A viscoplastic model for the active component in cardiac muscle

Junctional sarcoplasmic reticulum (JSR) in all its forms (extended JSR, JSR of couplings, corbular SR) in both skeletal and cardiac muscle is always located at the Z - I regions of the sarcomeres. The Z tubule is a tubule of the free SR (non-specialized SR) which is consistently located at the Z lines in cardiac muscle (1). Short connections between JSR and Z lines have been described (2), and bundles of filaments at Z lines have been seen in skeletal (3) and cardiac (4) muscle. In opossum cardiac muscle, we have seen bundles of 10 nm filaments stretching across interfibrillary spaces and adjacent myofibrils with extensions to the plasma- lemma in longitudinal (Fig. 1) and transverse (Fig. 2) sections. Only an occasional single filament is seen elsewhere along a sarcomere. We propose that these filaments represent anchor fibers that maintain the observed invariant topography of the free SR and JSR throughout the contraction-relaxation cycle.

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Neuronal and Extraneuronal Uptake of 3H-Norepinephrine in the Heart of the Active Bat: An Electron Microscopic Radioautographic Study

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100073052 ◽

1973 ◽

Vol 31 ◽

pp. 522-523

Author(s):

Martin Hagopian ◽

Michael D. Gershon ◽

Eladio A. Nunez

Keyword(s):

Smooth Muscle ◽

Monoamine Oxidase ◽

Vascular Smooth Muscle ◽

Cardiac Muscle ◽

Maximum Rate ◽

External Medium ◽

Extraneuronal Uptake ◽

Electron Microscopic ◽

Cardiac Tissues ◽

High Affinity

The ability of cardiac tissues to take up norepinephrine from an external medium is well known. Two mechanisms, called Uptake and Uptake respectively by Iversen have been differentiated. Uptake is a high affinity system associated with adrenergic neuronal elements. Uptake is a low affinity system, with a higher maximum rate than that of Uptake. Uptake has been associated with extraneuronal tissues such as cardiac muscle, fibroblasts or vascular smooth muscle. At low perfusion concentrations of norepinephrine most of the amine taken up by Uptake is metabolized. In order to study the localization of sites of norepinephrine storage following its uptake in the active bat heart, tritiated norepinephrine (2.5 mCi; 0.064 mg) was given intravenously to 2 bats. Monoamine oxidase had been inhibited with pheniprazine (10 mg/kg) one hour previously to decrease metabolism of norepinephrine.

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Morphological Basis of the Disparity Between Muscle Length and Sarcomere Length in the Myocardium

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100072551 ◽

1973 ◽

Vol 31 ◽

pp. 422-423

Author(s):

G.E. Adomian ◽

L. Chuck ◽

W.W. Pannley

Keyword(s):

Cardiac Muscle ◽

Sarcomere Length ◽

Muscle Length ◽

Contractile Force ◽

Direct Function ◽

Morphological Basis ◽

Tension Curve

Sonnenblick, et al, have shown that sarcomeres change length as a function of cardiac muscle length along the ascending portion of the length-tension curve. This allows the contractile force to be expressed as a direct function of sarcomere length. Below L max, muscle length is directly related to sarcomere length at lengths greater than 85% of optimum. However, beyond the apex of the tension-length curve, i.e. L max, a disparity occurs between cardiac muscle length and sarcomere length. To account for this disproportionate increase in muscle length as sarcomere length remains relatively stable, the concept of fiber slippage was suggested as a plausible explanation. These observations have subsequently been extended to the intact ventricle.

