Effects of Changing Temperature on the Transmembrane Potentials and Spontaneous Rhythm of the Sinoatrial Muscle Cells of Teleost Fishes

2015 ◽  
pp. 24-25 ◽  
Author(s):  
V. A. Golovko ◽  
M. P. Roshchevsky
Keyword(s):  
Muscle Cells ◽  
Teleost Fishes ◽  
Transmembrane Potentials ◽  
Spontaneous Rhythm

Coronary occlusion and reperfusion: effects on subendocardial cardiac fibers

1980 ◽  
Vol 238 (4) ◽  
pp. H581-H593 ◽  
Author(s):  
H. S. Karaguezian ◽  
J. J. Fenoglio ◽  
M. B. Weiss ◽  
A. L. Wit
Keyword(s):  
Action Potential ◽  
Action Potentials ◽  
Coronary Flow ◽  
Transmembrane Potential ◽  
Coronary Occlusion ◽  
Muscle Cells ◽  
Purkinje Fibers ◽  
Transmembrane Potentials ◽  
Purkinje System ◽  
Potential Parameters

Coronary flow and transmembrane potentials of Purkinje and muscle fibers in reperfused infarcts and infarcts caused by permanent coronary occlusion were compared. Purkinje fibers in permanently occluded infarcts at 24 h had markedly reduced resting potentials. Action potential amplitudes, and Vmax were reduced and duration markedly prolonged. In reperfused infarcts, changes in Purkinje fiber transmembrane potentials were not as marked. Action potential duration in 3-day-old permanently occluded infarcts were longer than at 24 h, but in reperfused infarcts durations had returned to normal. Premature impulses conducted more rapidly in the reperfused infarct Purkinje system than in the permanently occluded. Other transmembrane potential parameters of Purkinje fibers in 3-day-old and 9- to 10-day-old reperfused and permanently occluded infarcts were not significantly different from each other. The ventricular muscle cells that survived in reperfused infarcts at all times also had reduced resting potentials and action potentials with decreased amplitudes, reduced Vmax, and prolonged durations. Almost no muscle cells survived in permanently occluded infarcts. Therefore, reperfusion salvages subendocardial fibers and prevents some but not all of the electrophysiological abnormalities.

Vascular Smooth Muscle Membrane Potential and a Ouabain-Like Humoral Factor in One-Kidney, One-Clip Hypertension in Rats

1982 ◽  
Vol 63 (s8) ◽  
pp. 31s-33s ◽  
Author(s):  
Motilal B. Pamnani ◽  
David R. Harder ◽  
Stephen J. Huot ◽  
Howard J. Bryant ◽  
Francis A. Kutyna ◽  
...  
Keyword(s):  
Muscle Cells ◽  
Muscle Membrane ◽  
Hypertensive Rats ◽  
Transmembrane Potentials ◽  
Voltage Dependent ◽  
Smooth Muscle Membrane ◽  
Vascular Muscle Cells ◽  
Dependent Mechanism ◽  
Normotensive Control

1. Transmembrane potentials (Em) of vascular muscle cells in caudal arteries in vitro from one-kidney, one-clip hypertensive and one-kidney, sham-clipped normotensive rats were measured. 2. The Em recorded in hypertensive rats was significantly lower (depolarized) than that recorded in normotensive control rats. 3. Boiled plasma supernatants from hypertensive rats depolarized the muscle cells in normotensive caudal artery but had no effect on muscle cells in arteries from hypertensive rats. 4. Boiled plasma supernatants from normotensive control rats had no effect on the Em of either animal. 5. Ouabain depolarized muscle cells of the normotensive artery only and the magnitude of depolarization induced was nearly the same as that produced by the supernatant from the hypertensive animals. 6. These data suggest that a ouabain-like humoral substance may play a role in the pathophysiology of one-kidney, one-clip hypertension through a voltage-dependent mechanism.

Ultrastructure of myoepithelial cell in parotid gland

1988 ◽  
Vol 46 ◽  
pp. 342-343
Author(s):  
C. N. Sun
Keyword(s):  
Parotid Gland ◽  
Osmium Tetroxide ◽  
Individual Cell ◽  
Branching Processes ◽  
Muscle Cells ◽  
Myoepithelial Cells ◽  
Uranyl Acetate ◽  
Thin Sections ◽  
Gland Carcinoma ◽  
Parotid Gland Carcinoma

Myoepithelial cells have been observed in the prostate, harderian, apocrine, exocrine sweat and mammary glands. Such cells and their numerous branching processes form basket-like structures around the glandular acini. Their shapes are quite different from structures seen either in spindleshaped smooth muscle cells or skeletal muscle cells. These myoepithelial cells lie on the epithelial side of the basement membrane in the glands. This presentation describes the ultrastructure of such myoepithelial cells which have been found also in the parotid gland carcinoma from a 45-year old patient.Specimens were cut into small pieces about 1 mm3 and immediately fixed in 4 percent glutaraldehyde in phosphate buffer for two hours, then post-fixed in 1 percent buffered osmium tetroxide for 1 hour. After dehydration, tissues were embedded in Epon 812. Thin sections were stained with uranyl acetate and lead citrate. Ultrastructurally, the pattern of each individual cell showed wide variations.

Immunogold localization of HMB-45 antigen in pulmonary lymphangiomyomatosis

1995 ◽  
Vol 53 ◽  
pp. 998-999
Author(s):  
J.M. Minda ◽  
E. Dessy ◽  
G. G. Pietra
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Room Temperature ◽  
Osmium Tetroxide ◽  
Muscle Cells ◽  
Ultrastructural Localization ◽  
Reproductive Age ◽  
Thin Sections ◽  
Smooth Muscle Proliferation ◽  
Hmb 45

Pulmonary lymphangiomyomatosis (PLAM) is a rare disease occurring exclusively in women of reproductive age. It involves the lungs, lymph nodes and lymphatic ducts. In the lungs, it is characterized by the proliferation of smooth muscle cells around lymphatics in the bronchovascular bundles, lobular septa and pleura The nature of smooth muscle proliferation in PLAM is still unclear. Recently, reactivity of the smooth muscle cells for HMB-45, a melanoma-related antigen has been reported by immunohistochemistry. The purpose of this study was the ultrastructural localization of HMB-45 immunoreactivity in these cells using gold-labeled antibodies.Lung tissue from three cases of PLAM, referred to our Institution for lung transplantation, was embedded in either Poly/Bed 812 post-fixed in 1% osmium tetroxide, or in LR White, without osmication. For the immunogold technique, thin sections were placed on Nickel grids and incubated with affinity purified, monoclonal anti-melanoma antibody HMB-45 (1:1) (Enzo Diag. Co) overnight at 4°C. After extensive washing with PBS, grids were treated with Goat-anti-mouse-IgG-Gold (5nm) (1:10) (Amersham Life Sci) for 1 hour, at room temperature.

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