scholarly journals Function and localization of oxytocin receptors in the reproductive tissue of rams

Reproduction ◽  
2001 ◽  
pp. 317-325 ◽  
Author(s):  
K Whittington ◽  
SJ Assinder ◽  
T Parkinson ◽  
KR Lapwood ◽  
HD Nicholson
Keyword(s):  
Smooth Muscle ◽  
Epithelial Cells ◽  
Cellular Localization ◽  
Reproductive Tract ◽  
Testicular Artery ◽  
Ductus Deferens ◽  
Circular Smooth Muscle ◽  
Oxytocin Receptors ◽  
Duct Ligation ◽  
Oxytocin Antagonist

Oxytocin is present in the male reproductive tract and has been shown to increase contractility in the epididymis and to modulate steroidogenesis. This study investigated the effects of oxytocin in the testis in vivo, and the presence and cellular localization of oxytocin receptors in the reproductive tract of rams. During the breeding season, mature rams underwent efferent duct ligation before injection of either oxytocin (20 microg) or oxytocin plus an oxytocin antagonist (20 microg) into the testicular artery; the contralateral testicular artery received saline. Injection of oxytocin caused a significant increase (P < 0.05) in the concentration of spermatozoa collected from the rete testis. This effect was not observed after treatment with the oxytocin antagonist plus oxytocin. Western blot analysis performed using a specific oxytocin receptor antibody (020) identified a single immunoreactive band of 66 kDa in testicular and epididymal tissue. This band was present in uterine tissue but not in liver or muscle. Immunocytochemistry identified oxytocin receptors on Leydig and Sertoli cells of the testis, on epithelial cells throughout the epididymis, on peritubular smooth muscle cells in the cauda epididymidis, and on the epithelial cells and circular smooth muscle layer of the ductus deferens. These findings indicate that oxytocin can modulate sperm transport in the ram testis. A role for oxytocin in promoting sperm transit is supported by the localization of oxytocin receptors in the cauda epididymis and ductus deferens, and the presence of receptors on Leydig, Sertoli and epididymal epithelial cells provides further evidence that oxytocin may be involved in the local regulation of steroidogenesis.

scholarly journals Location of a membrane-bound carbonic anhydrase isoenzyme (CA IV) in the human male reproductive tract.

1993 ◽  
Vol 41 (5) ◽  
pp. 751-757 ◽  
Author(s):  
S Parkkila ◽  
A K Parkkila ◽  
K Kaunisto ◽  
A Waheed ◽  
W S Sly ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Carbonic Anhydrase ◽  
Reproductive Tract ◽  
Muscle Layer ◽  
Apical Plasma Membrane ◽  
Specific Staining ◽  
Ductus Deferens ◽  
Male Reproductive Tract ◽  
Human Male ◽  
Membrane Bound

We studied the location of a membrane-bound carbonic anhydrase (CA IV) in the human male reproductive tract using a specific antiserum to human CA IV in conjunction with immunoblotting, immunoperoxidase, and immunofluorescence techniques. The microvilli and apical plasma membrane of the epithelial cells and the subepithelial smooth muscle layer of the epididymis, ductus deferens, and ampulla of the ductus deferens showed specific staining for CA IV. The epithelial cells of the prostate and seminal vesicle failed to stain for CA IV, however, whereas the subepithelial smooth muscle layer showed positive staining. No specific staining for CA II was seen in the epithelium of the epididymal duct or the proximal ductus deferens. The presence of CA IV in the epididymis was confirmed by immunoblotting, which revealed 35 KD and 33 KD polypeptides. The results show that the microvilli and the apical plasma membrane of the lining epithelium of the epididymal duct, ductus deferens, and ampulla of the ductus deferens contain the membrane-bound carbonic anhydrase isoenzyme IV. The presence of the enzyme in the epithelium of the epididymis and ductus deferens is probably linked to the acidification of the epididymal fluid that prevents premature sperm activation. Its physiological role in the smooth muscle cells remains to be elucidated.

scholarly journals Expression Of Cytokeratin 18 In The Peripheral Nerves

2016 ◽  
Vol 60 (2) ◽  
pp. 5-10
Author(s):  
E. Marettová
Keyword(s):  
Skeletal Muscle ◽  
Smooth Muscle ◽  
Epithelial Cells ◽  
Peripheral Nerves ◽  
Cytokeratin 18 ◽  
Ductus Deferens ◽  
Nerve Sheath ◽  
Myelinated Nerves ◽  
Perineurial Cells ◽  
Perineurial Sheath

Abstract The perineurium constitutes the basis for the regulation of endoneurial fluid homeostasis. In the work presented here, cytokeratin 18, as an immunohistochemical marker for epithelial cells, was used to identify the perineurium in the peripheral nerves of two species. Two organs, rich in peripheral nerves, were used; the tongue of the bull and the ductus deferens of the male goat. Special attention was paid to one of the the nerve sheath cells - the perineurial cells of myelinated nerves in the skeletal muscle of the tongue and in the smooth muscle in the wall of the ductus deferens. A positive reaction to cytokeratin 18 was found in the perineurial cells of the perineurial sheath in the nerves of various sizes. No difference in the reactivity was observed between the peripheral nerves of the tongue and that of the ductus deferens.

