To investigate the effect of in vivo heart irradiation on myocardial energy metabolism, we measured myocardial adenosine nucleotide concentrations and mitochondrial oxygen consumption in left ventricular tissue of rats 0-16 months after local heart irradiation (20 Gy). At 24 h and 2 months no difference in myocardial adenosine nucleotide concentration was apparent between irradiated and control hearts. The total myocardial adenosine nucleotide concentrations in irradiated hearts compared to those of nonirradiated controls tended to be lower from 4 months onward. The rate of oxidative energy production (state 3 respiration) in irradiated hearts was significantly reduced compared with that of age-matched controls from 2 months onward. Moreover, as a result of aging, a time-dependent decrease in the rate of oxidative energy production was observed in both irradiated and control hearts (P < 0.001). The respiratory control index (RCI = oxygen consumption in state 3/oxygen consumption in state 4) in irradiated hearts was not different from the RCI measured in age-matched control animals. During the period of study the RCI diminished significantly with age in both groups (P < 0.005). The number of oxygen atoms used per molecule of ADP phosphorylated (P/O ratio) was not influenced by the irradiation. The P/O ratio for the NAD(+)-linked substrates remained unchanged at a value of about 3 during the period studied. At 6 months after irradiation activities of myocardial enzymes such as lactate dehydrogenase, creatine kinase, citrate synthase, and cytochrome c oxidase were reduced. The reduction in myocardial energy production and the changes in energy supplies provide a mechanism to explain impaired contractility after local heart irradiation.
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
PD-L1 monoclonal antibody alleviated MI injury of left ventricular function via modulating CD47/SHP2/SIRPα/SYK/FcγR signalings in tumor associated macrophages.
Sci Rep
January 2025
Department of Radiotherapy, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei, China.
To investigate how PD-L1 monoclonal antibodies (mAbs) affect the left ventricular function in mice with myocardial infarction (MI) and through what mechanisms they exert their effects. In vivo experiments were conducted using 27 female BALB/c mice, which were divided equally into 3 groups. Cardiac function was assessed by ultrasound.
View Article and Find Full Text PDFMulti-institutional Knowledge-Based (KB) plan prediction benchmark models for whole breast irradiation.
Phys Med
January 2025
Medical Physics Dept IRCCS San Raffaele Scientific Institution Milano Italy.
Purpose: To train and validate KB prediction models by merging a large multi-institutional cohort of whole breast irradiation (WBI) plans using tangential fields.
Methods: Ten institutions (INST1-INST10, 1481 patients) developed their KB-institutional models for left/right WBI (ten models for right and eight models for left). The transferability of models among centers was assessed based on the overlap of the geometric Principal Component (PC1) of each model when applied to other institutions and/or on the presence of significantly different optimization policies.
Cardiac strangulation with chronic ab-extrinseco occlusion of the left-circumflex artery from an epicardial lead: a case report.
Eur Heart J Case Rep
January 2025
Department of Radiological and Hematological Sciences, Section of Radiology, Università Cattolica del Sacro Cuore, Largo Agostino Gemelli 8 - 00168 Rome, Italy.
Background: Cardiac strangulation (CS) from epicardial pacing leads (EPLs) is a rare and potentially lethal mechanical complication associated with epicardial pacemaker (PM) implantation.
Case Summary: We report a case of a 44-year-old-female patient presenting with chest and left shoulder pain in the absence of reported trauma with history of congenital atrioventricular block treated with epicardial PM implantation during the childhood and subsequent transvenous reimplantation over the years. Troponin I resulted within normal values and ECG, transthoracic echocardiography and chest X-ray documented no acute cardiopulmonary findings.
Multicentric Cross-Sectional Survey to Assess the Variation of Fractionation Strategies Used in the Management of Head and Neck Cancers in the Asian Region (INNOCENCE-ASIA).
JCO Glob Oncol
January 2025
Department of Radiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
Purpose: Head and neck cancers (HNCs) are in general treated with conventional fractionation regimen of 1.8-2 Gy per fraction. Altered fractionation (ALFT) strategies such as hypofractionation radiotherapy (HYPO-RT), accelerated fractionation radiotherapy (AFRT), and hyperfractionation radiotherapy (HFRT) have not been practiced uniformly across centers in different parts of the world.
View Article and Find Full Text PDFFrom skin to heart: The rare journey of pleomorphic dermal sarcoma metastasis.
Radiol Case Rep
March 2025
Department of Cardiology, Division of Specialist Medical Services, Gold Coast Hospital and Health Services, Southport, QLD 4215, Australia.
Cardiac tumours can be classified as neoplastic or non-neoplastic, with secondary tumours being significantly more common than primary ones. Among secondary tumours, melanoma has the highest propensity for cardiac involvement. Pleomorphic dermal sarcoma (PDS) is a rare skin neoplasm, with an estimated metastatic risk of 10% to 20%.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!