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1.
J Fungi (Basel) ; 10(2)2024 Feb 18.
Article in English | MEDLINE | ID: mdl-38392831

ABSTRACT

Chromoblastomycosis (CBM) and phaeohyphomycosis (FEO) are infections caused by melanized filamentous fungal agents, primarily found in tropical and subtropical regions. Both infections pose significant challenges for the correct identification of the causative agent due to their morphological similarity, making conventional methods of morphological analysis highly subjective. Therefore, molecular techniques are necessary for the precise determination of these species. In this regard, this study aimed to contribute to a new methodology based on PCR-RFLP for the identification of agents causing CBM and FEO. Sequences from the Internal Transcribed Spacer (ITS) region were used to identify potential restriction enzyme sites in silico, followed by in vitro validation using the selected restriction enzymes. The obtained results were compared with species identification through morphological analyses and sequencing. The results demonstrated that the PCR-RFLP applied in this study accurately identified two major agents of chromoblastomycosis, Fonsecaea pedrosoi and Fonsecaea monophora, as well as Cladophialophora bantiana and Exophiala dermatitidis, both causative agents of phaeohyphomycosis. In this context, the proposed assay can complement current methods for identifying these species, aiding in diagnosis, and contributing to the proper management of these infections.

2.
Tissue Cell ; 85: 102245, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37856937

ABSTRACT

Molossus molossus is an insectivorous molossid bat that is important in the control of nocturnal insects. It is the nominal and the most representative species of the family. However, there are few studies about its reproduction. Thus, this study aimed to evaluate variations of its female reproductive organs during the different reproductive phases. Twenty adult females, divided into four sample groups (non-reproductive, early and advanced pregnancy and lactation), were submitted to morphological and morphometric analyses. Results show that the female reproductive system of M. molossus is composed of ovaries, a short bicornuate uterus, slightly convoluted uterine tubes and vagina. The system presents a distinct morphofunctional asymmetry, with a marked dextro-dominance. The right ovaries of all analyzed groups (NON, P1, P2, and LAC) showed follicles at different stages of development, a large number of interstitial glands and a small, but persistent corpus luteum. Ovulation is simple, unilateral and preferential, occurring exclusively in the right ovary. Follicular development in the left ovary usually does not pass the secondary stage. Implantation is fundic and preferential, occurring exclusively in the right uterine horn. The placenta is formed with two distinct chorioallantoic portions, one diffuse endotheliochorial, which covers the entire uterine cavity and regresses in the final stages of pregnancy, and the principal discoidal hemochorial portion, formed in the implantation site. The uterine cervix presents a pseudostratified epithelium, while the vagina has a little keratinized stratified epithelium, which does not accentually vary in the different reproductive stages, but can disrupt and shed in some cases.


Subject(s)
Chiroptera , Pregnancy , Animals , Female , Chiroptera/anatomy & histology , Uterus , Reproduction/physiology , Placenta , Vagina
3.
Eur J Appl Physiol ; 121(8): 2323-2336, 2021 Aug.
Article in English | MEDLINE | ID: mdl-33988746

ABSTRACT

PURPOSE: To investigate within the one study potential molecular and cellular changes associated with mitochondrial biogenesis following 15 days of exposure to moderate hypoxia. METHODS: Eight males underwent a muscle biopsy before and after 15 days of hypoxia exposure (FiO2 = 0.140-0.154; ~ 2500-3200 m) in a hypoxic hotel. Mitochondrial respiration, citrate synthase (CS) activity, and the content of genes and proteins associated with mitochondrial biogenesis were investigated. RESULTS: Our main findings were the absence of significant changes in the mean values of CS activity, mitochondrial respiration in permeabilised fibers, or the content of genes and proteins associated with mitochondrial biogenesis, after 15 days of moderate normobaric hypoxia. CONCLUSION: Our data provide evidence that 15 days of moderate normobaric hypoxia have negligible influence on skeletal muscle mitochondrial content and function, or genes and proteins content associated with mitochondrial biogenesis, in young recreationally active males. However, the increase in mitochondrial protease LON content after hypoxia exposure suggests the possibility of adaptations to optimise respiratory chain function under conditions of reduced O2 availability.


