Fast-starts associated with escape responses were studied in short-horn sculpin (Myoxocephalus scorpius L.), ranging from 5.5 to 32 cm in total length (L). Electromyography and sonomicrometry were used simultaneously to measure muscle activation and length changes, respectively, in the superficial layers of fast muscle in rostral myotomes. Escape responses consisted of a half tailbeat to bend t...

The current understanding is that longitudinal muscle contraction begins before and outlasts circular muscle contraction during esophageal peristalsis in normal subjects. The goal of our study was to reassess the relationship between the contractility of two muscle layers using novel ways to look at the muscle contraction. We studied normal subjects using synchronized high-frequency ultrasound ...

It is known that muscle temperature (T(m)) increases with exercise. The purpose of this study was to examine if contraction-induced increase in T(m) was altered in rats with heart failure (HF) induced by chronic myocardial infraction (MI) as compared with healthy control animals. A temperature probe was inserted in the triceps surae muscle to continuously measure T(m) throughout experiments. St...

The mechanism of uterine muscle contraction stimulated by a triterpenoid glycoside (dalsaxin) isolated from the root of D. saxatilis was investigated by in vitro methods in the rat. Dalsaxin caused a dose-related increase in uterine muscle contraction. The contraction was single and transient and was abolished by moderate doses of isoprenaline (1.80 nmol-0.40 mumol) and salbutamol (0.13-25 mumo...

The pro-inflammatory cytokine IL-1beta contributes to the reduced contractile responses of gut smooth muscle observed in both animal colitis models and human inflammatory bowel diseases. However, the mechanisms are not well understood. The effects of IL-1beta on the signaling targets mediating acetylcholine (ACh)-induced initial and sustained contraction were examined using rabbit colonic circu...

Electrical stimulation has been used to prevent muscle atrophy, but this method is different in many previous studies, appropriate stimulation protocol is still not decided. Although resistance exercise has also been shown to be an effective countermeasure on muscle atrophy, almost previous studies carried out an electrical stimulation without resistance. It was hypothesized that electrical sti...

c-Jun NH(2)-terminal kinase (JNK) is highly expressed in skeletal muscle and is robustly activated in response to muscle contraction. Little is known about the biological functions of JNK signaling in terminally differentiated muscle cells, although this protein has been proposed to regulate insulin-stimulated glycogen synthase activity in mouse skeletal muscle. To determine whether JNK signali...

[Purpose] During exercise, skeletal muscle motor units are recruited based on afferent sensory input following peripheral metabolic by-product accumulation. The purpose of this study was to investigate whether lactate plays a role in conveying fatigue-related information to the brain. [Subjects] Eleven healthy adults participated in this study. [Methods] Subjects performed handgrip exercises at...

The purpose of this study was to test the hypothesis that increasing muscle contraction frequency, which alters the duty cycle and metabolic rate, would increase the contribution of the contractile phase to mean venous blood flow in isolated skeletal muscle during rhythmic contractions. Canine gastrocnemius muscle (n = 5) was isolated, and 3-min stimulation periods of isometric, tetanic contrac...