RESUMO
Diets rich in taurine can increase the production of taurine-conjugated bile acids, which are known to exert antihypertensive effects. Despite their benefits to the heart, kidney and arteries, their role in the central nervous system during the antihypertensive process remains unclear. Since hypothalamic paraventricular nucleus (PVN) plays a key role in blood pressure regulation, we aimed to investigate the function of bile acids in the PVN. The concentration of bile acids in the PVN of spontaneously hypertensive rats (SHRs) and normotensive Wistar-Kyoto rats (WKY) fed with normal chow was measured using LC-MS/MS, which identified taurocholic acid (TCA) as the most down-regulated bile acid. To fully understand the mechanism of TCA's functions in the PVN, bi-lateral PVN micro-infusion of TCA was carried out. TCA treatment in the PVN led to a significant reduction in the blood pressure of SHRs, with decreased plasma levels of norepinephrine and improved morphology of cardiomyocytes. It also decreased the number of c-fos+ neurons, reduced the inflammatory response, and suppressed oxidative stress in the PVN of the SHRs. Most importantly, the TGR5 receptors in neurons and microglia were activated. PVN infusion of SBI-115, a TGR5 specific antagonist, was able to counteract with TCA in the blood pressure regulation of SHRs. In conclusion, TCA supplementation in the PVN of SHRs can activate TGR5 in neurons and microglia, reduce the inflammatory response and oxidative stress, suppress activated neurons, and attenuate hypertension.
Assuntos
Hipertensão , Núcleo Hipotalâmico Paraventricular , Receptores Acoplados a Proteínas G , Ácido Taurocólico , Animais , Masculino , Ratos , Anti-Hipertensivos/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Hipertensão/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Núcleo Hipotalâmico Paraventricular/metabolismo , Núcleo Hipotalâmico Paraventricular/efeitos dos fármacos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/genéticaRESUMO
The pathogenesis of attention-deficit/hyperactivity disorder (ADHD) has not been fully elucidated. Gestational hypertension could double the probability of ADHD in the offspring, while the initial bacterial communication between the mother and offspring has been associated with psychiatric disorders. Thus, we hypothesize that antihypertensive treatment during pregnancy may abate the impairments in neurodevelopment of the offspring. To test this hypothesis, we chose Captopril and Labetalol, to apply to pregnant spontaneously hypertensive rat (SHR) dams and examined the outcomes in the male offspring. Our data demonstrated that maternal treatment with Captopril and Labetalol had long-lasting changes in gut microbiota and behavioral alterations, including decreased hyperactivity and increased curiosity, spatial learning and memory in the male offspring. Increased diversity and composition were identified, and some ADHD related bacteria were found to have the same change in the gut microbiota of both the dam and offspring after the treatments. LC-MS/MS and immunohistochemistry assays suggested elevated expression of brain derived neurotrophic factor (BDNF) and dopamine in the prefrontal cortex and striatum of offspring exposed to Captopril/ Labetalol, which may account for the improvement of the offspring's psychiatric functions. Therefore, our results support the beneficial long-term effects of the intervention of gestational hypertension in the prevention of ADHD.