Subject(s)
Hypoxia/physiopathology , Mitochondria, Muscle/metabolism , Mitochondrial Proteins/metabolism , Muscle, Skeletal/metabolism , Organelle Biogenesis , RNA, Messenger , Biopsy , Citrate (si)-Synthase/metabolism , Exercise Test , Humans , Male , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/metabolism , RNA, Messenger/metabolism , Transcription Factors/metabolism , Young Adult
4.
Acta Histochem ; 123(3): 151697, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33662820

ABSTRACT

Responsible for post-testicular maturation, concentration, protection and sperm storage, the epididymis is an organ that can be easily subdivided into three segments: caput, corpus and cauda. Each epididymal region displays different morphology and functions within the sperm maturation process. Despite the great importance of this organ, studies on its morphology and hormonal control in bats remain scarce. Thus, the aim of this study was to morphologically analyze the epididymis of the bat Molossus molossus (Chiroptera: Molossidae), in order to evaluate its morphological and morphometric variations, as well as some aspects of its hormonal control during the annual reproductive cycle. For this purpose, 60 sexually adult males were used in this study, comprising five specimens collected monthly for one year to form 12 sample groups. The epididymis was subjected to morphological, morphometric and immunohistochemical analyses. The results demonstrated that the processes of total testicular regression and posterior recrudescence suffered by M. molossus also impacts the physiology of the epididymis, however, a delay in the epididymal response is seen due to the storage of sperm. Similar to other mammals, the epididymis of M. molossus has a large predominance of principal and basal cells. The epididymal seasonal variations appear to be directly correlated to rainfall and photoperiod, but not to temperature. Meanwhile, epididymal physiology appears to be regulated, at least partially, by the expression of the androgen receptor in epithelial cells, which has agonist effects on cell proliferation.


Subject(s)
Chiroptera/metabolism , Epididymis/metabolism , Sperm Maturation/physiology , Spermatozoa/cytology , Animals , Gonadal Dysgenesis, 46,XY/physiopathology , Male , Receptors, Androgen/metabolism , Reproduction/physiology , Seasons , Spermatogenesis/physiology , Testis/abnormalities , Testis/physiopathology
5.
Theriogenology ; 158: 297-308, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33007715

ABSTRACT

Bats are mammals that play a fundamental role in the regulation of the ecosystems by, for example, controlling the insect populations. Therefore, insectivorous species, such as Molossusmolossus, have become the target of great scientific interest. Despite the different studies that exist on the species, there is still no consensus regarding its reproduction. Thus, this study aimed to analyze the morphophysiology and some aspects of the hormonal control of the testes of M. molossus (Chiroptera: Molossidae), by evaluating its morphological and morphometric variations throughout the annual reproductive cycle. Sixty sexually adult males of M. molossus were used in the study, with five specimens collected each month for one year, forming 12 sample groups. The testes of each bat were submitted to morphological, morphometric, and immunohistochemical analyses. Molossusmolossus presented an annual reproductive cycle with two peaks of spermatogenic activity, one in April and the other in September, and a period of total testicular regression in December, which has never been described. The cycle appeared to be regulated by rainfall and was, at least partially, controlled by the expression of the androgen receptor in Sertoli cells, which has agonist effects on cell proliferation.


