Unstriated Muscle Research Articles

The effect of temperature and ions on the impedance of unstriated muscle and its relation to permeability and excitability

The effect of temperature and ions on the impedance of unstriated muscle and its relation to permeability and excitability

Visco-elastic properties and contraction of unstriated muscle

(1) The similarity of the effects of ions on the protoplasmic viscosity of simple organisms and that on unstriated muscle suggest that the latter consists of a viscous protoplasmic non-contractile element. The similarity of the reactions of isolated myosin strips and isolated muscle suggests that it contains a contractile element. This view is supported by (a) the differential action of drugs, (b) viscous elastic properties of plain muscle, and by its histological picture. (2) Similarity of the responses of isolated muscle and isolated myosin suggests that plain muscle can contract without the use of oxygen.

The electrical resistance of unstriated muscle and other tissues and its relation to permeability and excitability

(1) As shown by the effect of death, resistance of the muscle to alternating current of low frequency is a measure of the permeability of the cell. (2) Permeability is high at low and high temperatures; frog muscle if heated beyond 35°C. and mammalian muscle beyond 40°C, is irreparably damaged, the resistance being permanently lowered. (3) Cations such as potassium, calcium, ammonium, magnesium increase the resistance of the muscle in small concentrations. (4) Anions such as Cl, Br, I, NO3, SCN, CN increase the resistance of the muscle in small concentrations. (5) Drugs and narcotics such as adrenaline, caffeine, novocaine, chloral hydrate, ether, chloroform, ethyl alcohol, butyl alcohol, octyl alcohol increase the resistance in small and decrease it in large concentrations. (6) Inhibition and narcosis are associated with increased resistance or decreased permeability. Increased excitability to ions without is associated with an opposite change. Excitability to electric current is increased with diminished permeability. (7) For excitation an optimum permeability is necessary. (8) The resistance of frog skin is higher than that of muscle.

Relation between Experiments on Isolated Muscle and Isolated Strips of Myosin

Astbury and Dickinson1 have shown that isolated strips of myosin from unstriated muscle show thermal contraction below 40° C. It is interesting to note that living muscle also begins to show increased tone at this temperature2, 3. The effect of alkalis is to increase the contraction of myosin ; in actual muscle, tone is increased in alkaline solutions4-7.

Reversal effects in unstriated muscle

(1) Hydrogen ions may convert an excitatory effect into an inhibitory one. (2) Calcium, sodium chloride and caffeine may produce reversal effects. (3) Presence of tone alters an excitatory effect into an inhibitory one. (4) Anions may convert an inhibitory effect into an excitatory one, and cations may produce an opposite effect. (5) Reversal effects are also produced by adaptation, fatigue, inexci-tability and change of length.

Surface and interior effects in unstriated muscle produced by various ions

Ions such as potassium, ammonium, hydrogen, to which the mu scleis permeable, neutralise the contractures produced by ions to which the muscle is comparatively less permeable, such as sodium chloride, adrenaline, acetylcholine. This suggests that excitation is caused by difference in concentrations of ions within and without the cells.

Isotonic extension of unstriated muscle

There are many variables involved in the extension of plain muscle. These are (1) tone, (2) viscosity, (3) extending force, (4) tonic contraction, (5) adaptation, (6) change of contraction with length, (7) change of viscosity with length, (8) change of viscosity with time, (9) stretch, (10) restoring force.

The effect of hydrogen ions and tonic contraction on the viscosity of unstriated muscle

(1) Plain muscle is capable of great changes in viscosity. The viscosity of plain muscle is about 100 to 1,000 times that of striated muscle and its movements correspondingly slower. (2) The viscosity of plain muscle increases as a result of tonic contraction, but is decreased during active contraction. (3) Hydrogen ions increase the viscosity; the optimum pH is 7·8, change on either side increasing the viscosity. The excitability is maximum at this pH. (4) Substances that decrease the rate of relaxation, increase the viscosity; plain muscle is thus able to keep up tension without expenditure of energy. During active contraction, viscosity decreases to facilitate movement.

The effect of the interaction of ions, drugs and electrical stimulation as indicated by the contraction of mammalian unstriated muscle

Human unstriated muscle differs from unstriated muscle of lower animals in the following respects: (1) The optimum temperature for excitability is higher, 37°. (2) Many substances affect the tone as well as the excitability to alternating current and potassium similarly. It is suggested that this is due to decrease of adaptation, as an increase produces inhibition.

The effect of temperature on the mechanical response and the viscosity and oxygen consumption of unstriated muscle

The effect of temperature on the mechanical response and the viscosity and oxygen consumption of unstriated muscle

A comparative study of the effect of the interaction of ions, drugs and electrical stimulation as indicated by contraction of unstriated muscle

A comparative study of the effect of the interaction of ions, drugs and electrical stimulation as indicated by contraction of unstriated muscle

The unstriated muscle fiber of the female pelvis

An imperfect smooth muscle diaphragm is present and embedded in fibrous tissue, lying between the pelvic peritoneum and the superior surface of the levator ani muscle. The bands which constitute this diaphragm may be divided into anterior, lateral, and posterior groups, converging on the cervix uteri. The attachments of these to the visceral and pelvic walls, and their function, are discussed in terms of the individual bands and the musculature as a whole. Operative procedures for the correction of sacropubic hernia are criticized, and their success or failure interpreted in the light of the dual nature of both parametrium and pelvic subperitoneal tissue.

