Membrane fluidity is a widely recognized biophysical variable that provides information about structural organization of the subcellular membranes exhibiting physical characteristics of liquid crystals. The term “fluidity” reflects in this case the tightness in packing of acyl parts of the membrane phospholipid molecules, a feature that may influence considerably the molecular mobility and via that also the sensitivity and reactivity of membranebound transporters, receptors and enzyme systems. Data presented in this review are aimed to demonstrate the substantial role of changes in membrane fluidity occurring in the processes associated with endogenous protection observed in cardiac sarcolemma and mitochondria in diverse pathologies, particularly in diabetes and hypertension.
- MeSH
- buněčná membrána metabolismus MeSH
- fluidita membrány fyziologie MeSH
- fosfolipidy metabolismus MeSH
- krysa rodu rattus MeSH
- membránové lipidy metabolismus MeSH
- myokard metabolismus MeSH
- sarkolema metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- přehledy MeSH
Our previous preliminary results pointed to possible seasonal variations in Mg2+-ATPase activity of rat heart mitochondria (MIT). It is not too surprising since seasonal differences were already reported in myocardial function, metabolism and ultrastructure of the intact as well as hemodynamically overloaded rabbit hearts and also in other tissues. The present study is aimed to elucidate whether seasonal differences observed in rat heart MIT Mg2+-ATPase activity will be accompanied with changes in membrane fluidity and in the content of conjugated dienes (CD) in the lipid bilayers of MIT membranes as well as whether the above seasonal differences will also be present in the diabetic heart. Our results revealed that values of Mg2+-ATPase activity in the winter/spring-period (W/S-P) exceeded significantly (p<0.05-0.001) those in the summer/autumn-period (S/A-P). Similar trend was also observed in hearts of animals with acute (8 days) streptozotocin diabetes. With the exception of values of CD in the S/A-P, all values of Mg2+-ATPase activities, membrane fluidity and CD concentrations in diabetic hearts exceeded those observed in the healthy hearts. Our results indicate that seasonal differences may play a decisive role in the evaluation of properties and function of rat heart MIT.
- MeSH
- Ca(2+)-Mg(2+)-ATPasa metabolismus MeSH
- experimentální diabetes mellitus enzymologie MeSH
- fluidita membrány * MeSH
- krysa rodu rattus MeSH
- membránové lipidy metabolismus MeSH
- mitochondriální membrány enzymologie MeSH
- peroxidace lipidů MeSH
- potkani Wistar MeSH
- roční období * MeSH
- srdeční mitochondrie enzymologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
The aim of present study was to investigate functional and physical alterations in membranes of heart mitochondria that are associated with remodeling of these organelles in acute phase of streptozotocin-induced diabetes and to elucidate the role of these changes in adaptation of the heart to acute streptozotocin-induced diabetes (evaluated 8 days after single dose streptozotocin application to male Wistar rats). Action of free radicals on the respiratory chain of diabetic-heart mitochondria was manifested by 17 % increase (p<0.05) in oxidized form of the coenzyme Q(10) and resulted in a decrease of states S3 and S4 respiration, the respiratory control index, rate of phosphorylation (all p<0.01) and the mitochondrial transmembrane potential (p<0.05), but the ADP/O ratio decreased only moderately (p>0.05). On the contrary, membrane fluidity and the total mitochondrial Mg2+-ATPase activity increased (both p<0.05). In diabetic heart mitochondria, linear regression analysis revealed a reciprocal relationship between the increase in membrane fluidity and decrease in trans-membrane potential (p<0.05, r = 0.67). Changes in membrane fluidity, transmembrane potential, Mg2+-ATPase activity and the almost preserved ADP/O ratio appear as the manifestation of endogenous protective mechanisms participating in the functional remodeling of mitochondria which contributes to adaptation of the heart to diabetes.
- MeSH
- Ca(2+)-Mg(2+)-ATPasa metabolismus MeSH
- experimentální diabetes mellitus metabolismus patofyziologie MeSH
- fluidita membrány MeSH
- fyziologická adaptace MeSH
- krysa rodu rattus MeSH
- membránový potenciál mitochondrií MeSH
- mitochondriální membrány metabolismus MeSH
- myokard enzymologie metabolismus MeSH
- oxidativní fosforylace MeSH
- potkani Wistar MeSH
- srdeční mitochondrie enzymologie metabolismus MeSH
- transport elektronů MeSH
- ubichinon analogy a deriváty metabolismus MeSH
- volné radikály metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- financování vládou MeSH
- Publikační typ
- abstrakty MeSH
- MeSH
- diabetické angiopatie farmakoterapie komplikace metabolismus MeSH
- finanční podpora výzkumu jako téma MeSH
- mitochondriální nemoci enzymologie metabolismus patofyziologie MeSH
- myokard enzymologie metabolismus patologie MeSH
- potkani Wistar anatomie a histologie MeSH
- reaktivní formy kyslíku chemie metabolismus škodlivé účinky MeSH
- synthasa oxidu dusnatého biosyntéza účinky léků MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- srovnávací studie MeSH
