Changes in subcellular membranes in rat heart perfused with diethyl ether

1979 ◽  
Vol 57 (12) ◽  
pp. 1412-1420
Author(s):  
Gina M. L. Taam ◽  
Satoshi Takeo ◽  
Vincenzo Panagia ◽  
Attila Ziegelhoffer ◽  
Naranjan S. Dhalla
Keyword(s):  
Calcium Binding ◽  
Electron Microscopic Examination ◽  
Membrane System ◽  
Contractile Force ◽  
Perfused Heart ◽  
Electron Microscopic ◽  
Irreversible Damage ◽  
Control Value ◽  
Subcellular Membrane ◽  
Rat Hearts

Alterations in contractile force as well as heart sarcolemmal, microsomal, and mitochondrial activities were investigated by perfusing rat hearts with different concentrations (0.5–1.5% (v/v)) of ether for 2 min. Contractile force of the perfused heart was depressed by 0.5–1.0% ether and completely abolished by 1.25–1.5% ether. The contractile force recovered fully upon reperfusion when the hearts were preperfused with 0.5–0.75% ether but the recovery was partial in hearts preperfused with 1.0–1.25% ether. The hearts preperfused with 1.5% ether did not recover their ability to generate contractile force upon reperfusion. The Na+–K+-ATPase activity of sarcolemma obtained from hearts perfused with 0.75–1.0% ether was higher than the control value. The sarcolemmal Na+–K+-ATPase, Mg2+-ATPase, Ca2+-ATPase, calcium binding, and adenylate cyclase activities were decreased in hearts perfused with 1.5% ether and these activities were further decreased upon reperfusion. The microsomal calcium binding and uptake activities were depressed in hearts perfused with 1.0–1.5% ether and these changes were irreversible. The mitochondrial calcium binding and uptake activities as well as oxidative phosphorylation activity were also depressed in hearts perfused with 1.0–1.5% ether; however, irreversible damage was seen in hearts perfused with 1.5% ether. Electron microscopic examination showed occasional vacuolization of mitochondria in hearts perfused with 1% ether and swelling of sarcoplasmic reticulum and mitochondria as well as damage to myofilaments were seen in hearts perfused with 1.5% ether. These results suggest the involvement of alterations in subcellular membrane system in the cardiotoxic actions of ether.

Ischemic preconditioning-mediated restoration of membrane dystrophin during reperfusion correlates with protection against contraction-induced myocardial injury

2004 ◽  
Vol 287 (1) ◽  
pp. H81-H90 ◽  
Author(s):  
Masakuni Kido ◽  
Hajime Otani ◽  
Shiori Kyoi ◽  
Tomohiko Sumida ◽  
Hiroyoshi Fujiwara ◽  
...  
Keyword(s):  
Ischemic Preconditioning ◽  
Myocardial Injury ◽  
Contractile Activity ◽  
Integral Membrane Protein ◽  
Contractile Force ◽  
Global Ischemia ◽  
Blue Dye ◽  
Perfused Heart ◽  
Complete Restoration ◽  
Rat Hearts

Dystrophin is an integral membrane protein involved in the stabilization of the sarcolemmal membrane in cardiac muscle. We hypothesized that the loss of membrane dystrophin during ischemia and reperfusion is responsible for contractile force-induced myocardial injury and that cardioprotection afforded by ischemic preconditioning (IPC) is related to the preservation of membrane dystrophin. Isolated and perfused rat hearts were subjected to 30 min of global ischemia, followed by reperfusion with or without the contractile blocker 2,3-butanedione monoxime (BDM). IPC was introduced by three cycles of 5-min ischemia and 5-min reperfusion before the global ischemia. Dystrophin was distributed exclusively in the membrane of myocytes in the normally perfused heart but was redistributed to the myofibril fraction after 30 min of ischemia and was lost from both of these compartments during reperfusion in the presence or absence of BDM. The loss of dystrophin preceded uptake of the membrane-impermeable Evans blue dye by myocytes that occurred after the withdrawal of BDM and was associated with creatine kinase release and the development of contracture. Although IPC did not alter the redistribution of membrane dystrophin induced by 30 min of ischemia, it facilitated the restoration of membrane dystrophin during reperfusion. Also, myocyte necrosis was not observed when BDM was withdrawn after complete restoration of membrane dystrophin. These results demonstrate that IPC-mediated restoration of membrane dystrophin during reperfusion correlates with protection against contractile force-induced myocardial injury and suggest that the cardioprotection conferred by IPC can be enhanced by the temporary blockade of contractile activity until restoration of membrane dystrophin during reperfusion.

