Evaluation of bioassays for measuring the of biological activity of Human Chorionic Gonadotropin (hCG)

Abstract

Biological activity of a given hormone is measured by its capacity to exert a specific, quantifiable biological effect. Aim of biological assays that measure activity of hCG is to construct prediction equations that associate increasing doses of hCG with changes in weights of genitalia, seminal vesicles and prostate gland in pre-pubertal male rats and weights of uterus and ovaries in pre-pubertal female mice. Objective of the present study was to evaluate efficiency of bioassays which used pre-pubertal male rats and female rats and mice to measure hCG activity. In experiment 1, male rats received 0, 4, 8 or 16IU of hCG daily, for 4 days. Prostate and seminal vesicles were weighed 24 hours after last injection. In experiment 2, female mice received 0, 3.33, 10, 33.33 or 100IU of hCG in one day. Ovaries and uteri were weighed 24 hours after the last injection. The hCG increased weights of genitalia in female mice. However, there were no satisfactory linear or quadratic associations between doses of hCG used and variables measured. It was concluded that assays tested showed only limited efficiency and sensibility to quantify hCG biological activity.