CYP4A mRNA, protein, and product in rat lungs: novel localization in vascular endothelium

2002 ◽  
Vol 93 (1) ◽  
pp. 330-337 ◽  
Author(s):  
Daling Zhu ◽  
Chenyang Zhang ◽  
Meetha Medhora ◽  
Elizabeth R. Jacobs
Keyword(s):  
Arachidonic Acid ◽  
Smooth Muscle ◽  
Epithelial Cells ◽  
Cellular Localization ◽  
Muscle Tone ◽  
Pulmonary Arteries ◽  
Cell Types ◽  
Male Rat ◽  
Type I ◽  
Rat Lungs

The vasodilatory effect of 20-hydroxyeicosatetraenoic acid (20-HETE) on lung arteries is opposite to the constrictor effect seen in cerebral and renal vessels. These observations raise questions about the cellular localization of 20-HETE-forming isoforms in pulmonary arteries and other tissues. Using in situ hybridization, we demonstrate for the first time CYP4A (a family of cytochrome P-450 enzymes catalyzing formation of 20-HETE from the substrate arachidonic acid) mRNA in pulmonary arterial endothelial and smooth muscle cells, bronchial smooth muscle and bronchial epithelial cells, type I epithelial cells, and macrophages in adult male rat lungs. Moreover, we detect CYP4A protein in rat pulmonary arteries and bronchi as well as cultured endothelial cells. Finally, we identify endogenously formed 20-HETE by using fluorescent HPLC techniques, as well as the capacity to convert arachidonic acid into 20-HETE in pulmonary arteries, bronchi, and endothelium. These data show that 20-HETE is an endogenous product of several pulmonary cell types and is localized to tissues that optimally position it to modulate physiological functions such as smooth muscle tone or electrolyte flux.

scholarly journals Immunohistochemical Localization of Microsomal PGE Synthase-1 and Cyclooxygenases in Male Mouse Reproductive Organs

Endocrinology ◽  
2002 ◽  
Vol 143 (6) ◽  
pp. 2410-2419 ◽  
Author(s):  
Michael Lazarus ◽  
Craig J. Munday ◽  
Naomi Eguchi ◽  
Shigeko Matsumoto ◽  
Gary J. Killian ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Male Mouse ◽  
Cellular Localization ◽  
Reproductive Tract ◽  
Vas Deferens ◽  
Reproductive Organs ◽  
Progressive Increase ◽  
Northern Blotting ◽  
Cox 2 ◽  
Cox 1

Abstract We investigated the tissue distribution and cellular localization of microsomal PGE synthase-1 (mPGES-1) and cyclooxygenase (COX)-1 and -2 in the male mouse reproductive organs. Northern blotting revealed that the mPGES-1 mRNA was expressed intensely in the epididymis and weakly in the lung, spleen, skin, kidney, colon, and brain. In the male reproductive tract, the expression of mPGES-1 increased from the testis to the cauda epididymis and was highest in the vas deferens when examined by Northern blotting, RT-PCR, and Western blotting. By immunohistochemistry, mPGES-1 was detected in Leydig cells of the testis and in epithelial cells of the epididymis, vas deferens, and seminal vesicles. In addition, the caput and cauda regions of the epididymis and the vas deferens in this order showed a progressive increase in the expression of COX-1 mRNA and immunoreactivity, whereas COX-2 was dominantly expressed in the vas deferens. COX-1 was localized in epithelial cells of the caput, corpus and cauda epididymis and of the vas deferens, and COX-2 was evident in epithelial cells of the distal cauda epididymis and vas deferens. These results show that mPGES-1 is expressed coordinately with COX-1 and COX-2 and is involved in PGE2 production in male genital organs.

Influence of a lymphocyte-conditioned medium on the expression of smooth-muscle α-aktin in lens epithelial cells in situ

1999 ◽  
Vol 96 (3) ◽  
pp. 174-181
Author(s):  
Kerstin Wunderlich ◽  
Marcus Knorr ◽  
H. Northoff ◽  
Hans-J. Thiel
Keyword(s):  
Smooth Muscle ◽  
Epithelial Cells ◽  
Conditioned Medium ◽  
Lens Epithelial Cells

Nitric oxide mediates outward potassium currents in opossum esophageal circular smooth muscle

1996 ◽  
Vol 270 (6) ◽  
pp. G932-G938 ◽  
Author(s):  
J. Jury ◽  
K. R. Boev ◽  
E. E. Daniel
Keyword(s):  
Nitric Oxide ◽  
Smooth Muscle ◽  
Circular Muscle ◽  
Outward Current ◽  
Equilibrium Potential ◽  
Patch Clamp Technique ◽  
Pipette Solution ◽  
Whole Cell ◽  
Circular Smooth Muscle ◽  
Outward Currents

