Effects of Insulin and Activity on Pentose Transport Into Muscle

1958 ◽  
Vol 192 (2) ◽  
pp. 287-289 ◽  
Author(s):  
Jacob Sacks ◽  
Jolynn F. Smith
Keyword(s):  
Cell Membrane ◽  
Muscular Activity ◽  
Pentose Transport ◽  
Steric Configuration ◽  
Humoral Agent

The effects of insulin and muscular activity on the transport across the cell membrane of muscle of pentoses having the same steric configuration about carbon atoms 1, 2 and 3 as d-glucose has, were found to be additive in the nephrectomized cat. The degree of intracellular penetration of l-arabinose into muscle was found to be related to the extent of activity. The results suggest that the effect of muscular activity on pentose penetration is not due to a humoral agent. They also suggest that insulin and muscular activity exert their effects by different mechanisms.

Insulin and Tissue Distribution of Pentose in Nephrectomized Cats

1957 ◽  
Vol 189 (2) ◽  
pp. 339-342 ◽  
Author(s):  
Jacob Sacks ◽  
Stanley Bakshy
Keyword(s):  
Cell Membrane ◽  
Tissue Distribution ◽  
Insulin Injection ◽  
The Other ◽  
Exogenous Insulin ◽  
Apparent Effect ◽  
Cell Interior ◽  
Intracellular Compartment ◽  
Phosphorylation Reaction ◽  
Steric Configuration

A comparison has been made of the ‘pentose space’ and ‘chloride space’ of various tissues in the nephrectomized cat injected intravenously with various pentoses, and of the effect of insulin injection on the pentose space. The four pentoses tested, d- and l-arabinose and D- and L-xylose, were found to pass readily into the intracellular compartment of liver. With this exception, and the apparent failure to penetrate the blood-brain barrier, d-arabinose and l-xylose, which have steric configurations about carbon atoms 1, 2 and 3 opposite to that of D-glucose, showed purely extracellular distribution which was not affected by insulin. In the absence of exogenous insulin, extracellular distribution of L-arabinose and D-xylose was found in lung, intestine, skin, spleen and muscle; under these conditions brain and heart showed partial penetration of these sugars into the intracellular compartment. The injection of insulin resulted in partial intracellular penetration into muscle, increased penetration intracellularly in brain and heart, and was without apparent effect on the other tissues analyzed. The findings are discussed in terms of the postulate of Levine that insulin acts to facilitate the transfer across the cell membrane of glucose and of those sugars with the same steric configuration as D-gluclose about carbon atoms 1, 2 and 3. It is concluded that if the mechanism of transport of glucose across the cell membrane is the same as that of transport of these pentoses, then the entry of glucose into the cell interior precedes any phosphorylation reaction.

Regulation of Respiration During Muscular Activity

1956 ◽  
Vol 185 (1) ◽  
pp. 145-151 ◽  
Author(s):  
Frederick F. Kao
Keyword(s):  
Oxygen Consumption ◽  
Steady State ◽  
Regression Line ◽  
Muscular Activity ◽  
Voluntary Exercise ◽  
Regulation Of Respiration ◽  
Jugular Veins ◽  
Arterial Blood ◽  
Humoral Agent ◽  
Type Of Exercise

The mechanism of exercise hyperpnea was investigated employing a cross-circulation technique in which the head of a dog (humoral dog) was perfused exclusively by blood from another dog (neural dog) by way of the carotid arteries and the external jugular veins. The lower extremities of both dogs were induced to exercise separately by stimulating with 60-cycle alternating current, which is modulated sinusoidally. Forty-four experiments were performed on nine pairs of such preparations. The ventilation of the neural dog (exercising) first overshot, then attained a steady state, but the ventilation of the humoral dog overshot to a much higher level when its hind legs were exercised. During the steady state the ventilation of the neural dog (when it was exercising) increased in direct proportion to oxygen consumption. The slope of the regression line expressing the increment in ventilation as a function of oxygen consumption in the neural dog is 0.0298, which is not statistically different from that established for intact dogs during induced exercise or from that in normal dogs during voluntary exercise. The humoral dog whose head was perfused by arterial blood from the exercising neural dog showed no change in ventilation. Therefore, it is concluded that there is no humoral agent produced in the arterial blood of a dog subjected to this type of exercise. The normalcy of the respiratory apparatus in the humoral dog after the establishment of the cross circulation was tested by CO2 inhalation and lobeline administration and it was found to be adequate.

