ATCvet code: QG03GA01
Pharmacotherapeutic group
Sex hormones and modulators of the genital system.
Pharmacodynamic properties
Chorulon is a freeze-dried presentation of hCG together with solvent for reconstitution. hCG is a gonadotrophin. It is a large glycoprotein composed of two non-covalently associated alpha and beta subunits.
The extensive glycosylation of the CTP tail of the beta subunit of hCG results in its extended half-life which reaches 27h in pigs. hCG increases follicle maturation by stimulating androgen production by the cal cells and causes ovulation of the dominant follicle . Owing to its long half-life, it also stimulates formation and function of the corpus luteum.
In the male, hCG stimulates formation of testosterone, thus influencing the development and maintenance of primary and secondary male sexual characteristics.
Pharmacokinetic properties
Following i.m or i.v. injection, hCG is rapidly absorbed. Bioavailability following i.m. injection is high. Cmax is reached within 8hours in all target species. More specifically, peak hCG concentration (0.05 IU/ml) in plasma of cows is achieved 45 minutes after i.v. injection of a dose of 3000 IU. The elimination half-life of hCG is about 10 hours in cattle, and 27h in pigs.