The Stressful Personality: A Meta-Analytical Review of the Relation Between Personality and Stress.

The current study presented the first meta-analytic review on the associations between the Big Five personality traits and stress measured under different conceptualizations (stressor exposure, psychological and physiological stress responses) using a total of 1,575 effect sizes drawn from 298 samples. Overall, neuroticism was found to be positively related to stress, whereas extraversion, agreeableness, conscientiousness, and openness were negatively linked to stress. When stress assessed under different conceptualizations was tested, only neuroticism, agreeableness, and conscientiousness were related to stressor exposure. All of the Big Five personality traits were significantly associated with psychological stress perception, whereas the five personality traits showed weak to null associations with physiological stress response. Further moderation analyses suggested that the associations between personality traits and stress under different conceptualizations were also contingent upon different characteristics of stress, sample, study design, and measures. The results supported the important role of personality traits in individual differences in stress.

Outcome of Ultrasound Guided Anterior Quadratus Lumborum Block After Video Laparoscopic Cholecystectomies: A Prospective Randomized Clinical Trial.

BACKGROUND: Laparoscopy revolutionizing digital and robotic technology for surgical practice. The ability of anesthetic agents and neuronal blockade to modify the response to surgical trauma has been widely studied in the last few years. OBJECTIVES: evaluate if Anterior Quadratus Lumborum Block contributes to attenuate surgical repercussions, having as primary parameters analgesia and secondary the pulmonary function and neuroendocrine response to trauma. METHODS: prospective, controlled, Double-blind study, in which 51 patients scheduled for eletive laparoscopic cholecystectomy were randomly selected and distributed into 2 groups. Control group received general anesthesia, and the intervention group was submitted to general anesthesia plus Anterior Quadratus Lumborum Block. The parameters evaluated were: postoperative pain, respiratory muscle pressure, and inflammatory response to surgical stress with the plasma dosage of Interleukin 6, C-Reactive protein and cortisol. The following situations were excluded: refusal to participate in the study; body mass index greater than or equal to 40, peripheral neuropathies, coagulopathies or hypersensitivity to drugs used; infection at the puncture site; fever, purities; dementia or other states that would prevent the adequate understanding of the use of the numeric-verbal scale of pain; immunological diseases, diabetes, malignant neoplasia, use of opioids or anti-inflammatory drugs in the preoperative period; antidepressants and anticonvulsants, conversion open surgery, re-exploration and hospital stay. RESULTS: Slowed Interleukin 6 cytokine production and decrease in cortisol release, accompanied by significant attenuation of surgical repercussion on lung function and significant reduction in postoperative pain scores and consumption of pain medication. CONCLUSION: An important strategy for analgesia in abdominal laparoscopic surgery.

Parental Self-Efficacy and Physiological Responses to Stress among Mothers of Early Adolescents.

Little research addresses how parental self-efficacy is related to stress responses, and no research does so among parents of early adolescents. To fill this research gap, the current study examined the association between maternal self-efficacy and physiological stress responses during early adolescence. Participants were 68 mother-early adolescent dyads with youth in the 6th grade (M = 11 years; 56% female). Physiological responses (i.e., skin conductance, respiratory sinus arrythmia, cortisol) were measured before and after mothers observed their children engage in a modified Trier Social Stress Test for Children. Mothers reported on parental self-efficacy. Mothers with higher parental self-efficacy exhibited a more moderate skin conductance response to the speech portion of the task, and a smaller increase in cortisol, compared to mothers with lower parental self-efficacy. Respiratory sinus arrhythmia change was not related to parental self-efficacy. The findings are consistent with a "caring but confident" physiological profile among mothers with high parental self-efficacy, suggesting that greater confidence about parental influence might reduce parents' experience of stress/anxiety as they observe children face certain challenges.

Lipid metabolic disorders and physiological stress caused by a high-fat diet have lipid source-dependent effects in juvenile black seabream Acanthopagrus schlegelii.

