scholarly journals Influence of type 2 diabetes mellitus on the development of hypoxic pulmonary vasoconstriction

2020 ◽  
Vol 14 (5) ◽  
Author(s):  
O. S. Khromov ◽  
N. V. Dobrelia ◽  
O. V. Parshikov ◽  
L. V. Boytsova
Keyword(s):  
Diabetes Mellitus ◽  
Pulmonary Artery ◽  
Right Ventricular ◽  
High Fat Diet ◽  
Hypoxic Pulmonary Vasoconstriction ◽  
Circulatory System ◽  
Ventricular Pressure ◽  
High Fat ◽  
Pulmonary Vasoconstriction ◽  
The Right

Hypoxia is currently considered to be an universal factor involved in the development of complications in many diseases including diabetes mellitus (DM). Acute hypoxia causes a systemic reaction with the large circulatory system developing vasodilation and the lesser circulatory system arteries developinghypoxic pulmonary vasoconstriction (HPV), which demonstrates the arteries' ability to regulate pulmonary circulation and maintain normal ventilation-perfusion ratio. Lack of the adequate response to hypoxic effects may be an additional mechanism for the diabetic complications in the cardiovascular system. Despite years of study, the mechanisms of HPV remain largely unclear, as does the effect of diabetes on pulmonary artery reactivity.The aim of the study was to evaluate the effect of high-fat diet and diabetes on the development of the HPV reaction in vivo and in vitro.Studies in rats divided into three groups (control group, a group of rats on a high-fat diet (HFD), and a group of animals with experimental type 2 diabetes mellitus (T2DM)) showed that in rats kept on the high-fat diet, an injection of streptozotocin leads to significant increase in blood glucose levels. In rats kept on the high-fat diet only, this parameter did not differ from the levels in the control animals. In rats kept on HFD and in rats with T2DM model, the right ventricular pressure was significantly higher compared to the control rats.The lung ventilation with a hypoxic gas mixture led to decrease in blood pressure in the systemic circulation in animals of all groups. In the control rats, the pressure in the right ventricular cavity of the heart increased indicating the development of hypoxic pulmonary vasoconstriction. In HFD rats, hypoxic hypoxiahad virtually no effect on the right ventricular pressure. In T2DM rats, an inversion of the hypoxic pulmonary vasoconstriction reaction with decrease in the right ventricular pressure was observed.These results have been confirmed in the in vitro experiments. In lung sections, the responses of the intrapulmonary arteries to hypoxic effects were multi-directional: the pulmonary artery luminal area decreased in the control animals, almost did not change in HFD animals, and increased in T2DM animals.In the rats with experimental diabetes mellitus, the contractile responses of the pulmonary artery ring segments to hypoxia were significantly suppressed compared to the vessels from the control animals.Finding out the exact mechanisms involved in the inversion of the pulmonary vasoconstriction response in diabetes will contribute to a better understanding of the fundamental pathophysiological processes that will promote development of pathogenetically justified approaches to the treatment of this disease and its complications.

Delayed depolarization of the cog-wheel valve and pulmonary-to-systemic shunting in alligators

2002 ◽  
Vol 205 (13) ◽  
pp. 1843-1851 ◽  
Author(s):  
Douglas A. Syme ◽  
Kurt Gamperl ◽  
David R. Jones
Keyword(s):  
Pulmonary Artery ◽  
Right Ventricle ◽  
Right Ventricular ◽  
Systemic Circulation ◽  
Heart Beat ◽  
Alligator Mississippiensis ◽  
Ventricular Pressure ◽  
Conduction Delay ◽  
The Right ◽  
Secondary Rise

SUMMARYAlligators and other crocodilians have a cog-wheel valve located within the subpulmonary conus, and active closure of this valve during each heart beat can markedly and phasically increase resistance in the pulmonary outflow tract. If this increased resistance causes right ventricular pressure to rise above that in the systemic circuit, right ventricular blood can flow into the left aorta and systemic circulation, an event known as pulmonary-to-systemic shunting. To understand better how this valve is controlled, anaesthetized American alligators (Alligator mississippiensis) were used to examine the relationships between depolarization of the right ventricle,depolarization/contraction of the cog-wheel valve muscle and the resultant right ventricular, pulmonary artery and systemic pressures. Depolarization swept across the right ventricle from the apex towards the base (near where the cog-wheel valve muscle is located) at a velocity of 91±23 cm s-1 (mean ± S.E.M., N=3). The cog-wheel valve electrocardiogram (ECG) (and thus contraction of the valve) trailed the right ventricular ECG by 248±28 ms (N=3), which was equivalent to 6-35 % of a cardiac cycle. This long interval between right ventricular and valve depolarization suggests a nodal delay at the junction between the base of the right ventricle and the cog-wheel valve. The delay before valve closure determined when the abrupt secondary rise in right ventricular pressure occurred during systole and is likely to strongly influence the amount of blood entering the pulmonary artery and thus to directly control the degree of shunting. Left vagal stimulation (10-50 Hz) reduced the conduction delay between the right ventricle and cog-wheel valve by approximately 20 % and reduced the integrated cog-wheel ECG by 10-20 %. Direct application of acetylcholine (1-2 mg) also reduced the integrated cog-wheel ECG by 10-100 %;however, its effect on the conduction delay was highly variable (-40 to +60%). When the cog-wheel valve muscle was killed by the application of ethanol,the cog-wheel ECG was absent, right ventricular and pulmonary pressures remained low and tracked one another, the secondary rise in right ventricular pressure was abolished and shunting did not occur. This study provides additional, direct evidence that phasic contraction of the cog-wheel valve muscle controls shunting, that nervous and cholinergic stimulation can alter the delay and strength of valve depolarization and that this can affect the propensity to shunt.

