Physical-chemical and biological characterization of different preparations of equine chorionic gonadotropin

Abstract

Ovarian stimulation with commercial preparations of equine chorionic gonadotropin (eCG) produces extremely variable responses in domestic animals, ranging from excessive stimulation to practically no stimulation, when applied on the basis of their declared unitage. This study was conducted to analyze four commercial preparations from different manufacturers via reversed-phase HPLC (RP-HPLC) in comparison with a reference preparation and an official International Standard from the World Health Organization. The peaks obtained by this qualitative and quantitative physical–chemical analysis were compared using an in vivo bioassay based on the ovarian weight gain of prepubertal female rats. The RP-HPLC data showed one or two peaks close to a main peak (tR = 27.9 min), which were related to the in vivo bioactivity. Commercial preparations that have this altered peak showed very little or no in vivo activity, as demonstrated by rat ovarian weight and in peripubertal gilts induced to ovulate. Overall, these findings indicate that RP-HPLC can be a rapid and reliable tool to reveal changes in the physicochemical profile of commercial eCG that is apparently related to decreased biological activity of this hormone.

Evaluación de un nuevo protocolo de superovulación en llamas: respuesta ovárica, recuperación embrionaria y alteraciones pos-tratamiento

“…La respuesta superovulatoria fue muy variable, encontrándose hembras con 1 a 9 folículos pos-tratamiento, lo cual está ampliamente descrito en camélidos (Ratto et al, 2013). Este resultado podría estar influenciado, además, por la alta variabilidad de la concentración de la hormona eCG en los preparados comerciales (Herrera et al, 2016).…”

Lack of effects of an equine chorionic gonadotropin (eCG) administration between days 9 and 15 postpartum on reproductive performance in a Holstein dairy herd

“…Alvarez et al. () reported that different commercial preparations of this hormone may differ in their physico‐chemical profile determined by reverse‐phase high pressure liquid chromatography (RP‐HPLC) and their in vivo bioactivity in prepubertal female rat and peripubertal gilt models.…”

“…Finally, eCG preparations from different manufacturers were used in the two studies. Alvarez et al (2016) reported that different commercial preparations of this hormone may differ in their physicochemical profile determined by reverse-phase high pressure liquid T A B L E 2 Effects of application time (days postpartum) of equine chorionic gonadotropin on calving to first service and calving to conception interval within study group eCG (Cox regression analysis) chromatography (RP-HPLC) and their in vivo bioactivity in prepubertal female rat and peripubertal gilt models.…”

The Potential Uses of Curcumin and PMSG Hormones to Increase Egg Production of Muscovy Ducks through Increasing Estradiol Concentrations and Shortening Laying Rest Period

“…Curcumin can increase metabolism, maximize vitellogenin synthesis, stimulate feed consumption, endogenous secretion, and poultry productivity (Park et al, 2012). Meanwhile, PMSG hormone has high effectiveness in stimulating superovulation because it has multiple actions, such as FSH and LH (Alvarez et al, 2016). P3 ducks during the 3rd laying period had the lowest egg production, presumably because the experimental ducks experienced physiological stress due to the first injection of PMSG.…”