Ground studies indicate that spaceflight may diminish vascular contraction. To examine that possibility, vascular function was measured in spontaneously hypertensive rats immediately after an 18-day shuttle flight. Isolated mesenteric resistance arterial responses to cumulative additions of norepinephrine, acetylcholine, and sodium nitroprusside were measured using wire myography within 17 h of...

We hypothesized that pregnancy modulates receptor-mediated responses of the uterine artery (UA) by altering G protein activation or coupling. Relaxation and contraction to NaF (0.5-11.5 mM), acetylcholine (10(-9)-10(-5) M), and bradykinin (10(-12)-3 x 10(-5) M) were measured in isolated UA of pregnant and nonpregnant guinea pigs. Responses were measured in the presence and absence of either cho...

BACKGROUND Perioperative bronchospasm refractory to β agonists continues to challenge anesthesiologists and intensivists. The TMEM16A calcium-activated chloride channel modulates airway smooth muscle (ASM) contraction. The authors hypothesized that TMEM16A antagonists would relax ASM contraction by modulating membrane potential and calcium flux. METHODS Human ASM, guinea pig tracheal rings, o...

Acetylcholine elicited a sustained contraction and an increase in potassium efflux in longitudinal muscle isolated from the guinea pig ileum. Stepwise increases in the calcium concentration of the bathing medium, from 0.06 to 36 mM generally reduced the increase in potassium efflux, but had a complex effect on the mechanical response. Contractions produced by high levels of acetylcholine became...

The effects of clenbuterol, a selective beta 2-agonist, on isolated smooth muscle preparations from the rabbit bladder body, bladder base and proximal urethra have been investigated. The inhibitory effects on resting tension and acetylcholine- and field stimulation-induced contractions in the bladder body were compared with those of flavoxate, atropine, and verapamil. Clenbuterol (10(-10)-10(-7...

BACKGROUND Airway instrumentation can evoke upper airway reflexes including bronchoconstriction and cough which can cause serious complications including airway trauma, laryngospasm or bronchospasm which may in turn lead to difficulty with ventilation and hypoxemia. These airway events are mediated in part by irritant-induced neuronal modulation of airway tone and cough responses. We investigat...

Introduction: Thymol has negative ionotropic effect on heart and has direct effect on calcium release from sarcoplasmic reticulum. Some of the herbal plants just like carum copticum consist of thymol. The postganglionic neurons of the gastrointestinal parasympathetic system are located mainly in the myenteric and submucosal plexuses. Stimulation of these parasympathetic nerves causes general in...

Reorganization of the cytoskeleton and association of contractile proteins are important steps in modulating smooth muscle contraction. Heat shock protein (HSP) 27 has significant effects on actin cytoskeletal reorganization during smooth muscle contraction. We investigated the role of phosphorylated HSP27 in modulating acetylcholine-induced sustained contraction of smooth muscle cells from the...