Prolactin Secretion in Normal Male Mice during a Circadian Period
| Autor: | C.L.A. Gómez Dumm, F. E. Estivariz, M. Souto, F.R. Moreno |
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| Rok vydání: | 1983 |
| Předmět: |
Diminution
endocrine system medicine.medical_specialty Histology Period (gene) Endoplasmic reticulum Golgi apparatus Biology Prolactin Prolactin cell symbols.namesake Endocrinology Internal medicine medicine symbols Secretion Circadian rhythm Anatomy hormones hormone substitutes and hormone antagonists |
| Zdroj: | Cells Tissues Organs. 115:212-219 |
| ISSN: | 1422-6421 1422-6405 |
| DOI: | 10.1159/000145692 |
| Popis: | A quantitative ultrastructural study on the prolactin (PRL) cells of normal male mice was correlated with serum PRL immunoassay determination at different times in a circadian period. Significant time fluctuations in the percentages of cytoplasmic volume occupied by most of the organelles, as well as cyclic variations in serum PRL concentrations were detected. The endoplasmic reticulum appeared more developed at the beginning of the light period, suggesting a higher synthesis of PRL at this time. The evaluation of the Golgi complex and the secretory granules would indicate that packaging of secretory material and storing of PRL granules ccurred mainly during the second half of the light period. This coincided with the lowest values in serum PRL concentration and an increment in mitochondrial mass. The highest emiocytotic activity together with a diminution of total secretory granules were found during the dark period. The peak of PRL serum concentration was also present in this phase, but some hours later. Evaluation of microtubules and lysosomes gave some additional information. The results are in keeping with those from some biochemical investigations performed in mice and rats, but are not in agreement with others. The importance of a morphometric approach to evaluate and corroborate the immunoassay methods in the study of cyclic hormone secretion is emphasized. |
| Databáze: | OpenAIRE |
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