Mounting behavior of female guinea pigs after prenatal and adult administration of the propionates of testosterone, dihydrotestosterone, and androstanediol.

Female guinea pigs were exposed prenatally (Day 28–58) to the propionates of testosterone (TP), dihydrotestosterone (DHTP), or androstanediol (ADP). Only TP females failed to display lordosis in adulthood after estrogen and progesterone treatment. When given TP in adulthood, females in all groups mounted, but TP and DHTP females showed augmented intromission frequencies and higher percentages of correctly oriented mounts relative to controls. Moreover, TP females responded more quickly to TP injections in adulthood and had higher over-all mounting frequencies than other groups, while DHTP females displayed mounting frequencies intermediate to controls and TP females. ADP females were not different from controls for any measure of mounting behavior.No female in any group mounted when given DHTP in adulthood, even after 7 wk of daily injections. Since male guinea pigs do mount in response to DHTP given in adulthood, the results raise the possibility that mechanisms determining sensitivity to specific steroids may not be mediated exclusively by steroids during critical periods of embryological differentiation.     

Estrogenic contributions to sexual differentiation in the female guinea pig: influences of diethylstilbestrol and tamoxifen on neural, behavioral, and ovarian development

We administered the synthetic estrogen, diethylstilbestrol (DES), or the antiestrogen, tamoxifen, to pregnant guinea pigs and observed the consequences for sexual differentiation of their female offspring. Hormones were administered during the period when treatment of fetuses with testosterone influences the development of sex-related traits (approximately Days 30 to 65 of gestation). Ovarian function, masculine and feminine sexual behavior, and the structure of a sexually dimorphic neural region in the preoptic area were assessed in adulthood in hormone-exposed animals and in oil-treated and untreated controls. Prenatal exposure to DES dipropionate (DESDP) caused masculinization and defeminization. DESDP-treated females mounted more than control females, both without hormonal stimulation and when given testosterone propionate (TP) as adults. The sexually dimorphic neural region was also masculinized in these females. In regard to defeminization, they showed delayed vaginal opening, impaired progesterone (P) production, an absence of corpora lutea, and impaired lordosis and mounting responses to estradiol benzoate (EB) and P. Prenatal treatment with tamoxifen produced a complicated pattern of results. Tamoxifen-exposed females evidenced less masculine-typical behavior, showing diminished mounting without hormonal stimulation and in response to TP. However, they also showed delayed vaginal opening, enhanced P production, and impaired mounting in response to EB and P. Their lordosis behavior and the volume of the sexually dimorphic neural region were unaffected. These results suggest that estrogens play a substantial role in sexual differentiation in the guinea pig. High levels of estrogen promote masculine-typical development, and unusually low levels may impair some aspects of both masculine-typical and feminine-typical development.     

Early androgen treatment and male and female sexual behavior in mice

To investigate the role of neonatal androgen stimulation in the development of the potential for masculine and feminine sexual behavior in the mouse, different groups of mice were hormonally manipulated early in life. One group of female mice was administered testosterone propionate (TP) within 24 hr of birth; a second group of females was given a control injection of oil on the day of birth; a third group of females received an injection of TP on the 10th day after birth. A group of males received a control injection of oil on the day of birth. All mice were gonadectomized at about 30 days of age. At 60 days of age, mice were injected with estrogen and progesterone and tested for sexual receptivity; several weeks later all mice were injected with TP and tested for male sexual behavior. Female behavior: Females given oil at birth and females given TP on the 10th day after birth showed high levels of sexual receptivity as adults following estrogen-progesterone treatment. Females given TP on the day of birth, and male mice, rarely exhibited lordosis following estrogen-progesterone treatment. Male behavior: Most mice, regardless of genetic sex or neonatal treatment, mounted in adulthood following administration of exogenous androgen. There was little difference in mounting frequency between groups, suggesting that exogenous or endogenous androgen stimulation of the neonatal mouse does not facilitate adult mounting behavior. These data for the mouse are in essential agreement with existing data for the rat, and indicate that sexual behavioral differentiation induced by androgen stimulation in infancy is best characterized as an inhibition of the potential to display feminine sexual behavior in adulthood.     

