Med. Weter. 79 (12), 633-636, 2023
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NATALIA SZYSIAK, URSZULA KOSIOR-KORZECKA, VINCENZO LONGO, ANDREA CAVALLERO, BARTŁOMIEJ SZYMCZAK, AGNIESZKA FURMAŃCZYK-GNYP, DOMINIKA NGUYEN NGOC, ANETA NOWAKIEWICZ, IWONA PUZIO, BARBARA SURÓWKA, NATALIA MINAKOW |
Effect of saturated fatty acid on GnRH-induced gonadotropin secretion from anterior pituitary cells of pubescent ewe lambs |
The pathologically changed pattern of gonadotropin secretion, responsible for ovulation disorders in fatty ewes, may result from the prolonged increase in leptin concentration as well as from diminution of leptin receptors expression in anterior pituitary cells. Leptin acting peripherally reduces the secretion of insulin – the potent inhibitor of lipolysis. Consequently, an increment in plasma fatty acids level is observed. It was also found that in ewe lambs born to obese sheep carrying twins or triplets, a high plasma level of saturated fatty acids (SFA) is in positive correlation with the delay in puberty. However, the relationship between SFA and gonadotropin secretion from the ovine pituitary cells in pubescent ewe lambs is not clear. Therefore, the aim of the study was to establish the effect of SFA on GnRH-induced secretion of FSH and LH. Pituitary glands were isolated from 7 month old ewe lambs. Pituitary cells were cultured in McCoy 5A medium without GnRH and SFA (negative control), with GnRH only (positive control), with GnRH and 10–9-10–3 M/l of the butyric (C4:0), caprylic (C8:0), lauric (C12:0), palmitic (C16:0) or stearic acid (C18:0). After 2 or 6 h of exposure to SFA followed by 2, 6, 12, 18, 24 or 30 h incubation, the media for LH and FSH analysis were collected. It was found that all used SFA reduce GnRH-induced LH and FSH secretion from pituitary cells in vitro. The most significant (P ≤ 0.05) suppressive effect was observed after 6 h exposure of cells to 10–3 M/l of caprylic acid, 10–4 M/l of palmitic acid and 10–4 M/l of stearic acid compared to the positive control. |
K Key words: saturated fatty acids, gonadotropin, pituitary cells in vitro, ewe lambs |