Manca, Maria Elena and Manunta, Maria Lucia Gabriella M. and Spezzigu, Antonio and Torres Rovira, Laura and Gonzalez Bulnes, Antonio and Pasciu, Valeria and Piu, Peter and Leoni, Giovanni Giuseppe and Succu, Sara and Chesneau, Didier and Naitana, Salvatore and Berlinguer, Fiammetta (2014) Melatonin deprival modifies follicular and corpus luteal growth dynamics in a sheep model. Reproduction, Vol. 147 (6), p. 885-895. ISSN 1470-1626. eISSN 1741-7899. Article.
Full text not available from this repository.
This study assessed the effect of melatonin deprival on ovarian status and function in sheep. Experimental procedures were carried out within two consecutive breeding seasons. Animals were divided into two groups: pinealectomised (n=6) and sham-operated (n=6). The completeness of the pineal gland removal was confirmed by the plasma concentration of melatonin. Ovarian status was monitored by ovarian ultrasonography for 1 year to study reproductive seasonality. Follicular and corpus luteal growth dynamics were assessed during an induced oestrous cycle. As the effects of melatonin on the ovary may also be mediated by its antioxidant properties, plasma Trolox equivalent antioxidant capacity (TEAC) was determined monthly for 1 year. Pinealectomy significantly extended the breeding season (310±24.7 vs 217.5±24.7 days in controls; P<0.05). Both pinealectomised and sham-operated ewes showed a well-defined wave-like pattern of follicle dynamics; however, melatonin deficiency caused fewer waves during the oestrous cycle (4.3±0.2 vs 5.2±0.2; P<0.05), because waves were 1 day longer when compared with the controls (7.2±0.3 vs 6.1±0.3; P<0.05). The mean area of the corpora lutea (105.4±5.9 vs 65.4±5.9 mm2; P<0.05) and plasma progesterone levels (7.1±0.7 vs 4.9±0.6 ng/ml; P<0.05) were significantly higher in sham-operated ewes compared with pinealectomised ewes. In addition, TEAC values were significantly lower in pinealectomised ewes compared with control ones. These data suggest that melatonin, besides exerting its well-known role in the synchronisation of seasonal reproductive fluctuations, influences the growth pattern of the follicles and the steroidogenic capacity of the corpus luteum.
I documenti depositati in UnissResearch sono protetti dalle leggi che regolano il diritto d'autore
Repository Staff Only: item control page