Sarcolemmal permeability changes during early myocardial anoxia

1978 ◽  
Vol 36 (2) ◽  
pp. 642-643
Author(s):  
M. Ashraf ◽  
L. Landa ◽  
L. Nimmo ◽  
C. M. Bloor
Keyword(s):  
Cell Membrane ◽  
Membrane Permeability ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Cell Membrane Permeability ◽  
Enzyme Release ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Sarcolemmal Permeability ◽  
Membrane Changes

Following coronary artery occlusion, the myocardial cells lose intracellular enzymes that appear in the serum 3 hrs later. By this time the cells in the ischemic zone have already undergone irreversible changes, and the cell membrane permeability is variably altered in the ischemic cells. At certain stages or intervals the cell membrane changes, allowing release of cytoplasmic enzymes. To correlate the changes in cell membrane permeability with the enzyme release, we used colloidal lanthanum (La+++) as a histological permeability marker in the isolated perfused hearts. The hearts removed from sprague-Dawley rats were perfused with standard Krebs-Henseleit medium gassed with 95% O2 + 5% CO2. The hypoxic medium contained mannitol instead of dextrose and was bubbled with 95% N2 + 5% CO2. The final osmolarity of the medium was 295 M osmol, pH 7. 4.

Flagellar Attachment in Selected Trypanosomes

1973 ◽  
Vol 31 ◽  
pp. 496-497
Author(s):  
J. J. Paulin
Keyword(s):  
Cell Membrane ◽  
Lateral Surface ◽  
The Body ◽  
Flagellar Pocket ◽  
Integral Component ◽  
Free Flagellum ◽  
Flagellar Axoneme

Movement in epimastigote and trypomastigote stages of trypanosomes is accomplished by planar sinusoidal beating of the anteriorly directed flagellum and associated undulating membrane. The flagellum emerges from a bottle-shaped depression, the flagellar pocket, opening on the lateral surface of the cell. The limiting cell membrane envelopes not only the body of the trypanosome but is continuous with and insheathes the flagellar axoneme forming the undulating membrane. In some species a paraxial rod parallels the axoneme from its point of emergence at the flagellar pocket and is an integral component of the undulating membrane. A portion of the flagellum may extend beyond the anterior apex of the cell as a free flagellum; the length is variable in different species of trypanosomes.

Trophoblast Cell Membrane Interactions at Implantation

1970 ◽  
Vol 28 ◽  
pp. 310-311
Author(s):  
A. C. Enders
Keyword(s):  
Epithelial Cells ◽  
Cell Membrane ◽  
Membrane Fusion ◽  
Trophoblast Cell ◽  
Membrane Interactions ◽  
Uterine Epithelial Cells ◽  
Functional Complex ◽  
Cytotrophoblast Cells ◽  
Complex Relationships ◽  
Syncytial Trophoblast

The alteration in membrane relationships seen at implantation include 1) interaction between cytotrophoblast cells to form syncytial trophoblast and addition to the syncytium by subsequent fusion of cytotrophoblast cells, 2) formation of a wide variety of functional complex relationships by trophoblast with uterine epithelial cells in the process of invasion of the endometrium, and 3) in the case of the rabbit, fusion of some uterine epithelial cells with the trophoblast.Formation of syncytium is apparently a membrane fusion phenomenon in which rapid confluence of cytoplasm often results in isolation of residual membrane within masses of syncytial trophoblast. Often the last areas of membrane to disappear are those including a desmosome where the cell membranes are apparently held apart from fusion.

Some Conditions Necessary for Pinocytosis

1968 ◽  
Vol 26 ◽  
pp. 142-143
Author(s):  
M. W. Brightman
Keyword(s):  
Smooth Muscle ◽  
Cell Membrane ◽  
Toxic Effects ◽  
Cytological Evidence ◽  
Cell Processes

The cytological evidence for pinocytosis is the focal infolding of the cell membrane to form surface pits that eventually pinch off and move into the cytoplasm. This activity, which can be inhibited by oxidative and glycolytic poisons, is performed only by cell processes that are at least 300A wide. However, the interpretation of such toxic effects becomes equivocal if the membrane invaginations do not normally lead to the formation of migratory vesicles, as in some endothelia and in smooth muscle. The present study is an attempt to set forth some conditions under which pinocytosis, as distinct from the mere inclusion of material in surface invaginations, can take place.