This study was conducted to evaluate the effects of different dietary lipid sources on growth performance, lipid metabolism, and physiological stress responses including oxidative stress (OS) and endoplasmic reticulum stress (ERS) of juvenile Acanthopagrus schlegelii (initial weight 0.88 ± 0.01 g) fed a high-fat diet (HFD). Four isonitrogenous and isolipidic experimental diets containing different lipid sources were formulated: fish oil (FO), palm oil (PO), linseed oil (LO), and soybean oil (SO), respectively. Results indicated that fish fed HFD supplemented with FO significantly improved growth than SO treatment. The high concentrations of aspartate aminotransferase and alanine transaminase were found in HFD supplemented with SO. Fish fed dietary LO supplementation showed significantly lower serum cholesterol, triglyceride, low-density lipoprotein, and high-density lipoprotein contents than those in SO group. Likewise, hepatic paraffin section analysis indicated that HFD with PO or SO supplementation increased fat drop. The expression levels of peroxisome proliferators-activated receptor alpha (pparα) and silent regulator 1 (sirt1) were significantly elevated by HFD with FO or LO supplementation. Additionally, the key marker of OS malonaldehyde was significantly increased in FO and SO groups. ERS-related genes were activated in dietary PO or SO supplementation and, hence, triggering inflammation and apoptosis by promoting the expression levels of nuclear factor kappa B (nf-κb) and c-Jun N-terminal kinase (jnk). Overall, the present study reveals that lipid metabolic disorders and physiological stress caused by a HFD have significant lipid source-dependent effects, which have important guiding significance for the use of HFD in marine fish.

The effect of water shower spray on stress physiology and mortality in broiler chickens subjected to road transportation under the hot and humid tropical condition.

This study was performed to investigate the effect of water shower spray on rectal temperature (RT), serum levels of corticosterone (CORT), heat shock protein (HSP) 70 and creatine kinase (CK) in broiler chickens road transported at different times of the day. A total of 320 male broiler chickens (35 days of age) were crated and subjected to either water shower spray (WS) for 10 min or no water shower (control). The WS and control broilers were then loaded into an open truck and transported either from 0900 to 1100 h (29.0 °C and 89.0% RH) (AM) or 1900 h to 2100 h (26.0 °C and 94.0% RH) (PM) with an average speed of 80 km/h. The CORT of AM birds were significantly reduced by WS, but the treatment had negligible influence on the PM group. Transportation during AM significantly elevated RT, CORT and HSP70 compared to the PM group. Water shower spraying of birds before transit significantly reduced RT and HSP70 compared to controls. Neither water shower treatment nor transportation time had a significant on CK and mortality rate of broilers. In conclusion, water shower spray is beneficial to alleviate the physiological stress response in road-transported broilers under the hot and humid tropical environment.

Influence of early rearing environment on water-borne cortisol and expression of stress-related genes in grass carp (Ctenopharyngodon idella).

Nowadays, lower post-release survivorship of hatchery-reared fish in natural aquatic bodies has attained great attention and research is in progress to determine the reasons for their higher mortality. It is assumed that hatchery rearing environments negatively affect the physiological stress response of the fish. Thus, understanding how rearing environments modulate this is important for the well-being of fish. Here, an attempt has been made to assess the influence of two early rearing environments, i.e., barren (BR), mimic the conventional hatchery rearing environment; without any substrate and enrichment items and structurally enriched (ER), containing multi-colored gravel substrate, cobbles and plants, on the stress regulators i.e., HPI-axis and brain monoaminergic system of fish. Three-day old grass carp (Ctenopharyngodon idella) postlarvae were reared up to the fingerling stage in the aforementioned environments. For the stress assay, fish were subjected to net capture followed by 30 min confinement in a small container at a lower water level. The pre- and post-stress responses were compared by evaluating their water-borne cortisol and the mRNA level of corticotropin releasing hormone (CRH), dopamine D1A receptor (DRD1A) and hydroxytryptamine receptor 2B (HTR2B) in the whole brain through qPCR analysis. Results of two-way ANOVA revealed significantly low (p < .001) post-stress concentration and release rate of water-borne cortisol and pre- and post-stress expression of CRH, DRD1A and HTR2B genes in the ER than BR fish. It is concluded that a structurally complex early rearing environment reduces the stress level in fish.

Physiological Changes from Violence-Induced Stress and Trauma Enhance HIV Susceptibility Among Women.

PURPOSE OF REVIEW: This theoretical review identifies physiological mechanisms by which violence against women (VAW) may increase women's susceptibility to HIV through trauma, stress, and immune dysfunction. RECENT FINDINGS: Research documents systemic and local immune responses are related to stress and trauma from abuse across the life course (i.e., childhood, IPV, adulthood re-victimization). Findings are interpreted within a theoretical framework grounded in the Social Stress Theory and the concept of toxic stress, and highlight the current state of the science connecting: (1) VAW to the physiological stress response and immune dysfunction, and (2) the physiological stress response and inflammation to HIV susceptibility and infection in the female reproductive tract. Despite a dearth of research in human subjects, evidence suggests that VAW plays a significant role in creating a physiological environment conducive to HIV infection. We conclude with a discussion of promising future steps for this line of research.

