The physiological reaction of Siberian hamsters (Phodopus sungorus, Cricetidae) to chemical signals of perspective mating partners before and during courtship

ABSTRACT In this investigation we assessed the physiological reaction of hamsters in response to chemical signals from potential sexual partners, and also after a private meeting with them, which allowed us to ascertain the type of mating system for this species. The reception of olfactory signals led to an increase in peroxidase activity in the blood for both sexes, indicative of activity of a non-specific line of immune defense in recipients. The increase in blood cortisol level in response to the chemical signals of a partner was only observed in females. Males spent more time near samples of estrous females, with elevated levels of cortisol in the urine. In olfactory tests, an hour after grouping all the individuals in pairs there was a significant increase in blood peroxidase activity, which indicates the reaction of a non-specific link in the immune system of partners. This increase was greater in the pairs with a mutual preference. Females from these pairs demonstrated a substantial decrease in stress hormone levels in the plasma after an hour of mating in comparison to females prior to mating, and in non-preferred coupling.

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Perinatal photoperiod organizes adult immune responses in Siberian hamsters (Phodopus sungorus)

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00869.2005 ◽

2006 ◽

Vol 290 (6) ◽

pp. R1714-R1719 ◽

Cited By ~ 28

Author(s):

Zachary M. Weil ◽

Leah M. Pyter ◽

Lynn B. Martin ◽

Randy J. Nelson

Keyword(s):

Immune System ◽

Immune Function ◽

Breeding Season ◽

Somatic Growth ◽

Developmental Trajectory ◽

Day Length ◽

Phodopus Sungorus ◽

Siberian Hamsters ◽

Time Of Year ◽

Induced Changes

Individuals of many nontropical rodent species display reproductive, immunological, and somatic responses to day length. In general, short day (SD) lengths inhibit reproduction and enhance immune function in the laboratory when all other conditions are held constant. Most studies to date have focused on seasonal variation in immune function in adulthood. However, perinatal photoperiods also communicate critical day length information and serve to establish a developmental trajectory appropriate for the time of year. Nontropical rodents born early in the breeding season undergo rapid reproductive development, presumably to promote mating success during their first reproductive season. Rodents born late in the breeding season suspend somatic growth and puberty until the following vernal breeding season. We tested the hypothesis that perinatal day lengths have similar enduring effects on the immune system of rodents. Siberian hamsters ( Phodopus sungorus) were maintained prenatally and until weaning (21 days) in either SDs (8 h light:16 h dark) or long days (LD) (16 h light:8 h dark), then they were weaned into either the opposite photoperiod or maintained in their natal photoperiod, forming four groups (LD-LD, LD-SD, SD-LD, and SD-SD). After 8-wk in these conditions, cell-mediated immune activity was compared among groups. SD-SD hamsters of both sexes enhanced immune function relative to all other groups. The reproductive effects of perinatal photoperiod were not evident by the end of the experiment; circulating testosterone and cortisol sampled at the end of the experiment reflected the postweaning, but not the perinatal photoperiod. This experiment demonstrates long-lasting organizational effects of perinatal photoperiod on the rodent immune system and indicates that photoperiod-induced changes in the immune system are dissociable from changes in the reproductive system.

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The Emerging Role of Macrophages in Immune System Dysfunction under Real and Simulated Microgravity Conditions

International Journal of Molecular Sciences ◽

10.3390/ijms22052333 ◽

2021 ◽

Vol 22 (5) ◽

pp. 2333

Author(s):

Yulong Sun ◽

Yuanyuan Kuang ◽

Zhuo Zuo

Keyword(s):

Immune System ◽

Mapk Signaling ◽

Immune Defense ◽

Mitogen Activated Protein Kinase ◽

Therapeutic Drugs ◽

Physiological Processes ◽

Immune System Dysfunction ◽

Cell Immunity ◽

Mitogen Activated Protein ◽

Microgravity Conditions

In the process of exploring space, the astronaut’s body undergoes a series of physiological changes. At the level of cellular behavior, microgravity causes significant alterations, including bone loss, muscle atrophy, and cardiovascular deconditioning. At the level of gene expression, microgravity changes the expression of cytokines in many physiological processes, such as cell immunity, proliferation, and differentiation. At the level of signaling pathways, the mitogen-activated protein kinase (MAPK) signaling pathway participates in microgravity-induced immune malfunction. However, the mechanisms of these changes have not been fully elucidated. Recent studies suggest that the malfunction of macrophages is an important breakthrough for immune disorders in microgravity. As the first line of immune defense, macrophages play an essential role in maintaining homeostasis. They activate specific immune responses and participate in large numbers of physiological activities by presenting antigen and secreting cytokines. The purpose of this review is to summarize recent advances on the dysfunction of macrophages arisen from microgravity and to discuss the mechanisms of these abnormal responses. Hopefully, our work will contribute not only to the future exploration on the immune system in space, but also to the development of preventive and therapeutic drugs against the physiological consequences of spaceflight.