scholarly journals Berberine elevates cardiolipin in heart of offspring from mouse dams with high fat diet-induced gestational diabetes mellitus

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Laura K. Cole ◽  
Genevieve C. Sparagna ◽  
Marilyne Vandel ◽  
Bo Xiang ◽  
Vernon W. Dolinsky ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Gestational Diabetes ◽  
Gestational Diabetes Mellitus ◽  
Mitochondrial Function ◽  
High Fat Diet ◽  
Fatty Acid Uptake ◽  
Isoquinoline Alkaloid ◽  
Acid Uptake ◽  
High Fat ◽  
Low Fat

AbstractBerberine (BBR) is an isoquinoline alkaloid from plants known to improve cardiac mitochondrial function in gestational diabetes mellitus (GDM) offspring but the mechanism is poorly understood. We examined the role of the mitochondrial phospholipid cardiolipin (CL) in mediating this cardiac improvement. C57BL/6 female mice were fed either a Lean-inducing low-fat diet or a GDM-inducing high-fat diet for 6 weeks prior to breeding. Lean and GDM-exposed male offspring were randomly assigned a low-fat, high-fat, or high-fat diet containing BBR at weaning for 12 weeks. The content of CL was elevated in the heart of GDM offspring fed a high fat diet containing BBR. The increase in total cardiac CL was due to significant increases in the most abundant and functionally important CL species, tetralinoleoyl-CL and this correlated with an increase in the expression of the CL remodeling enzyme tafazzin. Additionally, BBR treatment increased expression of cardiac enzymes involved in fatty acid uptake and oxidation and electron transport chain subunits in high fat diet fed GDM offspring. Thus, dietary BBR protection from cardiac dysfunction in GDM exposed offspring involves improvement in mitochondrial function mediated through increased synthesis of CL.

Hypoglycemic effects of Auricularia auricula polysaccharides on high fat diet and streptozotocin-induced diabetic mice using metabolomics analysis

2021 ◽  
Author(s):  
nannan liu ◽  
Xuefeng Chen ◽  
Juanna Song ◽  
Mengyin Chen ◽  
Pin Gong ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
High Fat Diet ◽  
Diabetic Mice ◽  
Male Mice ◽  
High Fat ◽  
Auricularia Auricula ◽  
Ultrahigh Performance Liquid Chromatography ◽  
Metabolomic Approach ◽  
Metabolomics Analysis

This study evaluated the hypoglycemic effect of Auricularia auricula polysaccharides (AAPs) on streptozotocin-induced type 2 diabetes mellitus (T2DM) male mice (C57BL/6J) using a metabolomic approach based on ultrahigh-performance liquid chromatography–Q...

Right ventricular pressure response to +GZ acceleration stress

1982 ◽  
Vol 53 (4) ◽  
pp. 908-913 ◽  
Author(s):  
J. E. Whinnery ◽  
M. H. Laughlin
Keyword(s):  
Right Ventricular ◽  
Diastolic Pressure ◽  
Vena Cava ◽  
Systolic Pressure ◽  
Ventricular Pressure ◽  
Miniature Swine ◽  
Right Ventricular Systolic Pressure ◽  
Ventricular Systolic Pressure ◽  
The Right ◽  
Acceleration Stress

Measurements of right ventricular pressure in miniature swine were made at +Gz levels from +1 through +9 Gz. Polyethylene catheters were chronically placed in the cranial vena cava of five 2-yr-old female miniature swine (35–50 kg). The catheters were large enough to allow the introduction of a Millar pressure transducer into the venous system for placement in the right heart. The animals were fitted with an abdominal anti-G suit, restrained in a fiberglass couch, and exposed to the various +Gz levels on a centrifuge while fully conscious and unanesthetized. Right ventricular pressure and heart rate were measured during and for 2 min following 30-s exposures to each level of +Gz stress. The maximum right ventricular systolic pressure observed during +Gz was 200 Torr at +5 Gz with the maximum diastolic pressure being 88 Torr observed at +5 Gz. Mean heart rates were 200–210 beats/min at all levels of +Gz greater than or equal to +3 Gz when the animal remained stable. Mean maximum right ventricular pressures during +Gz stress were observed to increase through +5 Gz (85 Torr) and to decrease at higher levels of +Gz, indicating that through +5 Gz there is at least a partial compensation during acceleration stress. Decompensation in response to the stress began to occur during acceleration above +5 Gz with all animals decompensating during +9 Gz.