Affective and physiological response to a novel parent-adolescent conflict stressor.

Few laboratory paradigms exist that expose adolescents to conflict that might commonly be experienced in parent-adolescent relationships. Given the continued importance of parent-adolescent relationships on adolescent development, as well as the changing expectations in these relationships, we examined the effect of a novel parent-adolescent conflict paradigm on physiological and affective response in a sample of 52 adolescents. The parent-adolescent conflict stressor (PACS) involved adolescent participants (50% girls; M = 14.75, SD = 0.88) watching a 12-minute scripted video that asked youth to imagine that they were the teenager in the video, which consisted of parent and adolescent actors having discussions about conflict in their relationship and solving this conflict in either a positive, typical, or hostile manner. Cortisol, alpha amylase, and self-report of negative and positive affect were collected at baseline, following the video, and during a recovery period. Heart rate also was taken continuously while adolescents watched the videos. Hierarchical linear modeling (HLM) analyses indicated significant linear change in alpha amylase and linear and quadratic change in negative affect to the PACS. There also was a significant linear and quadratic change in heart rate during the portion of the video where teens and parents discussed issues of personal responsibility. The PACS marks a preliminary but important first step in developing a parent-adolescent conflict paradigm that can be used across studies to understand the impact of parent-adolescent conflict on affective and physiological markers associated with stress response.

Immune-related gene expression and physiological responses in rainbow trout (Oncorhynchus mykiss) after intraperitoneal administration of Rhodomyrtus tomentosa leaf extract: A potent phytoimmunostimulant.

The immunostimulatory effects of Rhodomyrtus tomentosa leaf extract were evaluated in rainbow trout through changes in expression profile of genes involved in innate immune and antioxidant response, hematology and stress indicators. The concentrations of R. tomentosa at 10 and 100 µg per fish were administrated by intraperitoneal injection, alone or in combination with LPS. After 6 h of administration, the gene expression was measured in head kidney, spleen, and intestine. Results indicated that R. tomentosa exerted immunostimulatory effects by inducing the expression of il10, saa, hepcidin, and sod in head kidney and the expression of il10, tgfß, and inos in intestine. In combination with LPS, the plant suppressed the expression of pro-inflammtory cytokine il1ß, il8 and other consisting of saa and gpx1 in head kidney and il1ß in spleen, pointing out its anti-inflammatory activities. Furthermore, the plant did not exert any impact on hematological parameters, but it was able to reduce cortisol levels when co-administered with LPS, indicating that R. tomentosa could attenuate stress response in rainbow trout. Our observations suggest that R. tomentosa induced the expression of genes involved in cytokine and innate immune response and modulated the physiological stress response as indicated by the suppressed cortisol in rainbow trout.

Sexual dimorphism in baseline urinary corticosterone metabolites and their association with body-condition indices in a peri-urban population of the common Asian toad (Duttaphrynus melanostictus).

Field endocrinology research through the quantification of glucocorticoids or stress hormones in free-living wildlife is crucial for assessing their physiological responses towards pervasive environmental changes. Urinary corticosterone metabolite (UCM) enzyme-immunoassay (EIA) has been validated for numerous amphibian species as a non-invasive measure of physiological stress. Body-condition indices (BCIs) have also been widely used in amphibians as an indirect measure of animal health. Field endocrinology research on amphibian species in Asia is limited. In this study, we validated a UCM EIA in a peri-urban sub-population of the common Asian toad (Duttaphrynus melanostictus) in Pune, Maharashtra, India. We determined the baseline levels of UCMs in male (n=39) and female (n=19) toads. Secondly, we used a standard capture handling protocol to quantify changes in UCMs during short-term captivity. We also determined BCIs in the male and female toads using Fulton's index (K) and residual condition index (RCI). The results showed that mean baseline levels of UCMs were significantly higher in male toads than in females. There was no significant change in mean levels of UCMs of males and females between capture and captivity (0-12h). This highlights plausible habituation of the species to the peri-urban environment. Associations between UCMs with BCIs (K and R) were positive in male toads but negative in females. In conclusion, our UCMs EIA can be applied with BCIs to assess health of the Asian toads. We also suggest that direct fitness parameters such as sperm and oocyte quality, reproductive ecology and immunocompetence measurements should be applied in combination with these conservation physiology tools to quantify the fitness consequences of pervasive environmental changes on native amphibians.

