Search Results
You are looking at 1 - 3 of 3 items for
- Author: A. A. GERALL x
- Refine by access: All content x
Search for other papers by A. A. GERALL in
Google Scholar
PubMed
Search for other papers by J. L. DUNLAP in
Google Scholar
PubMed
While physiological and biochemical data show that the testes of neonatal rats release androgenic substances capable of influencing morphogenesis and behavioural potentiality, equivocal evidence is available concerning the secretory capacity of the ovaries during this period. Presi, Jirásek, Horský & Henzl (1965) reported no detectable steroid-3β-ol dehydrogenase in interstitial cells around follicles in rats less than 8 days old. Using a bioassay method, Cierciorowska & Russfield (1968) found no reliable activity in ovarian extracts from rats younger than 13 days. Fluorometric analyses also failed to reveal significant amounts of oestrogen in ovaries from rats younger than 10 days (Presl, Hermann & Horský, 1969). Since Carmichael & Marshall's (1908) research, it is known that unilateral ovariectomy is followed by hypertrophy in the remaining ovary, presumably resulting from increased circulating gonadotrophin associated with decreased negative feedback by ovarian hormone. If the ovary of the neonatal rat does not secrete active hormones, then
Search for other papers by A. A. GERALL in
Google Scholar
PubMed
Search for other papers by R. E. McCRADY in
Google Scholar
PubMed
SUMMARY
Receptivity ratings of female rats that had been injected neonatally with either sesame oil or varying amounts of testosterone propionate (TP) were compared, using either a currently used manual technique or males as the test stimuli. Females receiving more than 10 μg. TP when 5 days old either rejected the male or gave minimal lordotic responses when mounted. However, they often responded with complete lordosis when manually stimulated. Untreated females in heat tended to obtain higher receptivity ratings with males than with the manual stimulus. In general, manual test ratings were found to be less related to oestrous conditions than those recorded with males. Some of the limitations and advantages of each method are discussed.
Search for other papers by A. A. GERALL in
Google Scholar
PubMed
Search for other papers by MARCIA M. McMURRAY in
Google Scholar
PubMed
Search for other papers by ALICE FARRELL in
Google Scholar
PubMed
SUMMARY
Testosterone in its free form, and dihydrotestosterone (DHT) and androsterone, both androgens which are not aromatizable to oestrogen, injected in oil during the neonatal period have been reported not to modify the development of female sexual behaviour. This failure might be due to the short period of activity of these substances when injected in liquid vehicles. In the current study, a Silastic pellet containing 9% of its weight of testosterone, androsterone, or DHT was implanted subcutaneously in 42 female and 38 neonatally castrated male hamsters on day 2 of life and removed on day 10. Pellets of pure Silastic were implanted in 36 control animals. Males were gonadectomized on day 5 and females on day 45. Female sexual behaviour induced by oestradiol benzoate and progesterone was measured in a series of 10-min mating tests with vigorous males, starting at 55 days of age. The duration of lordosis was consistently reduced below control levels in females implanted with testosterone, DHT, and androsterone, and in males, with testosterone and DHT. Thus the free form of testosterone, and some non-aromatizable androgens, when present for a sufficiently long period after birth, can permanently suppress development of female reproductive behaviour.
