Dependence of energy transduction in intact skeletal muscles on the time in tension
| Autor: | M. Orentlicher, Masataka Kawai, Philip W. Brandt |
|---|---|
| Jazyk: | angličtina |
| Předmět: |
medicine.medical_specialty
Biophysics Astacoidea Biology In Vitro Techniques Contractility chemistry.chemical_compound Internal medicine Myosin medicine Animals Actin Adenosine Triphosphatases Tension (physics) Muscles Rana pipiens Actomyosin Crayfish Coupling (electronics) Kinetics Endocrinology chemistry Energy Transfer medicine.symptom Anura Caffeine Muscle contraction Research Article Muscle Contraction |
| Zdroj: | Biophysical Journal. (2):161-172 |
| ISSN: | 0006-3495 |
| DOI: | 10.1016/S0006-3495(77)85605-1 |
| Popis: | In intact single crayfish muscle fibers and frog semitendinosus muscles we have studied the tension response to sinusoidal length changes in the frequency range of 0.25–133 Hz. By this method we have resolved three processes in the interaction of myosin cross-bridges with actin in fully activated preparations. They are (A) a low-frequency phase advance, (B) a middle-frequency delay, and (C) a high-frequency advance. These processes can be used as probes to study the chemomechanical coupling of contractility. Process (B) represents net power output from the muscle preparation (oscillatory work). With maximal K or caffeine activation of crayfish muscle at 20 degrees C, it decreases to zero in the initial 45 s of maintained tension. Similar results were obtained with frog semitendinosus whole muscles. We interpret this decrease of (B) with time as a gradual decrease in actomyosin ATP-hydrolysis rate. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|