The Action of the Ionophores, X-537A and A-23187, on Smooth Muscle

1975 ◽  
Vol 53 (6) ◽  
pp. 1108-1114 ◽  
Author(s):  
V. C. Swamy ◽  
M. Ticku ◽  
C. R. Triggle ◽  
D. J. Triggle
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Vas Deferens ◽  
Intestinal Smooth Muscle ◽  
Contractile Effect ◽  
Longitudinal Smooth Muscle ◽  
A 23187 ◽  
Reserpine Treatment

The cation ionophore X-537A in the concentration range of 10−6 to 3 × 10−5 M produced contractions in the rat and guinea-pig vas deferens. No contractile effect was produced in either of the vasa deferentia preparations by the ionophore A-23187 in the concentration range of 10−7 to 5 × 10−5 M. In contrast, X-537A had no contractile effect on the guinea-pig ileal longitudinal smooth muscle while A-23187 produced a dose and [Ca2+] dependent contraction.The contractile effect of X-537A in the vasa deferentia preparations is abolished by phenoxybenzamine or prior reserpine treatment and is therefore attributed to the release of norepinephrine. The effect of A-23187 in the intestinal smooth muscle is attributed to a direct Ca2+ transporting action since its contractile effect is unaffected by histamine, acetylcholine, or 5-hydroxytryptamine antagonists.

The mechanism of action of ionophore A 23187 on guinea pig intestinal smooth muscle

1979 ◽  
Vol 57 (4) ◽  
pp. 348-358 ◽  
Author(s):  
Lois B. Rosenberger ◽  
D. J. Triggle
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Mechanism Of Action ◽  
Calcium Antagonists ◽  
Intestinal Smooth Muscle ◽  
Phase System ◽  
Muscarinic Agonist ◽  
Two Phase ◽  
Longitudinal Smooth Muscle ◽  
A 23187

The cation ionophore A 23187 behaves similarly to the potent muscarinic agonist, cis-2-methyl-4-dimethylaminomethyl-1,3-dioxolane methiodide (CD) in guinea pig ileal longitudinal smooth muscle generating contractile responses that are gradedly sensitive to the concentrations of Ca2+ext and Na+ext. A 23187 and CD responses are insensitive to tetrodotoxin and A 23187 responses are insensitive to atropine. The responses to CD, A 23187, and veratridine are all similarly sensitive to the calcium antagonists D 600 and BAY-1040. D 600 failed to antagonize the ability of A 23187 to transport Ca2+ in a toluene-butanol: water two-phase system. It is suggested that in guinea pig ileal smooth muscle A 23187 does not translocate Ca2+ext exclusively but serves also to activate Ca2+ channels perhaps by an initial depolarizing Na+ entry.

The action of the ionophore ionomycin in guinea-pig intestinal smooth muscle

1983 ◽  
Vol 61 (5) ◽  
pp. 535-538 ◽  
Author(s):  
G. T. Bolger ◽  
C. R. Triggle ◽  
D. J. Triggle
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Intestinal Smooth Muscle ◽  
Contraction Coupling ◽  
Longitudinal Smooth Muscle ◽  
A 23187 ◽  
Low Concentrations ◽  
Tissue Responses ◽  
Muscle Responses

The ionophore ionomycin produced concentration-dependent (5 × 10−9 to 5 × 10−6 M) contractions in guinea-pig ileal longitudinal smooth muscle. Responses were dependent on extracellular Ca2+, consistent with the known role of this Ca2+ source in supporting excitation–contraction coupling to a variety of stimulants in this tissue. Responses were insensitive to atropine (10−6 M) but were dependent upon extracellular Na+ and were completely blocked by low concentrations of the Ca2+-channel antagonists nicardipine. YC-93 (5 × 10−7 M), and D-600 (5 × 10−6 M). The behaviour of ionomycin is very similar to that shown by A 23187 in this tissue. Ionomycin, like A 23187, can apparently activate D-600 sensitive Ca2+ channels in the guinea-pig intestinal smooth muscle rather than simply translocating Ca2+EXT.

scholarly journals A CHOLINERGIC COMPONENT IN THE INNERVATION OF THE LONGITUDINAL SMOOTH MUSCLE OF THE GUINEA PIG VAS DEFERENS

1969 ◽  
Vol 41 (2) ◽  
pp. 462-476 ◽  
Author(s):  
Peter M. Robinson
Keyword(s):  
Smooth Muscle ◽  
Plasma Membrane ◽  
Guinea Pig ◽  
Smooth Muscle Cells ◽  
Plasma Membranes ◽  
Vas Deferens ◽  
Muscle Cells ◽  
Muscle Membrane ◽  
Smooth Muscle Tissue ◽  
Longitudinal Smooth Muscle

Acetylcholinesterase (AChE) has been detected on the plasma membrane of about 25% of the axons in the longitudinal smooth muscle tissue of guinea pig vas deferens. These axons are presumably cholinergic. No enzyme was detected in the remaining 75% of axons. These axons are presumably adrenergic. The plasma membrane of the Schwann cells associated with the cholinergic axons also stained for AChE. Some axon bundles contained only cholinergic or adrenergic axons while others contained both types of axon. When a cholinergic axon approached within 1100 A of a smooth muscle cell, there was a patch of AChE activity on the muscle membrane adjacent to the axon. It is suggested that these approaches are the points of effective transmission from cholinergic axons to smooth muscle cells. Butyrylcholinesterase activity was detected on the plasma membranes of all axons and smooth muscle cells in this tissue.

Histamine-operated calcium channels in intestinal smooth muscle of the guinea-pig

1987 ◽  
Vol 135 (1) ◽  
pp. 69-75 ◽  
Author(s):  
Nicole Morel ◽  
Jean-Paul Hardy ◽  
Théophile Godfraind
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Calcium Channels ◽  
Intestinal Smooth Muscle

scholarly journals Local Ca2+transients and distribution of BK channels and ryanodine receptors in smooth muscle cells of guinea-pig vas deferens and urinary bladder

2001 ◽  
Vol 534 (2) ◽  
pp. 313-326 ◽  
Author(s):  
Yoshiaki Ohi ◽  
Hisao Yamamura ◽  
Norihiro Nagano ◽  
Susumu Ohya ◽  
Katsuhiko Muraki ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Urinary Bladder ◽  
Guinea Pig ◽  
Smooth Muscle Cells ◽  
Vas Deferens ◽  
Ryanodine Receptors ◽  
Muscle Cells ◽  
Bk Channels
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