Electron microscopic radioautographic studies on the incorporation of 3H proline in the glomerular basement membrane (GBM) in antistreptococcal-cell-membrane (SCM) injected mice

1984 ◽  
Vol 42 ◽  
pp. 188-189
Author(s):  
R.P. Nayyar ◽  
C.F. Lange ◽  
J. L. Borke
Keyword(s):  
Body Weight ◽  
Cell Membrane ◽  
Basement Membrane ◽  
Glomerular Basement Membrane ◽  
Mesangial Matrix ◽  
Electron Microscopic ◽  
Group A ◽  
Injection Protocol

Streptococcal cell membrane (SCM) antiserum injected mice show a significant thickening of glomerular basement membrane (GBM) and an increase in mesangial matrix within 4 to 24 hours of antiserum administration (1,2,3). This study was undertaken to evaluate the incorporation of 3H proline into glomerular cells and GBM under normal and anti-SCM induced conditions. Mice were administered, intraperitoneally, 0.1 ml of normal or anti-SCM serum followed by a 10 µC/g body weight injection of 3H proline. Details of the preparation of anti-SCM (Group A type 12 streptococcal pyogenes) and other sera and injection protocol have been described elsewhere (2). After 15 minutes of isotope injection a chase of cold proline was given and animal sacrificed at 20 minutes, 1,2,4,8,24 and 48 hours. One of the removed kidneys was processed for immunofluorescence, light and electron microscopic radioautographic studies; second kidney was used for GBM isolation and aminoacid analysis.

High-voltage electron microscopy of patch-clamped membranes

1987 ◽  
Vol 45 ◽  
pp. 582-583
Author(s):  
F. Sachs ◽  
M. J. Song
Keyword(s):  
Electron Microscopy ◽  
Cell Membrane ◽  
Patch Clamp ◽  
High Voltage Electron Microscopy ◽  
Small Patch ◽  
Cellular Electrophysiology ◽  
Voltage Electron ◽  
Electron Microscopes ◽  
Patch Technique ◽  
Membrane Patch

Cellular electrophysiology has been revolutionized by the introduction of patch clamp techniques. The patch clamp records current from a small patch of the cell membrane which has been sucked into a glass pipette. The membrane patch, a few micons in diameter, is attached to the glass by a seal which is electrically, diffusionally and mechanically tight. Because of the tight electrical seal, the noise level is low enough to record the activity of single ion channels over a time scale extending from 10μs to days. However, although the patch technique is over ten years old, the patch structure is unknown. The patch is inside a glass pipette where it has been impossible to see with standard electron microscopes. We show here that at 1 Mev the glass pipette is transparent and the membrane within can be seen with a resolution of about 30 A.

Study on erythrocytes by SEM photogrammetry (SEMP) technique

1990 ◽  
Vol 48 (3) ◽  
pp. 724-725
Author(s):  
Tong Wensheng ◽  
Lu Lianhuang ◽  
Zhang Zhijun
Keyword(s):  
Quantitative Analysis ◽  
Cell Membrane ◽  
Clinical Diagnosis ◽  
Human Body ◽  
Blood Cells ◽  
Three Dimensional ◽  
Normal Person ◽  
Blood Disease ◽  
Computation Technique ◽  
Important Basis

This is a combined study of two diffirent branches, photogrammetry and morphology of blood cells. The three dimensional quantitative analysis of erythrocytes using SEMP technique, electron computation technique and photogrammetry theory has made it possible to push the study of mophology of blood cells from LM, TEM, SEM to a higher stage, that of SEM P. A new path has been broken for deeply study of morphology of blood cells.In medical view, the abnormality of the quality and quantity of erythrocytes is one of the important changes of blood disease. It shows the abnormal blood—making function of the human body. Therefore, the study of the change of shape on erythrocytes is the indispensable and important basis of reference in the clinical diagnosis and research of blood disease.The erythrocytes of one normal person, three PNH Patients and one AA patient were used in this experiment. This research determines the following items: Height;Length of two axes (long and short), ratio; Crevice in depth and width of cell membrane; Circumference of erythrocytes; Isoline map of erythrocytes; Section map of erythrocytes.

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