Developmental Programming-Aging Interactions Have Sex-Specific and Developmental Stage of Exposure Outcomes on Life Course Circulating Corticosterone and Dehydroepiandrosterone (DHEA) Concentrations in Rats Exposed to Maternal Protein-Restricted Diets.

The steroids corticosterone and dehydroepiandrosterone (DHEA) perform multiple life course functions. Rodent life-course circulating corticosterone and DHEA trajectories are unknown. We studied life course basal corticosterone and DHEA in offspring of rats fed protein-restricted (10% protein, R) or control (20% protein, C), pregnancy diet first letter, and/or lactation second letter, producing four offspring groups-CC, RR, CR, and RC. We hypothesize that 1. maternal diet programs are sexually dimorphic, offspring life course steroid concentrations, and 2. an aging-related steroid will fall. Both changes differ with the plastic developmental period offspring experienced R, fetal life or postnatally, pre-weaning. Corticosterone was measured by radioimmunoassay and DHEA by ELISA. Steroid trajectories were evaluated by quadratic analysis. Female corticosterone was higher than male in all groups. Male and female corticosterone were highest in RR, peaked at 450 days, and fell thereafter. DHEA declined with aging in all-male groups. DHEA: corticosterone fell in three male groups but increased in all-female groups with age. In conclusion, life course and sexually dimorphic steroid developmental programming-aging interactions may explain differences in steroid studies at different life stages and between colonies experiencing different early-life programming. These data support our hypotheses of sex and programming influences and aging-related fall in rat life course serum steroids. Life course studies should address developmental programming-aging interactions.

Androgen receptors immunoreactivity in the rat brain of males with same-sex preference.

Androgen receptors (AR) are crucial in the control of male sexual behavior and sex preference. AR are particularly concentrated in areas related with the neuroendocrine control of sex preference including the medial amygdala (MeA), the ventromedial nucleus of the hypothalamus (VMH), the bed nucleus of the stria terminalis (BNST), the medial preoptic area (MPOA), the nucleus accumbens (Acb), the suprachiasmatic (SCh) and supraoptic (SO) nuclei, but also seem to be important for the control of reproductive processes in the hippocampus (CA1-CA4 and dentate gyrus, DG). In the present study we analyzed the density of AR in these brain areas of adult male rats with sexual preference (established in a three-compartment box). Same-sex preference was produced in male rats by the prenatal administration of the aromatase inhibitor, letrozole (0.56 µg/kg/ml s.c. G10-22) that usually produces 1-2 animals per litter with same sex preference, while the others retain a female sex preference. We also included a group of proestrus females that had a clear preference for a sexually active male. AR were analyzed by immunocytochemistry using PG21 as primary antibody. We also measured total plasma testosterone concentrations by radioimmunoassay. In males with same sex preference there was a specific AR overexpression in CA3 and CA4 that suggests a feminized pattern because females in proestrus trend to show a higher density of AR in these hippocampal areas. Sex differences in AR density were found in the anterior cingulate cortex (ACg) and frontoparietal cortex (FrPa). Serum levels of testosterone did not differ between groups. Data are discussed based on the role of AR in the hippocampus.

Sex-differential RXRα gene methylation effects on mRNA and protein expression in umbilical cord of the offspring rat exposed to maternal obesity.

