Médecine comparative : modèles de pathologie de l’axe somatotrope/Comparative medicine: Models of somatotropic axis pathology

Sepsis is defined as “life-threatening organ dysfunction caused by a dysregulated host response to infection”. One of the elements of dysregulated host response is an endocrine system disorder. Changes in its functioning in the course of sepsis affect almost all hormonal axes. In sepsis, a function disturbance of the hypothalamic–pituitary–adrenal axis has been described, in the range of which the most important seems to be hypercortisolemia in the acute phase. Imbalance in the hypothalamic–pituitary–thyroid axis is also described. The most typical manifestation is a triiodothyronine concentration decrease and reverse triiodothyronine concentration increase. In the somatotropic axis, a change in the secretion pattern of growth hormone and peripheral resistance to this hormone has been described. In the hypothalamic–pituitary–gonadal axis, the reduction in testosterone concentration in men and the stress-induced “hypothalamic amenorrhea” in women have been described. Catecholamine and β-adrenergic stimulation disorders have also been reported. Disorders in the endocrine system are part of the “dysregulated host response to infection”. They may also affect other components of this dysregulated response, such as metabolism. Hormonal changes occurring in the course of sepsis require further research, not only in order to explore their potential significance in therapy, but also due to their promising prognostic value.

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Markers of Genetic Variation in Blue Gourami (Trichogaster trichopterus) as a Model for Labyrinth Fish

Biology ◽

10.3390/biology10030228 ◽

2021 ◽

Vol 10 (3) ◽

pp. 228

Author(s):

Gad Degani ◽

Isana Veksler-Lublinsky ◽

Ari Meerson

Keyword(s):

Growth Hormone ◽

Genetic Variation ◽

Genetic Markers ◽

Basic Research ◽

Coi Gene ◽

12S Rrna ◽

Rrna Gene ◽

Somatotropic Axis ◽

Genes Encoding ◽

Growth And Reproduction

Markers of genetic variation between species are important for both applied and basic research. Here, various genes of the blue gourami (Trichogaster trichopterus, suborder Anabantoidei, a model labyrinth fish), many of them involved in growth and reproduction, are reviewed as markers of genetic variation. The genes encoding the following hormones are described: kisspeptins 1 and 2, gonadotropin-releasing hormones 1, 2, and 3, growth hormone, somatolactin, prolactin, follicle- stimulating hormone and luteinizing hormone, as well as mitochondrial genes encoding cytochrome b and 12S rRNA. Genetic markers in blue gourami, representing the suborder Anabantoidei, differ from those in other bony fishes. The sequence of the mitochondrial cytochrome c oxidase subunit 1 (COI) gene of blue gourami is often used to study the Anabantoidei suborder. Among the genes involved in controlling growth and reproduction, the most suitable genetic markers for distinguishing between species of the Anabantoidei have functions in the hypothalamic–pituitary–somatotropic axis: pituitary adenylate cyclase-activating polypeptide and growth hormone, and the 12S rRNA gene.

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Extracts from an Address of Welcome to the Alumni of the Faculty of Comparative Medicine and Veterinary Science, McGill University, On February 11, 1899

The Veterinary Journal and Annals of Comparative Pathology ◽

10.1016/s2543-3377(17)32309-9 ◽

1899 ◽

Vol 48 (6) ◽

pp. 461-466

Author(s):

Duncan Mceachran

Keyword(s):

Veterinary Science ◽

Mcgill University ◽

Comparative Medicine

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Synopsis of the film Schistosomiasis in the Sudan: a study in comparative medicine

Transactions of the Royal Society of Tropical Medicine and Hygiene ◽

10.1016/0035-9203(80)90135-2 ◽

1980 ◽

Vol 74 (5) ◽

pp. 558

Keyword(s):

Comparative Medicine

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Egg size-dependent expression of growth hormone receptor accompanies compensatory growth in fish

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2011.1104 ◽

2011 ◽

Vol 279 (1728) ◽

pp. 592-600 ◽

Cited By ~ 27

Author(s):

F. H. I. D. Segers ◽

G. Berishvili ◽

B. Taborsky

Keyword(s):

Growth Hormone ◽

Hormone Receptor ◽

Egg Size ◽

Growth Hormone Receptor ◽

Yolk Sac ◽

Juvenile Growth ◽

Somatotropic Axis ◽

Expression Levels ◽

Potential Link ◽

Adaptive Adjustment

Large egg size usually boosts offspring survival, but mothers have to trade off egg size against egg number. Therefore, females often produce smaller eggs when environmental conditions for offspring are favourable, which is subsequently compensated for by accelerated juvenile growth. How this rapid growth is modulated on a molecular level is still unclear. As the somatotropic axis is a key regulator of early growth in vertebrates, we investigated the effect of egg size on three key genes belonging to this axis, at different ontogenetic stages in a mouthbrooding cichlid ( Simochromis pleurospilus ). The expression levels of one of them, the growth hormone receptor ( GHR ), were significantly higher in large than in small eggs, but remarkably, this pattern was reversed after hatching: young originating from small eggs had significantly higher GHR expression levels as yolk sac larvae and as juveniles. GHR expression in yolk sac larvae was positively correlated with juvenile growth rate and correspondingly fish originating from small eggs grew faster. This enabled them to catch up fully in size within eight weeks with conspecifics from larger eggs. This is the first evidence for a potential link between egg size, an important maternal effect, and offspring gene expression, which mediates an adaptive adjustment in a relevant hormonal axis.

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