scholarly journals Testosterone Deprivation Aggravates Left-Ventricular Dysfunction in Male Obese Insulin-Resistant Rats via Impairing Cardiac Mitochondrial Function and Dynamics Proteins

Gerontology ◽  
2018 ◽  
Vol 64 (4) ◽  
pp. 333-343 ◽  
Author(s):  
Nattayaporn Apaiajai ◽  
Titikorn Chunchai ◽  
Thidarat Jaiwongkam ◽  
Sasiwan  Kerdphoo ◽  
Siriporn C. Chattipakorn ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Mitochondrial Function ◽  
Mitochondrial Dynamics ◽  
Left Ventricular ◽  
Normal Diet ◽  
Male Rats ◽  
Lv Function ◽  
Sham Operation ◽  
Insulin Resistant ◽  
Lv Dysfunction

Background: We have previously reported that testosterone deprivation at a very young age accelerated, but did not aggravate, left-ventricular (LV) dysfunction in obese insulin-resistant rats. However, the effects of testosterone deprivation during adulthood on LV function in obese insulin-resistant rats remains unclear. We hypothesized that testosterone deprivation aggravates LV dysfunction and cardiac autonomic imbalance via the impairment of cardiac mitochondrial function and dynamics proteins, a reduction in insulin receptor function, and an increase in apoptosis in obese insulin-resistant rats. Methods: Male rats were fed on either a normal diet (ND) or a high-fat diet (HFD) for 12 weeks. They were then subdivided into 2 groups: sham operation (NDS, HFS) and orchiectomy (NDO, HFO). Metabolic parameters, blood pressure, heart rate variability (HRV), and LV function were determined at baseline and before and after orchiectomy. Mitochondrial function and dynamics proteins, insulin signaling, and apoptosis were determined 12 weeks postoperatively. Results: HFS rats exhibited obese insulin resistance, depressed HRV, and LV dysfunction. In HFO rats, systolic blood pressure was increased with more excessive depression of HRV and increased LV dysfunction, compared with HFS rats. These adverse cardiac effects were consistent with markedly increased mitochondrial dysfunction, reduced mitochondrial complex I and III proteins, reduced mitochondrial fusion proteins, and increased apoptosis, compared with HFS rats. However, testosterone deprivation did not lead to any alteration in the insulin-resistant condition in HFO rats, compared with HFS rats. Conclusion: We concluded that testosterone deprivation during adulthood aggravated the impairment of mitochondrial function, mitochondrial respiratory complex, mitochondrial dynamics proteins, and apoptosis, leading to LV dysfunction in obese insulin-resistant rats.

scholarly journals Testosterone deprivation accelerates cardiac dysfunction in obese male rats

2016 ◽  
Vol 229 (3) ◽  
pp. 209-220 ◽  
Author(s):  
Wanpitak Pongkan ◽  
Hiranya Pintana ◽  
Sivaporn Sivasinprasasn ◽  
Thidarat Jaiwongkam ◽  
Siriporn C Chattipakorn ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Mitochondrial Function ◽  
Cardiac Dysfunction ◽  
Left Ventricular ◽  
Normal Diet ◽  
Metabolic Parameters ◽  
Male Rats ◽  
Lv Function ◽  
Insulin Resistant ◽  
Aging Men

Low testosterone level is associated with increased risks of cardiovascular diseases. As obese-insulin-resistant condition could impair cardiac function and that the incidence of obesity is increased in aging men, a condition of testosterone deprivation could aggravate the cardiac dysfunction in obese-insulin-resistant subjects. However, the mechanism underlying this adverse effect is unclear. This study investigated the effects of obesity on metabolic parameters, heart rate variability (HRV), left ventricular (LV) function, and cardiac mitochondrial function in testosterone-deprived rats. Orchiectomized or sham-operated male Wistar rats (n=36per group) were randomly divided into groups and were given either a normal diet (ND, 19.77% of energy fat) or a high-fat diet (HFD, 57.60% of energy fat) for 12weeks. Metabolic parameters, HRV, LV function, and cardiac mitochondrial function were determined at 4, 8, and 12weeks after starting each feeding program. We found that insulin resistance was observed after 8weeks of the consumption of a HFD in both sham (HFS) and orchiectomized (HFO) rats. Neither the ND sham (NDS) group nor ND orchiectomized (NDO) rats developed insulin resistance. The development of depressed HRV, LV contractile dysfunction, and increased cardiac mitochondrial reactive oxygen species production was observed earlier in orchiectomized (NDO and HFO) rats at week 4, whereas HFS rats exhibited these impairments later at week 8. These findings suggest that testosterone deprivation accelerates the impairment of cardiac autonomic regulation and LV function via increased oxidative stress and impaired cardiac mitochondrial function in obese-orchiectomized male rats.