Effects of lanthanum on the heart sarcolemmal ATPase and calcium binding activities

1979 ◽  
Vol 57 (5) ◽  
pp. 496-503 ◽  
Author(s):  
Satoshi Takeo ◽  
Peter Duke ◽  
Gina M. L. Taam ◽  
Pawan K. Singal ◽  
Naranjan S. Dhalla
Keyword(s):  
Atpase Activity ◽  
Calcium Binding ◽  
Calcium Concentration ◽  
Treatment Method ◽  
Binding Activity ◽  
Outer Cell ◽  
Control Value ◽  
Rat Hearts ◽  
Dense Deposits ◽  
Perfused Hearts

Effects of lanthanum on Ca2+-ATPase, Mg2+-ATPase, Na+–K+-ATPase, and calcium binding activities were studied in rat heart sarcolemma. Ten to 100 μM lanthanum depressed significantly the Ca2+-ATPase activity and 50–200 μM lanthanum inhibited the calcium binding activity. Lineweaver–Burk plots of the Ca2+-ATPase activity showed that the inhibition by lanthanum was competitive with calcium concentration. Neither Mg2+-ATPase nor Na+–K+-ATPase activities were affected by lanthanum when the assay medium contained 1 mM EDTA; however, in the absence of EDTA, these enzyme activities were significantly decreased by 10–100 μM lanthanum. Rat hearts perfused with HEPES buffer containing 0.5 mM lanthanum showed electron-dense deposits restricted to the outer cell surface and the sarcolemma obtained from these hearts also had the deposits, indicating that the membrane fraction isolated by the hypotonic shock – LiBr treatment method is of sarcolemmal origin. The Ca2+-ATPase activity of the sarcolemma isolated from lanthanum-perfused hearts, unlike the Mg2+-ATPase, Na+–K+-ATPase, and calcium binding activities, was significantly less than the control value. From these observations it is suggested that lanthanum may influence calcium movement across the sarcolemma by affecting sarcolemmal ATPase and calcium binding activities.

Subcellular calcium transport in failing hearts due to calcium deficiency and overload

1976 ◽  
Vol 231 (4) ◽  
pp. 1159-1165 ◽  
Author(s):  
SL Lee ◽  
NS Dhalla
Keyword(s):  
Intracellular Calcium ◽  
Calcium Binding ◽  
Calcium Transport ◽  
Calcium Deficiency ◽  
Contractile Force ◽  
Calcium Overload ◽  
Mitochondrial Calcium ◽  
Control Medium ◽  
Free Medium ◽  
Rat Hearts

Mitochondrial and heavy microsomal fractions were isolated from rat hearts perfused for different intervals with Ca2+-free medium, as well as from hearts reperfused with control medium after perfusion with Ca2+-free medium. Contractile failure due to intracellular calcium deficiency produced by perfusing the isolated rat hearts with Ca2+-free medium resulted in a marked decline of calcium binding and uptake activities of the mitochondrial fraction without any effect on the microsomal fraction. On the other hand, inability of the rat hearts to recover their contractile force due to intracellular calcium overload produced by reperfusion for 10 min with control medium after 5-20 min of perfusion with Ca2+-free medium was associated with decreased microsomal calcium-binding and uptake activities and increased mitochondrial calcium-binding and uptake activities. When the hearts perfused with Ca2+-free medium in the presence of low sodium (35 mM) for 5 min were reperfused with control medium, the contractile force recovered completely, and appreciable augmentation in mitochondrial calcium transport or depression in microsomal calcium transport as seen in conditions of intracellular calcium overload did not occur. These results suggest dramatic alterations in calcium-transporting properties of mitochondria and sarcoplasmic reticulum in hearts failing due to intracellular calcium deficiency and calcium overload, respectively.

Excitation–contraction coupling in heart. XIX. Effect of hypoxia on calcium transport by subcellular particles in the isolated perfused rat heart

1976 ◽  
Vol 54 (1) ◽  
pp. 49-58 ◽  
Author(s):  
S. L. Lee ◽  
V. Balasubramanian ◽  
N. S. Dhalla
Keyword(s):  
Calcium Binding ◽  
Calcium Transport ◽  
Calcium Uptake ◽  
Microsomal Fraction ◽  
Contractile Force ◽  
Mitochondrial Calcium ◽  
Rat Hearts ◽  
Mitochondrial Calcium Uptake ◽  
Contractile Failure