The Relationship Between Autonomy and Relatedness and Adolescents' Adrenocortical and Cardiovascular Stress Response.

Developing autonomy and maintaining relatedness within the parent-adolescent relationship marks a realignment process that shifts adolescents' decision making and regulation from parents to youth. This process may be stressful for some adolescents, particularly those who perceive their daily lives as stressful. This study examined the associations of autonomy, relatedness and perceived stress with adolescents' cortisol and blood pressure response to conflict in a mother-adolescent interaction task among 100 adolescents (M age = 15.09; 68 % girls, 78 % Caucasian). Few direct associations were found, but results indicated that perceived stress moderated the effect of autonomy and relatedness such that youth who reported more perceived stress and whose mothers' restricted their autonomy and undermined their relatedness evidenced increased cortisol and systolic blood pressure when compared to youth lower in perceived stress. The results highlight the importance of examining individual differences in the association between normative developmental transitions and adolescents' neurobiological response to stress.

Evaluating capture stress in wild gray mouse lemurs via repeated fecal sampling: method validation and the influence of prior experience and handling protocols on stress responses.

Reliable measurements of physiological stress are increasingly needed for eco-physiological research and for species conservation or management. Stress can be estimated by quantifying plasma glucocorticoid levels, but when this is not feasible, glucocorticoid metabolites are often measured from feces (FGCM). However, evidence is accumulating on the sensitivity of FGCM measurements to various nuisance factors. Careful species- and context-specific validations are therefore necessary to confirm the biological relevance and specificity of the method. The goals of this study were to: (1) establish and validate sampling methods and an enzymeimmunoassay to measure FGCM in the gray mouse lemur (Microcebus murinus); (2) explore causes of variability in the FGCM measurements, and; (3) assess the consequences of capturing and handling for free-living individuals by quantifying their stress responses via repeated fecal sampling within capture sessions. We further assessed the influence of different handling protocols and the animals' previous capture experience on the magnitude of the physiological response. Our validations identified the group-specific measurement of 11ß-hydroxyetiocholanolone as the most suitable assay for monitoring adrenocortical activity. The sample water content and the animal's age were found to significantly influence baseline FGCM-levels. Most captured animals exhibited a post-capture FGCM-elevation but its magnitude was not related to the handling protocol or capture experience. We found no evidence for long-term consequences of routine capturing on the animals' stress physiology. Hence the described methods can be employed to measure physiological stress in mouse lemurs in an effective and relatively non-invasive way.

Effects of pretransport handling stress on physiological and behavioral response of ostriches.

Ostrich (Struthio camelus) production is a relatively young industry and there has been little research on ostrich welfare during pretransport handling and the transportation process. A heavy body with a high center of gravity makes ostriches' handling and transportation problems different from other livestock. The main objective of this study was to investigate the effects of the pretransport holding time duration on ostrich behavior and physiological responses. A second objective was to identify and validate behavioral indicator(s) that could be used to identify stressed birds during pretransport handling. Prior to shipping, twenty-four 2.5-yr-old ostriches were moved into a holding pen. Birds were then individually restrained, hooded, and walked from the holding pen (approximately 12 min/bird) to a sampling pen (visually isolated from the holding pen) where they were weighed and a 10-mL blood sample obtained. A second blood sample was taken from each bird after a 1,100-km transportation. Blood samples were analyzed for concentrations of blood metabolites, enzymes, corticosterone, and white blood cell and differential counts. Behavioral responses and physical damages of ostriches were also recorded before and after transport. Results indicated that birds that spent longer time in the pretransport holding pen had higher pretransport plasma concentrations of aspartate aminotransferase, alanine aminotransferase, sodium, and packed cell volume. Immobile sitting behavior, observed in 5 out of the last 11 birds handled, was positively correlated with higher pretransport handling stress, higher posttransport aspartate aminotransferase, alanine aminotransferase, creatine phosphokinase, and glucose concentrations, and transport losses. Knowledge of pretransport handling impacts on ostrich stress and availability of behavioral indicators (e.g., immobile sitting response) could be used to improve handing processes, thereby decreasing potential weight loss, injury, and mortality.

Assessing the usability of aromatic mouthwashes in alleviating physiological stress responses.

