Regulation of sulfotransferase mRNA expression in male and female rats of various ages

Sulfotransferases (SULTs) are Phase II drug-metabolizing enzymes that catalyze the addition of a sulfuryl moiety to both endogenous compounds, including steroids and neurotransmitters, and certain xenobiotics, including N-hydroxy-2-acetylaminoflourine and phenolic compounds, like alpha-naphthol. In contrast to certain Phase I drug-metabolizing enzymes, little is known about the regulation of the sulfotransferases. These series of studies were designed to analyze SULT mRNA expression and hormonal regulation in male and female rats. The hepatic expression of six different SULT isoforms was examined including three phenol SULTs and three hydroxysteroid SULTs. SULT mRNA expression was examined in adult and developing rats, as well as, in hypophysectomized (HX) and growth hormone-supplemented HX animals. SULT1A1 is thought to be important for the sulfation of simple phenols and its mRNA expression is about twice as high in adult male as in female rats. This difference in SULT1A1 mRNA levels is largely due to a greater decrease in mRNA levels after puberty in female than in male rats. Hypophysectomy resulted in a decrease in expression of SULT1A1 mRNA in both male and female rats. Replacement of growth hormone (GH) by either intermittent injection (male pattern) or infusion (female pattern) failed to restore SULT1A1 expression. Sulfotransferase SULT1C1 has been implicated in activation of N-hydroxyacetylaminoflourine. In contrast to SULT1A1, SULT1C1 mRNA expression is about 10-fold higher in adult males than in adult female rats. This male-dominant expression pattern emerges at 40-50 days of age and is due to an increase in SULT1C1 mRNA in males. Hypophysectomy abolished SULT1C1 expression in male rats. Interestingly, replacement of GH by injection (male pattern) restored SULT1C1 mRNA expression in males and enhanced SULT1C1 expression in female rats to levels observed in adult male rats. GH infusion (female pattern) did not affect SULT1C1 mRNA expression in either male or female rats. Estrogen sulfotransferase (SULT1E2) may play a role in estrogen homeostasis. Adult male rats express SULTIE2 mRNA at levels 10-fold higher than those observed in adult females and similar to SULT1C1, this is due to an increase in SULT1E2 mRNA occurring during puberty in the male rat. Hypophysectomy did not appreciably affect SULT1E2 expression in male rats, however in contrast to males, hypophysectomy markedly enhanced SULT1E2 expression in female rats. GH infusion suppressed SULT1E2 levels in HX male rats. The expression of hydroxysteroid sulfotransferases was also examined. The SULT-20/21 isoform was expressed in both male and female rats. Male expression of this isoform peaked at 30 days of age and then declined to approximately 30% of the level observed in adult females. SULT-20/21 mRNA expression increased sharply at 45 days of age in female rats and remained elevated. Expression of SULT-20/21 mRNA was decreased markedly by hypophysectomy in both male and female rats. GH injection did not affect SULT-20/21 mRNA expression in HX males, however this treatment resulted in a 4-fold increase in SULT-20/21 mRNA in HX females. GH infusion restored SULT-20/21 expression in HX-male rats. GH infusion did elevate SULT-20/21 mRNA expression in female-HX rats, but not to the level observed in intact females. Hydroxysteroid SULT isoform SULT-40/41 was expressed in adult female but not adult male rats. SULT-40/41 expression peaked at 15 days of age in both male and female rats and decreased thereafter. The decrease in expression was more pronounced in male rats. SULT-60 mRNA, like SULT-40/41, was expressed only in adult female rats. Male rats express SULT-60 at 30 days of age, but SULT-60 mRNA is undetectable at 60 days. SULT-60 mRNA was expressed in females only after day 30 and female SULT-60 mRNA expression remains high thereafter. SULT-40/41 and SULT-60 mRNA expression was increased by HX in male rats and decreased by HX in female rats. (ABSTRACT TRUNCATED)     

Differential responses to male and female depressive reactions.

Suggests that the commonly reported preponderance of female over male depression in incidence and prevalence studies requires further analysis. One explanation is that the social consequences of expression of depressive symptomatology are different for males and females. A comparison of 157 male and 189 female undergraduates' reactions to male and female case histories of common reactions to stress confirmed the hypothesis. Depression elicited more rejection of males than of females, and the sex difference in rejection of depression was more pronounced than for anxiety or flat affect-detached responses. A discriminant analysis suggested that depressed males are especially likely to be perceived as impaired in role functioning as compared with depressed females. Results suggest that depressed males are not rejected for expression of emotionality as such. Speculations about the causes and consequences of differential rejection of depression are noted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Context-dependent acquisition of copulatory behavior in the male rat: Role of female availability.

