Further investigations on specificity and precision in the Igarashi-McCann FSH assay method.

Abstract

The Igarashi-McCann method, reported in 1964 as a new biological method assaying FSH with MED corresponded to 2μg equivalents of NIH-FSH-Sl utilizing intact female mice of Swiss-Albino, would be appreciated to be indispensable for sensitive evaluation of FSH, in spite of having been suffered from poor precision which had been destined with the principle of uterine weight augmentation response. The optimum dose of HCG to be added was confirmed to be 0.075 iu through variance analysis of regression line and statistical investigation of linearity and stability in the dose response curve. The limitation and unification of beginning body weight of recipient were concluded to be inevitable not only for improvement of precision but also for qualitative unification in uterine weight response. Utilizing the unified recipient of 8 g, the stable and specific estimation of FSH in normal urine and plasma can be performed within such levels of maximum permitted contaminating dose (MPCD) as 2.0μg equiv. of NTH-LH-S13, 2.5μg equiv. of NIH-GH-S7, 1.0μg equiv. of NIH-GH-HS1082B, 400 mu equiv. of NIH-P-S7, 200mμ equiv. of Armour-ACTH, 200 mu equiv. of NIH-TSH-S5, and 0.005 μg of Estradiol with 0.075 iu of HCG, after referring reported contents of these hormones in pituitary, in plasma, and in urine. In conclusion, the results of Igarashi-McCann assay are specific for FSH, if less than 14.4 μg of rat anterior pituitary extract or less than 2.0ml of rat or human plasma, or 1.0 hr and 0.2 hr equiv. or less of non-pregnant human urinary extract except of acromegaly is injected into one mouse, respectively.