Effect of chronic ACTH treatment on the physical state of lipid droplets in rat adrenocortical cells
| Autor: | K.Sz. Szalay, F. Czakó, Ida E. Tóth, K. Krasznai, Ervin Stark, D. Szabó |
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| Rok vydání: | 1992 |
| Předmět: |
Male
endocrine system medicine.medical_specialty Endocrinology Diabetes and Metabolism Clinical Biochemistry Acth treatment Biochemistry Thermotropic crystal Free cholesterol Endocrinology Adrenocorticotropic Hormone Zona fasciculata Reference Values Lipid droplet Internal medicine medicine Animals Molecular Biology Birefringence Chemistry Lipid mobilization Rats Inbred Strains Cell Biology Lipid Metabolism Zona Reticularis Rats medicine.anatomical_structure Zona glomerulosa Adrenal Cortex Molecular Medicine lipids (amino acids peptides and proteins) Chromatography Thin Layer Microscopy Polarization Zona Fasciculata Zona reticularis |
| Zdroj: | The Journal of Steroid Biochemistry and Molecular Biology. 41:781-784 |
| ISSN: | 0960-0760 |
| DOI: | 10.1016/0960-0760(92)90424-h |
| Popis: | A histophysical method has been adapted to determine the thermotropic phase transitions of adrenocortical lipid droplets using a polarizing microscope equipped with a cold/hot stage. Cryosections of freshly-removed, unfixed adrenals, derived from control (untreated), and 14 days ACTH-treated rats were examined. The lipid droplets in the zona fasciculata and zona reticularis of the untreated rats were birefringent at room temperature (22 degrees C). The birefringence of zona glomerulosa lipids selectively increased in the temperature range from -10 to -15 degrees C. In cryosections prepared from ACTH-treated rats, thermotropic phase transitions of the lipid droplets appeared at a temperature range between -30 and -40 degrees C in each cortical zone. The chemical analysis of the isolated lipids revealed that the relative amount of triglycerides in the zona fasciculata lipids increased, while that of free and esterified cholesterol decreased after chronic ACTH treatment. Present data suggest that the increased fluidity of lipid droplets promotes lipid mobilization in response to the enhanced demand of the chronically stimulated adrenocortical cells. Viscosity-dependent mobilization of free cholesterol from lipid droplets is not a rate-limiting process in adrenal steroidogenesis, but rather may represent an important control of the availability of precursor from lipid stores. |
| Databáze: | OpenAIRE |
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