Browsing by Subject "HORMONES"

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  • Eriksson, C. J. P.; Etelälahti, T. J.; Apter, S. J. (2017)
    A number of studies have shown that stress and an activated hypothalamic-pituitary-adrenal (HPA) axis are associated with increased voluntary alcohol drinking. Recently, associations have been found between activated HPA and hypothalamic-pituitary-gonadal (HPG) axes in alcohol-preferring AA and non-preferring ANA, F2 (crossbred second generation from original AA and ANA), and Wistar rats. The aim of the present study has been to determine the role of corticosterone and alcohol-related testosterone-effects in subsequent alcohol drinking in AA, ANA, F2 and Wistar rats. The present study comprises of four substudies presenting new analyses of existing data, by which correlations between basal corticosterone levels, changes in testosterone levels during alcohol intoxications and subsequent voluntary alcohol consumption are investigated. The results displayed positive correlations between basal corticosterone levels and subsequent alcohol-mediated testosterone elevations, which was positively associated with voluntary alcohol consumption. The results also showed a negative correlation between basal corticosterone levels and alcohol-mediated testosterone decreases, which was negatively associated with alcohol consumption. In conclusion, the present study displays novel results, according to which the HPA axis, one hand, relates to testosterone elevation (potentially causing and/or strengthening reinforcement) during alcohol intoxication, which in turn may relate to higher voluntary alcohol consumption (AA rats). Vice versa, the HPA axis may also relate to alcohol-mediated testosterone decrease (causing testosterone reduction and disinforcement) and low-alcohol drinking (ANA, F2 and Wistar rats). In addition, the present results showed that alcohol-mediated testosterone changes may also, independently of the HPA axis, correlate with voluntary alcohol drinking, which indicate the impact of genetic factors. Thus, the role of the HPA-axis may be more related to situational stress than to intrinsic factors. In further studies, it should be investigated, whether the present results also apply to stress and human alcohol drinking.
  • Valros, Anna; Pedersen, Lene Juul; Pöytäkangas, Merja; Jensen, Margit Bak (2017)
    There are very few studies on the need to perform exploratory behaviour of sows around farrowing and during lactation, except for during the nest-building period. Exploratory behaviour in pigs may reflect appetitive foraging motivated by hunger, or appetitive behaviour related to other motivations, such as nest building. However, exploration may also be motivated by curiosity, stimulated by novelty or search for novelty. The aim of this study was to test novel methods of evaluating exploratory motivation in sows around farrowing and during lactation. We used ten second or third parity sows, housed in conventional crates from day 8 before expected farrowing until weaning, on day 28 after farrowing. Motivation to perform exploratory behaviour was evaluated by measuring the use of a manipulable and chewable object (a wooden device, MCO) and responses during a novel object test (NO). In addition, we studied if exploratory motivation is related to the energy status of the sow, measured as sow weight change during lactation, piglet weight gain, and leptin level in saliva. The exploratory motivation of sows appeared to change during the period of study. Although all sows used the MCO, the use was very low throughout the study (below 3 g per day on average), and almost non-existent during the first weeks after farrowing. The latency to touch the object in the NO test was correlated between test days before and after farrowing, while the sow showed more interest in the object before than after farrowing. MCO use during the last week of lactation was higher in sows with a lower weight after weaning, suggesting a link between explorative motivation and energy status in the sow. These results indicate a need for further studies on how to best meet the possible exploratory need of sows during their time in the farrowing room.
  • Santangeli, Andrea; Wistbacka, Ralf; Morosinotto, Chiara; Raulo, Aura (2019)
    Intact ecosystems are being lost or modified worldwide, and many animal species are now forced to live in altered landscapes. A large amount of scientific studies have focused on understanding direct effects of habitat alterations on species occurrence, abundance, breeding success, and other life history aspects. Much less attention has been placed on understanding how habitat alterations impact on the physiology of species, e.g., via elevated chronic stress when living in an altered landscape. Here, we quantify the effects of individual age and sex, as well as effects of landscape and social factors on chronic stress of an endangered forest specialist species, the Siberian flying squirrel Pteromys volans. We collected hair samples over 2years from across 192 flying squirrels and quantified their chronic stress response via cortisol concentrations. We then ran statistical models to relate cortisol concentrations with landscape and social factors. We show that cortisol concentrations in flying squirrels are neither affected by habitat amount and connectivity, nor by the density of conspecifics in the area. We however found that cortisol concentration was higher in adults than in pups, and in males compared with females. Lack of an effect of environmental factors on cortisol concentrations may indicate low physiological sensitivity to alterations in the surrounding environment, possibly due to low densities of predators that could induce stress in the study area. Further research should focus on possible effects of varying predator densities, alone and in interaction with landscape features, in shaping chronic stress of this and other species.