Assuntos
Anti-Hipertensivos , Transtorno do Deficit de Atenção com Hiperatividade , Comportamento Animal , Captopril , Microbioma Gastrointestinal , Efeitos Tardios da Exposição Pré-Natal , Ratos Endogâmicos SHR , Animais , Microbioma Gastrointestinal/efeitos dos fármacos , Gravidez , Transtorno do Deficit de Atenção com Hiperatividade/tratamento farmacológico , Transtorno do Deficit de Atenção com Hiperatividade/induzido quimicamente , Feminino , Anti-Hipertensivos/farmacologia , Captopril/farmacologia , Masculino , Ratos , Comportamento Animal/efeitos dos fármacos , Labetalol/farmacologia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Hipertensão Induzida pela Gravidez/induzido quimicamente , Dopamina/metabolismoRESUMO
BACKGROUND: Yinhua Miyanling tablets (YMT), comprising 10 Chinese medicinal compounds, is a proprietary Chinese medicine used in the clinical treatment of urinary tract infections. Medicinal compounds, extracts, or certain monomeric components in YMT all show good effect on ulcerative colitis (UC). However, no evidence supporting YMT as a whole prescription for UC treatment is available. PURPOSE: To evaluate the anti-UC activity of YMT and elucidate the underlying mechanisms. The objective of the study was to provide evidence for the add-on development of YMT to treat UC. METHODS: First, YMT's protective effect on the intestinal barrier was evaluated using a lipopolysaccharide (LPS)-induced Caco-2 intestinal injury model. Second, the UC mouse model was established using dextran sodium sulfate (DSS) to determine YMT's influence on symptoms, inflammatory factors, intestinal barrier, and histopathological changes in the colon. Third, an integrated method combining metabolomics and network pharmacology was employed to screen core targets and key metabolic pathways with crucial roles in YMT's therapeutic effect on UC. Molecular docking was employed to identify the key targets with high affinity. Finally, western blotting was performed to validate the mechanism of YMT action against UC. RESULTS: YMT enhanced the transepithelial electrical resistance value and improved the expression of proteins of the tight junctions dose-dependently in LPS-induced Caco-2 cells. UC mice treated with YMT exhibited alleviated pathological lesions of the colon tissue in the in vivo pharmacodynamic experiments. The colonic lengths tended to be normal, and the levels of inflammatory factors (TNF-α, IL-6, and iNOS) along with those of the core enzymes (MPO, MDA, and SOD) improved. YMT effectively ameliorated DSS-induced colonic mucosal injury; pathological changes along with ultrastructure damage were significantly alleviated (evidenced by a relatively intact colon tissue, recovery of epithelial damage, repaired gland, reduced infiltration of inflammatory cells and epithelial cells arranged closely with dense microvilli). Seven key targets (IL-6, TNF-α, MPO, COX-2, HK2, TPH, and CYP1A2) and four key metabolic pathways (arachidonic acid metabolism, linoleate metabolism, glycolysis, and gluconeogenesis and tyrosine biosynthesis) were identified to play vital roles in the treatment on UC using YMT. CONCLUSIONS: YMT exerts beneficial therapeutic effects on UC by regulating multiple endogenous metabolites, targets, and metabolic pathways, suggestive of its potential novel application in UC treatment.
Assuntos
Colite Ulcerativa , Sulfato de Dextrana , Modelos Animais de Doenças , Medicamentos de Ervas Chinesas , Metabolômica , Farmacologia em Rede , Animais , Colite Ulcerativa/tratamento farmacológico , Colite Ulcerativa/induzido quimicamente , Humanos , Células CACO-2 , Medicamentos de Ervas Chinesas/farmacologia , Masculino , Camundongos , Colo/efeitos dos fármacos , Colo/metabolismo , Colo/patologia , Comprimidos , Lipopolissacarídeos , Simulação de Acoplamento Molecular , Camundongos Endogâmicos C57BLRESUMO
The purpose of this study was to explore the therapeutic effect of the oral administration of pseudo-ginsenoside RT4 (RT4) on ulcerative colitis (UC), and to determine the rate of absorption and distribution of RT4 in mice with UC. Balb/c mice were induced using dextran sulfate sodium salts (DSS) to establish the UC model, and 10, 20, or 40 mg/kg of RT4 was subsequently administered via gavage. The clinical symptoms, inflammatory response, intestinal barrier, content of total short-chain fatty acids (SCFAs), and gut microbiota were investigated. Caco-2 cells were induced to establish the epithelial barrier damage model using LPS, and an intervention was performed using 4, 8, and 16 µg/mL of RT4. The inflammatory factors, transient electrical resistance (TEER), and tight-junction protein expression were determined. Finally, pharmacokinetic and tissue distribution studies following the intragastric administration of RT4 in UC mice were performed. According to the results in mice, RT4 decreased the disease activity index (DAI) score, restored the colon length, reduced the levels of pro-inflammatory cytokines (TNF-α, IL-6, and IL-1ß), and boosted the levels of immunosuppressive cytokine IL-10, increased the content of SCFAs, improved the colonic histopathology, maintained the ultrastructure of colonic mucosal epithelial cells, and corrected disturbances in the intestinal microbiota. Based on the results in caco-2 cells, RT4 reduced the levels of TNF-α, IL-6, and IL-1ß; protected integrity of monolayers; and increased tight-junction protein expression. Additionally, the main pharmacokinetic parameters (Cmax, Tmax, t1/2, Vd, CL, AUC) were obtained, the absolute bioavailability was calculated as 18.90% ± 2.70%, and the main distribution tissues were the small intestine and colon. In conclusion, RT4, with the features of slow elimination and directional distribution, could alleviate UC by inhibiting inflammatory factors, repairing the intestinal mucosal barrier, boosting the dominant intestinal microflora, and modulating the expression of SCFAs.