Single smooth muscle cells from the opossum body circular muscle were isolated and whole cell currents were characterized by the whole cell patch-clamp technique. When the cells were held at -50 mV and depolarized to 70 mV in 20-mV increments, initial small inactivating inward currents were evoked (-30 to 30 mV) followed by larger sustained outward currents. Depolarization from a holding potential of -90 mV evoked an initial fast inactivating outward current sensitive to 4-aminopyridine but not to high levels of ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA). The outward currents reversed near K+ equilibrium potential and were abolished when KCl was replaced by CsCl in the pipette solution. The sustained outward current was inhibited by quinine and cesium. High EGTA in the pipette solution reduced but did not abolish the sustained outward currents, suggesting that both Ca(2+)-dependent and -independent currents were evoked. The nitric oxide (NO)-releasing agents Sin-1 and sodium nitroprusside increased outward K+ currents. High levels of EGTA in the pipette solution abolished the increase in outward current induced by Sin-1. The presence of cyclopiazonic acid, an inhibitor of the sarcoplasmic reticulum (SR) Ca2+ pump, blocked the effects of NO-releasing agents. We conclude that NO release activates K+ outward currents in opossum esophagus circular muscle, which may depend on Ca2+ release from the SR stores.

NUMERICAL SIMULATION OF THE ROLE OF CO-TRANSMISSION BY ACETYLCHOLINE AND SEROTONIN ON MOTILITY OF THE GUT

2006 ◽  
Vol 06 (04) ◽  
pp. 399-428
Author(s):  
R. MIFTAHOF
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Transit Time ◽  
Receptor Agonist ◽  
Muscle Cells ◽  
Receptor Antagonists ◽  
One Dimensional ◽  
Circular Smooth Muscle ◽  
Spatio Temporal ◽  
Stimulation Of

Electrophysiological mechanisms of co-transmission by serotonin (5-HT) and acetylcholine (ACh), co-expression of their receptor types, i.e., 5-HT type 3 and 4, nicotinic cholinerginc (nACh) and muscarinic cholinergic (μACh), and effects of selective and non-selective 5-HT3 and 5-HT4 receptor agonists/antagonists, on electromechanical activity of the gut were studied numerically. Two series of numerical experiments were performed. First, the dynamics of the generation and propagation of electrical signals interconnected with the primary sensory (AH) neurons, motor (S) neurons and smooth muscle cells were studied in a one-dimensional model. Simulations showed that stimulation of the 5-HT3 receptors reduced the threshold of activation of the mechanoreceptors by 17.6%. Conjoint excitation of the 5-HT3 and 5-HT4 receptors by endogenous serotonin converted the regular firing pattern of electrical discharges of the AH and S neurons to a beating mode. Activation confined to 5-HT3 receptors, located on the somas of the adjacent AH and S type neurons, could not sustain normal signal transduction between them. It required ACh as a co-transmitter and co-activation of the nACh receptors. Application of selective 5-HT3 receptor antagonists inhibited dose-dependently the production of action potentials at the level of mechanoreceptors and the soma of the primary sensory neuron and increased the threshold activation of the mechanoreceptors. Normal mechanical contractile activity depended on co-stimulation of the 5-HT4 and μACh receptors on the membrane of smooth muscle cells. In the second series of simulations, which involved a spatio-temporal model of the functional unit, effects of co-transmission by ACh and 5-HT on the electromechanical response in a segment of the gut were analyzed. Results indicated that propagation of the wave of excitation between the AH and S neurons within the myenteric nervous plexus in the presence of 5-HT3 receptor antagonists was supported by co-release of ACh. Co-stimulation of 5-HT3, nACh and μACh receptors impaired propulsive activity of the gut. The bolus showed uncoordinated movements. In an ACh-free environment Lotronex (GlaxoSmithKline), a 5-HT3 receptor antagonist, significantly increased the transit time of the pellet along the gut. In the presence of ACh, Lotronex produced intensive tonic-type contractions in the longitudinal and circular smooth muscle layers and eliminated propulsive activity. The 5HT4 receptor agonist, Zelnorm (Novartis), preserved the reciprocal electromechanical relationships between the longitudinal and circular smooth muscle layers. The drug changed the normal propulsive pattern of activity to an expulsive (non-mixing) type. Treatment of the gut with selective 5HT4 receptor antagonists increased the transit time by disrupting the migrating myoelectrical complex. Cisapride (Janssen), a mixed 5HT3 and 5HT4 receptor agonist, increased excitability of the AH and S neurons and the frequency of slow waves. Longitudinal and circular smooth muscle syncytia responded with the generation of long-lasting tonic contractions, resulting in a "squeezing" type of pellet movement. Comparison of the theoretical results obtained on one-dimensional and spatio-temporal models to in vivo and in vitro experimental data indicated satisfactory qualitative, and where available, quantitative agreement.

Sign in / Sign up

Export Citation Format

Share Document