Organites cellulaires. Le développement d'indicateurs fluo rescents de synthèse, de prermere (Quin2) et de deuxième génération (Fura2, Indol, Fluo3, Fura red. III. Formation séquentielle, à partir de la phénylalanine, des acides cinnamique, p-coumarique et caféique, par des organites cellulaires isolés. Les modifications des organites cellulaires au cours de la megasporogenese et de la megagametogenese chez Gasteria verrucosa (Mill) Haw. [gametogenese.
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Les organites cellulaires : quiz
A common abnormality is the partial loss of ribosomes from the membrane of the rough endoplasmic reticulum RERwith moderate les organites cellulaires of the cisternae and loss of aggregation into parallel arrays by comparison with controls Fig. Free ribosomes are not commonly seen in the cytoplasm.
Mitochondria displayed varying degrees of vacuolation. Gross distortions of the rough endoplasmic reticulum les organites cellulaires frequent.
Increased dilation in the RER with partial loss of attached ribosomes was observed. Discussion Feeding chickens with oral contraceptive steroids Anovlar leads to the formation of high estrogen residues in muscle and liver by comparison with controls.
Electron microscopy of the liver of oral contraceptive-treated chicken reveals les organites cellulaires changes at the ultrastructural level. These alterations involve both the nucleus and cytoplasmic organelles.
Les organites cellulaires : quiz
The nuclear envelope is evidently irregular and obviously dilated as in the case of DMBA-treated chicken. Irregularity of nuclear configuration has been reported to occur in nuclei of tumour cells .
It is worth mentioning that DMBA is among the most potent chemical carcinogens known les organites cellulaires date and has been shown to induce tumours in different animal species [5,6]. The electron micrographs also clearly demonstrate that contraceptive pills are capable of changing mitochondrial structure.
The vacuolation of mitochondria in the liver of chickens fed les organites cellulaires oral contraceptive pills was observed. In contrast, mitochondria with a few cristae and varying degrees of vacuolation were observed in the liver of toads fed with DMBA . Also, this phenomenon has been observed in rats after exposure to carcinogenic substances .
It is well known that mitochondrial functional or structural abnormality is one of the most sensitive indicators of cell injury .
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The ultrastructural results revealed gross distortions in the RER in Anovlar-treated chickens, observed as moderate dilation les organites cellulaires the RER cisternae and the detachment of ribosomes over some areas of the cisternal membranes.
The same abnormalities in the RER have been reported by Ghadially and Parry  in human hepatocellular carcinoma, and by Smuckler  in carbon tetrachloride-induced liver injury in the rat. Several workers have suggested that oral contraceptive les organites cellulaires can act as promoters [12,13].
It is well known that the synthetic estrogens have been shown to stimulate liver cell proliferation .
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On the other hand, the results of several studies have described the appearance of hepatocellular carcinoma in women using oral les organites cellulaires steroids for prolonged periods of time .
From the results obtained in this work, it is suggested that oral contraceptives have a serious detrimental impact on the livers les organites cellulaires chickens, and these hazardous effects are similar to those induced by DMBA in chickens.
It is concluded that the use of oral contraceptive steroids in chickens as anabolic agents entails a special risk to the experimental animal, and probably to the consumer.
Laws and regulations concerning the use of anabolic agents in chicken and meat should be updated to les organites cellulaires their use.
Acknowledgements The authors gratefully acknowledge the les organites cellulaires given by the World Health Organization for this work. Use of radioimmunoassay procedures for the determination of sex hormones in animal tissues.
J Steroid Bio-chem, Hoffmann B, Evers P. Anabolic agents with sex-hormone like activities: Drug residues in animals. Veterinary science and comparative medicine.