The biological assay of A. P. G. was conducted on the extract of 4, 000 sow hypohysis collected at the slaughter house.
The results obtained by the Imamichi's method, using the hypohysectomized immature male rat, indicated that the activity of 952 μg of sow A. P. G. extract was equivalent of 1 prostate Unit. And testicular weight of hypophysectomized male rat injected with 27 μg of sow A. P. G. extract was 2 times as compared with that of the control animal.
The activity of 25 μg of sow A. P. G. extract was equivalent to 1 R. ov. U. by adult female rat ovulation inducing reaction and 67 μg of the extract was determined to be 1 Rab. U. by Friedmann reaction.
Moreover, on the mouse uterine weight reaction, 20 mg increase was obtained by injecting 1, 000 μg of the extract.
For the treatment to ovarian dysfunction in the cow, effect was obtained with 5 mg of the extract by intravenous injection.

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Some observation was made concerning the ovulation with treatment of neural blocking agent (Nembutal) and the estimation of pituitary ovulating hormone (O. H.) in 3 I.U. PMS-primed immature rats.
1) The effect of Nembutal treatment on PMS-primed rats at 25 days of age (Table 1)
Nembutal was treated at various times after 3 I.U. PMS injection. In the case of 52hrs. after PMS treatment, ovulation was inhibited in high rate of 90% at the time of autopsy 74hr after PMS injection, whereas the inhibition was not observed in the case of 55 hrs.
The inhibition of ovulation at 52hrs. treatment of Nembutal was not observed by injection of 10 I.U. HCG. Therefore, the neural surge for release of O.H. seems to occur from 52 to 55hrs. after PMS injection. When autopsy was made at 98 hrs. after PMS injection, tubal ova was recognized in all animals in 52hr. Nembutal injection, showing delayed ovulation in 24 hrs. by neural blocking.
2) Potency of pituitary O.H. in ovulation-blocked or ovulated rats primed 3 I.U. PMS (Table 2)
The potency of pituitary O.H. of rats primed 3 I.U. PMS at 25 and 31 days of age were compared between ovulation-blocked group (a) and ovulated group (b). The potency of immature rat was determined by the induction of ovulation in adult rats (recipient) of late diestrus stage. In the case of 25 days of age slightly but insignificant decrease of the potency (ovulation rate) was shown in (b) and (a). However, the distinct decrease of the number of ova in (b) was found for 1/10 glands compared with (a). In the case of 31 days of age, the decrease of the potency was clearly shown in the ovulation rate. The decrease of pituitary O.H. at the time of ovulation was observed in both days of age, whereas the level of this decrease was different between 25 and 31 days of age.
3) Potency of pituitary O.H. in ovulated rats by 3 I.U. PMS treatment from 25 to 31 days of age (Table 4)
When the potency of pituitary O.H. was compared between the rats of 25, 27, 29 and 31 days treatment, the sudden decrease of the potency was observed after 27 days of age and after that time the constant level was indicated in the same as the potency of the first ovulation at vaginal opening (Table 3).
4) Potency of pituitary O.H. in rats ovulated by the increased dose of PMS at 25 days of age (Table 5)
The potency of pituitary O.H. was determined in 25 days rats primed with increasing the dose of PMS (9 I.U. and 30 I.U.). The pituitary of immature rat treated with high dose of PMS induced fully ovulation in recipient treated 1/4 pituitary glands (5/7 in 9 I.U. and 6/9 in 30 I.U.). When this potency was compared with that of 3 I.U. PMS treatment after 27 days of age, the potency in the case of the high dose treatment was clearly higher in spite of indicating more stimulated follicles by the elevated dose of PMS. It is suggested from results of this investigation that the responsibility of central nervous system to estrogen secreted from ovarian follicles by PMS stimulation was distinctly different between 25 days of age and the ages after 27 days. It seems important to make more detailed investigation of the difference of the responsibility in explaining the mechanism of puburty.

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[in Japanese]

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It has been suggested (IV, VI) that biological activity of PMSG was neutralized with anti-PMSG immune rabbit serum and then biological and immunological activity were reversible in heat-dissociated solution of PMSG antigen-antibody complex.
Gonadotropic activity and antigenicity in mice injected with the PMSG antigen-antibody complex were observed by hemorrhagic follicles and corpus luteum formation reaction, uterine weight reaction and serological ring test. No gonadotropic activities of PMSG were observed and antibody to PMSG was not detected in the mice for 270 days after injection.

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In 14 dairy cows (Holstein), the corpus luteum was diagnosed as to be cystic for the reason that the presence of fluid in its cavity was detected by rectal palpation 6 to 11 days after artificial insemination (A.I.) as shown in Table 1. Ovulation had been recognized 1 or 2 days after the A.I. in all of these animals except 1 animal in which examination could not be performed. They were treated by removing the fluid from the cavity of the corpus luteum with finger pressure or intrafollicular (I.F.) injector.
The results obtained were summarized as follows: 1) In 6 animals, the cystic corpus luteum was ruptured easily by finger pressure per rectum and the remaining tissues were felt as those of ruptured follicular cyst. However, within 3 to 4 days after the treatment, the corpus luteum developed into almost normal size, and then it was maintained as the corpus luteum of pregnancy in 4 of these 6 animals (Fig. 1: Cow No. 5 and No. 6).
2) In 2 animals, the corpus luteum seemed to decrease shightly in size following the fluid explusion by finger pressure, but maintained its original form. Immediately after the treatment, the cavity of the corpus luteum could be detected per rectum. One of the 2 animals became pregnant by A.I. carried out before the treatment.

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