Author/Editor		Petrač, Z
Title		Vpliv metaboličnih inhibitorjev na tetanično kontrakcijo skeletnih mišic laboratorijske podgane
Type		monografija
Place		Ljubljana
Publisher		Medicinska fakulteta
Publication year		1993
Volume		str. 39
Language		slo
Abstract		Metabolic inhibitors and anoxia were used for evaluating the role of particular re-synthetic adenosine-triphosphate (ATP) mechanisms in isotonic tetanic rise-time (tR) of isolated rat skeletal muscles. tR was defined as a time from 20 to 80 per cent of maximal isotonic tetanic contraction and was determined from tetanic mechanograms of isolated soleus and extensor digitorum longus (FDL) muscles of Wistar rats. Soleus is mostly composed of slow twitching, oxidative fibres. On the contrary EDL contains predominantly fast twitching, glycolytic fibres. The effect of anoxia on tR at 22 degrees C was established by comparing tR of muscles, perfused in Ringer solution in normoxic conditions and paired muscles, perfused the same, but under anoxic conditions. tR of paired muscles were compared. The effects of inhibitors on tR at 22 degrees C were established by comparing tR of muscles, perfused with inhibitors in Ringer solution, and paired muscles, perfused with Ringer solution alone in normoxic and in anoxic conditions. The effects of following inhibitors were determined: -iodoacetate (IA), 2.4-dinitrofluorobenzene (2,4-DNFB) and a mixture of both in normoxic conditions, - IA, 2.4-DNFB and a mixture of both in anoxic conditions. IA is the inhibitor of glyceraldehyde-3-phosphate dehydrogenase and blocks the substrate phosphorylation of adenosine diphosphate (ADP) during glycoly$is. 2.4-DNFB inhibits creatine kinase and blocks ATP re-synthesis from creatine phosphate. The anoxia prevents oxidative phosphorylation of ADP in mitochondria. IA had no statistical significant effects on tR. Glycogenolysis, anaerobic and aerobic metabolism of glucosis are less important sources of ATP in soleus muscle.(trunc.)
Descriptors		MUSCLE CONTRACTION IODOACETATES DINITROFLUOROBENZENE ANOXIA RATS ISOTOPIC CONTRACTION HISTOCYTOCHEMISTRY MUSCLES ANIMALS, LABORATORY