Abstract 15634: High-fat Diet Consumption Accelerates Cardiometabolic Impairment via Deteriorating Mitochondrial Function in Non-obese Spontaneously Type 2 Diabetic Rats

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Wanpitak Pongkan ◽  
KEWARIN JINAWONG ◽  
Siriporn Chattipakorn ◽  
Nipon CHATTIPAKORN
Keyword(s):  
Mitochondrial Function ◽  
High Fat Diet ◽  
Time Course ◽  
Left Ventricular ◽  
Normal Diet ◽  
The Body ◽  
Lv Function ◽  
High Fat ◽  
Lv Dysfunction

Introduction: Type 2 Diabetes Mellitus (T2DM) is a complex disease which is related to genetic, environmental, and lifestyle factors. In genetically-induced T2DM rats, normal diet could induce spontaneous diabetes, and induce left ventricular (LV) dysfunction over time. However, the effect of high-fat diet (HFD) in these genetically-induced T2DM rats on the cardiometabolic changes, including LV function and cardiac mitochondrial function has rarely been investigated. Hypothesis: High-fat diet (HFD) consumption accelerates the development of T2DM and LV dysfunction by inducing mitochondrial dysfunction in genetically-induced non-obese T2DM-Spontaneously Diabetic Torii (SDT) rats. Methods: Male SDT rats (n=18/group) were divided into 2 groups to receive either normal diet (ND, 19.77% fat) or HFD (57.60% fat) for 4, 8 or 12 weeks. At each time course, cardiac function determined by echocardiography and the pressure-volume loop determined by invasive intracardiac catheterization were assessed. The heart was removed to study cardiac mitochondrial function at each time-course. Results: The body weight, food intake, and visceral fat were not different between ND and HFD rats at any times. Increased blood glucose was seen earlier at week 4 in HFD rats, but later at week 12 in ND rats. The development of LV contractile dysfunction and decreased stroke volume was observed earlier at week 8 in HFD rats, compared to ND rats and HFD rats at the baseline. Increased cardiac mitochondrial ROS production and decreased mitochondrial membrane potential (i.e. mitochondrial depolarization) was observed earlier at week 8 in HFD rats, compared to ND rats (Fig). Conclusions: High-fat diet accelerates cardiometabolic impairments via impaired cardiac mitochondrial function in genetically-induced non-obese T2DM rats.

scholarly journals Necroptosis inhibitor directly reduced left ventricular dysfunction in obese-insulin resistant rats, independent of the metabolic status

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
N Apaijai ◽  
K Jinawong ◽  
K Singhanat ◽  
T Jaiwongkam ◽  
S Kerdphoo ◽  
...  
Keyword(s):  
Cell Death ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Function ◽  
Left Ventricular ◽  
Metabolic Parameters ◽  
Lv Function ◽  
Cardiac Diseases ◽  
Funding Source ◽  
Insulin Resistant ◽  
Lv Dysfunction