Regulation of estrogen-induced uterine hyperemia and contractility in the guinea pig: cholinergic modulation of an alpha-adrenergic response

The effects of estradiol (1 microgram: E-1) treatment on uterine hyperemia and uterine sensitivity to various biogenic compounds were evaluated in ovariectomized (OVX) animals treated with either sesame oil or E-1 for 3 days. The E-1 treatments induced significant elevations in uterine weight, blood flow, and alpha- and beta-receptor numbers as compared with oil-treated controls. In contrast, uterine norepinephrine (NE) levels were reduced in E-1-treated, OVX guinea pigs as compared with oil-treated controls. Uterine sensitivity and responsivity to NE (10(-6) M) and acetylcholine (ACH: 10(-8) M) were either comparable to, or enhanced, in E-1-treated animals as compared with controls. In particular, combined ACH-NE treatment induced a dramatic increase in contraction force in E-1-treated uteri as compared with uteri from oil-treated animals. The use of specific adrenergic alpha- (phentolamine: 10(-6) M) or beta- (propranolol: 10(-6) M) receptor blocking agents indicated that the estrogenic response was mediated via the alpha-adrenergic receptor complex. Since atropine (10(-8) M) effectively blocked the cholinergic accentuation of this uterine response, it is suggested that a cholinergic priming, or beta-receptor block, is necessary for the full expression of the alpha-adrenergic-mediated, estrogenic response in the guinea pig. The estrogen-associated increase in available alpha- and beta-receptors and depressed tissue NE levels probably account for both the hyperemic response and enhanced tissue sensitivity to biogenic compounds in the guinea pig.     

Estrogens before birth and development of sex-related reproductive traits in the female guinea pig

Influences of estrogens on the differentiation of psychosexual traits in the female guinea pig were studied. Pregnant animals were injected intramuscularly with either 1, 2, or 3.3 micrograms estradiol benzoate (EB) or with 1 or 3 micrograms diethylstilbestrol dipropionate (DESDP). Injections were started on the 29th day of pregnancy, given daily for 6 days, and continued every other day until parturition. Female offspring were evaluated for onset of puberty, ovarian function, and lordosis and mounting behavior in adulthood. Prenatal treatment with 3 micrograms DESDP caused delayed puberty, impaired ovarian function, reduced responsiveness of lordosis to EB and P in adulthood (defeminization), augmented mounting in the absence of hormones (masculinization), and reduced responsiveness of mounting to exogenous EB and P in adulthood (defeminization). Prenatal treatment with 1 microgram DESDP produced similar but less pronounced effects. Prenatal treatment with 3.3 micrograms EB also caused a delay in puberty. However, responsiveness of lordosis to EB and P in adulthood was enhanced by treatment with either 1 or 3.3 micrograms EB prenatally. Further, neither mounting in the absence of hormones nor mounting in response to EB and P in adulthood were affected in any measurable way by any prenatal treatment with EB. These results show that estrogens can have masculinizing and defeminizing effects on sexually dimorphic reproductive traits in guinea pigs. The failure of EB to duplicate or parallel the effects of DESDP is not completely understood at this time, but it may indicate that less of the active substance reaches the target tissues following maternal and placental metabolism of EB than of DESDP.     