Subject(s)
Chiroptera , Testis , Animals , Ecosystem , Male , Reproduction , Seasons
6.
Am J Physiol Endocrinol Metab ; 318(2): E224-E236, 2020 02 01.
Article in English | MEDLINE | ID: mdl-31794264

ABSTRACT

Exercise-induced increases in peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) and p53 protein content in the nucleus mediate the initial phase of exercise-induced mitochondrial biogenesis. Here, we investigated whether exercise-induced increases in these and other markers of mitochondrial biogenesis were altered after 40 sessions of twice-daily high-volume, high-intensity interval training (HVT) in human skeletal muscle. Vastus lateralis muscle biopsies were collected from 10 healthy recreationally active participants before, immediately postexercise, and 3 h after a session of high-intensity interval exercise (HIIE) performed at the same absolute exercise intensity before and after HVT (pre-HVT and post-HVT, respectively). The protein content of common markers of exercise-induced mitochondrial biogenesis was assessed in nuclear- and cytosolic-enriched fractions by immunoblotting; mRNA contents of key transcription factors and mitochondrial genes were assessed by qPCR. Despite exercise-induced increases in PGC-1α, p53, and plant homeodomain finger-containing protein 20 (PHF20) protein content, the phosphorylation of p53 and acetyl-CoA carboxylase (p-p53 Ser15 and p-ACC Ser79, respectively), and PGC-1α mRNA Pre-HVT, no significant changes were observed post-HVT. Forty sessions of twice-daily high-intensity interval training blunted all of the measured exercise-induced molecular events associated with mitochondrial biogenesis that were observed pre-HVT. Future studies should determine whether this loss relates to the decrease in relative exercise intensity, habituation to the same exercise stimulus, or a combination of both.


Subject(s)
Cell Nucleus/metabolism , DNA-Binding Proteins/metabolism , Exercise/physiology , High-Intensity Interval Training , Muscle, Skeletal/metabolism , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/metabolism , Acetyl-CoA Carboxylase/metabolism , Cytosol/metabolism , Exercise Test , Gene Expression/genetics , Humans , Male , Mitochondria, Muscle/genetics , Mitochondria, Muscle/metabolism , Organelle Biogenesis , RNA, Messenger/biosynthesis , Young Adult
7.
J Ethnobiol Ethnomed ; 14(1): 49, 2018 Jul 20.
Article in English | MEDLINE | ID: mdl-30029663

ABSTRACT

BACKGROUND: This study aimed to investigate the local botanical knowledge of native food plants in three rural communities, located in the semiarid region of Paraíba State, Brazil, verifying possibilities of differences of knowledge among communities and between men and women. METHODS: Semi-structured interviews about native plant knowledge and use were conducted with all householders in each community, totaling 117 informants. The species similarity among the communities of Pau D'Arco, Várzea Alegre, and Barroquinha was compared with Jaccard index, and the use value index (UVgeneral, UVcurrent, UVpotential) was used to determine the most important species. The Kruskal-Wallis test was used to compare the use values among communities and genders. The consensus factor among the informants was calculated according to the uses cited, and the Wilcoxon test was used to compare the use values between men and women. RESULTS: We recorded 9 species belonging to 8 genera and 8 families in Várzea Alegre; 10 species, 9 genera, and 9 families in Barroquinha; and 7 species, 7 genera and 7 families in Pau D'Arco. Spondias tuberosa Arruda (Anacardiaceae) in Várzea Alegre, Spondias sp. (Anacardiaceae) in Barroquinha, and Ximenia americana L. (Olacaceae) in Pau D'Arco were the most prominent species. Preparation methods are slightly different in the three communities, and there is low similarity about species use among the communities. Regarding gender, the analysis of use value among the communities evidenced significant differences only for UVgeneral among women, specifically between Barroquinha and Pau D'Arco. For men and women within each community, there is a difference only for UVpotential in Barroquinha. CONCLUSION: This study showed that the residents of the three rural communities have limited knowledge of native food plants found in their communities, but they know where to find them, which parts they may use and how to consume them. The fact is that men know plants that are more distant from the residences and women know those that are next to them.


