Single Injection Of Estradiol Benzoate Research Articles

Aggression in adult mice: modification by neonatal injections of gonadal hormones.

Incidence of spontaneous aggression in adult male mice given a single injection of estradiol benzoate (0.4 milligram) when they were 3 days old was less than that of controls injected with oil. Aggressiveness was increased among adult females injected with either estradiol or testosterone propionate (1 milligram) at the same age. The increased aggressiveness noted among females given androgen was further documented during subsequent mating tests, when these females often attacked, wounded, and, in one case, killed naive males.

The effect of a single injection of estradiol benzoate on thyroid function in intact male rats.

The changes observed in the metabolism of radioiodide and radiophosphorus by the thyroid gland of intact adult male rats following a single injection of estradiol benzoate (4 μg/100 g body weight) are consistent with the suggestion (F. Labrie, G. Pelletier, and C. Fortier. Federation Proc. 26, 484 (1967). Abstr.) that at this dose level estrogen causes a hypersecretion of TSH in such animals.

The progestational activity of 9-alpha-halogenated steroids in the ovariectomized ewe.

SUMMARY A flock of 135 ovariectomized ewes was used in five tests designed to investigate the ability of three 9α-halogenated steroids to condition the spayed ewe to exhibit oestrus after a single injection of oestradiol benzoate (ODB). The experimental steroids (9α-fluoro-11β-hydroxypregn-4-ene-3,20-dione, 9α-chloro-11β-hydroxypregn-4-ene-3,20-dione and 9α-bromo-11β-hydroxypregn-4-ene-3,20 dione) were tested against a progestagen of known characteristics (17α-acetoxy-9α-fluoro-11β-hydroxypregn-4-ene-3,20-dione = SC-9880, G. D. Searle) and against each other. The steroids were injected intramuscularly, daily for 12 days and ODB was given at one of three doses as a single intramuscular injection 48 or 96 hr. after the final steroid injection. The effects of the three experimental steroids, as indicated by the oestrous responses to ODB, differed little from that of SC-9880, thus proving them to be highly potent progestagens; 0·4 mg./day appeared to be about the minimum daily effective dose of all three experimental steroids indicating a potency about 15–20 times that of progesterone.

Modification of embryonic development of reproductive and lymphoid organs in the chick

ABSTRACT Following the publication of Lillie’s (1917) observations and theories on the endocrine basis of the development of the bovine freemartin, experiments were initiated to determine if heterosexual gonad grafts to the chorio-alantoic membrane of chicks could stimulate formation of intersexes (Willier, 1927). Hormone extracts of testes and urine were used by Dantchakoff (1935) and Kozelka & Gallagher (1934), and synthetic hormones were tested in the chick by Wolff & Ginglinger (1935). Estrogens feminized the left gonad of male embryos and resulted in retention of Mullerian ducts in males and occasional cystic develop-ment of Mullerian ducts in females. Less extensive feminization of the left testis, dilation of Wolffian ducts, and partial deletion of Mullerian ducts occurred in androsterone-treated embryos (Wolff, 1935). Sensitivity of the genital papilla to exogenous steroids was described by Reinbold (1951). Riddle & Dunham (1942) demonstrated that a single injection of estradiol benzoate into laying birds resulted in feminization of genetic males which developed from ova released shortly thereafter. Lutz & Lutz-Ostertag (1959) described spontaneous chick freemartins developing in double-yolked eggs. Studies of individual male embryos which had access to the resources of two yolks in double-yolked eggs (Ruch, 1961) revealed the occurrence of gonadal modifications similar to those resulting from administration of estrogens or from implantation of female gonads adjacent to the genital ridge of young male embryos (Wolff, 1946–47). When heterosexual implants of gonads of sufficient size were placed on the chorioallantoic membrane, male left testes developed into ovotestes and Mullerian ducts were reduced in the female (Groenedijk-Huijbers, 1960). The immunological consequences of vascular anastomoses between bovine twins discussed by Owen (1945), and more recently by Fecheimer, Herschler & Gilmore (1963) and Goodfellow, Strong & Stewart (1965) afford an additional point of departure in studying the freemartin.

The influence of hormones on cell division: I. Time-response of ear, seminal vesicle, coagulating gland and ventral prostate of castrate male mice to a single injection of estradiol benzoate

The development of mitotic activity following the administration of a small dose of estradiol benzoate has been followed in the epithelia of ear, seminal vesicle, and coagulating gland of the castrate male mouse. Intrinsic and extrinsic variability have been closely controlled. All tissues respond to estrogen by increased mitotic activity. Seminal vesicle and coagulating gland reach the highest absolute values; ear is intermediate in response; and ventral prostate responds weakly. Ear epidermis responds significantly within 6 hours after hormone administration; seminal vesicle and coagulating gland respond significantly about 24 hours following treatment; and significantly elevated activity is not noted in ventral prostate until 72 hours after hormone treatment. Periodic fluctuations are noted in the mitotic activity curves which suggest the presence of tissue specific rhythms in addition to the previously demonstrated 24-hour mitotic cyle. These results are discussed in terms of the hormonal effects upon the metabolic systems which may be involved in mitotic activity.

Effect of Single Injections of Estradiol Benzoate on the Normal Human Menstrual Cycle with Special Reference to the Problem of Estrogen Sensitivity

Despite the fact that estrogens are extensively used in clinical gynecology, from the literature available it appears that, with one exception (1), there is no information concerning the effect of estrogens on the human ovary. Even when estrogen has been used to postpone the onset of mestruation in normal women (2) it has not been possible to predicate how it was accomplished except that it is commonly stated that this hormone inhibits temporarily the gonadotropic function of the anterior lobe of the pituitary. The understanding of the action of estrogen in the human female is further complicated by the fact that even in laboratory mammals and especially in primates there is still a paucity of data as to how estrogen affects the normal ovary. According to Allen, Hisaw and Gardner (3) estrogens given over long periods of time inhibit the ovary. The ovaries of mice after treatment with 500 i.u. of estrogen weekly for 150 days are usually small (3).

TEMPORARY OVARIAN DAMAGE PRODUCED IN BABOONS BY SINGLE ADMINISTRATIONS OF ESTRADIOL BEN2OATE AND PROGESTERONE IN THE FIRST PART OF THE CYCLE1

IT HAS BEEN SHOWN that single injections of estradiol benzoate, progesteroneor of combinations of both into normal adult female baboons in the first part of the cycle will cause the turgescent perineum to undergo deturgescence (11, 12, 13). Deturgescenceof the perineum is normally encountered in the second part of the cycle when the corpus luteum develops on the ovary. In castrate animals treated repeatedly with estrogen the perineum becomes turgescent, but when the estrogen is withdrawn the perineum undergoes deturgescence. It was felt that progesterone could cause perineal deturgescence by acting directly on the perineum as this substance is normally present in the second half of the cycle. Gillman and Stein (16) have shown that, even in the presence of enormous quantities of estrogen, the perineum will undergo deturgescence, provided adequate quantities of progesterone are simultaneously administered.