Maternal obesity (MO) induces negative consequences in the offspring development. Adiposity phenotype is associated with maternal diet at early pregnancy and DNA methylation marks in the RXRα promotor at birth. Glucocorticoids play an important role in the regulation of metabolism through the activation of nuclear hormone receptors such as the RXRα protein. The aim of the study was to analyze steroid hormone changes at the end of pregnancy in the obese mother and RXRα gene methylation in the umbilical cord. For this purpose, in a well-established MO model, female Wistar rats were fed either standard chow (controls: C) or high-fat obesogenic diet (MO) before and during pregnancy to evaluate at 19 days of gestation (19 dG): 1) maternal concentration of circulating steroid hormones in MO and C groups, 2) maternal and fetal weights, 3) analysis of correlation between hormones concentration and maternal and fetal weights, 4) DNA methylation status of a single locus of RXRα gene near the early growth response (EGR-1) protein DNA binding site, and 5) RXRα mRNA and protein expressions in umbilical cords. Our results demonstrate that at 19 dG, MO body weight before and during pregnancy was higher than C; MO progesterone and corticosterone serum concentrations were higher and estradiol lower than C. There were not differences in fetal weight between male and female per group, therefore averaged data was used; MO fetal weight was lower than C. Positive correlations were found between progesterone and corticosterone with maternal weight, and estradiol with fetal weight, while negative correlation was observed between corticosterone and fetal weight. Additionally, male umbilical cords from MO were hypermethylated in RXRα gene compared to male C group, without differences in the female groups; mRNA and protein expression of RXRα were decreased in F1 male but not in female MO compared to C. In conclusion, MO results in dysregulation of circulating steroid hormones of the obese mothers and low fetal weight in the F1, modifying DNA methylation of RXRα gene as well as RXRα mRNA and protein expression in the umbilical cord in a sex-dependent manner.

Effects of post-ovariectomy time frame and age on the antidepressant-like actions of estradiol and prolame in female rats.

Estrogen replacement therapy (ERT) is an effective treatment for symptoms associated with climacteric and depression some women experience during perimenopause and menopause. The antidepressant-like effects of ERT may depend on the type of estrogen, age, and time when restitution is initiated after hormonal decline. Prolame is a synthetic steroid with estrogenic and antidepressant-like effects that may produce fewer adverse effects. We hypothesize that such actions of prolame on females depend on age and the duration of hormone deprivation period. We assessed the antidepressant-like effects of 17ß-estradiol (E2) and prolame in young and middle-aged rats across different post-ovariectomy (Ovx) time frames. Independent groups of young adults and middle-aged female rats were tested in the forced swimming test (FST) at 3, 8, 16, and 24 weeks post-Ovx. Prolame and E2 were administered in a sub-chronic schedule consisting of three injections before the FST. Likewise, the utero-trophic effects of these hormones were analyzed. We found that E2 and prolame reduced immobility in young rats 3 and 8 weeks after Ovx; in contrast, only prolame produced this effect in middle-aged rats three weeks post-Ovx. E2 and prolame increased the animals' utero-somatic index at all post-Ovx times, but the action of E2 and prolame produced a greater response in young adult rats. Our findings showed that the antidepressant-like effects of E2 and prolame depend on the post-Ovx time frame, age, and estrogen type. Interestingly, our results indicate that, in contrast to E2, prolame maintained its antidepressant effect in middle-aged rats.

Placentas associated with female neonates from pregnancies complicated by urinary tract infections have higher cAMP content and cytokines expression than males.

PROBLEM: The cAMP pathway is involved in important biological processes including immune regulation and hormone signaling. At the feto-maternal unit, cAMP participates in placental function/physiology and the establishment of immunoendocrine networks. Low cAMP in male fetuses cord blood has been linked to poorer perinatal outcomes; however, cAMP placental content and its relationship with immune factors and fetal sex in an infectious condition have not been investigated. METHOD OF STUDY: Sex-dependent changes in cAMP content and its association with cytokines and antimicrobial peptides expression were studied in human placentas collected from normal pregnancies and with urinary tract infections (UTI). Radioimmunoassay was used to quantify cAMP in placental tissue, while immune markers expression was studied by qPCR. Additionally, cAMP effect on antimicrobial peptides expression was studied in cultured trophoblasts challenged with lipopolysaccharide, to mimic an infection. RESULTS: In UTI, placentas from female neonates had higher cAMP tissue content and increased expression of TNFA, IL1B, and IL10 than those from males, where IFNG was more elevated. While cAMP negatively correlated with maternal bacteriuria and IFNG, it positively correlated with the antimicrobial peptide S100A9 expression in a sex-specific fashion. In cultured trophoblasts, cAMP significantly stimulated ß-defensin-1 while reduced the lipopolysaccharide-dependent stimulatory effect on ß-defensin-2, ß-defensins-3, and S100A9. CONCLUSION: Our results showed higher cAMP content and defense cytokines expression in placentas associated with female neonates from pregnancies complicated by UTI. The associations between cAMP and bacteriuria/immune markers, together with cAMP's ability to differentially regulate placental antimicrobial peptides expression, suggest a dual modulatory role for cAMP in placental immunity.

