Chemosynthetic ethanolamine plasmalogen stimulates gonadotropin secretion from bovine gonadotrophs by acting as a potential GPR61 agonist

Ethanolamine plasmalogens derived from whale brain stimulate both follicle‐stimulating hormone and luteinizing hormone secretion by bovine gonadotrophs

“…This was an unexpected result, since the heifer brain EPl did not stimulate LH secretion in either this study or in a previous study (Kereilwe, Pandey, & Kadokawa, 2018), although EPl extracted from scallop stimulated the secretion of both hormones in a previous study (Kadokawa et al, 2022). Moreover, a chemosynthetic EPl molecular species, C18:0–C18:1, stimulates the secretion of both LH and FSH from cultured bovine AP cells (Kadokawa et al, 2022). Therefore, we must consider these differences by taking each species' living environment into account (Hong et al, 2022; Kato & Perrin, 2018; Murase et al, 2015; Takahashi et al, 2022; Watanabe et al, 2012) and EPl molecular species.…”

“…After incubation at 37°C for an additional 2 h, the medium from each well was collected for radioimmunoassay of FSH and LH concentrations using a previously reported method (Pandey et al, 2017). We used cultured bovine AP cell models as described in previous studies to evaluate the effects of various hormones, including insulin‐like growth factor I, kisspeptin, estrogens, anti‐Müllerian hormone, and EPl (Ezzat et al, 2010; Hashizume et al, 2002; Kadokawa et al, 2021, 2022, 2022; Kereilwe, Pandey, Borromeo, & Kadokawa, 2018; Kereilwe, Pandey, & Kadokawa, 2018; Otsuka & Kadokawa, 2017).…”

“…However, EPls extracted from old cows (approximately 8 years old or older) has no such stimulation (Kadokawa et al, 2021). Using a cultured AP cell model prepared from post‐pubertal Japanese Black heifers (approximately 2 years old), we recently reported that GPR61 from bovine gonadotrophs binds to a chemosynthetic EPl, activates the cytoplasmic Smad and ERK pathways, and stimulates FSH and LH secretion (Kadokawa et al, 2022). Thus, EPls may be involved in age‐related infertility in gonadotrophs through GPR61.…”

“…Lysophosphatidylethanolamine, which lacks an acyl group at the sn‐2 position, does not affect FSH and LH secretion (Kereilwe, Pandey, & Kadokawa, 2018). Thus, we previously proposed that the carbon chain at the sn‐2 position is crucial for the regulation of gonadotropic secretion (Kadokawa et al, 2022). Based on various possible combinations of fatty alcohols and acids, the brain contains various molecular EPl species.…”

Dynamic changes and importance of plasma concentrations of ether phospholipids, of which the majority are plasmalogens, in postpartum Holstein dairy cows

“…Brain EPls have another novel role as ligands of G protein-coupled receptor 61 (GPR61), a recently discovered receptor that stimulates gonadotropin secretion by bovine gonadotrophs in the anterior pituitary (Pandey et al 2017;Kereilwe et al 2018a;Kadokawa et al 2022a). The secretion of gonadotropins, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) from gonadotrophs is the key driver of the resumption of ovulation during the postpartum period (Beam and Butler 1997;Kadokawa et al 2000).…”