FSHが排卵誘起作用を有する可能性について

抄録

It has been believed that FSH stimulates the follicular growth and does not induce ovulation. However, there were some reports suggesting the posibility that FSH might have the luteinizing and ovulation promoting properties13, 17, 18, 19, 24).
In the present study, the ovulation inducing activity of swine FSH was investigated. Regular 4 day cyclic rats were used. Purified swine FSH was injected subcutaneously at the afternoon on the day of vaginal diestrus. Animals autopsied 20 hours after the injection and the tubal ova were inspected.
At the dose of 50 γ and 100 γ of FSH, 4 out of 10 and 8 out of 10 animals ovulated. From these results, 1 rat ovulating unit16) of this preparation of FSH was calculated as 60 γ.
Generally, the amount of contaminating ICSH in the preparation of FSH is estimated by the ventral prostate assay of hypophysectomized immature male rats. In this preparation of FSH, the amount of contaminating ICSH is estimated as 2-3% by the prostate assay22). As the amount of 1 Pr. U. of sheep ICSH was 40 γ15), 1, 300 to 2, 000 γ of the FSH preparation is equivalent to 1 Pr. U. The amount of 1 R. Ov. U. of the ICSH preparation was 7.5 γ which was equivalent to 0.19 Pr. U. If the ovulation was induced by the contaminating ICSH in the FSH preparation, the necessary amount of this preparation to induce ovulation in 50% of animals may be calculated as 250 to 375 γ. However, the practical amount of 1 R. Ov. U. of the FSH preparation was 60 γ which was equivalent to 0.03 to 0.0045 Pr. U. and its ICSH contamination is calculated as 1. 2 to 1. 8 γ by the ventral prostate stimulation.
By this result, ovulation inducing activity of the FSH preparation is 4 to 6 times potent that of the ICSH preparation. The ovarian interstitial cell stimulating effect of 400 γ of the FSH preparation was weaker than that of 5 to 10 γ of ICSH. Accordingly, ICSH contamination in 60 r of the FSH preparation may not exceed 2 γ. Although 200 γ of the FSH preparation stimulated effectively the follicular growth in hypophysectomized immature female rats18), 21), no follicle was luteinized by combined treatment of 200 γ of FSH and 5 to 1, 000 γ of ICSH17). On the other hand, partial luteinization was observed clearly in hypophysectomized immature animals received 500 γ of FSH alone. From these results, it may be reasonable to assume that the luteinizing and ovulation inducing activities may be intrinsic as biological properties of pituitary FSH.