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R W Goy

Publications and source records attributed to R W Goy.

At least 37 records · Page 2Linked to original sources
PubMed1986

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)

Animals↗
PubMed1986

Female-typical sexual behavior of rhesus and defeminization by androgens given prenatally.

Adult rhesus monkeys were observed in standardized tests for female-typical sexual and related social responses. In the first experiment reported, 7 castrated males and 5 spayed females were paired with each of 4 intact males on two occasions following intramuscular injection with estradiol benzoate (EB) (6 micrograms/kg X 14 days) and on two other occasions without such treatment. In tests without EB, males and females did not behave differently toward the intact male partners, and all responses were displayed at low frequencies. In tests with EB, females showed reliably higher frequencies than males of approaching, sitting close to, grooming, and soliciting, and they presented to a higher proportion of the male partner's sexual contacts. EB reliably increased the frequency of display of all of these same five responses in females but not in castrated males. The intact male partners displayed reliably fewer approaches, sexual contacts, mounts, intromissions, and ejaculations to castrated males than to spayed females regardless of estrogenization. In a second experiment 10 intact adult pseudohermaphroditic females and 6 intact control females were tested following EB injections with each of the same 4 intact males. Pseudohermaphrodites were experimentally produced by injecting pregnant females with either testosterone propionate (TP) or dihydrotestosterone propionate (DHTP). Pseudohermaphrodites, regardless of type of androgen used in their production, showed reliably fewer solicits than controls to male partners. Moreover, they displayed most of the other responses at lower average frequencies than controls. Frequencies of intromission and ejaculation by intact male partners were reliably lower with pseudohermaphrodites than with control females, but frequencies of approach, sexual contact, and mount were not reliably different. We conclude that in this testing and measurement situation male and female rhesus monkeys differ markedly in the degree of expression of female-typical sexual behaviors, and genotypic males are behaviorally less responsive to estrogens than females. Exposing genotypic females to androgens during fetal life decreases the expression of female-typical, estrogen-influenced responses, and the effect is most pronounced on those soliciting responses that subserve proceptivity.

Animals↗
PubMed1986

Does intermale mounting function as a dominance demonstration in rhesus monkeys?

The relationship between dominance and intermale mounting was analyzed in two troops of captive rhesus monkeys (Macaca mulatta). The data did not support the assumption that mounting among males functions as a dominance demonstration as described in the literature because mounting commonly (63% of 65 dyads) occurred in a bidirectional fashion, and mounting not only was performed by dominant males but also was shown with regularity (36% of 521 cases) by subordinate males. Intermale mounting was often (37% of 521 cases) associated with amicable interactions--commonly preceding them--but it was only rarely (2%) associated with dominance-subordination behaviors. It was concluded that intermale mounting may serve as a socially cohesive behavior in rhesus monkeys by promoting nonagonistic contact.

Animals↗
PubMed1985

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.

Animals↗
PubMed1985

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.

Animals↗
PubMed1985

Expression of adult female patterns of sexual behavior by male, female, and pseudohermaphroditic female rhesus monkeys.

Gonadally intact pseudohermaphroditic female and normal female and neonatally castrated male rhesus monkeys were given estrogen treatment as adults and evaluated for attractivity, proceptivity, and receptivity during tests with a tethered stud male. Pseudohermaphrodites were produced by injecting their mothers during pregnancy with either testosterone propionate (TP) or dihydrotestosterone propionate (DHTP). Castrated males had reliably lower attractivity than normal females on all indicator responses shown by the tethered males. Additionally, castrated males showed reliably fewer proceptive responses on 4 of 5 measures than normal females. Receptivity could not be assessed in this situation for castrated males, because tethered males never contacted them unless the castrated males were displaying presentation. No reliable differences were observed between pseudohermaphrodites produced by prenatal treatments with TP or DHTP. Pseudohermaphrodites generally showed reliably less attractivity and proceptivity than normal females and reliably more of these traits than castrated males. Attractivity scores for pseudohermaphrodites were not different from those for normal females until proximity to the tethered male was established. Receptivity was not different in pseudohermaphrodites compared with normal females. Results indicate prenatal androgenization and its developmental sequelae lead to a defeminization in adulthood which, in this testing situation, was principally manifested by a deficiency in the performance of proceptive behaviors. Additionally, defeminization in rhesus monkeys, unlike that demonstrated in rodents, does not depend upon actions of an aromatizable androgen.