Abstract Background The number of obese people is increasing globally. Our previous studies showed that chronic high-fat diet (HFD) consumption led to obesity with peripheral insulin resistance, which was associated with left ventricular (LV) dysfunction. Mechanistically, cardiac mitochondrial dysfunction and cell death are proposed as an underlying mechanism for LV dysfunction in obese subjects. Recently, necroptosis was defined as a novel cell death pathway, which can be found in various types of cardiac diseases such as myocardial ischaemia and heart failure. Pharmacological inhibition of necroptosis by necrostatin 1 (nec-1) provided the favorable outcomes to those cardiac diseases. However, the roles of necroptosis and the effects of nec-1 on the heart of obese-insulin resistant rats have never been investigated. Purpose We hypothesized that nec-1 attenuates LV dysfunction by reducing cardiac mitochondrial dysfunction, necroptosis, and apoptosis in obese-insulin resistant rats. Methods Male rats (n=32) were fed with normal diet (ND) or HFD for 12 weeks to induce obese-insulin resistance. At weeks 13, HFD-fed rats were assigned into 3 interventional groups (n=8/group) as follows: 1) HFD-fed rats treated with saline, 2) HFD-fed rats treated with nec-1 (1.65 mg/kg/day, subcutaneous injection), 3) HFD-fed rats treated with metformin (300 mg/kg/day, oral gavage feeding, served as a positive control). ND rats were treated with saline. Rats received their assigned interventions for additional 7 weeks. Blood pressure (BP), cardiac sympathovagal balance, and LV function were determined. At the end, the heart was excised to determine cardiac mitochondrial function including mitochondrial respiration, reactive oxygen species (ROS) levels, membrane potential changes, swelling, as well as apoptosis and necroptosis protein levels. Results HFD-fed rats had increased body weight, visceral fat deposition, hyperinsulinemia with euglycemia, and dyslipidemia. Moreover, HFD-fed rats had increased systolic and diastolic BP, reduced cardiac sympathovagal balance, and %LV ejection fraction (LVEF) (Fig. 1A). For mitochondrial function, respiratory control ratio was decreased, ROS levels were increased, along with mitochondrial membrane depolarization and swelling (Fig. 1B). Both necroptosis and apoptosis were observed in HFD-fed rats. Treatment with nec-1 reduced systolic and diastolic BP, cardiac sympathovagal imbalance, and increased %LVEF (Fig. 1A). Necroptosis and apoptosis were reduced, and all mitochondrial function parameters were improved in nec-1 treated rats (Fig. 1B). However, the metabolic parameters were not modified by nec-1. Treatment with metformin had similar benefits as nec-1 (Fig. 1), with additional improvement in metabolic parameters in HFD-fed rats. Conclusion Nec-1 directly improves LV function in obese-insulin resistant rats via attenuating cardiac mitochondrial dysfunction and cell death, independent of metabolic parameters. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Science and Technology Development Agency, Thailand Research Fund (TRF)

Hyperbaric oxygen therapy attenuates D-galactose-induced-age-related cardiac dysfunction through mitigating cardiac mitochondrial dysfunction in pre-diabetic rats

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
C Bo-Htay ◽  
T Shwe ◽  
S Palee ◽  
T Pattarasakulchai ◽  
K Shinlapawittayatorn ◽  
...  
Keyword(s):  
Mitochondrial Dysfunction ◽  
High Fat Diet ◽  
Diabetic Rats ◽  
Normal Diet ◽  
Lv Function ◽  
High Fat ◽  
Insulin Resistant ◽  
Lv Dysfunction ◽  
Age Related ◽  
Mitochondrial Functions

