The relationship of serum estradiol and progesterone concentrations to the enzyme immunoassay measurements of urinary estrone conjugates and immunoreactive pregnanediol‐3‐glucuronide in <i>Macaca mulatta</i>

Abstract

Paired urine and serum samples from four conceptive and six nonconceptive ovarian cycles of seven adult Macaca mullatta were analyzed by radioimmunoassay (RIA) for circulating estradiol (E₂) and progesterone (Po), and urinary estrone conjugates (E₁C) and immunoreactive preganediol-3-glucuronide (iPDG) using enzyme immunoassay (EIA). Nonconceptive cycles exhibited a fivefold increase in urinary E₁C and serum E₂ levels from follicular phase levels to the preovulatory peak. Linear correlation between urinary E₁C and serum E₂ nonconceptive cycle hormone levels was significant (P <0.01, r = 0.69). Luteal phase levels of iPDG and serum Po levels were approximately parallel in nonconceptive cycles. Similarly, conceptive cycle urinary E₁C levels and serum E₂ measurements had a correlation coefficient that was significant (P<0.01, r = 0.45). Nonconceptive and conceptive cycle iPDG and Po levels were significantly correlated (P = 0.05, r = 0.63, and P<0.01, r = 0.66, respectively). These data demonstrate that EIA measurements of ovarian hormones in daily urine samples can be used to accurately monitor ovarian function and early pregnancy in Macaca mulatta.