The relation between the mechanical and electrical activity of a molluscan unstriated muscle

The Journal of PhysiologyVolume 91, Issue 2 p. 172-185 ArticleFree Access The relation between the mechanical and electrical activity of a molluscan unstriated muscle C. M. Fletcher, C. M. FletcherSearch for more papers by this author C. M. Fletcher, C. M. FletcherSearch for more papers by this author First published: 26 November 1937 https://doi.org/10.1113/jphysiol.1937.sp003550Citations: 12AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume91, Issue2November 26, 1937Pages 172-185 RelatedInformation

Excitation of the action potential of a molluscan unstriated muscle

The Journal of PhysiologyVolume 90, Issue 4 p. 415-428 ArticleFree Access Excitation of the action potential of a molluscan unstriated muscle C. M. Fletcher, C. M. FletcherSearch for more papers by this author C. M. Fletcher, C. M. FletcherSearch for more papers by this author First published: 17 September 1937 https://doi.org/10.1113/jphysiol.1937.sp003527Citations: 9AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume90, Issue4September 17, 1937Pages 415-428 RelatedInformation

Action potentials recorded from an unstriated muscle of simple structure

The Journal of PhysiologyVolume 90, Issue 2 p. 233-253 ArticleFree Access Action potentials recorded from an unstriated muscle of simple structure C. M. Fletcher, C. M. FletcherSearch for more papers by this author C. M. Fletcher, C. M. FletcherSearch for more papers by this author First published: 15 July 1937 https://doi.org/10.1113/jphysiol.1937.sp003509Citations: 18AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume90, Issue2July 15, 1937Pages 233-253 RelatedInformation

The changes in viscosity of an unstriated muscle (Mytilus edulis) during and after stimulation with alternating, interrupted and uninterrupted direct currents

The Journal of PhysiologyVolume 88, Issue 4 p. 492-511 ArticleFree Access The changes in viscosity of an unstriated muscle (Mytilus edulis) during and after stimulation with alternating, interrupted and uninterrupted direct currents F. R. Winton, F. R. WintonSearch for more papers by this author F. R. Winton, F. R. WintonSearch for more papers by this author First published: 18 January 1937 https://doi.org/10.1113/jphysiol.1937.sp003455Citations: 49AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume88, Issue4January 18, 1937Pages 492-511 RelatedInformation

Experimental Production of Exophthalmos Resembling that Found in Graves Disease

Experimental production of exophthalmos has been accomplished repeatedly by stimulating the sympathetic innervation of the eye. MacCallum and Cornell,1 Code2 produced, by electrical stimulation of the cervical sympathetic ganglion of dogs and cats, a contraction of the smooth muscle elements in the orbit which caused exophthalmos. Schockaert,3 Loeb,4 Friedgood,5 and Marine6,7 have reported exophthalmos resulting from the injection of thyrotropic anterior pituitary extracts into ducks, normal and thyroidectomized guinea pigs, and by the injection of methylcyanide into normal and thyroidectomized rabbits. Loeb and Schockaert noted that the exophthalmos produced was functional, i. e., did not persist during anesthesia or after death. Marine showed that the protrusion resulting from injection of either pituitary or cyanide was accomplished through a nervous mechanism, presumably upon the unstriated orbital muscle of Muller, and that it could be prevented by removing the cervical sympathetic ganglion.In the fo...

An Inexpensive Tissue for Biological Testing

For some time we have been interested in reactions of the iris to various reagents and have observed that a strip of sphincter pupillae of the steer iris affords an excellent preparation for studying the effects of many drugs on unstriated muscle and its innervation. We suggest the adoption of this tissue for pharmacological studies because of its inexpensiveness, certainty and sensitivity of response, availability at any abattoir and its viability even after 3 to 7 hours post mortem. Precautions regarding preparation of iris strips are given elsewhere.1, 2Besides demonstrating the antagonistic relaxing action of various concentrations of atropine against sphincter contraction by physos-tigmine one is able to produce opposite effects with histamine and adrenalin. To date we have been able to demonstrate sphincter relaxation with so small a dose as 1-400,000,000 and a sphincter contracture with the minute dose of 1-1,000,000,000 of histamine. We suggest the study of the iris sphincter strip as a probable t...

Tonus in mammalian unstriated muscle

Tonus in mammalian unstriated muscle

The influence of temperature on the mechanical responses of certain unstriated muscles

The influence of temperature on the mechanical responses of certain unstriated muscles