Aging Endocrine and Metabolic Phenotypes Are Programmed by Mother's Age at Conception in a Sex-Dependent Fashion in the Rat.

Programming of offspring life-course health by maternal nutrition and stress are well studied. At postnatal day 850, we evaluated male and female steroid levels and metabolism in aged offspring of primigravid sister rats bred at 70, 90, 150, or 300 days' life. At 850 days life, male offspring corticosterone was similar regardless of maternal age. Female corticosterone was highest in offspring of 70- and 300-day mothers. Serum dehydroepiandrosterone:corticosterone was lowest in both sexes of offspring of 70- and 300-day mothers. Male and female fat depots were smaller in offspring of 150- than 70- and 90-day mothers. Insulin, glucose, and homeostatic model assessment were similar in all male offspring but higher in female offspring of 70-day mothers than other ages. We conclude, maternal age affects offspring aging in an offspring sex-dependent manner and merits consideration in designing and interpreting programming studies.

Serum testosterone levels in bipolar and unipolar depressed female patients and the role of medication status.

Objective: to compare testosterone levels between female depressed patients and female bipolar patients.Methods: Sixty-one female patients with major depressive disorder (MDD) (n = 23) or bipolar disorder (BD) (n = 38) between 18 and 45 years old were included in the study. Participants were evaluated during a depressive or manic episode with the Hamilton depression rating scale (HDRS) or Young mania rating scale (YMRS), respectively. No patients in the MDD group were taken valproate while in the BD group 14 (36.84%) were taken valproate. Total testosterone (TT) and free testosterone (FT) levels were quantified during the early follicular phase of the cycle, with radioimmunoassay or solid phase enzyme-linked immunoassay. Data were collected from May 2016 to February 2017.Results: Mean TT serum levels were significantly higher in BD patients in comparison to MDD patients. Although age and diagnosis were related to TT levels, however when we added valproate use in the analysis, only the relation between TT and valproate use remained significant.Conclusions: In this sample, TT levels were related to valproate use in patients with BD. More studies regarding the role of testosterone in affective symptoms should be conducted to clarify the relation between testosterone, affective disorders, and medication.KeypointsWe observed that testosterone levels were significant higher in bipolar women compared to women with MDD.The use of valproate could be associated with the testosterone levels in female patients with BD.Evaluation of women suffering BD should include a testosterone levels determination, particularly when they are taking valproate.

Estrogen Receptors Alpha and Beta in POA-AHA Region Regulate Asymmetrically Ovulation.

We examined the role of the estrogen receptors alpha (ERα) and beta (ERß) in of the preoptic-anterior hypothalamic area (POA-AHA) in the regulation of ovulation in rats. The number of ERα- and ERß-immunoreactive (-ir) cells was determined at 09:00, 13:00, and 17:00 h of each stage of the estrous cycle in intact rats. Additionally, the effects of blocking ERα and ERß on ovulation rate at 09:00 h on diestrus-2 or proestrus day through the microinjection of methyl-piperidino-pyrazole (MPP) or cyclofenil in either side of POA-AHA were evaluated. The number of ERα-ir and ERß-ir cells in POA-AHA varied in each phase of estrous cycle. Either MPP or cyclofenil in the right side of POA-AHA on diestrus-2 day reduced the ovulation rate, while at proestrus day it was decreased in rats treated in either side with MPP, and in those treated with cyclofenil in the left side. MPP or cyclofenil produced a decrease in the surge of luteinizing hormone levels (LH) and an increase in progesterone and follicle stimulating hormone (FSH). Replacement with synthetic luteinizing hormone-releasing hormone in non-ovulating rats treated with MPP or cyclofenil restored ovulation. These results suggest that activation of estrogen receptors on the morning of diestrus-2 and proestrus day asymmetrically regulates ovulation and appropriately regulates the secretion of FSH and progesterone in the morning and afternoon of proestrus day. This ensures that both, the preovulatory secretion of LH and ovulation, occur at the right time.