Sexual and social behavior of adult saddle-back tamarins (Saguinus fuscicollis), castrated as neonates

The behavior of four adult males castrated as neonates was compared with that of three neonatally sham-castrated males and two untreated males serving as controls. Two males castrated as sexually experienced adults served as additional controls. All males lived in permanent male-female pairs. The interactions of neonatally castrated, sham-castrated, and intact control males with strange conspecifics were tested in a situation analogous to territorial defense. In addition, the interactions of all males with their female pair mates were tested. Neonatally castrated males showed less injurious aggression against strangers and interacted with them less frequently than control males. There were significant differences between both groups of males in some of the agonistic behaviors recorded, but not in all. In pair tests, neonatally castrated males failed to show any coordinated male copulatory behavior but control males did. Males castrated as adults showed rates of mounting and thrusting similar to those of intact controls. Neonatally castrated males tended to interact with their females on a lower level than neonatally sham-castrated and untreated control males. How ever, most differences between both groups in the levels of pair mate interactions were not statistically significant. It is concluded that castration during neonatal life prevents the display of male copulatory behavior in adulthood and selectively affects the display of a number of other behaviors in adulthood. It is not possible at this point to decide whether these results are due to hormonal deficiencies on an organizational or activational level or both. However, data from studies currently in progress suggest that organizational processes might be responsible for part of the effect.     

Reversal of reproductive deficiency in the hpg male mouse by neonatal androgenization.

Some aspects of reproductive function in the GnRH-deficient hypogonadal (hpg) mutant mouse can be restored by transplanting normal fetal brain tissue containing GnRH cells into the central nervous system of adult hpg mice. However, hpg males showing physiological response to the graft fail to display sexual behavior and are infertile. We hypothesized that the reproductive deficit of these males is due to insufficient perinatal exposure to testicular androgens as a consequence of the GnRH deficiency. To test this hypothesis we androgenized hpg males by giving them neonatal injections of testosterone propionate (TP). Controls consisted of hpg males not androgenized neonatally and of normal males. All three groups received a TP implant in adulthood, and their copulatory behavior and reproductive capability were recorded. In addition, other hpg males, not androgenized neonatally, received fetal brain transplants containing GnRH neurons and were also tested for copulatory behavior and reproductive capability before and after receiving a TP implant. Three of 8 neonatally androgenized hpg males expressed the full repertoire of male sexual behavior, including intromission and ejaculation, and sired several litters. Three of 7 control hpg males that were not androgenized neonatally but received TP implants in adulthood also displayed mounting and intromission, but there was no evidence of ejaculation, and these males failed to impregnate normal females. Of the 8 hpg males that responded to a fetal transplant with testicular growth, only 1 displayed mounting behavior. However, when given a TP implant, 4 of 8 hpg males with grafts displayed mounting and intromissions.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of the absence of neonatal testosterone imprinting on the activity of the microsomal enzyme system and on the dexamethasone binding of the thymus in adulthood

Healthy and neonatally castrated male rats were treated with testosterone twice perinatally, while other groups were treated with testosterone also in adulthood or received testosterone only in adulthood. Castration resulted in a moderate (but in some instances significant) decrease of PSMO (polysubstrate monooxygenase) level measured in adulthood. The decrease could partially be compensated by perinatal testosterone treatment. Further testosterone treatment administered in adulthood did not result in further alteration when compared either with the controls or with the neonatally treated animals. However, since in the controls the second testosterone treatment (following the neonatal one), had a decreasing effect, therefore the testosterone treatment administered in adulthood was responsible for the disappearance of the difference between the castrated animals and the controls treated both perinatally and in adulthood. On the basis of these findings it seems likely that the perinatal presence of testosterone plays a major role in the development of enzymatic imprinting and thus, in securing the capability of the liver to split testosterone in adulthood. Since testosterone influences the glycocorticoid receptors of the thymus (presumably by its overlapping effect), so the amount of free glycocorticoid receptors is always higher in the animals castrated neonatally than in the controls. Conversely, neonatal testosterone treatment somewhat increases the number of receptors detectable in adulthood.     