Assuntos
Colite Ulcerativa , Microbioma Gastrointestinal , Ginsenosídeos , Animais , Camundongos , Humanos , Distribuição Tecidual , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/tratamento farmacológico , Células CACO-2 , Interleucina-6 , Fator de Necrose Tumoral alfa , Citocinas , Interleucina-1beta , Camundongos Endogâmicos BALB CRESUMO
BACKGROUND: (-)-Syringaresinol (SYR), a natural lignan with significant antioxidant and anti-inflammatory activities, possesses various pharmacological benefits including cardio-protective, antibacterial, anticancer, and anti-aging effects. It was shown that the effectiveness of (+)-syringaresinol diglucoside on the ulcerative colitis (UC) was attributed to the active metabolite (+)-syringaresinol (the enantiomor of SYR). However, the efficacy of SYR against UC remains unclear, and the associated molecular mechanism has not been revealed yet PURPOSE: This study aimed to assess the protective effect of SYR in UC and its underlying mechanism STUDY DESIGN AND METHODS: We examined SYR's protective impact on the intestinal epithelial barrier and its ability to inhibit inflammatory responses in both a lipopolysaccharide (LPS)-induced Caco-2 cell model and a dextran sodium sulfate (DSS)-induced UC mouse model. We also explored the potential signaling pathways regulated by SYR using transcriptome analysis and western blot assay RESULTS: In Caco-2 cells, SYR significantly increased trans-epithelial electrical resistance, reduced tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interferon-γ (IFN-γ), and cyclooxygenase-2 (COX-2) levels, and enhanced cellular tight junction protein expression and distribution. In mice with UC, oral treatment with SYR (10, 20, 40 mg·kg-1) dose-dependently increased body weight, colon length, and expression of tight junction proteins, decreased disease activity index score, spleen coefficient, cytokine serum levels, bacterial translocation, and intestinal damage, and also preserved the ultrastructure of colonic mucosal cells. Transcriptomics indicated that the anti-UC effect of SYR is mediated via the PI3K-Akt/MAPK/Wnt signaling pathway. CONCLUSION: In summary, SYR effectively mitigated the development of UC by enhancing the intestinal epithelial barrier function and attenuating the inflammatory response. The plant-derived product SYR might be a potentially effective therapeutical agent against UC.
