| 1. |
Provoked ovulation in both hamsters and rats after spontaneous ovulation was blocked by phenobarbital, fluphenazine, or pentobarbital and atropine. In rats, a single I.V. injection of HRF proved far more potent in reversing the antiovulatory effects of these substances than the isolated natural releasing hormone. |
| 2. |
Showed no evidence of LH activity, as evidenced by its failure to induce ovulation in hypophysectomized or pseudo-pregnant rats. |
| 3. |
Induced the secretion of no more than physiological amounts of LH and FSH, as evidenced by the fact that administration on the day of mating did not increase the number of implantations. |
| 4. |
Proved effective in reversing a persistent oestrus syndrome used as an experimental model of the Stein-Leventhal syndrome. Administration of HRF (1 µg/day) to rats in whom permanent oestrus had been established induced a return to regular cycling that lasted until sacrifice. |
| 5. |
Did not cause an oversecretion of gonadotropins (particularly FSH) as evidenced by the fact that periodic injections of high doses did not increase uterine and ovarian masses. Similar periodic high dosages in immature, prepubertal, or adult males had no effect on masses of androgen-dependent organs (ventral prostate, seminal vesicles, testes, and levator ani). |
| 6. |
Was effective at doses of 4,0 and 10,0 µg in advancing ovulation by 24 hours in dioestrus rats. It also proved active at 0,5 µg in provoking ovulation on the date of late proestrus in fluphenazine-treated rats, but inactive in oestrus, metoestrus or dioestrus animals. |
| 7. |
Caused the release of LH in rats treated with medroxyprogesterone acetate, inducing ovulation when the follicle maturation process was effected by pregnant mare serum. |
| 8. |
Caused the release of LH in rats treated with ethinyl oestradiol, inducing partial ovulation (66,7%) at a dose level of 2,5 µg when pregnant mare serum was given with the oestrogen. |
| 1. |
Even when administered experimentally at levels as high as 50 times the recommended clinical dosage, it was impossible to achieve an LD-50. |
| 2. |
A complete lack of toxicity in experimental animals was seen regardless of whether the drug was administered by intramuscular, subcutaneous, or intravenous injection, or by intravenous infusion. |
| 3. |
It had virtually no effect on blood pressure, ECG, or heart or respiratory rate in experimental animals, nor could any effect be seen on general behaviour, body organs, or a wide variety of haematology, urine, and other clinical chemistry parameters. |
| 4. |
It had no teratogenic or embryopathic effect, and no effect upon reproductive capacity. |
| 5. |
The liver and kidneys are apparently the major sites for inactivation and excretion of the compound. |