To examine the role of changes in calcium transport by subcellular particles in the pathogenesis of contractile failure due to oxygen lack, both mitochondrial and microsomal fractions were obtained from the isolated hypoxic rat hearts and their calcium binding and uptake abilities were determined by the Millipore filtration technique. The contractile force decreased by about 40, 60 and 70% of the control within 5, 10 and 30 min respectively, of perfusing the heart with hypoxic medium containing glucose. In hearts perfused for 10 min with hypoxic medium containing glucose, calcium binding and uptake by the microsomal fraction decreased significantly. However, mitochondrial calcium binding, but not uptake, decreased significantly on perfusing the hearts with hypoxic medium containing glucose for 20 to 30 min when the microsomal calcium transport was markedly depressed. Reduction in contractile force, calcium binding and uptake by the microsomal fraction as well as calcium binding by mitochondria of hearts made hypoxic for 30 min recovered towards normal upon reperfusion with control medium for 15 min. On the other hand, omitting glucose from the hypoxic medium significantly decreased calcium binding by mitochondrial and microsomal fractions within 10 min of perfusion in comparison to the control and accelerated the effects of hypoxia upon contractile force and microsomal calcium uptake. In contrast to the hypoxic hearts, the mitochondrial calcium uptake decreased significantly and the magnitude of depression in the microsomal calcium binding was appreciably greater in hearts made to fail to a comparable degree upon perfusion with substrate-free medium. The observed defects in calcium transporting properties of microsomal and mitochondrial membranes appear secondary to the contractile failure in hypoxic hearts.

Electron microscopic studies on ultrathin frozen sections of lactating mouse mammary gland

1978 ◽  
Vol 36 (2) ◽  
pp. 46-47
Author(s):  
Jan Zarzycki ◽  
Joseph Szroeder
Keyword(s):  
Mammary Gland ◽  
Protein Denaturation ◽  
Chemical Constituents ◽  
Freeze Substitution ◽  
Electron Microscopic Examination ◽  
Mouse Mammary Gland ◽  
Electron Microscopic ◽  
Preparation Methods ◽  
Microscopic Studies ◽  
Ultrathin Frozen Sections

The mammary gland ultrastructure in various functional states is the object of our investigations. The material prepared for electron microscopic examination by the conventional chemical methods has several limitations, the most important are the protein denaturation processes and the loss of large amounts of chemical constituents from the cells. In relevance to this,one can't be sure about a degree the observed images are adequate to the realy ultrastructure of a living cell. To avoid the disadvantages of the chemical preparation methods,some autors worked out alternative physical methods based on tissue freezing / freeze-drying, freeze-substitution, freeze-eatching techniqs/; actually the technique of cryoultraraicrotomy,i,e.cutting ultrathin sections from deep frozen specimens is assented as a complete alternative method. According to the limitations of the routine plastic embbeding methods we were interested to analize the mammary gland ultrastructure during lactation by the cryoultramicrotomy method.

A Comparative Study of Fractographic Replicas

1974 ◽  
Vol 32 ◽  
pp. 566-567
Author(s):  
Loren Anderson ◽  
Pat Pizzo ◽  
Glen Haydon
Keyword(s):  
Electron Microscopy ◽  
Electron Microscopic Examination ◽  
Direct Examination ◽  
Electron Microscopic ◽  
Reliable Technique ◽  
Service Failures ◽  
Transmission Electron ◽  
Mode Of Failure ◽  
Scanning Electron Microscopic ◽  
Scanning Electron

Transmission electron microscopy of replicas has long been used to study the fracture surfaces of components which fail in service. Recently, the scanning electron microscope (SEM) has gained popularity because it allows direct examination of the fracture surface. However, the somewhat lower resolution of the SEM coupled with a restriction on the sample size has served to limit the use of this instrument in investigating in-service failures. It is the intent of this paper to show that scanning electron microscopic examination of conventional negative replicas can be a convenient and reliable technique for determining mode of failure.

Novel methods for demonstrating osseointegration of hydroxylapatite-coated titanium hip prostheses

1991 ◽  
Vol 49 ◽  
pp. 34-35 ◽  
Author(s):  
P. Frayssinet ◽  
J. Hanker ◽  
D. Hardy ◽  
B. Giammara
Keyword(s):  
Hip Prosthesis ◽  
Ethanol Concentration ◽  
Bone Matrix ◽  
Electron Microscopic Examination ◽  
Electron Microscopic ◽  
Hip Prostheses ◽  
Cellular Inclusions ◽  
Microscopic Studies ◽  
Diamond Saw ◽  
Plasma Sprayed

Prostheses implanted in hard tissues cannot be processed for electron microscopic examination or microanalysis in the same way as those in other tissues. For these reasons, we have developed methods allowing light and electron microscopic studies as well as microanalysis of the interface between bone and a metal biomaterial coated by plasma-sprayed hydroxylapatite(HA) ceramic.An HA-coated titanium hip prosthesis (Corail, Landos, France), which had been implanted for two years, was removed after death (unrelated to the orthopaedic problem). After fixation it was dehydrated in solutions of increasing ethanol concentration prior to embedment in polymethylmethacrylate(PMMA). Transverse femur sections were obtained with a diamond saw and the sections then carefully ground to a thickness of 200 microns. Plastic-embedded sections were stained for calcium with a silver methenamine modification of the von Kossa method for calcium staining and coated by carbon. They have been examined by back-scatter SEM on an ISI-SS60 operated at 25 KV. EDAX has been done on cellular inclusions and extracellular bone matrix.