The effect of the environment in which sexual experience is acquired was examined on patterns of male rat copulatory behavior. Males trained in a pacing chamber with a 4-hole partition had significantly shorter ejaculation latencies compared with males trained in chambers with a 1-hole partition. Those differences persisted when males were switched into the other pacing condition, suggesting that the pattern of copulation in these males had become "fixed." In the second experiment, males were trained to associate an almond odor with copulation in either the 1-hole or 4-hole condition. Males ejaculated preferentially with females associated with the 4-hole pacing condition. Copulatory behavior in male rats is sensitive to female availability, and females associated with greater availability are preferred. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lordosis behaviour in male, female and androgenized female rats

Sex differences in the lordodis response of adult rats to ovarian hormones were studied in a series of experiments. Male rats were less sensitive to oestradiol benzoate (OB, a single injection of 10, 100 or 1000 mug/kg or seven daily injections of 2, 10, or 50mglkg)then were female rats. Oestradiol benzoate-primed (10 mglkg)female, but not male, rats showed dose-dependent responses to progesterone (0-4, 2-0 or 10-0 mg/kg/. male rats responded clearly to progesterone (2 mg/rat) only when primed with a high dose of OB (100 mug/rat). Display of the whole pattern of female sexual behaviour was induced in male rats by treatment with 100 mug OB and 2 mg progesterone. Female rats treated with 1 mg testosterone propionate (TP) on day 4 of life, ovariectomized as adults and tested under the same endocrine conditions as the rats described above, retained behavioural OB sensitivity but responded poorly to progesterone. Evidence is presented that ovarian secretions during development significantly modify the response of neonatally TP-treated and normal female rats to OB in adulthood.     

Research productivity and impact of male and female psychologists.

Investigated whether the marked underrepresentation of females in lists of highly cited psychologists reflected differences in the quality or the quantity of research produced by males and females. Citation counts were established for 396 papers reporting dissertation research published by male and female psychologists in 14 journals between 1967 and 1972. Females attracted as many citations as males for dissertation research over the 6 yrs following publication. Although females had by 1978 published significantly fewer papers than males, there was no difference between sexes in the number of citations gained/published paper. However, more males than females were prolific researchers with heavy outputs of highly cited papers. Sex differences in productivity, impact, and recognition are discussed in the context of factors that facilitate or hinder research achievement. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Performance of male and female children, adolescents and adults on spatial tasks that involve everyday objects and settings.

Administered 9 spatial tasks to 52 male and 52 female children (aged 7–9 yrs), 30 male and 33 female adolescents (aged 18–19 yrs), and 46 male and 48 female undergraduate (adult) Ss. Eight of the tests involved stimuli and settings with which Ss would have everyday experience. Significant sex differences were observed on 2 of the 9 tasks: estimating the length of a floor and identifying embedded figures. Adults performed better than other age groups on the embedded figures task and a wall height estimation task. In those cases where sex differences were observed, the effect sizes were well below .100, suggesting the magnitudes of sex differences were minimal. The fact that no sex differences were found on 7 or the 9 spatial tasks allows, at most, the statement that males perform better than females on some spatial tasks. There is no justification for the global statement that males excel in spatial abilities. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of iodinated contrast agents in MR imaging

At least two classes of mRNA for the GH receptor (GHR) and GH binding protein (GH BP) with different 5' untranslated first exons exist in the rat. One such class, the GHR1 is predominantly expressed in the liver of female rats. The hepatic expression of the GHR1 mRNA in normal and hypophsectomized rats of both sexes was studied by employing an RNase protection/solution hybridization assay. Normal females expressed 10-fold more GHR1 mRNA than males, hypophysectomy of female rats decreased the GHR1 level to that observed in male rats. Continuous GH treatment of hypophysectomized male and female rats for 6 days increased the expression of GHR1 mRNA to levels found in normal females, whereas intermittent GH treatment without effect. Bovine GH(bGH) induced the GHR1 expression in a time- and dose-dependent manner in primary cultures of adult rat hepatocytes as determined by solution hybridization. Maximal induction was achieved after 72 h of treatment with 50 ng bGH/ml medium. Female enriched expression of receptor and binding protein mRNAs raises the possibility that they participate in determining the ability of the liver to respond differently to the male and female GH secretory patterns. Our in vitro model utilizing cultures of primary adult rat hepatocytes could be used to address this issue as well as explore a hormonal interplay in regulation of GHR1 expression.     