Assuntos
Colite Ulcerativa , Colite , Furanos , Lignanas , Humanos , Animais , Camundongos , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/tratamento farmacológico , Colite Ulcerativa/metabolismo , Células CACO-2 , Fosfatidilinositol 3-Quinases/metabolismo , Colo/patologia , Lignanas/farmacologia , Lignanas/uso terapêutico , Mucosa Intestinal/metabolismo , Modelos Animais de Doenças , Sulfato de Dextrana/efeitos adversos , Camundongos Endogâmicos C57BL , Colite/induzido quimicamenteRESUMO
OBJECTIVE: To evaluate the efficacy and safety of oral traditional Chinese medicine combined with conventional anti-osteoporosis drugs in the treatment of osteoporosis and fractures. METHODS: The database of China national knowledge infrastructure, China Science and Technology Journal Database, Wangfang (WANGFANG DATA), ChineseBioMedicalLiteratureDatabase, PubMed, Embase, and Cochrane Library databases were searched from inception to June 1st, 2023 for randomized controlled trials on oral Chinese medicine combined with conventional anti-osteoporosis drugs for the treatment of osteoporosis and fractures. Quality assessment was performed using the Cochrane Handbook for Systematic Reviews of Interventions version 5.1.0. STATA 15.0 software was used for meta-analysis. Outcome measures included overall response rate, adverse events, T-score, bone mineral density, Oswestry Disability Index score, fracture healing time, and visual analog scale score. RESULTS: A total of 72 studies were included, involving 7847 participants. Different treatment options showed different advantages in the adjuvant treatment of osteoporosis and fractures. The total response rate, complication reduction, Oswestry Disability Index and visual analog scale score reduction, bone mineral density improvement and fracture healing time were all superior to drug therapy alone. The differences were statistically significant, but the improvement in T-score was not significant. CONCLUSION: The combination of oral traditional Chinese medicine and conventional anti-osteoporosis drugs is more effective and safer than Western medicine alone in the treatment of osteoporosis and fractures, which indicated that the treatment of integrated Chinese and western medicine can promote the healing of osteoporosis and fracture. This approach had a promising clinical application prospect. Due to the limitations of included studies, the ranking results should be interpreted with caution. In the next step, we will further conduct subgroup data based on factors, such as conventional Western medicine treatment regimens, whether surgical treatment was performed, fracture locations.
Assuntos
Medicamentos de Ervas Chinesas , Fraturas Ósseas , Osteoporose , Humanos , Medicina Tradicional Chinesa/métodos , Ensaios Clínicos Controlados Aleatórios como Assunto , Revisões Sistemáticas como Assunto , Osteoporose/complicações , Osteoporose/tratamento farmacológico , Fraturas Ósseas/tratamento farmacológico , Medicamentos de Ervas Chinesas/efeitos adversosRESUMO
PURPOSE: Postoperative limb length discrepancy (LLD) is a common complication of total hip arthroplasty, and several methods exist to prevent LLD, but each has its benefits and drawbacks. The study investigates the application of intraoperative lower limb length measurement in preventing postoperative LLD. METHODS: This study retrospectively analyzed 70 patients who underwent total hip arthroplasty from October 2018 to July 2022. The length of the lower limb on the operated side was measured intraoperatively using a sterilized paper ruler after the fitting of the trial mould and compared with the healthy side. Then the prosthesis size, depth and neck length were adjusted accordingly. RESULTS: The absolute value of postoperative LLD was found to be 6.68 ± 4.48 mm, of which 53 cases (75.7%) were less than or equal to 10 mm, while 30 patients (42.9%) were less than or equal to 5 mm. CONCLUSION: The use of intraoperative measurement is effective in reducing LLD after total hip arthroplasty.