Abstract Background D-galactose (D-gal) induced ageing has been shown to exacerbate left ventricular (LV) dysfunction via worsening of apoptosis and mitochondrial dysfunction in the heart of obese rats. Hyperbaric oxygen therapy (HBOT) has been demonstrated to exert anti-inflammatory and anti-apoptotic effects in multiple neurological disorders. However, the cardioprotective effect of HBOT on inflammation, apoptosis, LV and mitochondrial functions in D-gal induced ageing rats in the presence of obese-insulin resistant condition has never been investigated. Purpose We sought to determine the effect of HBOT on inflammation, apoptosis, mitochondrial functions and LV function in pre-diabetic rats with D-gal induced ageing. We hypothesized that HBOT attenuates D-gal induced cardiac mitochondrial dysfunctions and reduces inflammation and apoptosis, leading to improved LV function in pre-diabetic rats. Methods Forty-eight male Wistar rats were fed with either normal diet or high-fat diet for 12 weeks. Then, rats were treated with either vehicle groups (0.9% NSS, subcutaneous injection (SC)) or D-gal groups (150 mg/kg/day, SC) for 8 weeks. At week 21, rats in each group were equally divided into 6 sub-groups: normal diet fed rats treated with vehicle (NDV) sham, normal diet fed rats treated with D-gal (NDDg) sham, high fat diet fed rats treated with D-gal (HFDg) sham, high fat diet fed rats treated with vehicle (HFV) + HBOT, NDDg + HBOT and HFDg + HBOT. Sham treated rats were given normal concentration of O2 (flow rate of 80 L/min, 1 ATA for 60 minutes), whereas HBOT treated rats were subjected to 100% O2 (flow rate of 250 L/min, 2 ATA for 60 minutes), given once daily for 2 weeks. Results Under obese-insulin resistant condition, D-gal-induced ageing aggravated LV dysfunction (Fig 1A) and impaired cardiac mitochondrial function, increased cardiac inflammatory and apoptotic markers (Fig 1B). HBOT markedly reduced cardiac TNF-α level and TUNEL positive apoptotic cells, and improved cardiac mitochondrial function as indicated by decreased mitochondrial ROS production, mitochondrial depolarization and mitochondrial swelling, resulting in the restoration of the normal LV function in HFV and NDDg rats, compared to sham NDDg rats. In addition, in HFDg treated rats, HBOT attenuated cardiac TNF-α level, TUNEL positive apoptotic cells and cardiac mitochondrial dysfunction, compared to sham HFDg rats, leading to improved cardiac function as indicated by increased %LV ejection fraction (LVEF) (Figure 1). Conclusion HBOT efficiently alleviates D-gal-induced-age-related LV dysfunction through mitigating inflammation, apoptosis and mitochondrial dysfunction in pre-diabetic rats. Figure 1 Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): 1. The National Science and Technology Development Agency Thailand, 2. Thailand Research Fund Grants

Differential temporal inhibition of mitochondrial fission by Mdivi-1 exerts effective cardioprotection in cardiac ischemia/reperfusion injury

2018 ◽  
Vol 132 (15) ◽  
pp. 1669-1683 ◽  
Author(s):  
Chayodom Maneechote ◽  
Siripong Palee ◽  
Sasiwan Kerdphoo ◽  
Thidarat Jaiwongkam ◽  
Siriporn C. Chattipakorn ◽  
...  
Keyword(s):  
Infarct Size ◽  
Mitochondrial Function ◽  
Ischemia Reperfusion Injury ◽  
Mitochondrial Dynamics ◽  
Ischemia Reperfusion ◽  
Mitochondrial Fission ◽  
Left Ventricular ◽  
Lv Function ◽  
Male Wistar Rats ◽  
Group A

Altered cardiac mitochondrial dynamics with excessive fission is a predominant cause of cardiac dysfunction during ischemia/reperfusion (I/R) injury. Although pre-ischemic inhibition of mitochondrial fission has been shown to improve cardiac function in I/R injury, the effects of this inhibitor given at different time-points during cardiac I/R injury are unknown. Fifty male Wistar rats were subjected to sham and cardiac I/R injury. For cardiac I/R injury, rats were randomly divided into pre-ischemia, during-ischemia, and upon onset of reperfusion group. A mitochondrial fission inhibitor, Mdivi-1 (mitochondrial division inhibitor 1) (1.2 mg/kg) was used. During I/R protocols, the left ventricular (LV) function, arrhythmia score, and mortality rate were determined. Then, the heart was removed to determine infarct size, mitochondrial function, mitochondrial dynamics, and apoptosis. Our results showed that Mdivi-1 given prior to ischemia, exerted the highest level of cardioprotection quantitated through the attenuated incidence of arrhythmia, reduced infarct size, improved cardiac mitochondrial function and fragmentation, and decreased cardiac apoptosis, leading to preserved LV function during I/R injury. Mdivi-1 administered during ischemia and upon the onset of reperfusion also improved cardiac mitochondrial function and LV function, but at a lower efficacy than when it was given prior to ischemia. Taken together, mitochondrial fission inhibition after myocardial ischemic insults still exerts cardioprotection by attenuating mitochondrial dysfunction and dynamic imbalance, leading to decreased infarct size and ultimately improved LV function after acute cardiac I/R injury in rats. These findings indicate its potential clinical usefulness.

scholarly journals Cardioprotection of dapagliflozin and vildagliptin in rats with cardiac ischemia-reperfusion injury

