Marvanova, Aneta* Dotaz Zobrazit nápovědu
The infarct size-limiting effect elicited by cold acclimation (CA) is accompanied by increased mitochondrial resistance and unaltered β1-adrenergic receptor (AR) signaling persisting for 2 wk at room temperature. As the mechanism of CA-elicited cardioprotection is not fully understood, we examined the role of the salvage β2-AR/Gi/Akt pathway. Male Wistar rats were exposed to CA (8°C, 5 wk), whereas the recovery group (CAR) was kept at 24°C for additional 2 wk. We show that the total number of myocardial β-ARs in the left ventricular myocardium did not change after CA but decreased after CAR. We confirmed the infarct size-limiting effect in both CA and CAR groups. Acute administration of β2-AR inhibitor ICI-118551 abolished the protective effect in the CAR group but had no effect in the control and CA groups. The inhibitory Giα1/2 and Giα3 proteins increased in the membrane fraction of the CAR group, and the phospho-Akt (Ser473)-to-Akt ratio also increased. Expression, phosphorylation, and mitochondrial location of the Akt target glycogen synthase kinase (GSK-3β) were affected neither by CA nor by CAR. However, GSK-3β translocated from the Z-disk to the H-zone after CA, and acquired its original location after CAR. Our data indicate that the cardioprotection observed after CAR is mediated by the β2-AR/Gi pathway and Akt activation. Further studies are needed to unravel downstream targets of the central regulators of the CA process and the downstream targets of the Akt protein after CAR.NEW & NOTEWORTHY Cardioprotective effect of cold acclimation and that persisting for 2 wk after recovery engage in different mechanisms. The β2-adrenoceptor/Gi pathway and Akt are involved only in the mechanism of infarct size-limiting effect occurring during the recovery phase. GSK-3β translocated from the Z-line to the H-zone of sarcomeres by cold acclimation returns back to the original position after the recovery phase. The results provide new insights potentially useful for the development of cardiac therapies.
- MeSH
- aklimatizace MeSH
- beta-2-adrenergní receptory MeSH
- fosforylace MeSH
- GSK3B MeSH
- krysa rodu rattus MeSH
- potkani Wistar MeSH
- protoonkogenní proteiny c-akt metabolismus MeSH
- reperfuzní poškození myokardu * MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Quaternary ammonium salts (QUATs) are compounds with wide use in organic synthesis, pharmacy or other fields of industry. Thanks to their specific physical and chemical properties resulting from their amphiphilic character they are already used as phase-transfer catalysts, ionic liquids, dyes, antimicrobial agents and disinfectants, antiarrhythmics, bronchodilators etc. There is still an effort to prepare new active compounds. Several organosynthetic methods are used to prepare QUATs: probably the best way is the Menshutkin reaction. Recently, also a microwave synthesis was introduced to prepare QUATs bringing better yields, shorter reaction times and a possibility of solvent-free reactions.
PURPOSE OF THE STUDY: The study was designed to investigate whether anatomical variations of the anterior and posterior divisions of the internal iliac artery and their branches are associated with different risks of bleeding resulting from injury to the posterior pelvic segment. MATERIAL AND METHODS: The study was carried out on 19 cadavers. The dissected area included the internal iliac artery from the common iliac artery bifurcation to the origins of the superior gluteal artery, the inferior gluteal artery and the internal pudendal artery. Using an electronic slide rule, distances between the bifurcation and the origin of each branch from either the anterior or the posterior division were measured. The diameter of each vessel was also determined. Findings of the study were compared with variations described in the literature. The degree of risk for bleeding related to different anatomical variations of the internal iliac artery and its branches was evaluated based on the proximity to the bone. RESULTS: There are six anatomical variations of internal iliac artery branches. Four of them were found: type A1 was recorded in 10 specimens, type A2 in six, type B1 in two and type C in one specimen. Types B2 and D were not seen. DISCUSSION: The type B2 and C anatomical variations were considered to carry higher risks of bleeding due to injury to the posterior pelvic segment. These variations are characterized by vessels larger in diameter and a longer course of the posterior division along the posterior part of the greater sciatic notch (area often involved in unstable pelvic ring fractures). On the other hand, the type C variation showed a longer internal iliac artery separated from the bone with a thick layer of soft tissue, which suggested lower risk than was attributed to the dominant type A1 variation. It was not possible to evaluate type B2 variation because it is very rare and was not found in study material. In type A2 and B1 variations, the branches were separated from bony structures similarly to the dominant type A1 variation. CONCLUSIONS: The cadaver study designed to assess the risk of bleeding associated with different morphological variations of the branching pattern of the internal iliac artery did not identify any anatomical arrangement that might carry a higher risk of injury to the vessels by free bone fragments of the posterior segment in unstable pelvic fractures. It can be concluded that less common branching patterns of the internal iliac artery are not associated with higher risk of bleeding than the dominant type A1 variation.
- MeSH
- arteria iliaca anatomie a histologie zranění MeSH
- fraktury kostí komplikace MeSH
- hodnocení rizik metody MeSH
- krvácení etiologie MeSH
- lidé MeSH
- mrtvola MeSH
- pánevní kosti zranění MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