Assuntos
Artroplastia de Quadril , Humanos , Artroplastia de Quadril/efeitos adversos , Artroplastia de Quadril/métodos , Estudos Retrospectivos , Desigualdade de Membros Inferiores/etiologia , Desigualdade de Membros Inferiores/prevenção & controle , Desigualdade de Membros Inferiores/cirurgia , Extremidade Inferior/cirurgia , Período Pós-OperatórioRESUMO
BACKGROUND: Saussurea pulchella (SP) is a traditional medicinal plant that is widely used in folk medicine because of its diverse biological activities, particularly its anti-inflammatory effects. However, the alleviation effect of SP on ulcerative colitis (UC) has not yet been realized. PURPOSE: To investigate the chemical composition and therapeutic effect of SP extract against UC. METHODS: First, qualitative and quantitative analysis of SP 75% ethanol extract was performed by UPLC-Q/TOF-MS. Second, a dextran sodium sulfate (DSS) model of UC mice was developed to study the effects of SP on the symptoms, inflammatory factors, oxidative stress indexes and colon histopathology. Third, an integration of network pharmacology with metabolomics was performed to investigate the key metabolites, biological targets and metabolisms closely related to the effect of SP. RESULTS: From the SP ethanol extract, 149 compounds were identified qualitatively and 20 were determined quantitatively. The SP could dose-dependently decrease the DAI score, spleen coefficient and the levels of TNF-α, IL-6, iNOS, MPO and MDA; increase the colon length, GSH level and SOD activity; and protect the intestinal barrier in the UC mice. Moreover, 10 metabolite biomarkers,18 targets and 5 metabolisms were found to play crucial roles in the treatment of UC with SP. CONCLUSIONS: SP 75% ethanol extract could effectively alleviate the progression of UC and, therefore, could be classified as a novel natural treatment for UC.
Assuntos
Colite Ulcerativa , Saussurea , Fator de Necrose Tumoral alfa , Animais , Camundongos , Colite Ulcerativa/tratamento farmacológico , Colo/metabolismo , Sulfato de Dextrana , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL , Estresse Oxidativo , Saussurea/química , Fator de Necrose Tumoral alfa/metabolismo , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Compostos Fitoquímicos/químicaRESUMO
OBJECTIVE: Cervical fractures with ankylosing spondylitis (CAS) are a specific type of spinal fracture with poor stability, low healing rate, and high disability rate. Its treatment is mainly surgical, predominantly through the anterior approach, posterior approach, and the anterior-posterior approach. Although many clinical studies have been conducted on various surgical approaches, controversy still exists concerning the choice of these surgical approaches by surgeons. The authors present here a systematic evaluation and meta-analysis exploring the utility of the anterior-posterior approach versus the anterior approach and the posterior approach. METHODS: After a comprehensive literature search of PubMed, Cochrane, Web of Science, and Embase databases, 12 clinical studies were included in the final qualitative analysis and 8 in the final quantitative analysis. Of these studies, 11 conducted a comparison between the anterior-posterior approach and the anterior approach and posterior approaches, while one examined only the anterior-posterior approach. Where appropriate, statistical advantage ratios and 95% confidence intervals were calculated. RESULTS: The present meta-analysis of postoperative neurological improvement showed no statistical difference in the overall neurological improvement rate between the anterior-posterior approach and anterior approach (OR 1.70, 95% CI 0.61 to 4.75; p = 0.31). However, the mean change in postoperative neurological function was lower in patients who received the anterior approach than in those who received the anterior-posterior approach (MD 0.17, 95% CI -0.02 to 0.36; p = 0.08). There was an identical trend between the anterior-posterior approach and posterior approach, with no statistically significant difference in the overall rate of neurological improvement (OR 1.37, 95% CI 0.70 to 2.56; p = 0.38). Nevertheless, the mean change in neurological function was smaller in patients receiving the anterior-posterior approach compared with the posterior approach, but there was no statistically significant difference between the two (MD 0.17, 95% CI -0.02 to 0.36; p = 0.08). CONCLUSIONS: The results of this review and meta-analysis suggest that the benefits of the anterior-posterior approach are different from those of the anterior and posterior approaches in the treatment of ankylosing spondylitis-related cervical fractures. In a word, there is no significant difference between the cervical surgical approach and the neurological functional improvement. Therefore, surgeons should pay more attention to the type of cervical fracture, the displacement degree of cervical fracture, the spinal cord injury, the balance of cervical spine and other aspects to comprehensively consider the selection of appropriate surgical methods.