2018 ◽  
Vol 236 (2) ◽  
pp. 69-84 ◽  
Author(s):  
Pongpan Tanajak ◽  
Piangkwan Sa-nguanmoo ◽  
Sivaporn Sivasinprasasn ◽  
Savitree Thummasorn ◽  
Natthaphat Siri-Angkul ◽  
...  
Keyword(s):  
Infarct Size ◽  
Myocardial Dysfunction ◽  
Ischemia Reperfusion ◽  
Combined Therapy ◽  
Left Ventricular ◽  
Cardiac Ischemia ◽  
Lv Function ◽  
Insulin Resistant ◽  
Lv Dysfunction ◽  
Dipeptidyl Peptidase 4 Inhibitors

Sodium-glucose cotransporter 2 inhibitor (SGLT2-i) effects on cardiac ischemia/reperfusion (I/R) injury are unclear. Unlike SGLT2-i, dipeptidyl peptidase 4 inhibitors (DPP4-i) have shown effective cardioprotection in cardiac I/R injury. We aimed to investigate whether SGLT2-i reduces myocardial dysfunction and myocardial injury to a greater extent than DPP4-i in obese insulin-resistant rats with/without cardiac I/R injury. The high-fat (HF) diet-induced obese insulin-resistant rats were divided into 4 groups and received the following treatments for 28 days: vehicle (HFV); vildagliptin at a dosage of 3 mg/kg/day (HFVil); dapagliflozin at a dosage of 1 mg/kg/day (HFDa) and combination drugs (HFDaVil). At the end, I/R injury was induced by a 30-min left anterior descending coronary occlusion and 120-min reperfusion. Dapagliflozin showed a greater efficacy than vildagliptin in improving the metabolic impairments, low frequency/high frequency (LF/HF) ratio, systolic blood pressure and left ventricular (LV) function in comparison to HFV rats. In cardiac I/R injury, dapagliflozin had a greater efficacy than vildagiptin in decreasing mitochondrial DRP1, cleaved caspase 3, LV dysfunction and infarct size in comparison to HFV rats. However, the combined therapy showed the greatest efficacy in attenuating LV dysfunction, mitochondrial DRP1 and infarct size in comparison to HFV rats. In conclusion, dapagliflozin has a more pronounced effect than vildagliptin in obese insulin-resistant rats for the improvement of LV function. In rats with cardiac I/R injury, although dapagliflozin had a greater efficacy on cardioprotection than vildagliptin, the combined therapy exerted the highest cardioprotective effects potentially by reducing mitochondrial fission.

scholarly journals Impact of Diabetes on Cardiac Function in Patients with High Blood Pressure

2021 ◽  
Vol 18 (12) ◽  
pp. 6553
Author(s):  
Nabila Soufi Taleb Bendiab ◽  
Souhila Ouabdesselam ◽  
Latefa Henaoui ◽  
Marilucy Lopez-Sublet ◽  
Jean-Jacques Monsuez ◽  
...  
Keyword(s):  
Blood Pressure ◽  
High Blood Pressure ◽  
Global Longitudinal Strain ◽  
Left Ventricular ◽  
Left Ventricular Geometry ◽  
Lv Function ◽  
Hypertensive Patients ◽  
Concentric Hypertrophy ◽  
Lv Dysfunction ◽  
The Impact

Background: Although the combination of high blood pressure (HBP) and type 2 diabetes (T2DM) increases the risk of left ventricular (LV) dysfunction, the impact of T2DM on LV geometry and subclinical dysfunction in hypertensive patients and normal ejection fraction (EF) has been infrequently evaluated. Methods: Hypertensive patients with or without T2DM underwent cardiac echocardiography coupled with LV global longitudinal strain (GLS) assessment. Results: Among 200 patients with HBP (mean age 61.7 ± 9.7 years) and EF > 55%, 93 had associated T2DM. Patients with T2DM had a higher body mass index (29.9 ± 5.1 kg/m2 vs. 29.3 ± 4.7 kg/m2, p = 0.025), higher BP levels (158 ± 23/95 ± 13 vs. 142 ± 33/87 ± 12 mmHg, p = 0.003), a higher LV mass index (115.8 ± 32.4 vs. 112.0 ± 24.7 g/m2, p = 0.004), and higher relative wall thickness (0.51 ± 0.16 vs. 0.46 ± 0.12, p = 0.0001). They had more frequently concentric remodeling (20.4% vs. 16.8%, p < 0.001), concentric hypertrophy (53.7% vs. 48.6%, p < 0.001), elevated filling pressures (25.8 vs. 12.1%, p = 0.0001), indexed left atrial volumes greater than 28 mL/m2 (17.2 vs. 11.2%, p = 0.001), and a reduced GLS less than −18% (74.2 vs. 47.7%, p < 0.0001). After adjustment for BP and BMI, T2DM remains an independent determinant factor for GLS decline (OR = 2.26, 95% CI 1.11–4.61, p = 0.023). Conclusions: Left ventricular geometry and subclinical LV function as assessed with GLS are more impaired in hypertensive patients with than without T2DM. Preventive approaches to control BMI and risk of T2DM in hypertensive patients should be emphasized.

