Muscle stimulant activity

Skeletal muscle stimulant activity. Ethanol (95%) extract of the seed, at a concentration of 10 mg/mL, was inactive on frog rectus abdominus muscle . 

Analgesic efficacy and clinical use Pethidine (Clark et al.,1995 Latta et al., 2002) is used for the treatment of moderate to severe pain including labor pain. It is also used as preoperative medication and as an adjunct to anesthesia. Due to its anti-muscarinic properties, it has a weaker muscle stimulant activity than other opioids and does not increase biliary pressure, which makes it suitable for the treatment of pain associated with pancreatitis or biliary colic. 

The discovery that polyporic acid (11) exhibits antileukemic activity (146) induced the synthesis of numerous analogues (148, 149, 150). The pigment also causes contraction of isolated rabbit ileum suspended in oxygenated Tyrode solution (395). Similarly, atromentin (13) shows significant smooth muscle stimulant activity (638) and proves to be an effective anticoagulant (226, 409). Polyporic acid lacks this latter property completely (409). 

Calcium is the trigger behind the muscle contraction process (24,25). Neural stimulation activates the release of stored Ca(Il) resulting in a dramatic increase in free calcium ion levels. The subsequent binding of Ca(Il) resulting in a dramatic increase in free calcium ion levels. The subsequent binding of Ca(Il) to the muscle protein troponin C provides the impetus for a conformational change in the troponin complex and sets off successive events resulting in muscle contraction. 

Caffeine is a mild to potent CNS stimulant, with the degree of its stimulating effect dependent on the dose administered. Caffeine stimulates the CNS at all levels, including the cerebral cortex, die medulla, and the spinal cord. Caffeine has mild analeptic (respiratory stimulating) activity. Other actions include cardiac stimulation (which may produce tachycardia), dilatation of coronary and peripheral blood vessels, constriction of cerebral blood vessels, and skeletal muscle stimulation. Caffeine also has mild diuretic activity. 

M Schramm, G Thomas, R Towart, G Frackowiak. (1983). Activation of calcium channels by novel 1,4-dihydropyridines. A new mechanism for positive inotropies of smooth muscle stimulants. Arzneim Forsch 33 1268-1272. 

As discussed in the previous section, all the effects of the ANS in tissues and organs throughout the body, including smooth muscle contraction or relaxation alteration of myocardial activity and increased or decreased glandular secretion, are carried out by only three substances acetylcholine, norepinephrine, and epinephrine. Furthermore, each of these substances may stimulate activity in some tissues and inhibit activity in others. How can this... 

Multiple motor unit summation involves recruitment of motor units. As the number of motor units stimulated at any given moment increases, the strength of contraction increases. Asynchronous motor unit summation refers to the condition in which motor unit activation within a muscle is alternated. In other words, at one moment, some of the motor units within the muscle are activated, while other motor units are relaxed. This is followed by the relaxation of previously activated motor units and activation of previously relaxed motor units. Consequently, only a fraction of the motor units within the muscle generate tension at any given moment. Therefore, this type of summation may generate submaximal contractions only. 

All of these factors (ANS stimulation, blood-borne and locally produced substances) alter smooth muscle contractile activity by altering the intracellular concentration of calcium. An increase in cytosolic calcium leads to an increase in crossbridge cycling and therefore an increase in tension... 

Activation of brain H receptors also stimulates cGMP synthesis [19]. Outside the brain, histamine is known to relax vascular smooth muscle by activation of endothelial H receptors, thereby increasing endothelial Ca2+ concentrations and stimulating the synthesis and release of nitric oxide. The latter, a diffusible agent, then activates the smooth muscle guanylyl cyclase [30]. Although less is known about these mechanisms in the CNS, there is evidence that brain H receptor activation can produce effects that depend on guanylyl cyclase activity [19]. 

The short-acting / -agonists (Table 80-1) are the most effective broncho-dilators available. /J2-Adrenergic receptor stimulation activates adenyl cyclase, which produces an increase in intracellular cyclic adenosine monophosphate. This results in smooth muscle relaxation, mast cell membrane stabilization, and skeletal muscle stimulation. 

PDGFR Overexpression and autocrine stimulation. Activation of blood vessel smooth muscle cells in the media Glioblastomas, Restenosis, Atherosclerosis... 

Valine A branched-chain essential amino add that has stimulant activity. It promotes muscle growth and tissue repair. It is a precursor in the penicillin biosynthetic pathway. [NIH]... 

Figure 13.9 k soldier wounded at the Battle of Corunna (a battle in the Peninsular War) suffering simultaneous contraction of all muscles after infection with the bacterium, Clostridium tetani. Both agonist and antagonist muscles are active in this condition. The bacterium is found in the earth, especially in places where animal faeces have been present. Bacteria invade the body through a wound, especially in soldiers in battle. The bacterium secretes a toxin that is absorbed into the motor nerves which then become acutely responsive to mild stimuli. It can lead to death unless treated (from Bell 1824). The toxin is now used in cosmetic manipulation to stimulate contraction of muscles in the face to tighten the skin which removes or conceals wrinkles (Botox). 

Beta 2 Postsynaptic effector cells, especially smooth muscle and cardiac muscle Stimulation of adenylyl cyclase and increased cAMP. Activates cardiac G under some conditions. 

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