Posttreatment changes in male and female patients: a comparative study

The purpose of this study was to determine whether the posttreatment changes in patients with Class II, Division 1 malocclusions who were treated with either extraction or nonextraction express similar trends in the male and female patients. The material for this investigation was obtained from the records available in the Graduate Orthodontic Clinic at the University of Iowa. Ninety-one patients were treated for their Class II, Division 1 malocclusions, 44 subjects (21 males and 23 females) had four first premolar extractions and 47 subjects (20 males and 27 females) were treated with nonextraction. Matched normal subjects included 20 male and 15 female subjects for whom complete sets of data were available for the period of this study. None of these subjects had undergone orthodontic therapy. Thirty-nine cephalometric anteroposterior and vertical skeletal, dental, and soft tissue linear and angular measurements were derived. Twenty-four dental arch parameters were evaluated and included: overbite, overjet, maxillary and mandibular arch lengths, and arch widths, as well as tooth size-arch length discrepancies. Student t tests were used to compare male and female subjects for the following parameters: (1) absolute dimensions recorded before treatment, after treatment, and at retention; (2) the incremental changes between the various stages; (3) the relative posttreatment changes. The level of significance was predetermined at p < 0.05. From the current findings the following can be concluded: (1) There were significant differences in the size as well as the incremental changes of the various cephalometric dentofacial parameters between normal male and female subjects. (2) There were significant differences in the absolute posttreatment cephalometric changes between male and female subjects, particularly in linear dimensions. Similar, but less frequent, findings were observed in the relative posttreatment changes. (3) Significant differences in the posttreatment dental arch changes between male and female subjects were the least frequent. (4) Male and female subjects expressed similar statistical trends in the direction of posttreatment changes. Therefore clinicians should not expect to observe significant differences in the posttreatment trends on the basis of the gender of the patient. On the other hand, the changes in linear dimensions are larger in male than female subjects. Therefore, for a more accurate interpretation of growth and/or treatment changes, it is advisable to independently analyze data on male and female subjects.     

Medial amygdala involvement in discrimination of same-species and closely-related-species male stimuli in estrous female Mesocricetus hamsters.

Efficient discrimination between individuals of closely related species is important to maximize reproductive potential. Some studies using males as subjects have indicated that the medial amygdala (MeA) is involved in discrimination between odors of conspecific females and females from distantly related species. The authors investigated the involvement of the MeA in discrimination by females between odors of conspecific males and odors of males of a closely related species. The authors exposed estrous or diestrous female hamsters (Mesocricetus auratus) to saline, conspecific male odors, or heterospecific (M. brandti) male odors and quantified the expression of c-fos–related antigens in the anterior and posterior MeA. They found that estrous (but not diestrous) females investigated conspecific male odors longer than heterospecific male odors. Neural activity in both the anterior and the posterior MeA was higher in estrous than in diestrous females. In the anterior MeA, there were no significant differences in response to odors of conspecific and heterospecific males. In the posterior MeA, however, neural activity was higher when estrous females were exposed to conspecific odors than when they were exposed to heterospecific odors. No such difference was observed in diestrous females. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Steady-state methadone effect on generalized arousal in male and female mice.

Methadone is widely used in treatment of short-acting opiate addiction. The on-off effects of opioids have been documented to have profound differences from steady-state opioids. The authors hypothesize that opioids play important roles in either generalized arousal (GA) or aversive state of arousal during opioid withdrawal. Both male and female C57BL6 mice received steady-state methadone (SSM) through osmotic pumps at 10 or 20 mg/kg/day, and GA was measured in voluntary motor activity, sensory responsivity, and contextual fear conditioning. SSM did not have any effect on those GA behaviors in either sex. Females had higher activity and less fear conditioning than males. The effects of SSM on stress-responsive orexin gene expression in the lateral hypothalamus (LH) and medial hypothalamus (MH, including perifornical and dorsomedial areas) were measured after the behavioral tests. Females showed significantly lower basal LH (but not MH) orexin mRNA levels than males. A panel of GA stressors increased LH orexin mRNA levels in females only; these increases were blunted by SSM at 20 mg/kg. In summary, SSM had no effect on GA behaviors. In females, SSM blunted the GA stress-induced LH orexin gene expression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prolactin-releasing effect of buspirone in developing and adult male and female rats

