| Stress is an organism's response to a stressor such as an environmental change.Animals can be physically,mentally,or emotionally react to those changes,and requires an adjustment or response.Chronic stress can cause the natural defenses of the body resulting in a variety of physical symptoms,i.e.,the autonomic nervous system of the body has an integrated stress response which causes physiological changes to allow the body to act on stressful situations.Stress causes also false standards and hypocrisy for the reproductive system of mice.Scientists proved that stress increases the levels of stress hormones-glucocorticoids such as cortisol-that inhibit the body's main sex hormone,such as gonadotropin releasing hormone(GnRH),and subsequently reduce sperm count,sexual activity and ovulation.Likewise,maternal stress can also have a harmful effect on offspring's health and development.It could enhance the risk of developmental delay among offspring with low birth weight,even if they had no initial neonatal complications.It also may be recurrent,associated with ongoing events in a fetus life.The mechanisms by which stress influences reproduction remain unclear,in spite of extensive researches.Activation of stress mechanisms at any stage of the hypothalamo-pituitary gonadal axis may potentially affect reproduction.The mechanisms by which stress affects reproduction are likely to involve complex interactions between a variety of central and peripheral pathways in males.In order to understand these mechanisms,it is important to determine the stress pathways triggered by particular stressors and to determine how those pathways influence GnRH s secretion and behavior.One of the most widely used models is restraint stress(RS),which is a modified type of stress on immobilization.As well as explaining the mechanism by which stress contributes to mental and physical health problems,the RS model suggests that each step in this phase can be influenced by individual trait.This dimension of the model has become very significant,particularly in recent years,since a lot of research on RS has centered on how individual differences affect the stress cycle.In this process,unnecessary physical and mental stress is caused by putting the animals in a plastic tube to prevent their movement.This is an established experimental stressor that has simultaneous physical and psychological effects.Resveratrol(RES)is a compound of plants which acts as an antioxidant.This compound appears to be found mostly in grape and berry skins and seeds.However,with high amounts of the drug,much of the RES research was done in animals and test tubes.New research suggests that the plant compound RES used in red wine exhibits anti-stress effects by blocking the expression of an enzyme linked to stress regulation in the brain,according to a buffalo-led study by a university.It has a protective effect on the role of spermatozoa in RS in male infertility.Numbers of studies have reported that RES can regulate cell response to various stimuli that cause cell injury,as well as decrease germ cell apoptosis in mice and rats.This stress response reflects a layer of biology that has been widely ignored,and RES helps in triggering it at concentrations far lower than those used in previous studies.Many lines of studies on animal subjects have shown that RS contributes too many negative outcomes like increased psychopathologic,physiological,and reproductive incidence adversely.Especially different kind of animal models are required to make it more clearly about depressions.For RS,special experiment modeling and to understand different kind of factors which are necessary for the stress response should be designed for research objectives.The present study was conducted to investigate the potential role of RES in testing adult(stressed)and new born(maternal stressed)mice against the impact of RS on testicular development and spermatogenesis.1.Development of animal restraint stress modelsThe usage of restraint for animal physiology,anatomy,and pharmacology investigations has a long history.The primary application of this technique has been for the induction of stress response syndromes in animals as a "stressor.Such long-or short term impaction of a single restraint stress(RS)has not been extensively explored.In this study,we subjected mice to different days for restraint to simulate the confine episode,and investigated 3,9,15,and 18 days after the restraint for 5 hour/day impacts.We found that the mice displayed depression-like behaviors,increased blood glucose level,spleen weight,and water intake,in the RS groups of days(D)15 and days 18,while there was no any significant difference in the groups of D 3 and D 9 days of same parameters.On other hand,we found significant decreased body weight,feed intake,and testes weight in the groups of D 15 and 18.Results for sperm count,percentage of viability,and abnormality were also significantly increased at D 15,and D 18 in order to RS,while no any significant results were found during giving RS at D 3 and D 9.These findings demonstrated that a single severe stressful process could produce harm full effects for entire life of an organism.The present study established to investigate the most effective period of RS in mature mice which makes an easy understand pathways for future studies.2.Resveratrol ameliorates testicular histopathology of mice exposed to restraint stressThe search for effective medicines is challenging.Resveratrol is a phytoalexin,and its function remains elucidated.Therefore,we undertook the present study to investigate reproductive disturbances due to restraint stress in mice and whether resveratrol plays an anti-stress role.We evaluated immobilization stress and resveratrol supplementation in immature male mice at 30 days of age for 15 consecutive days.Fifty Swiss mice