Endocrine disruptor effect of perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) on porcine ovarian cell steroidogenesis.

Previous studies with perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) indicate that they act as endocrine disruptors, in addition to inducing alterations and damaging reproductive health; however, the biological mechanisms by which these disorders are produced are not yet understood. The aim of this study was to analyze the effect of PFOS and PFOA on in vitro steroidogenic secretion in porcine theca and granulosa cells, with or without gonadotropic stimulation. Granulosa and theca cells were isolated and cultured. Cell nature was performed by immunocytochemistry. PFOS and PFOA effect on steroid secretion was analyzed by chemiluminescence. In the present study, alterations in steroidogenic secretion were found when administering PFOS (0.12, 1.2, 12, 120 or 240µM) or PFOA (0.012, 0.12, 1.2, 12 or 24µM) to theca and granulosa cells. When theca and granulosa cells were stimulated with 500ng/mL LH or 500ng/mL FHS, respectively and immediately followed with 1.2µM of PFOS or PFOA, the perfluorinated compounds inhibited the secretion of steroid hormones in both stimulated cell types. The results indicate that PFOS and PFOA act on steroidogenic ovarian cells as endocrine disruptors, which could affect the dependent functions of sexual steroids.

The participation of the muscarinic receptors in the preoptic-anterior hypothalamic areas in the regulation of ovulation depends on the ovary.

BACKGROUND: Muscarinic receptors (mAChRs) of the preoptic and anterior hypothalamus areas (POA-AHA) regulate ovulation in an asymmetric manner during the estrous cycle. The aims of the present study were to analyze the effects of a temporal blockade of mAChRs on either side of the POA-AHA performed in diestrus-2 rats on ovulation, the levels of estradiol, follicle stimulating hormone (FSH) and luteinizing hormone (LH) and the mechanisms involved in changes in ovulation. METHODS: Cyclic rats on diestrus-2 day were anesthetized and randomly assigned to the following groups: 1) microinjection of 1 µl of saline or atropine solution (62.5 ng) in the left or right POA-AHA; 2) removal (unilateral ovariectomty, ULO) of the left (L-ULO) or right (R-ULO) ovary, and 3) rats microinjected with atropine into the left or right POA-AHA plus L-ULO or R-ULO. The ovulation rate and the number of ova shed were measured during the predicted estrus, as well as the levels of estradiol, FSH and LH during the predicted proestrus and the effects of injecting synthetic LH-releasing hormone (LHRH) or estradiol benzoate (EB). RESULTS: Atropine in the left POA-AHA decreased both the ovulation rate and estradiol and LH levels on the afternoon of proestrus, also LHRH or EB injection restored ovulation. L- or R-ULO resulted in a lower ovulation rate and smaller number of ova shed, and only injection of LHRH restored ovulation. EB injection at diestrus-2 restored ovulation in animals with L-ULO only. The levels of estradiol, FSH and LH in rats with L-ULO were higher than in animals with unilateral laparotomy. In the group microinjected with atropine in the left POA-AHA, ovulation was similar to that in ULO rats. In contrast, atropine in the right POA-AHA of ULO rats blocked ovulation, an action that was restored by either LHRH or EB injection. CONCLUSIONS: These results indicated that the removal of a single ovary at noon on diestrus-2 day perturbed the neuronal pathways regulating LH secretion, which was mediated by the muscarinic system connecting the right POA-AHA and the ovaries.

Unilaterally blocking the muscarinic receptors in the suprachiasmatic nucleus in proestrus rats prevents pre-ovulatory LH secretion and ovulation.