Abstract 15180: Myeloid Differentiation Factor 2 Inhibitor Improves Left Ventricular Function And Heart Rate Variability Via Attenuating Cardiac Mitochondrial Dysfunction In Pre-diabetic Rats

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Natticha Sumneang ◽  
Thura Thun Oo ◽  
thidarat jaiwongkam ◽  
Busarin Arunsak ◽  
Nattayaporn Apaijai ◽  
...  
Keyword(s):  
Heart Rate ◽  
Mitochondrial Dysfunction ◽  
Systemic Inflammation ◽  
Mitochondrial Function ◽  
Diabetic Rats ◽  
Left Ventricular ◽  
Myeloid Differentiation ◽  
Lv Function ◽  
Lv Dysfunction ◽  
Myeloid Differentiation Factor

Introduction: Systemic inflammation is known as a key mediator of left ventricular (LV) dysfunction in pre-diabetic models including obese-insulin resistance. In obese rats, lipopolysaccharide activates myeloid differentiation factor 2 (MD2)/toll-like receptor 4 complex, leading to systemic inflammation. Previously, MD2 inhibitor L6H21 (20 mg/kg) was shown to effectively reduce systemic inflammation in obese mice. However, its potential benefits on the heart and the underlying mechanisms in pre-diabetic obese-insulin resistant rats are unknown. Hypothesis: L6H21 exerts cardiometabolic protection in pre-diabetic rats by improving LV function and heart rate variability (HRV) via reducing cardiac mitochondrial dysfunction. Methods: Male Wistar rats were fed either a normal diet (n=8) or high-fat diet (HFD, n=40) for 12 weeks. In HFD group, rats were divided into 5 groups (n=8/group): 1) vehicle (1% Na-carboxymethyl cellulose), 2) metformin (300 mg/kg, positive control), 3-5) L6H21 at 10, 20, and 40 mg/kg. After 4 weeks of treatments, LV function and HRV were examined. Heart tissue was assessed for mitochondrial function. Results: Pre-diabetic rats had impaired glucose tolerance, depressed HRV, and decreased LV ejection fraction (LVEF), indicating cardiac autonomic imbalance and LV dysfunction. Cardiac mitochondrial dysfunction was also observed, shown by increased mitochondrial ROS levels, mitochondrial depolarization, and mitochondrial swelling. Although L6H21 at 20 and 40 mg/kg improved insulin sensitivity, cardiac autonomic balance, LV function, and mitochondrial function, L6H21 at 40 mg/kg exerted the highest cardioprotective effects, compared to metformin, in pre-diabetic rats by restoring LV function, HRV, and cardiac mitochondrial function (Fig) . Conclusions: L6H21 exerted cardiometabolic protection in pre-diabetic rats by improving insulin sensitivity and cardiac mitochondrial function, leading to restoring LV function.

scholarly journals Vildagliptin and caloric restriction for cardioprotection in pre-diabetic rats

2017 ◽  
Vol 232 (2) ◽  
pp. 189-204 ◽  
Author(s):  
Pongpan Tanajak ◽  
Hiranya Pintana ◽  
Natthaphat Siri-Angkul ◽  
Juthamas Khamseekaew ◽  
Nattayaporn Apaijai ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Function ◽  
Cardiac Dysfunction ◽  
Metabolic Regulation ◽  
Left Ventricular ◽  
Lv Function ◽  
Insulin Resistant