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Social Cues Attenuate Photoresponsiveness of the Male Reproductive System in Siberian Hamsters (Phodopus sungorus)

Journal of Biological Rhythms ◽

10.1177/074873099129000443 ◽

1999 ◽

Vol 14 (1) ◽

pp. 54-61 ◽

Cited By ~ 16

Author(s):

Carol D. Hegstrom ◽

S. Marc Breedlove

Keyword(s):

Reproductive System ◽

Social Cues ◽

Male Reproductive System ◽

Phodopus Sungorus ◽

Siberian Hamsters

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IMMUNE SYSTEM OF POIKILOTHERMIC AQUATIC ORGANISMS

Izvestiâ Timirâzevskoj selʹskohozâjstvennoj akademii ◽

10.26897/0021-342x-2021-2-71-91 ◽

2021 ◽

pp. 71-91

Author(s):

G.I. PRONINA ◽

◽

A.A. IVANOV ◽

A.G. MANNAPOV ◽

O.V. SANAYA

Keyword(s):

Bone Marrow ◽

Immune System ◽

Lymphoid Tissue ◽

Cellular Response ◽

Aquatic Organisms ◽

Immune Defense ◽

Cationic Protein ◽

Complement Components ◽

Red Bone Marrow

The paper shows features of the immune system of poikilothermic aquatic organisms of different taxonomic groups: crustaceans, fish, and amphibians. Defense mechanisms of crustaceans are presented by largely innate non-specific factors: external covers (including the exoskeleton), mucus, physical and chemical barriers lysozyme in the hemolymph, propanolamine system, and phagocytosis. The authors identified 4 types of cells (hemocytes) found in the circulating fluid of crayfish, depending on the morphological and functional properties: agranulocytes, progranulin,granulocytes, and transparent cells. Each type performs different functions in the process of immune defense. In fish, there is no red bone marrow and lymph nodes, the main organs of hematopoiesis include thymus, spleen, liver, lymphoid tissue of the brain and the trunk of the kidneys,accumulation of lymphoid tissue of the cranial box, intestine, and pericardium. Humoral components of the immune response of fish are represented by immunoglobulins, system complement components, lysozyme, C-reactive protein, interferon, lysine, hemolysin, hemagglutinin. Only IgM-like antibodies represent immunoglobulins in fish. The central organ of the amphibian immune system is the red bone marrow, but its role in the immune defense of amphibians has not been sufficiently studied. Peripheral organs of the immune system include kidneys, thymus, spleen, lymphomyeloid organs. Depending on the characteristics of the immune system of poikilothermic hydrobionts of different types, the authors offer methods for assessing their humoralimmunity (by determining phenoloxidase) and cellular response (by phagocytosis). Cellular immunity, and phagocytic activity, in particular, can be evaluated using cytochemical methods taking into account oxygenindependent factors – the content of enzymatic lysosomal cationic protein in phagocytes – and oxygendependent ones – NBT-test with nitrosonium tetrazolium that records cytotoxic oxygen radicals generated during the respiratory explosion of cell stimulation in vitro.

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Energy intake and fur in summer- and winter-acclimated Siberian hamsters (Phodopus sungorus)

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.2001.281.2.r519 ◽

2001 ◽

Vol 281 (2) ◽

pp. R519-R527 ◽

Cited By ~ 9

Author(s):

Alexander S. Kauffman ◽

Alessandra Cabrera ◽

Irving Zucker

Keyword(s):

Food Intake ◽

Energy Intake ◽

Ventral Surface ◽

Phodopus Sungorus ◽

Ambient Temperatures ◽

Siberian Hamsters ◽

Daily Food ◽

Brown Adipose ◽

Wide Range ◽

The Impact

Few studies have directly addressed the impact of fur on seasonal changes in energy intake. The daily food intake of Siberian hamsters ( Phodopus sungorus) was measured under simulated summer and winter conditions in intact animals and those with varying amounts of pelage removed. Energy intake increased up to 44% above baseline control values for approximately 2–3 wk after complete shaving. Increases in food intake varied with condition and were greater in hamsters housed in short than long day lengths and at low (5°C) than moderate (23°C) ambient temperatures. Removal of 8 cm2 of dorsal fur, equivalent to 30% of the total dorsal fur surface, increased food intake, but removal of 4 cm2 had no effect. An 8-cm2 fur extirpation from the ventral surface did not increase food consumption. Food intake was not influenced differentially by fur removal from above brown adipose tissue hot spots. Fur plays a greater role in energy balance in winter- than summer-acclimated hamsters and conserves energy under a wide range of environmental conditions.

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