Differential effects of testosterone metabolites in the neonatal period on open-field behavior and lordosis in the rat

Two experiments were done to compare the effects of neonatal exposure to testosterone and its major metabolites, dihydrotestosterone (DHT) and estradiol (E₂), on the development of sex differences in open-field behavior in the rat. In Experiment 1 female rats administered either testosterone propionate (TP), DHT, or estradiol benzoate (EB) were found as adults to have low activity scores, more typical of adult males, when compared to the high scores of oil-treated females. In Experiment 2 the adult open-field behavior of female rats treated neonatally with testosterone or the metabolites was compared to that of male rats treated from Day 1 to 10 of life with the aromatizing enzyme inhibitor, androst-1,4,6-triene-3,17-dione (ATD). These same animals were later tested for lordotic behavior after gonadectomy and priming with EB and progesterone. All male animals and female animals exposed neonatally to testosterone or to either of the metabolites had suppressed open-field activity scores compared to oil-treated females. However, the lordotic behavior of females exposed to DHT and of males exposed to ATD was not defeminized and was comparable to that of oil-treated females. These observations were discussed in terms of a role for the androgenic actions of testosterone in establishing sex differences in nonreproductive behavior in the rat.     

Sex-specific, behavior-specific actions of dihydrotestosterone: Activation of aggression, but not mounting in ovariectomized guinea pigs

Adult ovariectomized guinea pigs were tested for aggressive behavior during treatments with estradiol benzoate (EB), testosterone propionate (TP), dihydrotestosterone propionate (DHTP), or with DHTP + EB. Aggression was not influenced by EB, but was augmented by all other steroid treatments. DHTP given by itself was not as effective as TP, but was significantly potentiated by the concurrent administration of EB. When tested for mounting behavior, ovariectomized guinea pigs were refractory to DHTP and to DHTP + EB, whereas they mounted when given TP. The findings suggest that the hormone-sensitive neural systems which mediate aggression in female guinea pigs have in part different steroid requirements from those subserving the activation of mounting. In addition, the findings emphasize that DHTP + EB administration does not always duplicate the effects of TP for behavioral endpoints, since DHTP + EB and TP had similar effects on aggression, but quite different effects on mounting in female guinea pigs. These results stand in contrast to those obtained with male guinea pigs, in which DHTP has been reported to be as effective as TP for the activation of mounting. It is hypothesized that both sex-specific and hormone-specific activational phenomena may be genetically regulated by factors separate from those responsible for the establishment of prenatal hormonal conditions.     

The ovarian-adrenal axis in the guinea pig: effects of photoperiod, cyclic state and ovarian steroids on serum cortisol levels

The effect of photoperiod and reproductive cycle on the fluctuations in basal serum cortisol (F) levels were determined in adult female guinea pigs bled by intracardiac puncture under light methoxyflurane anesthesia. Blood samples were collected at regular intervals over a 24 hour period in order to assess the effects of the lighting regime (14 hr light/day: lights on 0600 hr) on basal levels of F. Peak F levels were observed at the beginning of the light cycle and lowest levels observed just prior to the onset of darkness in random, cyclic female guinea pigs. When analyzed for the influence of reproductive state, basal F levels were found to be elevated during proestrus, Day 2 (Day 0 = estrus) and the mid-luteal (Day 6-7) period of the estrus cycle. In ovariectomized animals a 10 microgram dose of estradiol (E) induced a dramatic rise (P less than 0.001) in adrenal weight and the basal levels of serum F as compared with oil-treated controls. Lower doses of E (1 microgram) and combined progesterone (2 mg)-E (1 microgram) treatment induced an elevation in adrenal weight and/or basal levels of serum F. Progesterone administration alone had no effect on either of these adrenal indices as compared with controls. These data indicate that both photoperiod and ovarian steroid hormone milieu affect adrenal function in the female guinea pig.     