Subject(s)
Ethnobotany , Knowledge , Plants, Edible , Brazil , Female , Humans , Male
8.
Sci Rep ; 7: 44227, 2017 03 10.
Article in English | MEDLINE | ID: mdl-28281651

ABSTRACT

Sprint interval training has been reported to induce similar or greater mitochondrial adaptations to continuous training. However, there is limited knowledge about the effects of different exercise types on the early molecular events regulating mitochondrial biogenesis. Therefore, we compared the effects of continuous and sprint interval exercise on key regulatory proteins linked to mitochondrial biogenesis in subcellular fractions of human skeletal muscle. Nineteen men, performed either 24 min of moderate-intensity continuous cycling at 63% of WPeak (CE), or 4 × 30-s "all-out" cycling sprints (SIE). Muscle samples (vastus lateralis) were collected pre-, immediately (+0 h) and 3 (+3 h) hours post-exercise. Nuclear p53 and PHF20 protein content increased at +0 h, with no difference between groups. Nuclear p53 phosphorylation and PGC-1α protein content increased at +0 h after SIE, but not CE. We demonstrate an exercise-induced increase in nuclear p53 protein content, an event that may relate to greater p53 stability - as also suggested by increased PHF20 protein content. Increased nuclear p53 phosphorylation and PGC-1α protein content immediately following SIE but not CE suggests these may represent important early molecular events in the exercise-induced response to exercise, and that SIE is a time-efficient and possibly superior option than CE to promote these adaptations.


Subject(s)
Cell Nucleus/metabolism , High-Intensity Interval Training , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/metabolism , Quadriceps Muscle/metabolism , Tumor Suppressor Protein p53/metabolism , Adolescent , Humans , Male , Phosphorylation/physiology
9.
FASEB J ; 30(10): 3413-3423, 2016 10.
Article in English | MEDLINE | ID: mdl-27402675

ABSTRACT

Increased mitochondrial content and respiration have both been reported after exercise training. However, no study has directly compared how different training volumes influence mitochondrial respiration and markers of mitochondrial biogenesis. Ten healthy men performed high-intensity interval cycling during 3 consecutive training phases; 4 wk of normal-volume training (NVT; 3/wk), followed by 20 d of high-volume training (HVT; 2/d) and 2 wk of reduced-volume training (RVT; 5 sessions). Resting biopsy samples (vastus lateralis) were obtained at baseline and after each phase. No mitochondrial parameter changed after NVT. After HVT, mitochondrial respiration and citrate synthase activity (∼40-50%), as well as the protein content of electron transport system (ETS) subunits (∼10-40%), and that of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), NRF1, mitochondrial transcription factor A (TFAM), PHF20, and p53 (∼65-170%) all increased compared to baseline; mitochondrial specific respiration remained unchanged. After RVT, all the mitochondrial parameters measured except citrate synthase activity (∼36% above initial) were not significantly different compared to baseline (all P > 0.05). Our findings demonstrate that training volume is an important determinant of training-induced mitochondrial adaptations and highlight the rapid reversibility of human skeletal muscle to a reduction in training volume.-Granata, C., Oliveira, R. S. F., Little, J. P., Renner, K., Bishop, D. J. Mitochondrial adaptations to high-volume exercise training are rapidly reversed after a reduction in training volume in human skeletal muscle.


Subject(s)
Adaptation, Physiological/physiology , Exercise/physiology , Mitochondria, Muscle/metabolism , Mitochondria/metabolism , Muscle, Skeletal/metabolism , Acclimatization , Adolescent , Adult , Exercise/psychology , Heat-Shock Proteins/metabolism , Humans , Male , PPAR gamma/metabolism , Young Adult
10.
FASEB J ; 30(2): 959-70, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26572168

