Physical-chemical and biological characterization of different preparations of equine chorionic gonadotropin.
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 anin vivobioassay 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 thein vivobioactivity. Commercial preparations that have this altered peak showed very little or noin vivoactivity, 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.
Agency for Agribusiness Technology of São Paulo, 13400-970 Piracicaba, Brazil.
Rafael Herrera
RH
Alvarez
Agency for Agribusiness Technology of São Paulo, 13400-970 Piracicaba, Brazil.
Fabio Luis Nogueira
FL
Natal
Biotechnology Department, IPEN-CNEN, Cidade Universitária Sao Paulo, 05508-000 São Paulo, Brazil.
Maria Teresa Carvalho Pinto
MT
Ribela
Biotechnology Department, IPEN-CNEN, Cidade Universitária Sao Paulo, 05508-000 São Paulo, Brazil.
Beatriz Elane
BE
de Almeida
Biotechnology Department, IPEN-CNEN, Cidade Universitária Sao Paulo, 05508-000 São Paulo, Brazil.
João Ezequiel
JE
de Oliveira
Biotechnology Department, IPEN-CNEN, Cidade Universitária Sao Paulo, 05508-000 São Paulo, Brazil.
Paolo
P
Bartolini
D000818:Animals; D006063:Chorionic Gonadotropin / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000662:veterinary; D056148:Chromatography, Reverse-Phase / Q000662:veterinary; D005260:Female; D006736:Horses / Q000502:physiology*
D006063:Chorionic Gonadotropin
equine chorionic gonadotropin; gilts; high pressure liquid chromatography; ovarian response; rats