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.