The prolactin-releasing effects of buspirone, an azaspirodecanedione anxiolytic drug unrelated to the benzodiazepines in structure and pharmacologic properties, was examined in developing and adult male and female rats. The possibility that effects of this drug on hormone release could be modulated by neonatal brain sexual differentiation was also evaluated. A single injection of buspirone, 2 or 10 mg/kg body wt, increased serum prolactin (PRL) levels in both sexes; the increase was significant from Day 12 onward. The PRL-releasing effect increased with age. No significant sexual differences were observed in younger rats, but in peripubertal and adult animals, the hyperprolactinemic response was higher in the female. Neonatal androgenization of females or orchidectomy of males failed to modify the PRL-releasing action of buspirone. Serum titers of luteinizing hormone and follicle-stimulating hormone were not modified by buspirone at any age. The present results show for the first time the ontogeny of the PRL-releasing effect of buspirone in male and female rats, and provide evidence that the response is higher in the female and that the effect does not depend on brain sexual differentiation.     

Motives for occupational goal setting among male and female college students.

Information regarding motives for occupational goals was gathered in an interview setting from 54 male and 54 female college students who were matched for occupational goal. In comparison to males, females expressed expectations for greater intrinsic work enjoyment (p?p?p?     

Individual variation in male vocal traits and female mating preferences in Bufo americanus

We investigated the amount of variation in mating behaviour between and within individual male and female American toads, because both sources of trait variation can influence the course of sexual selection. Males varied in all four call parameters investigated (dominant call frequency, pulse rate, call rate and call duration). Individual males lowered the dominant frequency of their call when they interacted vocally with nearby males. Dominant call frequency was more highly correlated with body size in vocally interacting males than in non-interacting males. Pulse rate of calls primarily varied with water temperature. Call rate and call duration showed the most variation of the four call properties, but this variation was unrelated to male morphology or social interactions. Females varied in three aspects of mating behaviour: two measures of pair formation and their preference for dominant frequency of male calls. The body size of paired males varied between females both in pairings initiated by either sex and in pairings initiated only by females. Males chosen by females were usually larger than average, although age and prior breeding experience of females did not affect mate choice. Playback experiments indicated that female preference for calls of low dominant frequency depended on the temporal patterning of alternative calls presented. Each of the four male vocal properties showed significant repeatability, but only one of the three aspects of female mating behaviour was repeatable. We discuss how different degrees of repeatability in sexual traits of males and females may influence the action and detection of sexual selection in this and other species. Copyright 1998 The Association for the Study of Animal Behaviour. Copyright 1998 The Association for the Study of Animal Behaviour.     

Assortative mating and female clutch investment in black grouse

Variation in female behaviour has only recently received attention in studies of sexual selection. It has been suggested that females may invest differentially in their offspring in relation to the quality of their mate. This may lead to females that mate with high-quality and/or attractive males laying larger clutches. Females may also differ in their ability to choose between males. For example, females in good physical condition may make better choices. If physical condition and clutch size are positively correlated, this hypothesis could also produce a relationship between male attractiveness and female clutch size. We found, in lekking black grouse, Tetrao tetrix, that females mated to the highest ranked males laid the largest clutches. Furthermore we found, regardless of female age, a positive relationship between a measure of female condition and male rank but not between female condition and her clutch size. In addition, females in good condition visited a larger number of different male territories, and old females produced the largest clutches. Our results suggest two mechanisms to explain our findings. First, females in good physical condition tend to mate with the top males, suggesting an assortative mating pattern. Second, females mating with the highest ranked males lay larger clutches as a consequence of their choice. In general, our result calls for caution in evaluating studies that look at the consequences of mate choice. It may be that differences in female quality produce effects that may be wrongly interpreted as male quality effects. (c) 1998 The Association for the Study of Animal Behaviour.     

