Gonadotrophin heterogeneity and its role in farm animal reproduction

Circulating FSH isoform patterns during recurrent increases in FSH throughout the oestrous cycle of heifers

“…FSH exists as a series of isoforms which have been identified in urine, serum and pituitary extracts of several mammals (Harlin et al, 1986;Padmanabhan et al, 1992;Kojima et al, 1995). It is now accepted that the observed molecular heterogeneity of these hormones arises through differential post-translational modification of core carbohydrate structures, leading to hormones with identical amino acid sequences but with distinct carbohydrate moieties (Chappel, 1995; UlloaAguirre et al, 1995;Cooke et al, 1996). These (Morell et al, 1971;Liu et al, 1984;Calvo et al, 1986).…”

“…To date, few studies have been carried out to characterize the patterns of circulating gonadotrophin isoforms in farm animals during different physiological states (Cooke et al, 1996). Many of the data generated are based on the patterns of isoforms present in the anterior pituitary rather than in the circulation (Chappel and Ramaley, 1985; Ulloa-Aguirre et al, 1988;Stumpf et al, 1992 (Snedecor and Cochran, 1989).…”

Structural and Functional Roles of FSH and LH as Glycoproteins Regulating Reproduction in Mammalian Species

“…Glycosylation patterns on the beta subunits of the gonadotropic hormones. Proteins are aligned with their cysteine residues in register [49]. Numbers indicate the positions of the glycosylated amino acids and numbering is based on ovine LH.…”

“…Figure 6. Structures of the sialylated dibranched and tribranched Asn-linked oligosaccharides in the pituitary glycoprotein hormones [49]. Only the highly sialylated structures are shown; see Green and Baenziger [11] for additional structures.…”

Resumption of Follicular Waves in Beef Cows is not Associated with Periparturient Changes in Follicle-Stimulating Hormone Heterogeneity Despite Major Changes in Steroid and Luteinizing Hormone Concentrations1

“…The circulating mix of FSH isoforms has been shown to vary from one physiological and neuroendocrine state to another (for review see [4,5]). For instance, a shift from the more acidic (less in vitro bioactivity) to the less acidic (more in vitro bioactivity) isoforms of circulating FSH has been observed during the follicular phase of the estrous cycle in cattle [6] and in the human menstrual cycle [7][8][9], when preovulatory concentrations of estradiol (E 2 ) are present, suggesting that E 2 may be involved in the modulation of FSH heterogeneity.…”