were divided into five groups(10 mice each):Controls,restraint stress(RS),restraint stress+vehicle(RS+V),RS+2 mg/kg,and RS+20 mg/kg 5 hours back to back days.We determined results on the basis of hematoxylin and eosin(HE),"Periodic acid-Schi" staining,and TUNEL assay.The results indicated that immobilization stress significantly decreased body weight,testis weight,and.water/food intake compared to the control;while resveratrol ameliorated these effects.The quantitative histologic evaluation of the seminiferous tubule diameter,luminal diameter,and area of seminiferous tubules,area of tubule lumen,epithelial height,Leydig cell number,and the width of the tunica albuginea were similarly decreased after exposure to RS.These parameters recovered back to normal in the RS+2 mg/kg group.The development of spermatogenesis was significantly delayed in the RS,RS+V,and RS+20 mg groups based upon our evaluation score system.However,we observed no significant differences in the RS+2mg group compared with the control group.The number of TUNELpositive cells also significantly decreased in the RS+2mg/kg group.In conclusion,we found that the administration of 2mg/kg was an effective dose against immobilization stress in mice.3.Mitigation of stress from testis injuries by resveratrol may occur via AIF signaling in miceThis study was undertaken to investigate whether restraint stress(RS)interferes with low 2mg/kg and high 20mg/kg doses of resveratrol(RES)-induced to check reproductive betterment in mice in comparison to control(C)groups.Mature male mice were subjected to RS(5 hr/day)and maintained feed and water for 15 days.In our results,testes weight,epididymal sperm count,sperm viability,and sperm abnormality was significantly decreased with RS compared to C and RES 2mg/kg groups.We also observed that RS increased lumen size and separations of germ cells,while,in the group of RS+RES 20mg/kg there was dramatically separations of germ cells compared to C and RS+RES 2mg/kg groups.Results of the apoptosis-inducing factor(AIF)antibody was significantly presented in the RS groups,while it was moderated in RES 2mg/kg group.In western blotting(WB),we found upregulated expression of caspase-9,and down-regulated Bcl-2 expression,while RES 2mg/kg treatment reduced the effects of RS on the expression Bcl-2,Bax,and caspase-9.These significant results of our study shows a positive and healing effects of Res against RS in mature male mice.4.Positive roles of resveratrol in early development of testicular germ cells against maternal restraint stress in miceMaternal stress during pregnancy affected the early programming of the brain in the fetus with changes in neuroendocrine regulation,and offspring behavior was proven in the literature.In addition,resveratrol was reported to play positive roles against stress.However,how maternal stress affects testicular development and whether RES has potential protecting roles is unknown.Our present study was designed to evaluate the effects of resveratrol(RES)in Swiss mice by exposing them to prenatal stress.Twenty-four Swiss mice were divided into four groups:control(C),maternal restraint stress(MRS),maternal restraint stress+resveratrol(MRS+RES)2mg/kg,and maternal restraint stress+resveratrol(MRS+RES)20mg/kg.Dams were exposed to stress by restraint in plastic tubes for four hours a day from 12-18 days of gestation.The results showed that male pups of MRS were significantly decreased in the testis weight,anogenital distance,area of seminiferous tubules,diameter of seminiferous tubules,area of the lumen,diameter of the lumen,and epithelial height of seminiferous tubules.However,the anomalies of the reproductive tract produced under restraint stress were neutralized by the use of RES 2 mg/kg.A significant difference was observed between terminal deoxynucleotidyl transferase dUTP nick ends labeling(TUNEL)-positive germ cells in MRS and MRS+RES 20mg/kg groups,while it was nonsignificant between MRS+RES 2mg/kg and C groups.Apart from these effects,blood glucose levels were increased in MRS and MRS+RES 20mg/kg groups,while experimental animals of the MRS+RES 2mg/kg group significantly recovered.These results suggested that a lower dose of RES could cure the adverse effects of prenatal stress in early age male progeny.Thus,our study suggests,for the first time,practical values for a lower dose of RES 2mg/kg as a safe and effective agent in the first week age of prenatally stressed mice.In conclusions,overall our results indicate that male health and reproductive systems have been impaired by RS stressor in the studies.The decline in male fertility due to especially stressful environment conditions plays a significant role in fertility levels,and its effect on the future of humans and animals population also makes this a significant topic of public health in this era,and there is no general agreement on how to quantify it objectively.This research is among the first to experiment with the different stress cycles across which RS stressor interact to affect reproduction.We demonstrate models that are doubtless important when it comes to understanding how animals react to RS,whether adaptive or not.Therefore,we urge further analysis of the adaptive nature and mechanisms that mediate the effect of RS on testicular histology and other parameters for evidence.Several studies have reported a beneficial role for antioxidants in stress-induced germ dysfunction especially in male infertility,their usage should be considered,but not before diagnostic research,as a reliable proof on this is a difficult process.We feel confident in suggesting a specific factor for RES administration to reduce the exposure to stressors and systematically increase the chances of good male fertility and reduce the possibility of possible newborn genetic disorders in females. |
PDF Full Text Request