The Origin and Development of Smooth Muscle and Contractility in the Ductus Epididymidis of the Rat

Development ◽  
1963 ◽  
Vol 11 (2) ◽  
pp. 369-382
Author(s):  
Robert L. Van De Velde ◽  
Paul L. Risley

The contractile activity of smooth muscles of the epididymal duct has long been overlooked in discussions relating to functional aspects of the epididymis and the problem of sperm transport in the male. Benoit (1926) described the occurrence of smooth muscle fibers, circularly arranged, surrounding the efferent ductuli and ductus epididymidis. Young and co-workers (1929–1931) emphasized that currents produced by vibrant cilia of the ductuli efferentes, the continued production of sperm in the testis, and the pressure of fluids transferred across the germinal epithelium to the lumina of the efferent duct system were responsible primarily for the movement of spermatozoa through the epididymis to their storage place in the caudal end of this organ prior to emmission. Simeone (1933) described contractile movements in the excised epididymis of the guinea-pig, and, although she discussed the probable occurrence also of peristaltic action, she concluded that the activity was mainly of a segmentationlike character.

2008 ◽  
Vol 7 (4) ◽  
pp. 31-37
Author(s):  
M. A. Medvedev ◽  
M. B. Baskakov ◽  
S. V. Gusakova ◽  
I. V. Kovalyov ◽  
O. S. Melnik ◽  
...  

The influence of modulation of cytoskeleton by colchicine, vinblastine, cytochalasine B and docetaxel on contractile reactions of smooth muscle cells caused by electric stimulus, depolarization, phenylephrine has been investigated by the mechanographical method, by the methods of the double sucrose gup junction. It is established, that induced by a isoosmotic hyperpotassium solution of reduction of smooth muscle of the rat’s aorta, and also caused depolarization stimulus potentials of action and reductions smooth muscle cells from guinea pig urethra, depend more on the condition of microfilaments cytoskeleton than on microtubules. The reduction of smooth muscles cells of an aorta of the rat, caused by isoosmotic striction, is suppressed under the destruction microfilaments whereas the reduction in a hyperosmotic solution depends on a condition of both microfilaments, and microtubules. Cytoskeleton’s microfilaments of aorta’s smooth muscles and microtubules of smooth muscles of cells ureter are involved in mechanisms of action phenylephrine’s action on contractile activity of smooth muscle cells of an aorta and ureter.


1987 ◽  
Author(s):  
G Kindel ◽  
J Fareed

Thrombin and related proteases produce varying pharmacologic responses in animal models. To more specifically study the in vivo actions of thrombin and related proteases, we have used isolated tissue preparations of the rabbit aortic strip (RAS), isolated guinea pig ileum (GPI) and isolated rat uterus (RU). Standard tissue-agonist regimens include epinephrine, thromboxane B2 with RAS; bradykinin, acetylcholine, histamine and serotonin with GPI; and acetylcholine, bradykinin and angiotensin with RU. The smooth muscle modulant action of numerous proteinases were screened in these regimens by bracketing the median dose response of the individual agonists. Protease complexes such as serum (rabbit, human and guinea pig), activated and nonactivated prothrombin complex concentrates and pancreatin were shown to produce varying but similar contractile responses as obtained by the standard agonists. Sera produced a dose-dependent contraction of the RAS, GPI and RU preparations. Various forms of thrombin produced different degrees of contraction of RAS accompanied by a desensitization process. On a molar basis the order of contractile activity ranged α > β>γ > nitro > DIP. All thrombins were found to augment the epinephrine and thromboxane B2 induced contraction of the RAS. Bovine and human factor Xa produced marked dilatation of the RAS but did not have any effect on the GPI and RU preparations. These results suggest that proteases exert direct musculotropic actions on smooth muscles. This should be taken into consideration in the pathophysiology of vascular spasms.


