hepatocytes from 17-day-old chick embryos has been investigated and the response of the cells in culture compared with that of the intact liver of the embryos in ovo. In this chick-embryo system, drugs that cause accumulation of uroporphyrin within 19-24 h can only do so in culture; in contrast, 2-allyl-2-isopropylacetamide and 3,5-diethoxycarbonyl-1,4-dihydrocollidine, which stimulate production of protoporphyrin, are effective both in culture and in ovo. A role of exogenous iron in worsening drug-induced uroporphyria was demonstrated in cultures of hepatocytes; iron also caused preferential accumulation of uroporphyrin from added 5-aminolaevulinate in the absence of a porphyrogenic chemical. Uroporphyria was induced in cultures of hepatocytes by drugs of widely different structures, suggesting that the primary molecular target with which they interact may be relatively aspecific in its binding characteristics. These results are briefly discussed, and two alternative hypotheses for the drug-induced effect in uroporphyrinogen metabolism are considered.

Ultrastructure of Blood Vessels of the Area Pellucida of Control and X-irradiated Chick Embryos

1968 ◽  
Vol 26 ◽  
pp. 118-119
Author(s):  
Margaret H. Sanderson ◽  
S. Phyllis Steamer
Keyword(s):  
Endothelial Cells ◽  
Chick Embryo ◽  
Blood Vessels ◽  
Vascular System ◽  
Smooth Endoplasmic Reticulum ◽  
Chick Embryos ◽  
In Ovo ◽  
Stage Of Development ◽  
Mesenchyme Cells ◽  
Area Pellucida

The chick embryo exposed to lethal doses of ionizing radiations develops a fatal circulatory failure within a few hours. This report describes the blood vessels of the area pellucida (a part of the extra-embryonic membranes of the chick embryo) and the effect of 250 kVp x-radiation upon them.Three-day chick embryos, x-irradiated in ovo with 1000-1200 R, were fixed 1-2 hours after exposure. The area pellucida is a multi-layered membrane consisting of ectoderm, somatic and splanchnic mesoderm, and endoderm (Fig. 1). The vascular system arises from the splanchnic mesoderm. The walls of small and medium-sized vessels are composed of endothelial cells, an occasional pericyte and processes of adjacent mesenchyme cells. Types of vessels cannot be distinguished at this stage of development; a basement membrane is seen only in isolated areas. The wall appears double or triple-layered, but the endothelium is frequently less than 0.1 micron thick (Fig. 2). Endothelial cells contain a large complement of polyribosomes, mitochondria, rough and smooth endoplasmic reticulum, a Golgi complex, pinocytotic vesicles and several kinds of inclusion bodies. The nucleus has a well-defined nucleolus.

Effects of L-phenylalanine on somite formation in the early chick embryo

Development ◽  
1981 ◽  
Vol 61 (1) ◽  
pp. 175-190
Author(s):  
K. Palén ◽  
L. Thörneby
Keyword(s):  
Chick Embryo ◽  
Regional Differences ◽  
Vitelline Membrane ◽  
Early Developmental Stage ◽  
Yolk Granule ◽  
Chick Embryos ◽  
In Ovo ◽  
Somite Formation ◽  
Early Developmental

Chick embryos were treated in ovo and in vitro with L-phenylalanine from the intermediate streak stage (Hamburger & Hamilton stage 3, 12–13 h of incubation) to the 7-somite stage (H & H stage 9, 29–33 h of incubation). Treatment in ovo resulted in a large number of embryos developing somite blocks, i.e. imperfectly segmented somites. In embryos treated at an early developmental stage (12–21 h of incubation), the blocks of unsegmented somite mesoderm occurred mostly in the somite pairs 1–5, whereas treatment that began at a later stage (24–30 h of incubation) caused blocks in the somite pairs 5–10, i.e. the appearance of blocks of unsegmented somite mesoderm is correlated in time with the onset of the treatment. No difference regarding mitotic indices could be distinguished between normally segmented somites and blocks of unsegmented somite mesoderm. Autoradiography based on tritiated L-phenylalanine showed no regional differences in labelling of the chick embryo body. Electronmicroscopical observations indicate a slightly suppressed formation of microvilli in the cells of the unsegmented mesoderm blocks compared with cells in normally segmented somites. The observed disturbances are probably caused by a suppressed yolk granule decomposition in the developing somite cells. The experiments in vitro support the findings in the in ovo material; at the same time, they reveal an unexpectedly slow diffusion of L-phenylalanine through the vitelline membrane.