BACKGROUND: The suprachiasmatic nucleus (SCN) and the cholinergic system of various regions of the hypothalamus participate in the regulation of gonadotropin-releasing hormone (GnRH) and gonadotropin secretion, which are necessary for the occurrence of ovulation. In the present study, our goal was to analyse the effects of unilaterally blocking the muscarinic receptors in the SCN on ovulation and steroid secretion. METHODS: Cyclic rats were randomly allotted to one of the experimental groups. Groups of 8-14 rats were anaesthetized and microinjected with 0.3 µl of saline or a solution of atropine (62.5 ng in 0.3 µl of saline) into the left or right SCN at 09.00 or 19.00 h during diestrus-1 or on the proestrus day. The rats were euthanized on the predicted day of oestrus, and evaluated ovulation and levels of progesterone and oestradiol. Other groups of 10 rats were microinjected with atropine into the left or right SCNs at 09.00 h on the proestrus day, were euthanized eight h later, and luteinizing hormone (LH) was measured. RESULTS: At 09.00 or 19.00 h during diestrus-1, atropine microinjections into the SCNs on either side did not modify ovulation. The atropine microinjections performed at 09.00 h of proestrus into either side of the SCN blocked ovulation (right SCN: 1/9 ovulated vs. 9/10 in the saline group; left SCN: 8/14 ovulated vs. 10/10 in the saline group). The LH levels at 17.00 h in the rats that were microinjected with atropine at 09.00 h of proestrus were lower than those of the controls. In the non-ovulating atropine-treated rats, the injection of synthetic LH-releasing hormone (LHRH) restored ovulation. Atropine treatment at 19.00 h of proestrus on either side of the SCN did not modify ovulation, while the progesterone and oestradiol levels were lower. CONCLUSION: Based on the present results, we suggest that the cholinergic neural information arriving on either side of the SCN is necessary for the pre-ovulatory secretion of LH to induce ovulation. Additionally, the regulation of progesterone and oestradiol secretion by the cholinergic innervation of the SCN varies with the time of day, the day of the cycle, and the affected SCN.

Prenatal letrozole produces a subpopulation of male rats with same-sex preference and arousal as well as female sexual behavior.

Disruption of the sexual differentiation process during critical periods in male rodents produces changes in partner preference and sexual behavior. In this study we used prenatal (gestation days 10-22) letrozole (0.31 and 0.56 µg/kg) to inhibit aromatase and alter normal sexual differentiation of males. These animals and control rats (injected with vehicle) were used when adults to study: a) sexual preference (where the experimental male could choose to interact with a receptive female or a sexually experienced male); b) masculine and feminine sexual behaviors (tested in cylindrical arenas); c) non-contact erections when exposed to a female or a male and, d) serum sex steroids and gonadotropin levels. The results showed that 30% of the males treated with letrozole (0.56 µg/kg) had same-sex preference, 33% displayed lordosis and 63% showed non-contact erections in the presence of a sexually experienced male. However, 44% of these males also exhibited complete masculine sexual behavior towards receptive females. None of the control males displayed lordosis when mounted by another male and very few (12%) showed non-contact erections when exposed to a sexually experienced male. Similar low percentages were found in those males prenatally treated with the low letrozole dose (0.31 µg/kg). No difference was found in the serum levels of testosterone, estradiol, LH and FSH between control and letrozole-treated males regardless of their sexual preference. These results indicate that prenatal selective inhibition of aromatization produces feminization of sexual partner preference, arousal and sexual behavior but does not affect masculine sexual behavior.

Primates living outside protected habitats are more stressed: the case of black howler monkeys in the Yucatán Peninsula.

The non-invasive monitoring of glucocorticoid hormones allows for the assessment of the physiological effects of anthropogenic disturbances on wildlife. Variation in glucocorticoid levels of the same species between protected and unprotect areas seldom has been measured, and the available evidence suggests that this relationship may depend on species-specific habitat requirements and biology. In the present study we focused on black howler monkeys (Alouatta pigra), a canopy-dwelling primate species, as a case study to evaluate the physiological consequences of living in unprotected areas, and relate them with intragroup competition and competition with extragroup individuals. From February 2006 to September 2007 we collected 371 fecal samples from 21 adults belonging to five groups (two from protected and three from unprotected areas) in Campeche, Mexico. We recorded agonistic interactions within groups and encounters with other groups (1,200 h of behavioral observations), and determined fecal glucocorticoid metabolite (FGM) concentrations with radioimmunoassays. We used linear mixed models and Akaike's information criterion to choose the best model explaining variation in FGM concentrations between protected and unprotected areas calculated from five categorical variables: habitat type (protected vs. unprotected), participation in agonistic interactions, intergroup encounters, sex and female reproductive state, and season. The best model included habitat type, the interaction between habitat type and agonism, and the interaction between habitat type and season. FGM concentrations were higher in unprotected habitats, particularly when individuals were involved in agonistic interactions; seasonal variation in FGM concentrations was only detected in protected habitats. High FGM concentrations in black howler monkeys living in unprotected habitats are associated with increased within-group food competition and probably associated with exposure to anthropogenic stressors and overall food scarcity. Because persistent high GC levels can be detrimental to health and fitness, populations living in disturbed unprotected areas may not be viable in the long-term.