ABSTRACT

Exercise training has been associated with increased mitochondrial content and respiration. However, no study to date has compared in parallel how training at different intensities affects mitochondrial respiration and markers of mitochondrial biogenesis. Twenty-nine healthy men performed 4 wk (12 cycling sessions) of either sprint interval training [SIT; 4-10 × 30-s all-out bouts at ∼200% of peak power output (WPeak)], high-intensity interval training (HIIT; 4-7 × 4-min intervals at ∼90% WPeak), or sublactate threshold continuous training (STCT; 20-36 min at ∼65% WPeak). The STCT and HIIT groups were matched for total work. Resting biopsy samples (vastus lateralis) were obtained before and after training. The maximal mitochondrial respiration in permeabilized muscle fibers increased significantly only after SIT (25%). Similarly, the protein content of peroxisome proliferator-activated receptor γ coactivator (PGC)-1α, p53, and plant homeodomain finger-containing protein 20 (PHF20) increased only after SIT (60-90%). Conversely, citrate synthase activity, and the protein content of TFAM and subunits of the electron transport system complexes remained unchanged throughout. Our findings suggest that training intensity is an important factor that regulates training-induced changes in mitochondrial respiration and that there is an apparent dissociation between training-induced changes in mitochondrial respiration and mitochondrial content. Moreover, changes in the protein content of PGC-1α, p53, and PHF20 are more strongly associated with training-induced changes in mitochondrial respiration than mitochondrial content.


Subject(s)
Exercise/physiology , Mitochondria, Muscle/metabolism , Muscle Proteins/metabolism , Muscle, Skeletal/metabolism , Oxygen Consumption/physiology , Transcription Factors/metabolism , Tumor Suppressor Protein p53/metabolism , Adolescent , Adult , Antigens, Neoplasm/metabolism , Biomarkers, Tumor/metabolism , DNA-Binding Proteins , Humans , Male , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha
11.
PLoS One ; 10(12): e0141317, 2015.
Article in English | MEDLINE | ID: mdl-26656911

ABSTRACT

Minimizing the decrease in intracellular pH during high-intensity exercise training promotes greater improvements in mitochondrial respiration. This raises the intriguing hypothesis that pH may affect the exercise-induced transcription of genes that regulate mitochondrial biogenesis. Eight males performed 10x2-min cycle intervals at 80% VO2speak intensity on two occasions separated by ~2 weeks. Participants ingested either ammonium chloride (ACID) or calcium carbonate (PLA) the day before and on the day of the exercise trial in a randomized, counterbalanced order, using a crossover design. Biopsies were taken from the vastus lateralis muscle before and after exercise. The mRNA level of peroxisome proliferator-activated receptor co-activator 1α (PGC-1α), citrate synthase, cytochome c and FOXO1 was elevated at rest following ACID (P<0.05). During the PLA condition, the mRNA content of mitochondrial- and glucose-regulating proteins was elevated immediately following exercise (P<0.05). In the early phase (0-2 h) of post-exercise recovery during ACID, PGC-1α, citrate synthase, cytochome C, FOXO1, GLUT4, and HKII mRNA levels were not different from resting levels (P>0.05); the difference in PGC-1α mRNA content 2 h post-exercise between ACID and PLA was not significant (P = 0.08). Thus, metabolic acidosis abolished the early post-exercise increase of PGC-1α mRNA and the mRNA of downstream mitochondrial and glucose-regulating proteins. These findings indicate that metabolic acidosis may affect mitochondrial biogenesis, with divergent responses in resting and post-exercise skeletal muscle.


Subject(s)
Ammonium Chloride/pharmacology , Calcium Carbonate/pharmacology , Exercise , Muscle, Skeletal/drug effects , RNA, Messenger/metabolism , Adult , Citrate (si)-Synthase/genetics , Citrate (si)-Synthase/metabolism , Cross-Over Studies , Cytochromes c/genetics , Cytochromes c/metabolism , Double-Blind Method , Forkhead Box Protein O1 , Forkhead Transcription Factors/genetics , Forkhead Transcription Factors/metabolism , Glucose Transporter Type 4/metabolism , Humans , Hydrogen-Ion Concentration , Male , Mitochondria/metabolism , Muscle, Skeletal/metabolism , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha , Real-Time Polymerase Chain Reaction , Transcription Factors/genetics , Transcription Factors/metabolism , Up-Regulation/drug effects , Young Adult
12.
Appl Physiol Nutr Metab ; 38(9): 928-34, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23905657

