Biomaterial Database

Effects of twitch train on the tetanic contractility of the frog skeletal muscle. 1983

H Kawata

The effects of twitch trains on the contractility of succeeding tetani were investigated in the frog toe muscle. The changes in isometric tension and its first derivative were analyzed. Tetani of 1 sec duration were induced every 5 min and trains of twitches (less than 250) with 0.1 to 3 Hz were interposed between two successive tetani. A twitch train which clearly shows an ascending staircase exerted at least three different effects on the following tetani. These were a rapidly decaying potentiation (P1), a slowly decaying potentiation (P2), and an inhibitory effect (I) which was regarded as fatigue. These after-effects were modified by various interventions. Increasing of the twitch frequency at a constant number of stimuli augmented both the potentiating and the inhibiting effects. When the bath temperature was lowered to 4 degrees C, the potentiation was masked by a marked inhibition. At a higher temperature (28 degrees C) the potentiating effect was facilitated. Prolonged perfusion of low concentration (0.5 mM) of caffeine mimicked the effects of low temperature. Effects of twitch train on the contracture induced by 5 mM caffeine were examined and it was found that the repetitive twitches had no effect on the following caffeine contracture. Although the exact mechanism for these after-effects was not clear, it was assumed that the intracellular calcium turnover may play some role in the observed phenomena.

UI	MeSH Term	Description	Entries
D009119	Muscle Contraction	A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.	Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
D011892	Rana catesbeiana	A species of the family Ranidae (true frogs). The only anuran properly referred to by the common name "bullfrog", it is the largest native anuran in North America.	Bullfrog,Bullfrogs,Rana catesbeianas,catesbeiana, Rana
D011898	Ranidae	The family of true frogs of the order Anura. The family occurs worldwide except in Antarctica.	Frogs, True,Rana,Frog, True,True Frog,True Frogs
D002110	Caffeine	A methylxanthine naturally occurring in some beverages and also used as a pharmacological agent. Caffeine's most notable pharmacological effect is as a central nervous system stimulant, increasing alertness and producing agitation. It also relaxes SMOOTH MUSCLE, stimulates CARDIAC MUSCLE, stimulates DIURESIS, and appears to be useful in the treatment of some types of headache. Several cellular actions of caffeine have been observed, but it is not entirely clear how each contributes to its pharmacological profile. Among the most important are inhibition of cyclic nucleotide PHOSPHODIESTERASES, antagonism of ADENOSINE RECEPTORS, and modulation of intracellular calcium handling.	1,3,7-Trimethylxanthine,Caffedrine,Coffeinum N,Coffeinum Purrum,Dexitac,Durvitan,No Doz,Percoffedrinol N,Percutaféine,Quick-Pep,Vivarin,Quick Pep,QuickPep
D004558	Electric Stimulation	Use of electric potential or currents to elicit biological responses.	Stimulation, Electric,Electrical Stimulation,Electric Stimulations,Electrical Stimulations,Stimulation, Electrical,Stimulations, Electric,Stimulations, Electrical
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures
D014034	Toes	Any one of five terminal digits of the vertebrate FOOT.	Toe