Physiological and analytical validations of fecal steroid hormone measures in black howler monkeys.

The measurement of hormones in fecal samples allows for the noninvasive assessment of the endocrine status of free-ranging primates. However, procedures and techniques for hormone analysis in feces must be validated, both analytically and physiologically. Few studies have addressed the endocrinology of black howler monkeys (Alouatta pigra). Due to its conservation status, direct handling of individuals from this species and invasive sample collection are highly regulated, and therefore traditional methods for the validation of hormone assays, such as pharmacological challenges, are not allowed. As a consequence, sometimes studies of the fecal hormones of free-ranging black howler monkeys do not report physiological validations and therefore the biological reliability of such measurements cannot be assessed. In order to stimulate future research with this species, the present study aimed at providing methodological bases for fecal endocrine monitoring. Specifically, we compared the validity of two immunoassays (radioimmunoassays, RIA; solid-phase chemiluminescent enzyme immunoassay, SPCEI) performed with commercial kits to measure cortisol, testosterone, estradiol, and progesterone; and demonstrate how the physiological functions of these steroid hormones can be determined through non-pharmacological validations. We found no differences between the analytical validity of RIA and SPCEI assays to measure cortisol and testosterone, whereas for estradiol and progesterone RIA showed better results. Concerning the physiological validation of our assays, we demonstrated that: (1) comparisons between pre- and post-stress situations may be used to assess cortisol response, (2) comparisons between females and males may be used to assess variation in testosterone levels, and (3) comparisons between pregnant and non-pregnant females may be used to determine variation in estradiol and progesterone activity. The analytical and physiological validations that we performed demonstrate that there are currently commercial kits that allow for correct endocrine monitoring of this species, and that there are non-pharmacological alternatives to assess the biological validity of hormone measurements.

Effects of unilaterally microinjecting ethanol in the preoptic-anterior hypothalamic areas of rats on ovulation.

BACKGROUND: Intragastric or intraperitoneal ethanol (EtOH) treatment inhibits reproductive functions in females and male rats. The area of the hypothalamus where these effects take place is unknown. As the participations of the preoptic-anterior hypothalamic area (POA-AHA) in regulating ovulation is asymmetric, this study aims to analyze the effects on 17ß-estradiol(E2 ), progesterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH) serum levels, the messenger ribonucleic acid (mRNA) expression of estrogen receptor alpha (ERα) and beta (ERß), and ovulation resulting from unilaterally microinjecting water or an EtOH solution into either side of the POA-AHA. METHODS: The treatment consisted of microinjecting a 8.6 µM EtOH solution into either side of the POA-AHA. The study was performed on groups of adult cyclic rats at 09.00 hours on diestrus-1, and sacrificed on diestrus-2 at 13.00, on proestrus at 09.00 or 17.00 or on estrus at 09.00 hours. Ovulation rates were assessed in rats sacrificed on estrus. Hormonal serum levels were measured using radioimmunoassay, and as a function of ERα and ERß mRNA expression in each side of the POA-AHA by reverse transcriptase polymerase chain reaction. RESULTS: EtOH treatment blocked ovulation and the preovulatory release of LH, and lowered E2 levels. Irrespective of the treated POA-AHA side, ERα mRNA expression was consistently lower in the left POA-AHA and higher on the right. EtOH treatment in the left POA-AHA decreased FSH serum levels and lowered ERß mRNA expression. In turn, EtOH treatment on the right POA-AHA resulted in higher FSH levels and ERß mRNA expression. CONCLUSIONS: The present results show that EtOH blocks the preovulatory surge of LH on the POA-AHA. The effects of EtOH treatment of preovulatory FSH surge on the POA-AHA are asymmetric (stimulative on the right and inhibiting in the left). The effects of EtOH treatment on preovulatory LH and FSH surge could be explained by the inhibition of ERα and ERß mRNA expression, respectively.

