Muscle action types

Polymer-metal composites Cationic mobility activated electrically in membranes of the Nafion (DuPont) and Flemion (Asahi Glass) type leads to a bending response, again mimicking muscle action. 

Opening membrane ion channels. These are the ion-channel ligands, which bind to and selectively open ion channels of nematode muscle. Three types of ion channel are the sites of action of this group of anthelmintics ... 

Holton My understanding is that the vena cava is a tonic smooth muscle, and therefore it is right at one end of a spectrum of smooth muscle contractile types. This means that, it generates tension slowly, it maintains tension when it is activated and it doesn t show action potentials. Its organization may be very different from a phasic smooth muscle that normally operates by action potentials and cannot maintain tension. 

Autonomic receptors further regulate calcium influx through the sarcolemma (Fig. 15.1). (3-Adrenergic stimulation results in the association of a catalytic subunit of a G protein coupled to the (3-receptor. This stimulates the enzyme adenylyl cyclase to convert ATP to cyclic adenosine monophosphate (cAMP). Increasing cAMP production results in a cAMP-dependent phosphorylation of the L-type calcium channel and a subsequent increase in the probability of the open state of the channel. This translates to an increase in transsarcolemmal calcium influx during phase 2 (the plateau phase) of the cardiac muscle action potential. The effects of transient increases in intracellular levels of cAMP are tightly con-... 

Takahashi, M., Kubo, T., Mizoguchi, A., Carlson, C. G., Endo, K. and Ohnishi, K. (2002) Spontaneous muscle action potentials fail to develop without fetal-type acetylcholine receptors. EMBORep 3, 674-681. 

Stimulation of the peripheral nerve trunk of intact animals leads to generation of muscle action potentials of three types. According to the duration of latent periods, they fall into the following order M-response (the result of the direct stimulation of a-motor neuron axons), Fl-response (the monosynaptic response), and polysynaptic responses with the variable latent period from 8-12 up to about 40 ms. In test animals of the III group, the changes of temporal parameters refer mainly to the latent period and duration of M-response (Table 7.4). Polysynaptic responses occur at all intensities of excitation and have a more pronounced character than in intact rats. A marked level and more distinct differentiation of the peaks of the complex action potential were noted. 

COMPOUNDS ACTING IN MUSCLE Ciglitazone-type compounds Animal studies Mechanism of action Clinical studies... 

Dihydropyridine calcium channel blockers (CCBs) have been used for many years in the treatment of angina pectoris and hypertension (81). Their mechanism of action is based on inhibition of the smooth muscle L-type calcium current, thereby... 

Action Type of movement made by a muscle contraction. 

Stimulation of the peripheral nerve trunk of intact animals leads to generation of muscle action potentials of three types. According to the dmation of latent periods, they fall into the following order (i) M-response... 

General types of physiological functions attributed to quaternary ammonium compounds are curare action, muscarinic—nicotinic action, and ganglia blocking action. The active substance of curare is a quaternary that can produce muscular paralysis without affecting the central nervous system or the heart. Muscarinic action is the stimulation of smooth-muscle tissue. Nicotinic action is primary transient stimulation and secondary persistent depression of sympathetic and parasympathetic ganglia. 

It resembles atropine in its range of activity but in particular types of action it may differ quantitatively thus its action on the pupil is equal to that of atropine but shorter in duration, and that is also true of its antagonisni to the effect of acetylcholine on the isolated perfused cat s COTt, but its activity on the salivary gland and the blood pressure of the. IS greater than that of atropine, while its action on smooth muscle... 

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