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High Resolution Stereography of Complementary Freeze-Fracture Replicas Reveals the Presence of Depressions Opposite Membrane Associated Particles of Split Membranes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100066267 ◽

1971 ◽

Vol 29 ◽

pp. 442-443

Author(s):

Russell L. Steere

Keyword(s):

High Resolution ◽

Cardiac Muscle ◽

Electron Micrographs ◽

Chromic Acid ◽

Freeze Fracture ◽

Distilled Water ◽

Fine Scale ◽

Acid Cleaning ◽

Cleaning Solution

Complementary replicas have revealed the fact that the two common faces observed in electron micrographs of freeze-fracture and freeze-etch specimens are complementary to each other and are thus the new faces of a split membrane rather than the original inner and outer surfaces (1, 2 and personal observations). The big question raised by published electron micrographs is why do we not see depressions in the complementary face opposite membrane-associated particles? Reports have appeared indicating that some depressions do appear but complementarity on such a fine scale has yet to be shown.Dog cardiac muscle was perfused with glutaraldehyde, washed in distilled water, then transferred to 30% glycerol (material furnished by Dr. Joaquim Sommer, Duke Univ., and VA Hospital, Durham, N.C.). Small strips were freeze-fractured in a Denton Vacuum DFE-2 Freeze-Etch Unit with complementary replica tooling. Replicas were cleaned in chromic acid cleaning solution, then washed in 4 changes of distilled water and mounted on opposite sides of the center wire of a Formvar-coated grid.

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Protection from Hg-Inactivation of Factor XIII by Mercaptalbumin

Thrombosis and Haemostasis ◽

10.1055/s-0038-1654244 ◽

1970 ◽

Vol 24 (03/04) ◽

pp. 352-355 ◽

Cited By ~ 2

Author(s):

P Fantl

Keyword(s):

Blood Plasma ◽

Factor Xiii ◽

Active Component ◽

Plasma Albumin ◽

Plasma Factor ◽

Mercuric Ions

SummaryThe blood plasma factor XIII (fibrin stabilizing factor) is inactivated by mercuric ions and can be reactivated by serum - or plasma albumin of which the active component is mercaptalbumin. A relation between mercaptalbumin concentration and factor XIII activity is pointed out.

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IN VITRO/IN SILICO CHARACTERIZATION OF ACTIVE AND PASSIVE STRESSES IN CARDIAC MUSCLE

International Journal for Multiscale Computational Engineering ◽

10.1615/intjmultcompeng.2011002352 ◽

2012 ◽

Vol 10 (2) ◽

pp. 171-188 ◽

Cited By ~ 7

Author(s):

Markus Boel ◽

Oscar J. Abilez ◽

Ahmed N Assar ◽

Christopher K. Zarins ◽

Ellen Kuhl

Keyword(s):

Cardiac Muscle ◽

In Silico ◽

In Silico Characterization

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Histopathological and morphological alterations in salivary gland of House fly induced by oral administration Thiamethoxam.

Kurdistan Journal of Applied Research ◽

10.24017/science.2018.1.8 ◽

2018 ◽

Vol 3 (1) ◽

pp. 40-44 ◽

Cited By ~ 1

Author(s):

Karim Mohammed Xider

Keyword(s):

Salivary Gland ◽

Cell Membrane ◽

Oral Administration ◽

Peak Concentration ◽

Active Component ◽

House Fly ◽

Morphological Alterations ◽

Gland Tissue ◽

Gland Duct ◽

Feeding Process

The current work the effect of Actara insecticide belongs to chemical family Neonicotinoid. The active component of thiamethoxam in three concentrations: 0.750 ppm, 1.5 ppm and 2.25ppm on adult house fly salivary glands. Histopathological and morphological effects revealed important alterations produced by this insecticide in histological and morphology of the adult house fly gland tissue categorized by increasing gland duct lumen diameter. These alterations are possibly related with excretion function of salivary gland might be accountable for removing this insecticide. Results show thiamethoxam is a powerful insecticide that performances histologically in salivary glant tissue, triggering alterations in the glands form, cytoplasm with extreme vacuolation ,disruption cell membrane, obvious disorganization tissues cells, terminating in progressive deteriorating phase with changes in nucleus glandular cell's, such alterations occurred together in its size and form of gland, disintegration of nucleus, and presence of apoptosis(fragmentation) nucleus, accelerating the process of glandular degeneration ,and interfering with feeding process of house fly particularly when the peak concentration of insecticide was used.

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