ABSTRACT

The purpose of the present study was to examine the effects of a high- or low-carbohydrate (CHO) diet on performance, aerobic and anaerobic contribution, and metabolic responses during supramaximal exercise. Six physically-active men first performed a cycling exercise bout at 115% maximal oxygen uptake to exhaustion after following their normal diet for 48 h (∼50% of CHO, control test). Seventy-two hours after, participants performed a muscle glycogen depletion exercise protocol, followed by either a high- or low-CHO diet (∼70 and 25% of CHO, respectively) for 48 h, in a random, counterbalanced order. After the assigned diet period (48 h), the supramaximal cycling exercise bout (115% maximal oxygen consumption) to exhaustion was repeated. The low-CHO diet reduced time to exhaustion when compared with both the control and the high-CHO diet (-19 and -32%, respectively, p < 0.05). The reduced time to exhaustion following the low-CHO diet was accompanied by a lower total aerobic energy contribution (-39%) compared with the high-CHO diet (p < 0.05). However, the aerobic and anaerobic energy contribution at the shortest time to exhaustion (isotime) was similar among conditions (p > 0.05). The low-CHO diet was associated with a lower blood lactate concentration (p < 0.05), with no effect on the plasma concentration of insulin, glucose and K(+) (p > 0.05). In conclusion, a low-CHO diet reduces both performance and total aerobic energy provision during supramaximal exercise. As peak K(+) concentration was similar, but time to exhaustion shorter, the low-CHO diet was associated with an earlier attainment of peak plasma K(+) concentration.


Subject(s)
Dietary Carbohydrates , Physical Exertion , Diet , Dietary Carbohydrates/metabolism , Exercise , Humans , Oxygen Consumption
13.
J Dent ; 41(3): 278-86, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23207519

ABSTRACT

OBJECTIVES: To evaluate the effects of surface treatment, surface hydration (SH) and application method (AM) on the tensile bond strength of the Silorane Adhesive System (SAS) to dentine. METHODS: Ninety bovine teeth were used. For the control group (n=10), each dentine surface was treated according to the manufacturer's instructions of the SAS. The remaining teeth were randomly distributed into two groups (n=40), according to the type of dentine surface treatment (ST)-37% phosphoric acid or Er:YAG Laser prior to the application of the SAS. Each group was further divided into 2 subgroups (n=20), according to the SH status: dry (D) or wet (W). Each subgroup was further divided into 2 subgroups (n=10), according to the application method [AM: Active (AC) mode or Passive (PA) mode]. A coat of resin composite (Filtek P90) was applied on the surface. Artificial ageing was performed with a thermo-mechanical cycling machine. The specimens were sectioned into 1mm×1mm×10mm sticks and stressed to failure using a universal testing machine. The remaining teeth in each group were used for Scanning Electron Microscopy to examine the fractured area. Data were subjected to a three-way ANOVA, Tukey's test and Dunnet's test (α=0.05). RESULTS: The ANOVA showed significant differences for SH and AM, but not for ST. For SH, the results of Tukey's test were (in MPa): D - 14.9(±3.8)(a), W - 17.1(±4.3)(b); and for AM: PA - 14. 9(±4.2)(a), AC - 17.1(±3.9)(b). CONCLUSIONS: Acid etching, when combined with a moist dentine surface and the use of primer agitation, improves the bond strength of the SAS to dentine. CLINICAL SIGNIFICANCE: According to the results of the present in vitro study, modification of the application protocols for the silorane-based adhesive system may improve its clinical performance.


