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
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
- MeSH
- Ca(2+)-Mg(2+)-ATPasa metabolismus MeSH
- hypothalamus metabolismus MeSH
- krysa rodu rattus MeSH
- lithium aplikace a dávkování metabolismus terapeutické užití MeSH
- modely nemocí na zvířatech MeSH
- mozková kůra metabolismus MeSH
- sodíko-draslíková ATPasa metabolismus MeSH
- thalamus metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- přehledy MeSH
- srovnávací studie MeSH
- MeSH
- Ca(2+)-Mg(2+)-ATPasa metabolismus MeSH
- experimentální diabetes mellitus enzymologie komplikace krev MeSH
- guanidiny farmakologie MeSH
- kardiomyopatie komplikace metabolismus MeSH
- krysa rodu rattus MeSH
- sarkolema enzymologie metabolismus účinky léků MeSH
- sodíko-draslíková ATPasa MeSH
- vápník metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- MeSH
- anestetika lokální farmakologie chemická syntéza MeSH
- Ca(2+)-Mg(2+)-ATPasa antagonisté a inhibitory metabolismus MeSH
- cinchokain farmakologie MeSH
- karbamáty farmakologie MeSH
- králíci MeSH
- piperidiny farmakologie chemická syntéza MeSH
- sarkoplazmatické retikulum enzymologie účinky léků MeSH
- techniky in vitro MeSH
- tetrakain farmakologie MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- MeSH
- adenosintrifosfát chemie metabolismus MeSH
- amitriptylin farmakologie MeSH
- Ca(2+)-Mg(2+)-ATPasa chemie metabolismus MeSH
- Ca2+-ATPasy metabolismus MeSH
- chlordiazepoxid farmakologie MeSH
- krysa rodu rattus MeSH
- mozek - chemie MeSH
- mozek enzymologie MeSH
- psychotropní léky farmakologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
