Search

Introduction The left ventricle differs anatomically and functionally from the right ventricle. Therefore, information on the pathophysiology of the left ventricle cannot be directly extrapolated to the right ventricle (Sanz [...], Exhaustive exercise can cause subclinical inflammation to the heart, as it is an oxidative tissue that works continuously. The effect of exhaustive exercise on left and right ventricles (LVs, RVs) may be different. It is claimed that paraoxonase-1 (PON1), an antioxidant enzyme, has a cardioprotective effect on oxidative stress. Rats were separated as non-exercised controls (Con), those euthanized immediately after (E-0) and 24 h after exhaustive exercise (E-24). Cardiac troponin-I (cTnI), total antioxidant status (TAS), total oxidant status (TOS), PON1 activities, and histological findings in LV and RV of the exhausted rats were evaluated. TAS and PON1 levels were lower in LVs compared with RVs of all groups. TOS levels were high in LVs compared with RVs of all groups. In LVs, TAS levels decreased significantly in the E-0 group while PON1 activity decreased in E-0 and E-24 groups compared with controls. In LVs, TOS levels decreased significantly in E-0 and E-24 groups, but in RVs a decrease was seen only in the E-0 group. cTnI levels increased significantly in the E-0 group and decreased to control levels in the E-24 group. Considering the histological and biochemical findings, exhaustive exercise affected the heart to the maximum during and just after exhaustion, and LV was influenced more than RV. Key words: exhaustive exercise, inflammation, paraoxonase-1, left ventricle, right ventricle. L'exercice physique jusqu'a l'epuisement peut entrainer une inflammation du coeur subclinique, puisqu'il s'agit de tissu oxydatif en travail continu. L'effet de l'exercice physique epuisant pourrait etre different entre les ventricules gauche et droit (VG et VD). On revendique que la paraoxonase-1 (PON1), une enzyme antioxydante, a un effet cardioprotecteur contre le stress oxydatif. Nous avons reparti les rats de la maniere suivante: temoins sans exercice physique (Tem), ceux qui etaient euthanasies immediatement apres (E-0) et 24 heures apres l'exercice physique epuisant (E-24). Nous avons evalue la troponine I cardiaque (cTnI), l'etat d'antioxydation total (EAT), l'etat d'oxydation total (EOT), l'activite de la PON1 et les observations histologiques dans le VG et le VD des rats epuises. L'EAT et l'activite de la PON1 etaient moins eleves dans les VG que dans les VD de tous les groupes. L'EOT etait plus eleve dans le VG que dans le VD de tous les groupes. Dans les VG, l'EAT diminuait de facon plus marquee dans le groupe E-0 que chez les temoins, tandis que l'activite de la PON1 diminuait de facon plus marquee dans les groupes E-0 et E-24 que chez les temoins. Dans les VG, l'EOT etait nettement moins eleve dans les groupes E-0 et E-24, mais on observait la diminution dans les VD uniquement dans le groupe E-0. Les taux de cTnI augmentaient de facon marquee dans le groupe E-0, et ils diminuaient jusqu'aux taux des temoins dans le groupe E-24. Etant donne les resultats histologiques et en biochimiques, l'exercice physique jusqu'a l'epuisement affectait le coeur a un degre maximal pendant ou juste apres l'epuisement, et le VG etait plus atteint que le VD. [Traduit par la Redaction] Mots-cles: exercice physique jusqu'a l'epuisement, inflammation, paraoxonase- 1, ventricule gauche, ventricule droit.

OBJECTIVE The growth arrest of epiphyseal plates is an inevitable complication of radiotherapy in most pediatric cancer patients, yet our understanding of the regulatory mechanisms governing the recovery response remains limited. This experiment sought to delve into the roles of yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ) transcriptional co-activators, crucial drivers of the regenerative process, in this recovery response. METHODS In the study, thirty-six 8-week-old male rabbits underwent radiotherapy targeting the left distal femur and proximal tibia growth plates, while the right extremity served as an unirradiated control. The rabbits were divided into six groups based on post-irradiation time points (1, 7, 10, 14, 17, and 21 days). Histomorphological assessments through hematoxylin-eosin staining and immunohistochemical labeling of PTHrP, YAP1, and TAZ were conducted on the excised growth plates from both irradiated and unirradiated sides. RESULTS The initial week post-radiotherapy exhibited arresting effects, including increased apoptosis, reduced proliferative activity, and disruption of the columnar structure. Evidence of the recovery response, characterized by regenerative chondrocyte clones, became evident around day 10 and peaked on day 14. Subsequently, cellular and structural degeneration prevailed, with a transition to osteogenesis in the following days. The radiation notably decreased the nuclear immunopositivity ratio of the three molecules. While nuclear expression levels of YAP1 and TAZ initially declined within the 1st week, they subsequently rebounded sharply, though not reaching control levels. CONCLUSION These preliminary findings suggest that YAP1 and TAZ could play a pivotal role as regulators in the recovery response of growth plates following irradiation. [ABSTRACT FROM AUTHOR]

Copyright of Gazi Medical Journal is the property of Galenos Yayinevi Tic. LTD. STI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Gazi Medical Journal is the property of Galenos Yayinevi Tic. LTD. STI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)