Animals↗
PubMed1985

Androgen and estrogen receptors in fetal rhesus monkey brain and anterior pituitary.

In this study, we sought to identify and characterize cytosolic androgen and estrogen receptors in the brain and anterior pituitary gland (AP) of fetal rhesus monkeys using the technique of DNA-cellulose chromatography. Cytosolic extracts were prepared from fetal monkey (days 135-162 of gestation) tissues including hypothalamus-preoptic area/amygdala (HPOA/AMG), cerebral cortex, and AP. Extracts were incubated with [3H]testosterone, [3H]5 alpha-dihydrotestosterone, or [3H] 17 beta-estradiol and applied to DNA-cellulose columns. [3H]Androgen- and [3H]estrogen-binding activities from cytosolic extracts adhered to DNA-cellulose. After elution with a linear salt gradient (10-500 mM NaCl) [3H]androgen-binding activity exhibited elution maxima between 130-150 mM NaCl, while [3H] estrogen-binding activity exhibited elution maxima between 200-220 mM NaCl. These elution patterns were similar in every region examined and were characteristic of putative androgen and estrogen receptors found in other vertebrate species. Additional experiments established the high affinity-low capacity nature of both androgen- and estrogen-binding activities, as well as their inhibition by known competitors of receptor binding. Estimates of binding activity at ligand concentrations that approximated saturation suggested that the concentration (moles specific bound per mg cytosolic protein) of both androgen and estrogen receptor were highest in the AP, intermediate in the HPOA/AMG, and lowest in the cerebral cortex. Comparisons of androgen- and estrogen-binding activities revealed that in the AP, apparent concentrations of the estrogen receptor exceeded those of androgen. Androgen and estrogen receptor concentrations were roughly equivalent in the HPOA/AMG, whereas, in the cerebral cortex, androgen receptor concentration was greater than estrogen. Collectively, these data demonstrate that in the fetal primate brain and AP, distinct androgen and estrogen receptors are present which might mediate the action of gonadal steroids on sexual differentiation.

Amygdala↗
PubMed1985

Sexually dimorphic regions in the medial preoptic area and the bed nucleus of the stria terminalis of the guinea pig brain: a description and an investigation of their relationship to gonadal steroids in adulthood.

Sexually dimorphic regions are described in two areas of the guinea pig brain: the medial preoptic area (MPOA) and the bed nucleus of the stria terminalis (BNST). The volume of a darkly staining portion of the MPOA is approximately 4-fold larger in male than in female guinea pigs, and the volume of a darkly staining portion of the BNST is approximately 36% larger in male than in female animals. The sex differences in both of these areas are present in animals that have been gonadectomized as adults as well as in intact animals, suggesting that they result from differences between the sexes in the hormonal environment during early development. Both the MPOA and the BNST bind high levels of gonadal steroids early in life, during the period when functional differentiation occurs. It is possible that dramatic morphological sex differences characterize such steroid-binding areas. Furthermore, these sexually dimorphic areas may form an anatomically and functionally interrelated system. Attention to these possibilities may help elucidate more precisely the neural basis for sexually dimorphic functions, as well as the basic mechanisms underlying sexual differentiation of behavior and the brain.

Animals↗
PubMed1984

Social influence on the display of sexually dimorphic behavior in rhesus monkeys: isosexual rearing.