Effects of perinatal exposure to a synthetic estrogen and progestin on mammary tumorigenesis in mice

The effects of perinatal exposure to synthetic estrogens and progestins on mammary tumorigenesis were studied in female C3H/HeN/MTV + mice. Mice were treated neonatally with 0.001 microgram/day diethylstilbestrol (DES), with 15 micrograms/day 17 alpha-hydroxyprogesterone caproate (HPC), or with oil on days 1-5 of life (birth = day 1). As adults, neonatally hormone-treated mice received long-term treatment with a synthetic estrogen and progestin combination or vehicle. Animals were palpated weekly for mammary gland tumors. The effect of treatment on the probability of tumor development was examined. Neonatal treatment with a low dose of DES increased the probability of mammary-gland tumor formation, whereas neonatal treatment with HPC had a slightly protective effect on tumorigenesis. Subsequent treatment of adult mice with synthetic steroids did not affect mammary gland tumorigenesis in neonatally DES-treated or oil-treated animals. There was a significant interaction between the effect of neonatal HPC treatment and subsequent steroid treatment on mammary tumorigenesis but examination of the data indicated that this interaction was due to the protective effect of HPC in the absence of subsequent exposure to synthetic steroids and the probability of tumor appearance in mice treated with both HPC and synthetic steroids as adults did not differ from that of neonatally oil-treated controls.     

Sexual differentiation of pheromone processing: Links to male-typical mating behavior and partner preference

Phoenix et al. (Phoenix, C., Goy, R., Gerall, A., Young, W., 1959. Organizing actions of prenatally administered testosterone propionate on the tissues mediating mating behavior in the female guinea pig. Endocrinology 65, 369–382.) were the first to propose an essential role of fetal testosterone exposure in the sexual differentiation of the capacity of mammals to display male-typical mating behavior. In one experiment control male and female guinea pigs as well as females given fetal testosterone actually showed equivalent levels of mounting behavior when gonadectomized and given ovarian steroids prior to adult tests with a stimulus female. This finding is discussed in the context of a recent, high-profile paper by Kimchi et al. (Kimchi, T., Xu, J., Dulac, C., 2007. A functional circuit underlying male sexual behaviour in the female mouse brain. Nature 448, 1009–1014.) arguing that female rodents possess the circuits that control the expression of male-typical mating behavior and that their function is normally suppressed in this sex by pheromonal inputs that are processed via the vomeronasal organ (VNO)-accessory olfactory nervous system. In another Phoenix et al. experiment, significantly more mounting behavior was observed in male guinea pigs and in females given fetal testosterone than in control females following adult gonadectomy and treatment with testosterone. Literature is reviewed that attempts to link sex differences in the anatomy and function of the accessory versus the main olfactory projections to the amygdala and hypothalamus to parallel sex differences in courtship behaviors, including sex partner preference, as well as the capacity to display mounting behavior.     

Neonatal hormonal influences on the development of proceptive and receptive feminine sexual behavior in rats

The objective of this study was to examine the influence of androgen and of the inhibiting of aromatization of androgen to estrogen during the early neonatal period on the development of receptive (lordosis and acceptance of stimulus male mounting attempts) and proceptive (affiliation with and solicitation of stimulus males) feminine sexual behavior. Within 8 hr of birth, male rats were castrated or received subcutaneous implants of the aromatase inhibitor androst-1,4,6-triene-3, 17-dione (ATD) while females received injections of testosterone propionate (TP). At 90 days of age all treated animals and controls were tested for receptive and proceptive feminine sexual behavior. It was found that androgen present neonatally blocked proceptive as well as receptive behavior patterns in adult rats. The proceptive and receptive feminine sexual behavior patterns displayed by adult males deprived of the effects of androgen neonatally either by castration or by treatment with ATD were comparable to those of normal females.     

Influence of androgen on the development of sexual behavior in rats : I. Time of administration and masculine copulatory responses, penile reflexes, and androgen receptors in females

The objective of the present study was to investigate the effect of the time of administration of androgen, during the neonatal period, on the development of masculine copulatory behavior in female rats. In addition, the influence of androgen, administered neonatally, on the development of penile reflexes and cytoplasmic androgen receptor levels in the hypothalamic-preoptic area (HPOA) was examined. Female rats were injected with 0.5 mg testosterone propionate (TP) at either 1, 8, or 24 hr after birth and again 24 hr after the first injection. Fifty percent of the females treated with TP at 1 and 8 hr after birth displayed the ejaculatory response when tested in adulthood. In contrast, 93 and 87.5% of oil-treated males and females, respectively, which were androgenized at 24 hr after birth exhibited this response. The results indicate that a considerable amount of masculinization occurs postnatally in the rat. However, none of the androgenized females displayed any penile reflexes even when tested following the display of an ejaculatory response. HPOA androgen receptor levels were somewhat higher in the oil-treated females than in males but were not correlated with the ability to exhibit ejaculation patterns.     