Properties of Isolated Mitochondria of Agaricus Bisporus: Their Relationship to Dormancy and the Germination of Spores

1973 ◽  
Vol 31 ◽  
pp. 458-459
Author(s):  
K. S. McCarty ◽  
R. F. Weave ◽  
L. Kemper ◽  
F. S. Vogel
Keyword(s):  
Mitochondrial Dna ◽  
Ethidium Bromide ◽  
Microscopic Examination ◽  
Agaricus Bisporus ◽  
Osmotic Shock ◽  
Electron Microscopic Examination ◽  
Electron Microscopic ◽  
Isolated Mitochondria ◽  
Dna Strands ◽  
Cytoplasmic Ribosomes

During the prodromal stages of sporulation in the Basidiomycete, Agaricus bisporus, mitochondria accumulate in the basidial cells, zygotes, in the gill tissues prior to entry of these mitochondria, together with two haploid nuclei and cytoplasmic ribosomes, into the exospores. The mitochondria contain prominent loci of DNA [Fig. 1]. A modified Kleinschmidt spread technique1 has been used to evaluate the DNA strands from purified whole mitochondria released by osmotic shock, mitochondrial DNA purified on CsCl gradients [density = 1.698 gms/cc], and DNA purified on ethidium bromide CsCl gradients. The DNA appeared as linear strands up to 25 u in length and circular forms 2.2-5.2 u in circumference. In specimens prepared by osmotic shock, many strands of DNA are apparently attached to membrane fragments [Fig. 2]. When mitochondria were ruptured in hypotonic sucrose and then fixed in glutaraldehyde, the ribosomes were released for electron microscopic examination.

Molecular Structure of the Outermost Cell Wall Component of Spirillum Serpens

1977 ◽  
Vol 35 ◽  
pp. 342-343
Author(s):  
Wah Chiu ◽  
David Grano
Keyword(s):  
Molecular Structure ◽  
Cell Wall ◽  
Outer Membrane ◽  
Gel Electrophoresis ◽  
Electron Microscopic Examination ◽  
Electron Microscopic ◽  
Cell Wall Component ◽  
Protein Components ◽  
Exposure Technique ◽  
Structural Aspects

The periodic structure external to the outer membrane of Spirillum serpens VHA has been isolated by similar procedures to those used by Buckmire and Murray (1). From SDS gel electrophoresis, we have found that the isolated fragments contain several protein components, and that the crystalline structure is composed of a glycoprotein component with a molecular weight of ∽ 140,000 daltons (2). Under an electron microscopic examination, we have visualized the hexagonally-packed glycoprotein subunits, as well as the bilayer profile of the outer membrane. In this paper, we will discuss some structural aspects of the crystalline glycoproteins, based on computer-reconstructed images of the external cell wall fragments.The specimens were prepared for electron microscopy in two ways: negatively stained with 1% PTA, and maintained in a frozen-hydrated state (3). The micrographs were taken with a JEM-100B electron microscope with a field emission gun. The minimum exposure technique was essential for imaging the frozen- hydrated specimens.

Electron Microscopic Examination of a Transplantable Rat Mammary Carcinoma

1968 ◽  
Vol 26 ◽  
pp. 20-21
Author(s):  
S. Shirahama ◽  
G. C. Engle ◽  
R. M. Dutcher
Keyword(s):  
Electron Microscope ◽  
Osmium Tetroxide ◽  
Electron Microscopic Examination ◽  
Undifferentiated Carcinoma ◽  
Uranyl Acetate ◽  
Sprague Dawley ◽  
Electron Microscopic ◽  
North West ◽  
X Irradiation ◽  
Tissue Specimens

A transplantable carcinoma was established in North West Sprague Dawley (NWSD) rats by use of X-irradiation by Engle and Spencer. The tumor was passaged through 63 generations over a period of 32 months. The original tumor, an adenocarcinoma, changed into an undifferentiated carcinoma following the 19th transplant. The tumor grew well in NWSD rats of either sex at various ages. It was invariably fatal, causing death of the host within 15 to 35 days following transplantation.Tumor, thymus, spleen, and plasma from 7 rats receiving transplants of tumor at 3 to 9 weeks of age were examined with an electron microscope at intervals of 8, 15, 22 and 30 days after transplantation. Four normal control rats of the same age were also examined. The tissues were fixed in glutaraldehyde, postfixed in osmium tetroxide and embedded in Epon. The plasma was separated from heparanized blood and processed as previously described for the tissue specimens. Sections were stained with uranyl acetate followed by lead citrate and examined with an RCA EMU-3G electron microscope.

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