Long-term high-fat diet (HFD) consumption causes cardiac dysfunction. Although calorie restriction (CR) has been shown to be useful in obesity, we hypothesized that combined CR with dipeptidyl peptidase-4 (DPP-4) inhibitor provides greater efficacy than monotherapy in attenuating cardiac dysfunction and metabolic impairment in HFD-induced obese-insulin resistant rats. Thirty male Wistar rats were divided into 2 groups to be fed on either a normal diet (ND, n = 6) or a HFD (n = 24) for 12 weeks. Then, HFD rats were divided into 4 subgroups (n = 6/subgroup) to receive just the vehicle, CR diet (60% of mean energy intake and changed to ND), vildagliptin (3 mg/kg/day) or combined CR and vildagliptin for 4 weeks. Metabolic parameters, heart rate variability (HRV), cardiac mitochondrial function, left ventricular (LV) and fibroblast growth factor (FGF) 21 signaling pathway were determined. Rats on a HFD developed insulin and FGF21 resistance, oxidative stress, cardiac mitochondrial dysfunction and impaired LV function. Rats on CR alone showed both decreased body weight and visceral fat accumulation, whereas vildagliptin did not alter these parameters. Rats in CR, vildagliptin and CR plus vildagliptin subgroups had improved insulin sensitivity and oxidative stress. However, vildagliptin improved heart rate variability (HRV), cardiac mitochondrial function and LV function better than the CR. Chronic HFD consumption leads to obese-insulin resistance and FGF21 resistance. Although CR is effective in improving metabolic regulation, vildagliptin provides greater efficacy in preventing cardiac dysfunction by improving anti-apoptosis and FGF21 signaling pathways and attenuating cardiac mitochondrial dysfunction in obese-insulin-resistant rats.

Abstract 14712: Cardiometabolic Differences Between Male and Female Obese-insulin Resistant Rats Following Sex Hormone Deprivation

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Krekwit Shinlapawittayatorn ◽  
Wanpitak Pongkan ◽  
Sivaporn Sivasinprasasn ◽  
Siriporn Chattipakorn ◽  
Nipon CHATTIPAKORN
Keyword(s):  
Mitochondrial Dysfunction ◽  
High Fat Diet ◽  
Left Ventricular ◽  
Normal Diet ◽  
Sex Hormone ◽  
Lv Function ◽  
High Fat ◽  
Insulin Resistant ◽  
Cardiometabolic Disorders ◽  
Hormone Deprivation

Introduction: Male gender and menopause increase the risk for cardiovascular incidence. However, less is known about gender differences in cardiometabolic disorders, particularly under obese-insulin resistant and sex hormone-deprived conditions. Hypothesis: Male have worse cardiometabolic disorders than female under obese-insulin resistant and sex hormone-deprived conditions. Methods: Adult Wistar rats of both sexes (n=20) were randomly assigned into four groups (n = 5/group): male normal diet sham (M-NDS), male high fat-diet with orchiectomy (M-HFO), female normal diet sham (F-NDS) and female high fat-diet with ovariectomy (F-HFO). Rats were fed either a normal diet (19.77% of energy fat) or a high-fat diet (57.60% of energy fat) for 12 weeks following the induction of sex hormone deprivation by either bilateral orchiectomy or ovariectomy. Temporal determinations of metabolic parameters, heart rate variability (HRV), left ventricular (LV) function, and cardiac mitochondrial function at 4, 8, and 12 weeks were done after starting each feeding program. Results: Insulin resistance was initially observed after 8 weeks of high-fat diet consumption in both M-HFO and F-HFO groups. In addition, M-HFO had depressed HRV, impaired LV performance indicated by decreased ejection fraction (%EF) and cardiac mitochondrial dysfunction indicated by increased mitochondrial ROS level, depolarization and swelling, as early as week 4, whereas F-HFO exhibited them at week 8 or 12. Moreover, at week 12, M-HFO have worse cardiometabolic disorders than F-HFO, particularly %EF and HRV. Conclusions: Under sex hormone-deprived condition, male are generally more susceptible to cardiometabolic disorders and cardiac mitochondrial dysfunction, especially in the presence of obese-insulin resistant condition.

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