Background: Mouthwashes play a pivotal role in oral care, and their efficacy has been explored extensively across various dimensions. As a contribution to the development of novel oral care products, this study aims to investigate the psychophysiological effects of aromatic mouthwashes during the resilience period from a short-term cognitive stressor utilizing biological signals and subjective evaluations. Methods: A within-participant experimental design with 22 healthy females was conducted with four mouthwashes; peppermint (Mint), peppermint + bergamot (MB), peppermint + sweet orange (MO), and peppermint + lavender (ML), and water as the control (Ctl), after a 20-min calculation task. Subjective evaluations and physiological responses including skin conductance level and electrocardiogram were recorded throughout the experiment. Results: Citrus mouthwashes (MO and MB) showed a greater decrease in heart rate and a significant increase in the high-frequency component of heart rate variability. The participants indicated a significant effect in terms of "flavor preference" and "refreshing sensation" for mouthwash use compared to the Ctl. Conclusion: The results suggest that rinsing with citrus-flavored mouthwashes has a positive impact in alleviating the physiological stress response (in terms of cardiac activity). These findings may have implications for the development of innovative, novel oral care products that promote stress reduction and improve oral health.

Impact of psychosocial stress on facial emotion recognition in schizophrenia and controls: an experimental study in a forensic sample.

Introduction: Psychotic disorders have been associated with dysregulated stress reactions and adaptation. Little is known about the neuroendocrine responses to psychosocial stress in justice-involved individuals with schizophrenia. Methods: Using an experimental research design, the present study aims to examine differences in the subjective and neuroendocrine responses to psychosocial stress and its impact on facial emotion recognition (FER) and performance on an arithmetic task in chronically ill justice-involved individuals with schizophrenia (PAT) and a healthy control group. PAT undergoing treatment in forensic psychiatric inpatient wards (n = 17) and a healthy control group (n = 17) were assessed regarding sociodemographic and clinical characteristics. Additionally, salivary cortisol levels, measured before and after performing a psychosocial stress task [Montreal Imaging Stress Task (MIST)], and performance on an arithmetic problem-solving task and two FER tasks were recorded. Two participants dropped out, one from each group. Therefore, the final sample consisted of 32 individuals. Results: Significant group differences in FER were recorded. There was a significant rise in subjective perception of momentary strain relating to the induction of psychosocial stress in both groups. Notably, the pre-stress level of subjective strain was higher in the PAT group than controls. Acute psychosocial stress induced an increase in FER performance in a sub-task related to naming emotions in individuals with schizophrenia spectrum disorder. Discussion: The results underline the importance of psychosocial and therapeutic interventions aimed at strengthening stress resilience in individuals with schizophrenia spectrum disorders.

Effects of Stocking Density on the Growth Performance, Physiological Parameters, Antioxidant Status and Lipid Metabolism of Pelteobagrus fulvidraco in the Integrated Rice-Fish Farming System.

Pelteobagrus fulvidraco is a freshwater fish commonly raised in rice fields, yet the optimal stocking density for this species remains unknown. Therefore, this study aimed to investigate the appropriate stocking density of P. fulvidraco in integrated rice-fish farming systems. Three different stocking densities--low density (LD, 125 g/m2), middle density (MD, 187.5 g/m2), and high density (HD, 250 g/m2)--were set up to evaluate P. fulvidraco's growth performance, stress indices, immune function, antioxidant status, and lipid metabolism after 90 days of farming. The results indicated that HD treatment had a detrimental effect on P. fulvidraco's growth parameters. HD treatment led to an increase in cortisol (Cor) and lactate (La) levels, but a decrease in glucose (Glu) content in serum. After 90 days of farming, an immune response accompanied by the increase of complement 3 (C3), C4, and immunoglobulin M (IgM) was observed in the HD group. Meanwhile, HD treatment induced oxidative stress and altered antioxidative status evidenced by the levels of catalase (CAT), glutathione peroxidase (Gpx), glutathione (GSH), malondialdehyde (MDA), superoxide dismutase (SOD), and total antioxidant capacity (T-AOC) in serum or liver. Additionally, the lipid metabolism-related genes including lipoprotein lipase (lpl), peroxisome proliferators-activated receptor (pparα), carnitine palmitoyltransferase-1 (cpt-1), and sterol regulatory element binding protein-1 (srebp-1) were markedly downregulated in the HD and/or MD group after 90 days of farming. In conclusion, this study contributes to a better understanding of P. fulvidraco's response to different stocking densities in integrated rice-fish farming systems. We suggest that the appropriate stocking density for P. fulvidraco in these farming systems should be below 250 g/m2, considering both fish growth and physiological responses.

Effect of Quadratus Lumborum Block on Pain and Stress Response after Video Laparoscopic Surgeries: A Randomized Clinical Trial.