scholarly journals STUDIES ON THE PSITTACOSIS-LYMPHOGRANULOMA GROUP

1951 ◽  
Vol 94 (5) ◽  
pp. 401-413 ◽  
Author(s):  
M. Michael Sigel ◽  
Anthony J. Girardi ◽  
Emma G. Allen
Keyword(s):  
Chick Embryo ◽  
Thermal Degradation ◽  
Growth Curve ◽  
Chick Embryos ◽  
In Ovo ◽  
Titration Method ◽  
Clear Cut ◽  
New Generation

Because of the peculiar properties of the psittacosis-lymphogranuloma group of viruses, the pattern of multiplication in the allantois of the chick embryo of one of their number, meningopneumonitis virus, was studied. This was done by determination of the changes in its infectivity for mice and chick embryos. Titration of infectivity in embryos proved to be a more sensitive procedure than titration in mice; the latter procedure however, had the advantage of greater simplicity and gave more clear-cut results. The mouse titration method was used in most of the experiments. Following inoculation of virus into the allantois, there was a slow decrease in infectivity in the allantoic fluids followed by an increase due to appearance of new virus between 24 and 48 hours. The slope of declining infectivity in the allantoic fluids in ovo was similar if not identical with the slope of decreasing infectivity in allantoic fluids in vitro caused by thermal degradation of virus. Multiplication of the virus in allantoic membranes was characterized by the following pattern: (a) Increase in infectivity in the first few hours (exact duration of increase depended on concentration of virus in inoculum) due to adsorption of virus. (b) Decrease in infectivity up to about 20 to 24 hours. (c) Increase in infectivity due to appearance of the new generation of virus. The growth curve of meningopneumonitis is analyzed and the pattern of growth is discussed in the light of the present concepts of viral multiplication.

scholarly journals Identification of increased amounts of UDP-glucuronyltransferase protein in phenobarbital-treated chick-embryo liver cells

1983 ◽  
Vol 214 (2) ◽  
pp. 517-523 ◽  
Author(s):  
B Burchell ◽  
G J Pratt ◽  
I Duffy ◽  
L West
Keyword(s):  
Tissue Culture ◽  
Chick Embryo ◽  
Microsomal Fraction ◽  
Microsomal Protein ◽  
Liver Cells ◽  
Transferase Activity ◽  
Chick Embryos ◽  
Embryo Liver ◽  
Liver Microsomal Fraction ◽  
First Time

UDP-glucuronyltransferase activity of neonatal-chick liver or phenobarbital-treated chick-embryo liver catalysed the glucuronidation of 1-naphthol, 4-nitrophenol and 2-aminophenol. Only low transferase activity towards testosterone was detected, and activity towards bilirubin was not detectable. Liver microsomal transferase activity towards the three phenols was increased approx. 20-50-fold by phenobarbital treatment of chick embryos or by transfer of liver cells into tissue culture. A single form of UDP-glucuronyltransferase, which appears to catalyse the glucuronidation of these three phenols, was purified to near homogeneity from phenobarbital-treated chick-embryo liver microsomal fraction for the first time. The use of this purified enzyme as a standard protein facilitated the identification of this protein in chick-embryo liver microsomal fraction. Further, the accumulation of this microsomal protein was observed following phenobarbital treatment of chick embryos and during tissue culture of chick-embryo liver cells. The value of this model system for the study of the induction of UDP-glucuronyltransferase by drugs and hormones is discussed.

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