Assuntos
Lesões do Pescoço , Traumatismos da Medula Espinal , Fraturas da Coluna Vertebral , Espondilite Anquilosante , Humanos , Fraturas da Coluna Vertebral/cirurgia , Espondilite Anquilosante/complicações , Espondilite Anquilosante/cirurgia , Vértebras Cervicais/cirurgia , Vértebras Cervicais/lesões , Pescoço , Resultado do TratamentoRESUMO
Gut microbiota is well-established to regulate host blood pressure. Diosgenin is a natural steroid sapogenin with documented anti-inflammatory, antioxidant and antihypertensive properties. We aimed to investigate whether the antihypertensive effects of diosgenin are mediated by the microbiota-gut-brain axis in spontaneously hypertensive rats (SHR). 15-Week-old male Wistar Kyoto rats (WKY) and age-matched SHR were randomly distributed into three groups: WKY, SHR treated with a vehicle, and SHR treated with diosgenin (100 mg kg-1). Our results showed that diosgenin prevented elevated systolic blood pressure (SBP) and ameliorated cardiac hypertrophy in SHR. Moreover, the gut microbiota composition and intestinal integrity were improved. Furthermore, increased butyrate-producing bacteria and plasma butyrate and decreased plasma lipopolysaccharides were observed in SHR treated with diosgenin. These findings were associated with reduced microglial activation and neuroinflammation in the paraventricular nucleus. Our findings suggest that diosgenin attenuates hypertension by reshaping the gut microbiota and improving the gut-brain axis.
Assuntos
Diosgenina , Hipertensão , Sapogeninas , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Anti-Hipertensivos/farmacologia , Anti-Hipertensivos/uso terapêutico , Antioxidantes/farmacologia , Pressão Sanguínea , Encéfalo , Butiratos , Diosgenina/farmacologia , Masculino , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Sapogeninas/farmacologiaRESUMO
OBJECTIVE: We investigated scoliosis incidence among junior high school students in Zhongshan city, Guangdong, China and the expression of miR-30e among those with scoliosis. METHODS: A total 41,258 students were included. From July 2015 to December 2017, all students underwent screening including routine observation of the standing and sitting posture, Adam's forward bend test, dorsal tilt angle measurement, and X-ray examination. Age, sex, height, weight, and body mass index (BMI) were recorded. Reverse transcription-quantitative polymerase chain reaction was used to assess miR-30e expression among students with scoliosis and 200 healthy students. RESULTS: Overall, 743 students were diagnosed with scoliosis, with an incidence rate of 1.80%. A total 646 (86.9%) students were diagnosed with idiopathic scoliosis, 38 (5.1%) with congenital scoliosis, and 59 (7.9%) with other scoliosis types. Compared with healthy students, height was significantly greater whereas weight and BMI were significantly lower among students with scoliosis, and expression of miR-30e was significantly lower. However, no significant difference was found in height, weight, BMI, and mean Cobb angle between high/low miR-30e groups. CONCLUSION: The incidence rate for scoliosis was 1.80%, Compared with healthy students, those with scoliosis were taller, had lower weight and BMI, and miR-30e expression was significantly downregulated.
Assuntos
MicroRNAs/genética , Escoliose/epidemiologia , Escoliose/genética , Adolescente , Antropometria/métodos , Índice de Massa Corporal , Criança , China/epidemiologia , Feminino , Humanos , Incidência , Masculino , Programas de Rastreamento , MicroRNAs/metabolismo , Postura/fisiologia , Radiografia , Instituições Acadêmicas , EstudantesRESUMO
Background. To explore influence of continuous illumination, luzindole, and Tamoxifen on incidence of scoliosis model of rats. Methods. Thirty-two one-month-old female rats were rendered into bipedal rats. The bipedal rats were divided into 4 groups: group A by intraperitoneal injection of luzindole and continuous illumination; group B by intraperitoneal injection of luzindole only; group C by intraperitoneal injection of luzindole and oral administration of Tamoxifen; and group D by intraperitoneal injection of equivalent saline. Radiographs were taken at 8th week and 16th week, and incidence and the Cobb angles of scoliosis were calculated. At 16th week, all rats were sacrificed. Before the sacrifice, the levels of calmodulin were measured in each group. Results. At 8th week, scoliosis occurred in groups A and B, with an incidence of 75% and 12.5%, respectively, while rats in group C or D had no scoliosis. At 16th week, scoliosis incidences in groups A and B were 57% and 62.5%, respectively. No scoliosis occurred in group C or D. Calmodulin in platelets in group B was significantly different, compared with groups A and D. There was no significant difference in calmodulin in platelets in groups B and C. Conclusion. By intraperitoneal injection of luzindole in bipedal rats, scoliosis rat models could be successfully made. Under light, incidence of scoliosis may be increased at an early period but it is reversible. Tamoxifen can suppress natural process of scoliosis.