Groups containing 5 or 6 infant rhesus monkeys and their mothers were formed when the infants were approximately 3 months old by random assignment from an available pool. There were 33 males and 38 females assigned to groups containing infants of both sexes (heterosexual groups); 15 males and 15 females were assigned to groups containing only infants of the same sex (isosexual groups). The social behavior of subjects in each group was observed and recorded during six 50-day periods from 3 months of age to 3 1/2 years of age. Two sexually dimorphic patterns, mounting and presenting, were recorded for each subject as indices of protosexual (i.e., patterns eventually used in adult mating behavior) development. In addition, rough play, a dimorphic response that is not protosexual, was also recorded. Both males and females in the isosexual condition were characterized by a partial inversion of the manifestation of protosexual behavior. Isosexual males showed statistically less foot-clasp mounting and more presenting than heterosexual males. Conversely, isosexually reared females showed statistically more mounting and less presenting than heterosexual females. The effect of rearing animals in same-sex groups was greater on heterotypical than on homotypical protosexual behavior. Among isosexual males, presenting responses deviated from the heterosexual male standard to a greater extent than did mounting. Among isosexual females, mounting behavior deviated from the heterosexual female standard more than presenting. Results suggested that presenting behavior by males was more easily augmented by isosexual rearing conditions than was mounting by females. At no time during the experiments did isosexual females mount at frequencies or at group proportions that were indistinguishable from those of heterosexually reared males. In contrast, males reared isosexually showed average frequencies of presenting that equaled or exceeded means for females reared heterosexually. While mounting and presenting were both modified by same-sex rearing, rough-and-tumble-play frequencies were not influenced markedly in either sex. However, isosexual males did show statistically higher frequencies of rough play than heterosexual males during the final period of observation (3 to 3 1/2 years of age), and isosexual females showed less rough play than heterosexually reared females during the first year of life. Results support the conclusion that isosexual conditions can have a selective effect on the developmental expression of protosexual responses without altering the probability of display of other sexually dimorphic social behavior.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1984

Effects of opiate antagonists on hormones and behavior of male and female rhesus monkeys.

Opiate antagonists, naloxone (100 micrograms/kg) and naltrexone (1 mg/kg) were given to singly housed adult male or female rhesus prior to a 20-minute behavioral test with an oppositely sexed stimulus monkey. Four of the intact adult males were socially and sexually experienced. The remaining two intact males and two castrated males had been reared in socially restricted conditions and were psychosexually deficient. Adult females were ovariectomized, and the effects of opiate antagonists were examined with or without concurrent estradiol treatment. Both antagonists inhibited sexual behavior of the socially reared, sexually active, intact males. No stimulatory effects on sexual behavior were observed for sexually deficient males, whether intact or castrated. Females showed little change in sexual behavior following opiate antagonist treatment, regardless of endocrine status. The proportion of approaches of the female to the male was increased when naloxone, but not naltrexone, was given. Specific endocrine effects of the opiate antagonists were only found in intact males. Naltrexone significantly increased LH concentrations in the two males tested, while the increase in LH in the four males receiving naloxone was not significant. In all intact males, increases in LH were accompanied by statistically significant increases in circulating concentrations of testosterone following naloxone and naltrexone. The gonadotropic stimulating effect of the opiate antagonists was specific to LH, and no changes were observed in circulating concentrations of FSH in either sex.

Aggression↗
PubMed1984

Developmental changes in luteinizing hormone secretion in the female guinea pig. I. Effects of ovariectomy, estrogen, and luteinizing hormone-releasing hormone.

