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Título: Influence of light-dark, seasonal and lunar cycles on serum melatonin levels and synaptic bodies number of the pineal gland of the rat
Fecha de publicación: 2002
Editorial: Murcia : F. Hernández
ISSN: 0213-3911
Materias relacionadas: CDU::6 - Ciencias aplicadas::61 - Medicina
Palabras clave: Pineal gland
Synaptic bodies
Resumen: Synaptic bodies (SB) are ultrastructural o rganelles observed in the pinealocytes of mammals. According to its shape, they have been classified into synaptic ribbons (SR), synaptic spherules (SS), and intermediate synaptic bodies (ISB). They have been related to the melatonin regulation and production mechanisms of the pineal gland. Circadian and circannual fluctuations of both melatonin and SB have been reported. The possibility that other external factors, apart from light-dark or seasonal cycles, might influence pineal function has been suggested. We studied the evolution of the number of SB and serum melatonin levels not only during light-dark and seasonal phases but also during lunar cycles. Forty male wistar rats were used. Experiment was first carried out in winter and repeated identically in spring. Each season, one group of animals was killed during the new-moon days and a second group during the full-moon days: half of both groups in the photophase and the other half in the scotophase. The number of SB was measured at electron microscopic level whereas serum melatonin levels were determined by radioimmunoassay techniques. Main results showed that SR number and serum melatonin levels were higher during scotophases, winter and fullmoon days. The SS only showed a light predominance during winter, whereas predominance of the ISB was found only during the scotophases. These results support the influence of the photophasic factors on the SR and ISB variations. In the case of the SS the influence of the lunar cycles is always dependent on the other factors. F i n a l l y, the serum level of melatonin is clearly influenced by the photophasic rhythms and the seasonal periods but not by the lunar cycles.
Autor/es principal/es: Martínez Soriano, F.
Ruíz Torner, A.
Armañanzas, E.
Valverde-Navarro, A.A.
Forma parte de: Histology and histopathology
URI: http://hdl.handle.net/10201/20755
Tipo de documento: info:eu-repo/semantics/article
Número páginas / Extensión: 10
Derechos: info:eu-repo/semantics/openAccess
Aparece en las colecciones:Vol.17, nº 1 (2002)



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