The effect of energetic and psychosocial stressors on glucocorticoids in mantled howler monkeys (Alouatta palliata).

The proximate causes of variation in glucocorticoids (GCs) of many free-ranging primates are still unclear, and in some cases, the available evidence is contradictory. Such is the case of mantled howler monkeys. In the present study, we tested whether variation in GC levels in this species could be predicted by energetic challenges or by psychosocial stressors. We focused on two groups living in Los Tuxtlas (Veracruz, Mexico) that differed in a number of parameters including: group size, habitat size, number of groups, and solitary males within the same habitat. Furthermore, one of the groups experienced changes in composition during our observations. From March to December 2009 we determined food availability in each group's habitat, studied the behavior of all adult individuals (N = 17), including, feeding, time budgets, ranging, and social interactions (N = 426.6 h), and measured weekly GCs in fecal samples (N = 160 individual/weeks) of both females and males. We found that participation in agonistic interactions, which were more frequent in the group that lived in the smaller habitat, was associated with increased weekly GCs, particularly in pregnant and lactating females. During the dry season weekly GCs were also higher in the group that lived in the smaller habitat. Although in this group individuals significantly increased travel time during the dry season, weekly GC levels were unrelated to time-budgets or ranging distances, contrasting with previous findings on mantled howler monkeys' GC response. We found no evidence that weekly variation in GC levels between groups resulted from differences in food availability. Our results indicate that mantled howler monkey GC levels respond to the effects of agonism, reproductive state, and the influence of a seasonal stressor, which may be attributable to anthropogenic disturbance. We conclude that psychosocial stressors affect the GC response of mantled howler monkeys, and that this response is modulated by reproductive state.

Unilateral or bilateral vagotomy induces ovulation in both ovaries of rats with polycystic ovarian syndrome.

BACKGROUND: Injecting estradiol valerate (EV) to pre-pubertal or adult female rat results in effects similar to those observed in women with polycystic ovarian syndrome (PCOS). One of the mechanisms involved in PCOS development is the hyperactivity of the sympathetic nervous system. In EV-induced PCOS rats, the unilateral sectioning of the superior ovarian nerve (SON) restores ovulation of the innervated ovary. This suggests that, in addition to the sympathetic innervation, other neural mechanisms are involved in the development/maintenance of PCOS. The aims of present study were analyze if the vagus nerve is one of the neural pathways participating in PCOS development. METHODS: Ten-day old rats were injected with EV dissolved in corn oil. At 24-days of age sham-surgery, unilateral, or bilateral sectioning of the vagus nerve (vagotomy) was performed on these rats. The animals were sacrificed at 90-92 days of age, when they presented vaginal estrous preceded by a pro-estrus smear. RESULTS: In EV-induced PCOS rats, unilateral or bilateral vagotomy restored ovulation in both ovaries. Follicle-stimulating hormone (FSH) levels in PCOS rats with unilateral or bilateral vagotomy were lower than in control rats. CONCLUSIONS: This result suggests that in EV-induced PCOS rats the vagus nerve is a neural pathway participating in maintaining PCOS. The vagus nerve innervates the ovaries directly and indirectly through its synapsis in the celiac-superior-mesenteric ganglion, where the somas of neurons originating in the SON are located. Then, it is possible that vagotomy effects in EV-induced PCOS rats may be explained as a lack of communication between the central nervous system and the ovaries.

Behavioral and physiological responses to subgroup size and number of people in howler monkeys inhabiting a forest fragment used for nature-based tourism.