Assuntos
Calmodulina/metabolismo , Escoliose/tratamento farmacológico , Tamoxifeno/administração & dosagem , Triptaminas/administração & dosagem , Animais , Modelos Animais de Doenças , Feminino , Humanos , Iluminação/efeitos adversos , Melatonina/metabolismo , Ratos , Escoliose/induzido quimicamente , Escoliose/diagnóstico por imagem , Escoliose/fisiopatologia , Triptaminas/efeitos adversosRESUMO
In free-living animals, it has been well demonstrated that the intensity of the adrenocortical response to acute restraint stress can vary with reproductive investment during breeding. The parental care hypothesis posits that the stress response is negatively correlated with parental investment in avian species. To further test this hypothesis, we examined changes in both free and total corticosterone (CORT) at baseline and stress-induced levels (maximal CORT) and corticosteroid-binding globulin (CBG) capacities, in both sexes of a multi-brooded Eurasian tree sparrows (Passer montanus), during the nest building, the early nestling, the later egg-laying, and the later nestling stages. Our results showed Eurasian tree sparrows did not exhibit any differences between sexes in CORT and CBG levels during the egg-laying or nestling stages. Both sexes had lowered CBG capacities and females exhibited lower maximal CORT during the early compared to later nestling stages. In addition, both sexes had lower maximal free CORT levels during the nest building stage than those of the early nestling stages, and males expressed higher total maximal CORT levels than females during nest building stage. The variation in CORT response and CBG levels during different breeding sub-stages in Eurasian tree sparrow may correlate with their energetic situations and parental investments. J. Exp. Zool. 325A:75-83, 2016. © 2015 Wiley Periodicals, Inc.
Assuntos
Corticosterona/metabolismo , Seleção Genética , Pardais/fisiologia , Transcortina/genética , Animais , Feminino , Masculino , Muda/fisiologia , Reprodução , Estações do Ano , Pardais/genética , Estresse Fisiológico , Transcortina/metabolismoRESUMO
Previous studies indicate most free-living avian species in both extreme and temperate environments seasonally modulate the adrenocortical responses to acute stress, and those breeding in harsh environments always express reduced adrenocortical responses, which may allow them to obtain maximal reproductive success. However, recent investigations showing a human commensal species, house sparrows (Passer domesticus), expressed similar corticosterone (CORT) responses in both benign and harsh environments. In this study, focusing on another human commensal species, Eurasian tree sparrows (P. montanus), we examined the adrenocortical response to acute stress in lowland populations, among the early and late breeding, the prebasic molt, and the wintering stages, and compared them with previously published data from populations on the Tibetan Plateau. Our results show: (1) similar to highland Eurasian tree sparrows, lowland populations show no differences in baseline CORT levels among life history stages, and the stress-induced CORT (maximal CORT, total and corrected integrated CORT) levels are lower during the early breeding and the prebasic molt stages than those in the late breeding and the wintering stages; (2) highland Eurasian tree sparrows show stronger adrenocortical responses during the prebasic molt stage than lowland populations, whereas there are no differences between the early and the breeding stages (except for maximal CORT). Our results suggest that Eurasian tree sparrows from both harsh and benign environments have similar patterns of adrenocortical responses in the breeding stage, whereas they are different in the prebasic molt stage. In highland birds, the increased maximal CORT levels during the late breeding and the small increases in adrenocortical responses during the prebasic molt are interesting but remain unexplained.