Negative feedback regulation of LH release was studied by ovariectomy and estrogen treatment in female guinea pigs of four different ages (days 10, 30, 50, and 150). The average age at first ovulation in guinea pigs in our colony was 60.1 +/- 2.2 days (n = 33). Bilateral ovariectomy (OVX) on day 30, 50, or 150 of age resulted in a sharp increase in serum LH concentrations within 3 days, and this rise continued for 9 days, when LH values reached a plateau. In contrast, when OVX was performed on day 10 of age, only a slight elevation in LH levels was observed during the first 16 days after surgery. Twenty days after OVX (day 30 of age), LH concentrations started to increase rapidly and reached the maximum value on day 38 of age; this latter response was similar to that observed immediately after OVX in animals in the three older age groups. Serum LH concentrations after LHRH administration (2 micrograms/kg BW) were similar in ovariectomized females on days 23 and 43 of age, suggesting that the postcastration increase in LH secretion after day 26 of age was not due to a change in pituitary sensitivity. Daily injections of estradiol benzoate at doses of 0.5 and 2.0 micrograms/kg BW from 15-20 days after OVX suppressed LH levels in all four age groups. The present findings indicate that an increase in the capacity for LH release occurs around day 30 in the female guinea pig. Since this increased LH release is not due to an apparent change in pituitary sensitivity to LHRH, the endogenous release of LHRH may be inhibited before day 30 of age. These results suggest that an alteration in the regulation of LH release by the brain may occur before the onset of puberty in female guinea pigs.

Aging↗
PubMed1984

Developmental changes in luteinizing hormone secretion in the female guinea pig. II. Positive feedback effects of ovarian steroids.

Developmental changes in the positive feedback effects of ovarian steroids on LH release in female guinea pigs were studied. Administration of estradiol benzoate (EB; 10 micrograms) to intact females on day 30 of age (prepubertal) elicited a LH surge in only 1 of 14 instances. However, by day 46 of age (peripubertal), EB induced a sharp rise in serum LH concentrations in 9 of 12 females. The magnitude and timing of the LH surge in these peripubertal animals were similar to those in cycling adults given EB on day 13 of the estrous cycle. Progesterone (P; 1.0 mg) administration to intact females 30 h after a priming dose (1.5 microgram) of EB was also effective in eliciting a LH surge on day 46, but not on day 30, of age. The magnitude of the P-induced LH surge was significantly greater (P less than 0.001) than that of the EB-induced LH surge on day 46 of age. Pentobarbital anesthesia delayed, but did not prevent, the EB-induced LH surge in peripubertal females, while it completely abolished the P-induced LH surge. These results suggest that ovarian steroids can stimulate LH release in the immature female guinea pig, but not until an age approaching the normal time of the first ovulation. Those observations together with results presented in a preceding paper suggest that establishment of the positive feedback system between days 30 and 46 of age is associated with an increased capacity of the hypothalamic-pituitary axis to stimulate LH release; such developmental changes may represent the major events leading to the onset of puberty in the female guinea pig.

Aging↗
PubMed1983

Proceptive behavior of female rhesus monkeys during tests with tethered males.

Proceptive behavior of female rhesus monkeys during follicular and luteal phases of the ovarian cycle was examined in laboratory tests with a tethered male partner. Cyclical changes in proceptive behavior were observed. In tests during the follicular phase of their cycles, females on the average approached and solicited the male at a higher rate, spent more time sitting within proximity of him, and less time at a maximum distance away from him than during tests in the luteal phase of their cycles. Additionally, in the follicular phase of their cycles, females exhibited an increase in proceptivity following the male's ejaculation. This latter finding was discussed in light of other observations demonstrating that male rhesus monkeys are capable of multiple ejaculations. When females were paired with a tethered, ovariectomized female as a partner, rather than an adult male, none of the cyclical changes in proceptive and sexual behavior were observed.

Animals↗
PubMed1983

Effects of neonatal estrogen treatment of female guinea pigs on mounting behavior in adulthood.

Female guinea pigs were treated with 200 micrograms estradiol dipropionate (ED) daily from Days 1 to 15 of life. As adults they all ovulated. After gonadectomy and estrogen-progesterone treatment in adulthood, lordosis behavior was evident and showed no decrements (compared with neonatally oil-treated controls) except for a marginal decrease in maximum duration scores. However, testosterone propionate treatment in adulthood significantly increased mounting behavior in neonatally ED-treated females compared to the controls. On the other hand, estrogen-progesterone treatment in adulthood stimulated mounting in the neonatally oil-treated group, but not in the neonatally estrogenized group. The results suggest that at least some aspects of steroid-dependent behaviors can be permanently influenced by estrogen treatment after the presumed prenatal critical period for sexual differentiation has been completed in guinea pigs.

