Effect of kisspeptin (KISS) and RFamide-related peptide-3 (RFRP-3) on the synthesis and secretion of FSH in vitro by pituitary cells in pigs

• Published in: Theriogenology Vol. 171; pp. 72 - 84
• Main Authors: Zmijewska, Agata, Czelejewska, Wioleta, Drzewiecka, Ewa M., Franczak, Anita
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01-09-2021
• Subjects: FSH; Kisspeptin; Pig; Pituitary; RFRP-3; Kisspeptin; FSH; RFRP-3; Pituitary; Pig
• ISSN: 0093-691X; 1879-3231
• DOI: 10.1016/j.theriogenology.2021.05.010

Kisspeptins (KISSs) and RFamide-related peptide-3 (RFRP-3) affect the synthesis and secretion of luteinizing hormone (LH) and modulate female reproductive processes. The presence of KISS and RFRP-3 in the porcine pituitary gland and their contribution to the regulation of follicle-stimulating hormone (FSH) synthesis and secretion is unknown. This study analyzed the presence of KISS and RFRP-3 in the pituitary of estrous-cyclic pigs on days 2 to 3, 10 to 11, 12 to 13, 15 to 16 and 19 to 20 and early pregnant pigs on days 10 to 11, 12 to 13 and 15 to 16, and evaluated the effect of KISS and RFRP-3 on β-Fsh mRNA expression and FSH secretion in vitro by pituitary cells collected on selected days of the estrous cycle. The cells were cultured in vitro and treated with KISS (10−6 M, 10−7 M) and RFRP-3 (10−6 M, 10−7 M) or gonadotropin-releasing hormone (GnRH; 100 ng/mL) alone and in combinations (4 h or 24 h). The relative abundance of Kiss and Rfrp-3 and their receptor mRNA transcripts, as well as the KISS and RFRP-3 proteins, were found in the pituitaries of estrous-cyclic and early pregnant pigs. KISS after 4 h increased the secretion of FSH in estrous cyclic pigs mostly during the early-luteal phase and luteolysis. RFRP-3 inhibited the synthesis and secretion of FSH in estrous-cyclic pigs on days 19 to 20 and the secretion of FSH on days 2 to 3 and 10 to 12 of the estrous cycle compared with GnRH-treated cells. KISS in co-treatment with GnRH after 24 h enhanced FSH release on days 2 to 3 and 15 to 16 of the estrous cycle. In conclusion, KISS and RFRP-3 systems are present in the pituitary of estrous-cyclic and pregnant pigs. In estrous-cyclic pigs, KISS and RFRP-3 may affect the synthesis and secretion of FSH by pituitary cells.
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•KISS and RFRP-3 are present in the pituitary of estrous-cyclic and pregnant pig.•KISS increases β-Fsh mRNA transcript abundance and FSH secretion by pituitary cells.•RFRP-3 may diminish GnRH-stimulated FSH synthesis and/or secretion.•The effect of KISS and RFRP-3 action in pigs depends on day of the estrous cycle.