Social play soliciting by male and female juvenile rats: Effects of neonatal androgenization and sex of cagemates.

Investigated the behavior of male and female Long-Evans hooded rats during individual exposure to nonplayful juvenile social stimuli in a novel test of play-soliciting behavior in 2 experiments examining hormonal and experiential determinants of sex differences. In Exp I, using 36 female and 18 male Ss, neonatally androgenized females engaged in play soliciting at a level equal to that of male controls and greater than that of nonandrogenized female controls. In Exp II, 52 males and 32 females were reared in unisexual and bisexual groups in order to compare long-term sex-related social experience effects on juvenile play soliciting. Males exposed only to other young males engaged in greater play soliciting than males exposed to both sexes; females, in contrast, were unaffected by sex of cagemates. Within rearing conditions, however, males engaged in greater play soliciting than females. The combined results suggest that perinatal gonadal androgen exposure effects on social play are prepotent and contribute essentially to sex differences in the initiation of social play behavior. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Role of olfactory stimuli during copulation in male and female rats.

Describes 3 experiments with a total of 74 gonadally-normal male and 29 ovariectomized female Long-Evans rats. Male and female reactions toward odors from novel and original partners were observed prior to the male's attaining his 1st or 2nd ejaculation. The male's reaction depended upon the sexual condition of the female. Only prior to their initial ejaculation did the males prefer their original partner's odors to those of novel females and only if the odors were collected from the females prior to copulation. This finding corresponded with observations of the male's random choice of partner during copulation. Females responded nonpreferentially if they had copulated prior to testing and showed a marked decrease in responsiveness as copulation continued. Prior to copulation females preferred the odors from males which had not copulated to those of males which had. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Competitive behavior in male, female, and pseudohermaphroditic female dogs.

Tested 36 male, spayed female, and pseudohermaphroditic female dogs in pairs for competition over a large bone. Pseudohermaphrodites had been exposed to testosterone propionate before and immediately after birth. In equal opportunity (EO) tests, both members of a pair had equal chance to seize the bone. Each EO test was followed by an established possession (EP) test. During an EP test, the loser of the preceding EO test was given possession of the bone before the former winner was returned to the test arena. Every S was tested against all other members of its own and the other groups. Males won 78 of 100 EO tests against normal females but only 61 of 100 against pseudohermaphrodites. Pseudohermaphrodites won 70 of 100 EO tests against normal females. When either normal or pseudohermaphroditic females were given possession of the bone in EP tests they were equally ineffective in defense against male challengers, losing 75 and 71% of their tests, respectively. Both types of females were more successful in defending possession during EP tests against each other. When normal and pseudohermaphroditic females were treated with testosterone, their performance in competition tests was not altered. Androgenic stimulation before and immediately after birth permanently modified the social behavior of pseudohermaphrodites as well as the behavior of males and normal females toward experimental Ss. (6 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An analysis of automatic teller machine usage by older adults: a structured interview approach

Sex differences in the activity of aromatase cytochrome P450 (CYP19) in the rat brain have been reported during pre- and postnatal development. It is unclear, however, whether these differences are reflected by corresponding differences in specific mRNA levels. To address this question, we have examined aromatase mRNA levels in specific regions of male and female rat brains by means of in situ hybridization (ISH). At prenatal stages of development, i.e. at gestational day 18 (GD18) and GD20, aromatase mRNA was detected in several preoptic, hypothalamic and limbic brain regions. Semiquantitative analysis of aromatase mRNA did not reveal sex differences in any of these regions. In contrast, clear-cut sex differences were determined at postnatal day (PN) 2; male animals expressed significantly more aromatase mRNA in the bed nucleus of stria terminalis (BST) and the sexually dimorphic nucleus of the preoptic area (SDN). Smaller but still significant differences (females > males) were obtained in the medial preoptic area (MPO). At PN6, sex differences of aromatase mRNA signals (males > females) were still present in the BST, but were no longer detectable in the SDN and the MPO. At PN15 and in adult animals, aromatase mRNA levels were similar in BST and medical amygdaloid nucleus of male and female rats. Since aromatase mRNA expression decreases during postnatal development, no ISH signals could be detected anymore in MPO, SDN and ventromedial hypothalamic nucleus. Our results are consistent with the concept that differential regulation of aromatase mRNA expression might be important for the establishment of different neuronal circuitry in male and female animals.