Subject(s)
Dental Bonding/methods , Dental Etching/methods , Dentin-Bonding Agents/chemistry , Dentin , Silorane Resins , Animals , Cattle , Composite Resins , Dental Etching/instrumentation , Dental Stress Analysis , Lasers, Solid-State , Microscopy, Electron, Scanning , Phosphoric Acids , Random Allocation , Tensile Strength , Vibration , Wettability , Wetting Agents
15.
J Appl Physiol (1985) ; 104(1): 103-9, 2008 Jan.
Article in English | MEDLINE | ID: mdl-17975126

ABSTRACT

Exercise training (ET) is a coadjuvant therapy in preventive cardiology. It delays cardiac dysfunction and exercise intolerance in heart failure (HF); however, the molecular mechanisms underlying its cardioprotection are poorly understood. We tested the hypothesis that ET would prevent Ca(2+) handling abnormalities and ventricular dysfunction in sympathetic hyperactivity-induced HF mice. A cohort of male wild-type (WT) and congenic alpha(2A)/alpha(2C)-adrenoceptor knockout (alpha(2A)/alpha(2C)ARKO) mice with C57BL6/J genetic background (3-5 mo of age) were randomly assigned into untrained and exercise-trained groups. ET consisted of 8-wk swimming session, 60 min, 5 days/wk. Fractional shortening (FS) was assessed by two-dimensional guided M-mode echocardiography. The protein expression of ryanodine receptor (RyR), phospho-Ser(2809)-RyR, sarcoplasmic reticulum Ca(2+) ATPase (SERCA2), Na(+)/Ca(2+) exchanger (NCX), phospholamban (PLN), phospho-Ser(16)-PLN, and phospho-Thr(17)-PLN were analyzed by Western blotting. At 3 mo of age, no significant difference in FS and exercise tolerance was observed between WT and alpha(2A)/alpha(2C)ARKO mice. At 5 mo, when cardiac dysfunction is associated with lung edema and increased plasma norepinephrine levels, alpha(2A)/alpha(2C)ARKO mice presented reduced FS paralleled by decreased SERCA2 (26%) and NCX (34%). Conversely, alpha(2A)/alpha(2C)ARKO mice displayed increased phospho-Ser(16)-PLN (76%) and phospho-Ser(2809)-RyR (49%). ET in alpha(2A)/alpha(2C)ARKO mice prevented exercise intolerance, ventricular dysfunction, and decreased plasma norepinephrine. ET significantly increased the expression of SERCA2 (58%) and phospho-Ser(16)-PLN (30%) while it restored the expression of phospho-Ser(2809)-RyR to WT levels. Collectively, we provide evidence that improved net balance of Ca(2+) handling proteins paralleled by a decreased sympathetic activity on ET are, at least in part, compensatory mechanisms against deteriorating ventricular function in HF.


Subject(s)
Calcium/metabolism , Exercise Therapy , Heart Failure/therapy , Myocardium/metabolism , Receptors, Adrenergic, alpha-2/metabolism , Sympathetic Nervous System/physiopathology , Ventricular Dysfunction/prevention & control , Animals , Calcium-Binding Proteins/metabolism , Disease Models, Animal , Echocardiography , Exercise Tolerance , Heart Failure/complications , Heart Failure/metabolism , Heart Failure/pathology , Heart Failure/physiopathology , Male , Mice , Mice, Congenic , Mice, Inbred C57BL , Mice, Knockout , Myocardial Contraction , Myocardium/enzymology , Myocardium/pathology , Norepinephrine/blood , Physical Exertion , Receptors, Adrenergic, alpha-2/deficiency , Receptors, Adrenergic, alpha-2/genetics , Research Design , Ryanodine Receptor Calcium Release Channel/metabolism , Sarcoplasmic Reticulum/metabolism , Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolism , Sodium-Calcium Exchanger/metabolism , Sympathetic Nervous System/metabolism , Time Factors , Ventricular Dysfunction/etiology , Ventricular Dysfunction/metabolism , Ventricular Dysfunction/pathology , Ventricular Dysfunction/physiopathology
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