Pectin and psyllium decrease the susceptibility of LDL to oxidation in guinea pigs

These studies were undertaken to determine whether pectin (PE) and psyllium (PSY) intake affect the circulating levels of alpha-tocopherol and the susceptibility of low density lipoprotein (LDL) to oxidation. For that purpose, male Hartley guinea pigs were fed 19 g/100 g of a fat mix with a 2:1:1 ratio of saturated:polyunsaturated:monounsaturated fatty acids and 35 g/100 g total carbohydrate with 80% of the carbohydrate energy contributed by sucrose. Diets were identical in composition except for the fiber source: cellulose (control diet), PE, or PSY. Guinea pigs fed PE or PSY had 36% and 67% lower plasma cholesterol concentrations, respectively, compared with controls (P < 0.001). This plasma cholesterol lowering was associated with both very low density lipoproteins and LDL cholesterol fractions. Intake of PE or PSY resulted in 54% lower plasma triacylglycerol (TAG) concentrations compared with the control group (P < 0.001). LDL from PE and PSY fed guinea pigs contained fewer molecules of cholesteryl ester, and alpha-tocopherol concentrations in this particle were 49% and 66% higher, respectively, compared with controls. In addition, LDL from guinea pigs fed soluble fiber exhibited less susceptibility to oxidation than those from the control group, as determined by thiobarbituric acid-reactive substances formation. Hepatic free and esterified cholesterol were 32% lower and hepatic TAG was 25% lower in guinea pigs fed PE and PSY compared with controls. The data from these studies confirm that PE and PSY reverse the hyperlipidemia associated with high fat-sucrose diets and demonstrate a potential antioxidant effect of soluble fiber on circulating LDL.     

Nonluteal source of lordosis-promoting progesterone secretion in guinea pigs

Prepubertal (21-24 days of age), intact female guinea pigs treated sequentially with estradiol benzoate and LH or FSH displayed lordosis behavior. The gonadotropins apparently caused release of progesterone from the ovaries, because lordosis behavior in guinea pigs is activated by sequential action of estrogen and progesterone. These data demonstrate that immature ovaries, completely devoid of corpus luteum tissue, are capable of secreting behaviorally significant concentrations of progesterone when stimulated by gonadotropins. Therefore, the luteal compartment of the guinea pig ovary is not essential for the preovulatory surges of progesterone that coincide with expression of lordosis behavior in adulthood. Likely candidates for sources of preovulatory progesterone in prepubertal females are antral follicle and interstitial gland tissue.     

Effects of neonatal septal lesions on reproductive behavior of male and female rats

The purpose of this study was to examine the effects of neonatally placed septal lesions (SL) in male, female, and androgenized female rats on reproductive behavior. Animals were castrated as adults and tested for both feminine and masculine sexual behavior. After treatment with estradiol benzoate (EB) alone (2 μg daily for 3 days), only the females with SL which had not been given testosterone propionate (TP) neonatally showed a facilitation of lordosis behavior. Following EB (2 μg for 3 days) plus 0.5 mg progesterone (P), both the lesioned and the sham-operated female groups showed an increase in the display of lordosis in either hormonal condition. All animals were given a pretest for masculine sexual behavior and tested on Days 4, 7, 11, and 15 of daily TP treatment (150 μg/day). There was no effect of the neonatally placed SL on masculine sexual behavior in female rats or in female rats androgenized with 30 μg TP. However, lesioned females treated neonatally with 1 mg TP showed a marginal enhancement of masculine sexual behavior. Male rats given SL neonatally showed a marked enhancement of masculine sexual behavior compared to that of controls. These results suggest that, depending on the neonatal hormone environment, SL selectively increase behavioral sensitivity to hormones. Although neonatally lesioned females show behavioral responses similar to females given SL as adults, male rats given SL neonatally are unique in that they show enhanced masculine sexual behavior whereas males lesioned as adults do not.     

