The »early-Androgen« Syndrome; Its Development and the Response to Hemi-Spaying

Abstract

The »early-androgen« syndrome in the rat – i. e. anovulatory ovaries in adult females after a single injection of testosterone propionate (TP) within a week of birth – may not become apparent until some time after the attainment of sexual maturity. Large doses (50 or 100 μg) of TP were effective earlier than lower doses (5 or 10 μg). Rats which received 5 μg TP were ovulating at 10 weeks of age, mated but were infertile at 13 weeks of age, and were anovulatory at 21 weeks. In rats between 10 and 13 weeks old there was a marked fall in the number of corpora lutea in the ovaries of animals which had been given 5 μg TP. Hemi-spaying was followed by compensatory growth of the remaining ovary which consisted of corpora lutea in ovulating, and of follicles in anovulatory rats; little or no compensatory weight increase occurred in animals which seemed to be in the transition stage from the ovulatory to the anovulatory condition.

Effect of androgenisation on the development of mammary tumours in rats induced by the oral administration of 9,10-dimethyl-1,2-benzanthracene

“…In the genital tract of the androgenised rats, typical changes were present identical with those described by previous authors (Barraclough, 1961 ;Jacobsohn, 1964;Swanson and van der Werff ten Bosch, 1964;Kovacs, 1965). The vaginal epithelium was cornified.…”

“…Because of the lack of ovulation, these androgenised rats are permanently sterile, and there is a constant cornification of the vaginal epithelium. The luteinizing hormone content of the pituitary is decreased (Barraclough, 1961 ; Gorski and Barraclough, 1962; Jacobsohn, 1964;Swanson and van der Werff ten Bosch, 1964; Kovaics, 1965).As has been shown by Huggins, Grand and Brillantes (1961), Huggins and Yang (1962) and other authors (Dao, 1962; Young, Cowan and Sutherland, 1963;Daniel and Prichard, 1964) the intragastric administration of 9,10-dimethyl-1,2-benzanthracene (DMBA) to normal female rats results in the development of mammary tumours in a very high percentage of animals within a few months. The present study is concerned with a comparison of the carcinogenic effect of oral administration of DMBA in androgenised and in non-androgenised rats.…”

“…Because of the lack of ovulation, these androgenised rats are permanently sterile, and there is a constant cornification of the vaginal epithelium. The luteinizing hormone content of the pituitary is decreased (Barraclough, 1961 ; Gorski and Barraclough, 1962; Jacobsohn, 1964;Swanson and van der Werff ten Bosch, 1964; Kovaics, 1965).…”

The effect of testosterone during the neonatal period on the thyroid gland of male and female rats

“…This is a large dose by current standards; as little as 5 gg (Swanson & van der Werff ten Bosch, 1964) or 10 ,ug (Gorski & Barraclough, 1963) may be sufficient to produce the typical syndrome in adult life. These workers have also reported various differences between rats treated with small and large (about 1 mg) doses of testosterone.…”

The Fertility of Mice After Androgen Injection in Early Infancy

“…The steroid acts on the central nervous system modifying the sexual differentiation of the hypothalamus and through it the adult pattern of gonadotrophin secretion necessary for ovulation and normal sexual behaviour [I, 10, 12]. Swanson and van der W erff ten Bosch sug gested [17] that the post androgen changes in the hypothalamus interfering with the stimulus for periodic discharge of gonadotrophins required for ovulation is not an 'all-or-none effect' as ovulation can occur shortly after puberty with the anovulatory syndrome only developing with increasing age of the animal. It has recently been shown [16], that in addition to the effect of the androgen on the central nervous system, there is a direct, immediate…”