Age Factors↗
PubMed1983

Cyclic excretion of urinary oestrogens in female tamarins (Saguinus oedipus).

Urine was collected from 6 female cotton-top tamarins (Saguinus o. oedipus) and urinary oestrone and oestradiol concentrations were measured by radioimmunoassay. Oestrone was excreted at 50-fold higher concentrations than oestradiol. Five females showed patterns of regular oestrone cyclicity, with a mean peak-to-peak oestrone cycle of 23.6 +/- 1.2 days. Levels of oestradiol tended to vary with levels of oestrone excretion, but peaks were less pronounced and more variable. The sixth female, diagnosed as having 'wasting marmoset syndrome', had very low levels of excreted oestrogens, suggesting infertility. We suggest that urinary oestrone provides a good index to ovarian cyclicity in female cotton-top tamarins.

Animals↗
PubMed1982

The pubescent rhesus monkey: some characteristics of the menstrual cycle.

Forty-eight untreated rhesus females (Macaca mulatta) were studied from birth until menarche and for the 12 intermenstrual periods following menarche. The 48 animals were studied in two subsets: one in Oregon (N = 22) and the other in Wisconsin (N = 26). The Oregon animals menstruated 127.3 +/- 6.6 (SEM) weeks after birth, whereas the Wisconsin animals reached menarche 133.0 +/- 3.1 weeks postnatum. These ages did not differ significantly nor was there a significant difference in mean body weight at menarche between the two groups. A linear pattern of ponderal growth was observed from birth to menarche with an acceleration in ponderal growth closely following menarche. The first 12 cycles after menarche gradually decreased in length from 13.0 to 13.6 weeks (range between groups) for the first intermenstrual interval to 4.9 to 6.1 weeks (range between groups) for the 12th cycle. In these cycles the percentage of animals ovulating gradually increased with time (0% in cycle 1, 6.3% in cycle 2, 50% in cycle 8 and 90% in cycle 12). These data showed a significant linear correlation (r = 0.9328, P less than 0.01). Although cycle lengths in adults were significantly greater during June through August than during the rest of the year, no effect of season could be ascertained in the pubescent animals. Serum samples from two animals bled frequently from the onset of menarche through the first ovulatory cycle contained preovulatory amounts of estradiol-17 beta in anovulatory cycles. This suggests that follicle growth in occurring but ovulation does not occur during the early cycles of adolescence. These data support the concept that recovery from adolescent sterility in rhesus monkeys takes approximately 18 months and that recovery occurs in a nearly linear fashion within a given population. We hypothesize that the inability of a young female to ovulate reflects an inability to respond to ovarian estrogen by releasing ovulatory amounts of gonadotropin.

Animals↗
PubMed1981

Prostaglandins, clonidine and sexual receptivity in the guinea pig.

Prostaglandins E1 and F2 alpha suppressed lordosis in ovariectomized guinea pigs brought into estrus with estradiol benzoate and progesterone. Pretreatment with clonidine prevented this action of the prostaglandins, but if the animals were first given prostaglandin and allowed to go out of estrus, then clonidine did not restore lordosis. In a previous study it was found that the abbreviation of estrus induced by copulation was also blocked by clonidine, again only if it were given before the inhibitory treatment. These results suggest tht prostaglandin, perhaps released from the female reproductive tract, could mediate the inhibitory effect of copulation, and radioimmunoassays of prostaglandin F2 alpha and its principal metabolite PGFM revealed substantial elevations in the concentrations of these materials in trunk blood after copulation. We discuss the possibility that prostaglandins may suppress sexual receptivity by interfering with an alpha-adrenergic mechanism.

Animals↗