Altered activation/detoxication enzymology following neonatal diethylstilbestrol treatment

The effects of neonatal exposure to diethylstilbestrol (DES) on hepatic activation/detoxication enzyme levels in the adult rat were investigated. Neonatal exposure of male rats to DES (DES males) decreased the endogenous levels of UDP-glucuronyltransferase as compared to control males. Female rats exposed neonatally to DES (DES females) had higher endogenous epoxide hydrolase and glutathione transferase activity levels than control females. Adult animals treated neonatally with DES also had altered metabolic potential following exposure to 3-methylcholanthrene and phenobarbital. The DES males treated in adulthood with 3-methylcholanthrene had higher benzo(a)pyrene hydroxylase activities and lower UDP-glucuronyltransferase activity levels than did control males treated in adulthood with 3-methylcholanthrene. The DES males exposed in adulthood to phenobarbital had reduced cytochrome P-450 and glutathione transferase activity levels as compared with respective controls. The DES females treated in adulthood with 3-methylcholanthrene had lower benzo(a)pyrene hydroxylase and epoxide hydrolase activity levels than control females receiving 3-methylcholanthrene. The DES females challenged in adulthood with phenobarbital also had decreased benzo(a)pyrene hydroxylase, epoxide hydrolase, UDP- glucuronyltransferase, and glutathione transferase activity levels as compared with respective controls. Our results demonstrated that neonatal exposure to DES changed the endogenous levels of specific hepatic enzymes and altered the metabolic response of these adult animals to a carcinogen and a drug.     

Expression of male-typical behavior in adult female pseudohermaphroditic rhesus: Comparisons with normal males and neonatally gonadectomized males and females

Two types of pseudohermaphroditic female rhesus produced by exposure to either testosterone propionate (TP) or dihydrotestosterone propionate (DHTP) prior to birth were ovariectomized postpuberally and evaluated for the display of male-typical sexual behavior in response to exogenous TP in adulthood (2 mg/kg/day for 12 weeks). Their performance in standardized tests with estrogenized female partners was compared to that of neonatally gonadectomized males and females identically tested and treated with exogenous TP as adults. In addition intact adult males not given exogenous TP were tested with the same estrogenized female partners. There were no reliable differences between the two types of pseudohermaphrodites on any measure of behavior shown during the tests. Accordingly results were combined. Reliable behavioral changes induced by the TP given in adulthood were limited to increases in purse-lip responses, the induced increases were similar in pseudohermaphrodites and castrated males, and increases were reliably greater in these two groups of subjects than in females. Pseudohermaphrodites and castrated males did not differ reliably from intact males in performance of purse-lip gestures during TP treatment. In the performance of mounting, however, pseudohermaphrodites and castrated males remained consistently below the standard of the intact males. The estrogenized female partners displayed proceptive responses most frequently to the intact males and least frequently to the females. Their proceptive responses with castrated males resembled their performance with intact males, but with pseudohermaphrodites their proceptive responses more closely resembled their performance with females. Receptive behavior of the female partners was displayed most frequently to intact males, at intermediate levels to castrated males, and least often to pseudohermaphrodites. Results are completely consistent with the notion that androgens in high concentrations before birth alter mechanisms related to the later display of masculine behavior. These alterations in behavioral mechanisms are of such a nature that the display of male-typical behavior induced by androgens in adulthood is more pronounced and more frequent than it would have been otherwise. The alterations in masculine behavior observed in pseudohermaphroditic rhesus are not different in kind or scope than those reported extensively for lower mammals.(ABSTRACT TRUNCATED AT 400 WORDS)