scholarly journals Metastatic adenocarcinoma involving the right ventricle and pulmonary artery leading to right heart failure: case report

2017 ◽  
Vol 136 (3) ◽  
pp. 262-265 ◽  
Author(s):  
Turgut Karabag ◽  
Caner Arslan ◽  
Turab Yakisan ◽  
Aziz Vatan ◽  
Duygu Sak
Keyword(s):  
Heart Failure ◽  
Case Report ◽  
Pulmonary Artery ◽  
Right Ventricle ◽  
Right Ventricular ◽  
Right Ventricular Outflow Tract ◽  
Right Heart Failure ◽  
Ventricular Outflow Tract ◽  
Right Heart ◽  
The Right

ABSTRACT CONTEXT: Obstruction of the right ventricular outflow tract due to metastatic disease is rare. Clinical recognition of cardiac metastatic tumors is rare and continues to present a diagnostic and therapeutic challenge. CASE REPORT: We present the case of a patient who had severe respiratory insufficiency and whose clinical examinations revealed a giant tumor mass extending from the right ventricle to the pulmonary artery. We discuss the diagnostic and therapeutic options. CONCLUSION: In patients presenting with acute right heart failure, right ventricular masses should be kept in mind. Transthoracic echocardiography appears to be the most easily available, noninvasive, cost-effective and useful technique in making the differential diagnosis.

scholarly journals The Association Between Notching of the Right Ventricular Outflow Tract Flow Velocity Doppler Envelope and Impaired Right Ventricular Function After Acute High-Altitude Exposure

2021 ◽  
Vol 12 ◽  
Author(s):  
Fangzhengyuan Yuan ◽  
Chuan Liu ◽  
Shiyong Yu ◽  
Shizhu Bian ◽  
Jie Yang ◽  
...  
Keyword(s):  
Pulmonary Artery ◽  
Right Ventricular ◽  
Flow Velocity ◽  
Healthy Subjects ◽  
Right Ventricular Outflow Tract ◽  
Ventricular Outflow Tract ◽  
Tricuspid Annulus ◽  
Doppler Flow ◽  
The Right ◽  
Rv Function

IntroductionPulmonary artery pressure (PAP) is increased and right ventricular (RV) function is well preserved in healthy subjects upon exposure to high altitude (HA). An increase in PAP may trigger notching of the right ventricular outflow tract Doppler flow velocity envelope (RVOT notch), which is associated with impaired RV function in patients with pulmonary hypertension. However, whether HA exposure can induce RVOT notch formation and the subsequent impact on cardiac function in healthy subjects remains unclear.MethodsA total of 99 subjects (69 males and 30 females) with a median age of 25 years were enrolled in this study; they traveled from 500 to 4100 m by bus over a 2-day period. All subjects underwent a comprehensive physiological and echocardiographic examination 1 day before ascension at low altitude and 15 ± 3 h after arrival at HA. The RVOT notch was determined by the presence of a notched shape in the RVOT Doppler flow velocity envelope. The systolic PAP (SPAP) was calculated as Bernoulli equation SPAP = 4 × (maximum tricuspid regurgitation velocity)2+5 and mean PAP (mPAP) = 0.61 × SPAP+2. Cardiac output was calculated as stroke volume × heart rate. Pulmonary capillary wedge pressure (PCWP) was calculated as 1.9+1.24 × mitral E/e’. Pulmonary vascular resistance (PVR) was calculated as (mPAP-PCWP)/CO.ResultsAfter HA exposure, 20 (20.2%) subjects had an RVOT notch [notch (+)], and 79 (79.8%) subjects did not have an RVOT notch [notch (−)]. In the multivariate logistic regression analysis, the SPAP, right ventricular global longitude strain (RV GLS), and tricuspid E/A were independently associated with the RVOT notch. The SPAP, mPAP, PVR, standard deviations of the times to peak systolic strain in the four mid-basal RV segments (RVSD4), peak velocity of the isovolumic contraction period (ICV), and the peak systolic velocity (s’) at the mitral/tricuspid annulus were increased in all subjects. Conversely, the pulse oxygen saturation (SpO2), RV GLS, and tricuspid annulus plane systolic excursion (TAPSE)/SPAP were decreased. However, the increases of SPAP, mPAP, PVR, and RVSD4 and the decreases of SpO2, RV GLS, and TAPSE/SPAP were more pronounced in the notch (+) group than in the notch (−) group. Additionally, increased tricuspid ICV and mitral/tricuspid s’ were found only in the notch (−) group.ConclusionHA exposure-induced RVOT notch formation is associated with impaired RV function, including no increase in the tricuspid ICV or s’, reduction of RV deformation, deterioration in RV-pulmonary artery coupling, and RV intraventricular synchrony.

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