2019 ◽  
Vol 13 ◽  
pp. 117906951882191 ◽  
Author(s):  
Rohit Manchanda ◽  
Shailesh Appukuttan ◽  
Mithun Padmakumar

As in other excitable tissues, two classes of electrical signals are of fundamental importance to the functioning of smooth muscles: junction potentials, which arise from neurotransmission and represent the initiation of excitation (or in some instances inhibition) of the tissue, and spikes or action potentials, which represent the accomplishment of excitation and lead on to contractile activity. Unlike the case in skeletal muscle and in neurons, junction potentials and spikes in smooth muscle have been poorly understood in relation to the electrical properties of the tissue and in terms of their spatiotemporal spread within it. This owes principally to the experimental difficulties involved in making precise electrical recordings from smooth muscles and also to two inherent features of this class of muscle, ie, the syncytial organization of its cells and the distributed innervation they receive, which renders their biophysical analysis problematic. In this review, we outline the development of hypotheses and knowledge on junction potentials and spikes in syncytial smooth muscle, showing how our concepts have frequently undergone radical changes and how recent developments hold promise in unraveling some of the many puzzles that remain. We focus especially on computational models and signal analysis approaches. We take as illustrative examples the smooth muscles of two organs with distinct functional characteristics, the vas deferens and urinary bladder, while also touching on features of electrical functioning in the smooth muscles of other organs.


1985 ◽  
Vol 63 (5) ◽  
pp. 453-462 ◽  
Author(s):  
F. B. Yousif ◽  
G. T. Bolger ◽  
A. Ruzycky ◽  
D. J. Triggle

The actions of a series of 15 Ca2+ channel antagonists including D-6(X), nifedipine, and diltiazem were examined against K+ depolarization and muscarinic receptor induced responses in guinea pig bladder smooth muscle. Responses of bladder are very dependent upon extracellular Ca2+ and sensitive to the Ca2+ channel antagonists, the tonic component more than the phasic component of response. Regardless of stimulant, K+ or methylfurmethide (MF), or component of response, the same rank order of antagonist activities is expressed, suggestive of a single structure–activity relationship and the existence of a single category of binding site which may, however, exist in several affinity states. High affinity binding of [3H]nitrendipine (KD = 1.1 × 10−10 M) occurs in bladder membranes, and similar high affinity binding was found in microsomal preparations from other smooth muscles including guinea pig and rat lung, rat vas deferens, uterus, and stomach. [3H]nitrendipine binding in the bladder was sensitive to displacement by other 1,4-dihydropyridines, paralleling their pharmacologic activities and showing excellent agreement with binding data previously obtained for guinea pig ileal smooth muscle. Comparison of pharmacologic data for inhibition of K+- and MF-induced responses by a common series of Ca2+ channel antagonists in bladder and ileum revealed excellent correlations. Neither pharmacologic nor binding studies suggest significant differences in Ca2+ channel antagonist properties in smooth muscle from bladder and intestine.


2000 ◽  
Vol 78 (9) ◽  
pp. 729-736 ◽  
Author(s):  
Mayumi Mori ◽  
Hiromi Tsushima

To elucidate the possible role of Rho A/Rho-kinase on lysophosphatidic acid (LPA)-induced contraction in intact guinea-pig ileal smooth muscle, we examined effects of pretreatment with a specific inhibitor of Rho-kinase (Y-27632) on the LPA-induced contraction and MLC20 phosphorylation. In addition, we investigated whether LPA actually elicits an activation of Rho A by studying subcellular distribution of Rho A in unstimulated and stimulated smooth muscles by LPA. LPA induced a less intense, but sustained, contraction compared with ACh, and was accompanied by significant increases in MLC20 phosphorylation. The effects of LPA on tension and MLC20 phosphorylation were inhibited by Y-27632. The ACh-induced contraction, but not increases in MLC20 phosphorylation, was partially inhibited by Y-27632. High K+-induced contraction was unaffected by the inhibitor. LPA stimulated translocation of Rho A from the cytosol to the membrane fraction of the muscle. Translocation of Rho A was also induced by ACh and high K+. These results suggest that LPA-induced contraction of intact ileal smooth muscle is dominated through activation of Rho A and Rho-kinase and subsequent increases in MLC20 phosphorylation.Key words: lysophosphatidic acid, Rho, Rho-kinase, ileal smooth muscle.