Animals' responses to potentially threatening factors can provide important information for their conservation. Group size and human presence are potentially threatening factors to primates inhabiting small reserves used for recreation. We tested these hypotheses by evaluating behavioral and physiological responses in two groups of mantled howler monkeys (Alouatta palliata mexicana) at the "Centro Ecológico y Recreativo El Zapotal", a recreational forest reserve and zoo located in the Mexican state of Chiapas. Both groups presented fission-fusion dynamics, splitting into foraging subgroups which varied in size among, but not within days. Neither subgroup size nor number of people had an effect on fecal cortisol. Out of 16 behavioral response variables tested, the studied factors had effects on six: four were affected by subgroup size and two were affected by number of people. With increasing subgroup size, monkeys increased daily path lengths, rested less, increased foraging effort, and used more plant individuals for feeding. As the number of people increased, monkeys spent more time in lower-quality habitat, and less time engaged in social interactions. Although fecal cortisol levels were not affected by the factors studied, one of the monkey groups had almost twice the level of cortisol compared to the other group. The group with higher cortisol levels also spent significantly more time in the lower-quality habitat, compared to the other group. Our results suggest that particular behavioral adjustments might allow howler monkeys at El Zapotal to avoid physiological stress due to subgroup size and number of people. However, the fact that one of the monkey groups is showing increased cortisol levels may be interpreted as a warning sign, indicating that an adjustment threshold is being reached, at least for part of the howler monkey population in this forest fragment.

Sex- and endocrine-stage-differences in middle-aged rats in an animal model of OCD.

Various clinical studies suggest that many features of OCD are influenced by sex, age and fluctuations in hormonal levels. Animal models have confirmed these differences, and suggest they are mediated by the serotonergic system. We compared the perseveration behavior in a T-maze after the administration of the 5-HT1A agonist, 8-OH-DPAT (2.0 mg/kg) and the preventive action of subchronic fluoxetine (10 mg/kg, 3 times) in middle-aged (11-14 months) males and female rats in two endocrine states: irregular cycles (tested in diestrus) or persistent diestrus. After 8-OH-DPAT, females with persistent diestrus presented higher perseveration scores than males and females with irregular cycles. Fluoxetine produced an anticompulsive-like effect only in females with persistent diestrus. Females in persistent diestrus showed higher estradiol levels than those in irregular cycles or males. In all groups 8-OH-DPAT increased ambulation and fluoxetine did not modify this action. In males, the combined administration of fluoxetine and 8-OH-DPAT impaired motor coordination. Data are discussed on the basis of estradiol levels and sex differences.

Dehydroepiandrosterone has strong antifibrotic effects and is decreased in idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is an ageing-related lung disorder characterised by expansion of the myofibroblast population and aberrant lung remodelling. Dehydroepiandrosterone (DHEA), a steroid pro-hormone, decreases with age but an exaggerated decline has been associated with chronic degenerative diseases. We quantified the plasma levels of DHEA and its sulfated form (DHEA-S) in 137 IPF patients and 58 controls and examined the effects of DHEA on human lung fibroblasts. Plasma DHEA/DHEA-S was significantly decreased in male IPF patients (median (range) DHEA: 4.4 (0.2-29.2) versus 6.7 (2.1-15.2) ng · mL(-1), p<0.01; DHEA-S: 47 (15.0-211) versus 85.2 (37.6-247.0) µg · dL(-1), p<0.001), while in females only DHEA-S was significantly decreased (32.6 (15.0-303.0) versus 68.3 (16.4-171) µg · dL(-1), p<0.001). DHEA caused a decrease in fibroblast proliferation and an approximately two-fold increase in fibroblast apoptosis, probably through the intrinsic pathway with activation of caspase-9. This effect was accompanied by upregulation of several pro-apoptotic proteins (Bax and cyclin-dependent kinase-inhibitor CDNK1A) and downregulation of anti-apoptotic proteins, such as cellular inhibitor of apoptosis (c-IAP)1 and c-IAP2. DHEA also caused a significant decrease of transforming growth factor-ß1-induced collagen production and fibroblast to myofibroblast differentiation, and inhibited platelet-derived growth factor-induced fibroblast migration. These findings demonstrate a disproportionate decrease of DHEA/DHEA-S in IPF patients and indicate that this molecule has multiple antifibrotic properties.