BACKGROUND: There are many surgical and anesthetic factors that affect pain and the endocrine-metabolic response to trauma. The ability of anesthetic agents and neuronal blockade to modify the response to surgical trauma has been widely studied in the last few years. OBJECTIVE: To evaluate if the anterior quadratus lumborum block contributes to improved surgical recovery, using as parameters analgesia, pulmonary function and neuroendocrine response to trauma. METHODS: We carried out a prospective, randomized, controlled, and blinded study, in which 51 patients scheduled for laparoscopic cholecystectomy. Patients were randomly selected and assigned to 2 groups. The control group received balanced general anesthesia and venous analgesia, and the intervention group was treated under general, venous analgesia and anterior quadratus lumborum block. The parameters evaluated were: demographic data, postoperative pain, respiratory muscle pressure and inflammatory response to surgical stress with the plasma dosage of IL-6 (Interleukin 6), CRP (C-Reactive protein) and cortisol. RESULTS: Anterior quadratus lumborum block induced the slowing of IL-6 cytokine production and a decrease in cortisol release. This effect was accompanied by the significant reduction of postoperative pain scores. CONCLUSION: Anterior quadratus lumborum block is an important strategy for analgesia in abdominal laparoscopic surgery and contributes to reducing the inflammatory response to surgical trauma with an early return of preoperative baseline physiological functions.

Genetic Variation, Stress, and Physiological Stress Response in Adults With Food Allergy or Celiac Disease.

BACKGROUND: Persistently high chronic stress can lead to maladaptive psychological, behavioral, and physiological stress responses and poor mental and physical health, highlighting the importance of identifying individuals at increased risk. Chronic health condition diagnosis and genetics are 2 characteristics that can influence stress, stress response, and health outcomes. PURPOSE: Food allergy (FA) and celiac disease (CD) require constant vigilance in daily life and can lead to increased stress. The purpose of this exploratory analysis was to examine the association of variants in selected stress-related genes with stress exposures, stress, clinical measures of physiological stress response, and mental health symptoms in adults with and without FA or CD. METHODS: We compared stress exposures, symptoms of PTSD, depression, anxiety, and stress, BMI, and waist-hip ratio between cases and controls. We analyzed the association of SNPs in genes with known or hypothesized associations with stress-related measures in 124 cases and 124 matched controls: CRHBP (rs7718461, rs10474485), CRHR1 (rs242940) and OXTR (rs2268490). For this exploratory study, p-values ≤ 0.10 were considered suggestive. RESULTS: For cases and controls, rs7718461 was associated with stress symptoms, rs2268490 with symptoms of stress and PTSD, and rs242940 with symptoms of stress, PTSD, anxiety, and depression. Further analyses found that stress-related outcomes in individuals with FA or CD may be influenced by SNP genotype. CONCLUSIONS: Given these suggestive findings, larger prospective studies should examine similar relationships in individuals with other chronic health conditions, incorporating factors such as environmental exposures, individual experiences, and epigenetic modifications.

Erratum: Physiological stress reactivity and recovery: Some laboratory results transfer to daily life.

[This corrects the article DOI: 10.3389/fpsyg.2022.943065.].

Effects of Stocking Density on the Growth Performance, Physiological Parameters, Redox Status and Lipid Metabolism of Micropterus salmoides in Integrated Rice-Fish Farming Systems.

Stocking density has been identified as one of the main factors affecting fish growth, welfare and behavior. However, few studies have focused on the effects of stocking density on fish health in integrated rice-fish farming systems. Thus, the aim of this study was to evaluate the effects of different stocking densities on the growth performance, physiological parameters, redox status and lipid metabolism of Micropterus salmoides in an integrated rice-fish farming system. The fish were reared at three densities: low density (LD, 40 g/m3), medium density (MD, 80 g/m3) and high density (HD, 120 g/m3) for 90 days. At the end of the experiment, fish reared in the MD and HD groups showed lower growth performance than those from the LD group. The HD treatment significantly altered the physiological parameters, including glucose and lactate. Meanwhile, the HD treatment induced oxidative stress and lipid peroxidation after 90 days of farming. Furthermore, transcriptomic analysis revealed that HD treatment led to abnormal lipid metabolism. Interestingly, we found the suppression of three key pathways related to lipid metabolism, including the PPAR, insulin and adipocytokine signaling pathways, in the HD group. Overall, our data indicated that the HD treatment inhibited growth and caused physiological responses, oxidative stress and abnormal hepatic lipid metabolism in M. salmoides in an integrated rice-fish farming system.