2007 ◽  
Vol 292 (3) ◽  
pp. G887-G898 ◽  
Author(s):  
Daniel P. Poole ◽  
John B. Furness

PKC is involved in mediating the tonic component of gastrointestinal smooth muscle contraction in response to stimulation by agonists for G protein-coupled receptors. Here, we present pharmacological and immunohistochemical evidence indicating that a member of the novel PKC isoforms, PKC-δ, is involved in maintaining muscarinic receptor-coupled tonic contractions of the guinea pig ileum. The tonic component of carbachol-evoked contractions was enhanced by an activator of conventional and novel PKCs, phorbol 12,13-dibutyrate (PDBu; 200 nM or 1 μM), and by an activator of novel PKCs, ingenol 3,20-dibenzoate (IDB; 100 or 500 nM). Enhancement was unaffected by concentrations of bisindolylmaleimide I (BIM-I; 22 nM) that block conventional PKCs or by a PKC-ε-specific inhibitor peptide but was attenuated by higher doses of BIM-I (2.2 μM). Relevant proteins were localized at a cellular and subcellular level using confocal analysis. Immunohistochemical staining of the ileum showed that PKC-δ was exclusively expressed in smooth muscles distributed throughout the layers of the gut wall. PKC-ε immunoreactivity was prominent in enteric neurons but was largely absent from smooth muscle of the muscularis externa. Treatment with PDBu, IDB, or carbachol resulted in a time- and concentration-dependent translocation of PKC-δ from the cytoplasm to filamentous structures within smooth muscle cells. These were parallel to, but distinct from, actin filaments. The translocation of PKC-δ in response to carbachol was significantly reduced by scopolamine or calphostin C. The present study indicates that the tonic carbachol-induced contraction of the guinea pig ileum is mediated through a novel PKC, probably PKC-δ.


2012 ◽  
Vol 11 (6) ◽  
pp. 51-58 ◽  
Author(s):  
I. V. Kovalyov ◽  
M. B. Baskakov ◽  
S. V. Gusakova ◽  
T. A. Vtorushina ◽  
A. S. Zheludeva ◽  
...  

Author(s):  
P. Virych ◽  
O. Shelyuk ◽  
V. Martynyuk ◽  
V. Pavlovsky

The effect of compounds based on 3-substituted-1,4-benzodiazepine-2-ones on contractile activity of smooth muscles of the rat's stomach was analyzed. Action substances MX-1626, MX-1775 for the smooth muscle contraction of like competitive inhibitor of bradykinin – des-Arg9- [Leu8]-Bradykinin acetate, which is observed as increase normalized rate of contraction with increasing of bradykinin concentration and characterized by a slowdown in the first phase of contraction. The most effective 3-subtituted 1,4-benzodiazepin-2-ones was at low concentrations of bradykinin, increasing it concentration their effect is reduced.


2009 ◽  
Vol 8 (4) ◽  
pp. 41-46
Author(s):  
I. V. Kovalyev ◽  
S. V. Gusakova ◽  
O. S. Melnik ◽  
M. B. Baskakov ◽  
L. V. Kapilevich ◽  
...  

The influence of of hydrogen peroxide on the contractile reactions of smooth muscle cells caused by hyperpotassium solution end phenylephrine in modulation a potassium conductance the membrane and the state of cytoskeleton elements has been investigated by the mechanographical method. It has multidirectional influence of hydrogen peroxide in the reduction of smooth muscles of rat aorta with the membrane depolarization hyperpotassium solution and action phenylephrine: phenylephrine decline in value and increase strength hyperpotassium contractures. We show that the cytoskeleton components involved in the mechanisms of action of hydrogen peroxide in the contractile reactions of smooth muscles of rat aorta caused by phenylephrine.


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