Showing papers in "General and Comparative Endocrinology in 2009"

TL;DR: The cellular and molecular mechanisms that link stress responses to immune adjustments over short time scales in domesticated species are reviewed and an attempt is made to place stress-immune interactions in a naturalistic, organismal context.

TL;DR: A positive relationship between baseline cort and fitness components during the nestling period suggests that reproductive investment may elicit higher cort levels that feedback to reallocate more effort to reproduction during critical periods of nestling provisioning.

TL;DR: It is suggested that the magnitude of the prolactin stress response may reflect parental investment, and the importance of considering both hormones when investigating the hormonal basis of parental investment is emphasized.

TL;DR: Environmental stress acts centrally to increase the activity of the two principle endocrine axes controlling metamorphosis, and the effectors of these axes synergize at the level of target tissues to promote morphogenesis.

TL;DR: The identification of regulatory gene networks that are stress activated, and modulated by cortisol, both in hepatic and extra-hepatic tissues, will provide a mechanistic framework to characterize the multifaceted role of cortisol during stress adaptation.

TL;DR: The results obtained by analysis of the HPG/T axes in sea lamprey may transcend the limited scope of the corresponding physiological compartments by providing important clues in respect to the interplay between genome-wide events (duplications), coding sequence (mutation) and expression control level evolutionary mechanisms in definition of the chemical control pathways in vertebrates.

TL;DR: Four alternative explanations for an observed attenuation in the response of hormonal stress mediators to a repeated stimulus or set of stimuli lead to six criteria that define habituation in a field context and four diagnostic tests are proposed to help distinguish hormonal habituation from these alternative explanations in field studies.

TL;DR: This review examines whether molecular components involved in the functioning of the hypothalamus-pituitary-interrenal (HPI) axis are present as single or duplicate genes, including corticotropin releasing hormone (CRH), adrenocorticotropic hormone (ACTH) and the glucOCorticoid receptor (GR).

TL;DR: In this article, a wild-caught chukar was used as a model avian species to assess how the initial 10 days of captivity alters the corticosterone (CORT) secretory pathway.

TL;DR: The stomatogastric nervous system plays a pivotal role in feeding behaviour, and involves the interaction of a number of mechanisms, one of which is the release, either centrally or locally, of neuropeptides.

TL;DR: Two working models are proposed which predict that enhanced FSHR expression and the progression ofgranulosa cell differentiation occurs as a result of a decline in MAPK signaling from within granulosa cells and/or elevated cAMP signaling promoted by an endocrine, neuroendocrine or neuronal factor (external model).

TL;DR: Results from this study establish the zebrafish as a model species for research on stress during ontogeny and offer new insights into an HPI-axis independent function for the CRF system during embryogenesis.

TL;DR: It is argued that separation of different kinds of androgen responsiveness and putting them into context with the natural history and ecology of a study species may help to better understand variations in androgen responsive to social and non-social environmental factors.

TL;DR: It is proposed that more predictable resources in the city than in rural areas may decrease the need to vary stress responsiveness across life history stages, highlighting the species-specific effects of urbanization on stress physiology and the difficulty to predict how urbanization impacts organisms.

TL;DR: The comprehensively surveyed leptin (LEP) and leptin receptor (LEPR) genes in medaka, Oryzias latipes and identified two LEP (mleP-A and mLEP-B) genes and one LEPR (mLEPR), which means that both mLEPs are orthologs of human LEP and paralogs derived from whole-genome duplication early in the teleost lineage.

TL;DR: Chickens and turkeys have higher circulating concentrations of glucose than those of livestock mammals and the biological basis for the high basal glucose concentrations is not known.

TL;DR: It is demonstrated that 6 days starvation led to, increased GHRL-1 mRNA levels in theGI tract (stomach), while there no significant changes in expression levels for the other hormones in the GI tract, which suggests an orexigenic role for GH RL-1 in Atlantic salmon.

TL;DR: The evidence points to tyramine being synthesized by, and present in, neurons; capable of being released from neurons; removed by high affinity plasma membrane transporters; acting upon specific tyraminergic neuron receptors; and producing physiological/behavioral effects that can be blocked by antagonists.

TL;DR: The data presented here not only catalog an extensive array of putative D. pulex peptide paracrines/hormones, but also provide a strong foundation for future investigations of the effects of environmental/anthropogenic stressors on peptidergic control in this model organism.

TL;DR: The results raise many questions concerning the evolutionary role of the PBAN/Pyrokinin receptors belonging to the GPCR family.

TL;DR: Data suggest that the relation between circulating Lep levels and energy status differs from that in mammals, and that it may not act as an adiposity signal in salmonids, possibly pointing to functional divergence among ectothermic and endothermic vertebrates.

TL;DR: The expression profile of the LHR seen in both sexes supports the involvement of LH in the regulation of the final stages of gamete maturation and spermiation/ovulation in male and female sea bass.

TL;DR: The data presented in this study not only greatly expand the number of identified C. maenas neuropeptides, but also provide a framework for future investigations of the physiological roles played by these molecules in this highly adaptable species.

TL;DR: Key peptide hormones involved in the control of appetite in vertebrates were identified, their genes characterized and their regulation studied in Atlantic salmon, suggesting that AgRP-1 and CART are involved in feeding regulation in Atlantic Salmon.

TL;DR: An overview of the effects that glucocorticoids, primarily the avian form, corticosterone, can have on the reproductive axis is presented and it may be that early CORT exposure effectively programs adult behaviors that have wide ranging effects, including upon reproduction.

TL;DR: Variation in corticosterone responses in birds is quantified for the first time in a species of free-living bird and coefficients of variation were used to provide a rule of thumb for determining differences between groups of birds in mean cortic testosterone concentrations to enable statistical analyses to have acceptable levels of statistical power for given sample sizes.

TL;DR: Geriatric cats form an animal model of disease because both hyperthyroidism and chronic kidney disease (CKD) have high prevalence among them, and the link between thyroid and kidney affects the evaluation of clinical wellbeing and the possible treatment options.

TL;DR: CDNAs encoding for neuropeptide Y, cocaine- and amphetamine-regulated transcript and cholecystokinin were cloned in an elasmobranch fish, the winter skate, providing basis for further investigation into the regulation of feeding in winter skate.

TL;DR: Quantitative PCR studies indicate that there is a significant increase in preproghrelin mRNA expression in the brain and gut of zebrafish fasted for 3, 5 and 7 days when compared to the expression in ad libitum fed fish, and suggests an orexigenic role for ghrelin in zebra fish.

TL;DR: Zebrafish has quickly risen as a model species for functional analysis of the brain-pituitary-gonad axis and the value of zebrafish in reproductive endocrinology is demonstrated, suggesting roles for these factors in the differential regulation of two gonadotropins and growth hormone and therefore the gonadotrophic and somatotrophic axes.