  • Kopperi, Matias; Parshintsev, Jevgeni; Ruiz-Jimenez, Jose; Riekkola, Marja-Liisa (2016)
    Emerging organic contaminants in wastewater are usually analyzed by targeted approaches, and especially estrogens have been the focus of environmental research due to their high hormonal activity. The selection of specific target compounds means, however, that most of the sample components, including transformation products and potential new contaminants, are neglected. In this study, the fate of steroidal compounds in wastewater treatment processes was evaluated by a nontargeted approach based on comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry. The potential of the nontargeted approach to generate comprehensive information about sample constituents was demonstrated with use of statistical tools. Transformation pathways of the tentatively identified compounds with steroidal four-ring structure were proposed. The purification efficiency of the wastewater treatment plants was studied, and the distribution of the compounds of interest in the suspended solids, effluent water, and sludge was measured. The results showed that, owing to strong adsorption of hydrophobic compounds onto the solid matter, the steroids were mostly bound to the suspended solids of the effluent water and the sewage sludge at the end of the treatment process. The most abundant steroid class was androstanes in the aqueous phase and cholestanes in the solid phase. 17 beta-estradiol was the most abundant estrogen in the aqueous phase, but it was only detected in the influent samples indicating efficient removal during the treatment process. In the sludge samples, however, high concentrations of an oxidation product of 17 beta-estradiol, estrone, were measured.
  • Kölliker, Mathias; Boos, Stefan; Wong, Janine W. Y.; Röllin, Lilian; Stucki, Dimitri; Raveh, Shirley; Wu, Min; Meunier, Joel (2015)
    The genetic conflict between parents and their offspring is a cornerstone of kin selection theory and the gene-centred view of evolution, but whether it actually occurs in natural systems remains an open question. Conflict operates only if parenting is driven by genetic trade-offs between offspring performance and the parent's ability to raise additional offspring, and its expression critically depends on the shape of these trade-offs. Here we investigate the occurrence and nature of genetic conflict in an insect with maternal care, the earwig Forficula auricularia. Specifically, we test for a direct response to experimental selection on female future reproduction and correlated responses in current offspring survival, developmental rate and growth. The results demonstrate genetic trade-offs that differ in shape before and after hatching. Our study not only provides direct evidence for parent-offspring conflict but also highlights that conflict is not inevitable and critically depends on the genetic trade-offs shaping parental investment.
  • Vihma, Veera; Wang, Feng; Savolainen-Peltonen, Hanna; Turpeinen, Ursula; Hamalainen, Esa; Leidenius, Marjut; Mikkola, Tomi S.; Tikkanen, Matti J. (2016)
    Estrone is the most abundant estrogen after the menopause. We developed a liquid chromatography-tandem mass spectrometric method (LC-MS/MS) for determination of estrone in adipose tissue. Subcutaneous adipose tissue from the breast was collected during elective surgery in postmenopausal women undergoing mastectomy for treatment of breast cancer (n = 13) or reduction mammoplasty (controls, n = 11). Homogenized adipose tissue was extracted with organic solvents and the estrone fraction was purified by LH-20 column chromatography from the excess of lipids. The concentration of estrone was analyzed by LC-MS/MS. The method was accurate with an intra-assay variation of 8% and an interassay variation of 10%. The median concentration of estrone in subcutaneous adipose tissue from the breast did not differ between breast cancer and control women, 920 pmol/kg and 890 pmol/kg, respectively. In breast cancer patients but not in the controls, breast adipose tissue estrone levels correlated positively with the serum estrone concentration. In conclusion, the new method provides a reliable means to measure estrone concentrations in adipose tissue in postmenopausal women. (C) 2015 Elsevier Ltd. All rights reserved.
  • Mikkola, Tomi S.; Gissler, Mika; Merikukka, Marko; Tuomikoski, Pauliina; Ylikorkala, Olavi (2013)
  • Acosta, Henriette; Kantojarvi, Katri; Tuulari, Jetro J.; Lewis, John D.; Hashempour, Niloofar; Scheinin, Noora M.; Lehtola, Satu J.; Fonov, Vladimir S.; Collins, D. Louis; Evans, Alan; Parkkola, Riitta; Lähdesmäki, Tuire; Saunavaara, Jani; Merisaari, Harri; Karlsson, Linnea; Paunio, Tiina; Karlsson, Hasse (2020)
    Polygenic risk scores for major depressive disorder (PRS-MDD) have been identified in large genome-wide association studies, and recent findings suggest that PRS-MDD might interact with environmental risk factors to shape human limbic brain development as early as in the prenatal period. Striatal structures are crucially involved in depression; however, the association of PRS-MDD with infant striatal volumes is yet unknown. In this study, 105 Finnish mother-infant dyads (44 female, 11-54 days old) were investigated to reveal how infant PRS-MDD is associated with infant dorsal striatal volumes (caudate, putamen) and whether PRS-MDD interacts with prenatal maternal depressive symptoms (Edinburgh Postnatal Depression Scale, gestational weeks 14, 24, 34) on infant striatal volumes. A robust sex-specific main effect of PRS-MDD on bilateral infant caudate volumes was observed. PRS-MDD were more positively associated with caudate volumes in boys compared to girls. No significant interaction effects of genotype PRS-MDD with the environmental risk factor "prenatal maternal depressive symptoms" (genotype-by-environment interaction) nor significant interaction effects of genotype with prenatal maternal depressive symptoms and sex (genotype-by-environment-by-sex interaction) were found for infant dorsal striatal volumes. Our study showed that a higher PRS-MDD irrespective of prenatal exposure to maternal depressive symptoms is associated with smaller bilateral caudate volumes, an indicator of greater susceptibility to major depressive disorder, in female compared to male infants. This sex-specific polygenic effect might lay the ground for the higher prevalence of depression in women compared to men.