Ultrastructural changes during in situ early postmortem autolysis in kidney, pancreas, liver, heart and skeletal muscle of rats

2004 ◽  
Vol 6 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Yukari Tomita ◽  
Makoto Nihira ◽  
Youkichi Ohno ◽  
Shigeru Sato
Author(s):  
A. V. Somlyo ◽  
H. Shuman ◽  
A. P. Somlyo

Electron probe analysis of frozen dried cryosections of frog skeletal muscle, rabbit vascular smooth muscle and of isolated, hyperpermeab1 e rabbit cardiac myocytes has been used to determine the composition of the cytoplasm and organelles in the resting state as well as during contraction. The concentration of elements within the organelles reflects the permeabilities of the organelle membranes to the cytoplasmic ions as well as binding sites. The measurements of [Ca] in the sarcoplasmic reticulum (SR) and mitochondria at rest and during contraction, have direct bearing on their role as release and/or storage sites for Ca in situ.


Author(s):  
Vivian V. Yang ◽  
S. Phyllis Stearner

The heart is generally considered a radioresistant organ, and has received relatively little study after total-body irradiation with doses below the acutely lethal range. Some late damage in the irradiated heart has been described at the light microscopic level. However, since the dimensions of many important structures of the blood vessel wall are submicroscopic, investigators have turned to the electron microscope for adequate visualization of histopathological changes. Our studies are designed to evaluate ultrastructural changes in the mouse heart, particularly in the capillaries and muscle fibers, for 18 months after total-body exposure, and to compare the effects of 240 rad fission neutrons and 788 rad 60Co γ-rays.Three animals from each irradiated group and three control mice were sacrificed by ether inhalation at 4 days, and at 1, 3, 6, 12, and 18 months after irradiation. The thorax was opened and the heart was fixed briefly in situwith Karnofsky's fixative.


2017 ◽  
Vol 312 (5) ◽  
pp. E394-E406 ◽  
Author(s):  
Samuel Lee ◽  
Teresa C. Leone ◽  
Lisa Rogosa ◽  
John Rumsey ◽  
Julio Ayala ◽  
...  

Peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α and -1β serve as master transcriptional regulators of muscle mitochondrial functional capacity and are capable of enhancing muscle endurance when overexpressed in mice. We sought to determine whether muscle-specific transgenic overexpression of PGC-1β affects the detraining response following endurance training. First, we established and validated a mouse exercise-training-detraining protocol. Second, using multiple physiological and gene expression end points, we found that PGC-1β overexpression in skeletal muscle of sedentary mice fully recapitulated the training response. Lastly, PGC-1β overexpression during the detraining period resulted in partial prevention of the detraining response. Specifically, an increase in the plateau at which O2 uptake (V̇o2) did not change from baseline with increasing treadmill speed [peak V̇o2 (ΔV̇o2max)] was maintained in trained mice with PGC-1β overexpression in muscle 6 wk after cessation of training. However, other detraining responses, including changes in running performance and in situ half relaxation time (a measure of contractility), were not affected by PGC-1β overexpression. We conclude that while activation of muscle PGC-1β is sufficient to drive the complete endurance phenotype in sedentary mice, it only partially prevents the detraining response following exercise training, suggesting that the process of endurance detraining involves mechanisms beyond the reversal of muscle autonomous mechanisms involved in endurance fitness. In addition, the protocol described here should be useful for assessing early-stage proof-of-concept interventions in preclinical models of muscle disuse atrophy.


Development ◽  
1993 ◽  
Vol 117 (4) ◽  
pp. 1409-1420 ◽  
Author(s):  
R. Moore ◽  
F.S. Walsh

The spatiotemporal distribution of M-cadherin mRNA has been determined by in situ hybridization in the mouse embryo and in adult skeletal muscle following experimental regeneration and denervation. M-cadherin mRNA is highly tissue specific and is found only in developing skeletal muscle. In contrast, N-cadherin mRNA has a broader tissue distribution in the embryo, being found on both neural elements and skeletal and cardiac muscle. M-cadherin is expressed in the myotomes shortly after they form, along with the myogenic regulatory factor myogenin. M-cadherin is expressed in muscles derived from the myotomes and is detected in forelimb bud precursor cells at embryonic day 11.5. In the latter case M-cadherin expression appears co-ordinately with that of myogenin and cardiac alpha-actin. Shortly before birth, M-cadherin expression is down regulated. M-cadherin can, however, be re-expressed following experimental regeneration of skeletal muscle. Here M-cadherin is transiently expressed on regenerating myoblasts but not myotubes. Following muscle denervation no evidence was found for re-expression of M-cadherin under conditions where there was strong expression of the nicotinic acetylcholine receptor on myofibres. The highly specific tissue distribution and unique developmental profile distinguishes M-cadherin from other cadherins and suggests a role in cell surface events during early myogenesis.


1993 ◽  
Vol 62 (2-3) ◽  
pp. 181-182 ◽  
Author(s):  
H.J. Eyre ◽  
P.A. Akkari ◽  
C. Meredith ◽  
S.D. Wilton ◽  
D.C. Callen ◽  
...  

2001 ◽  
Vol 79 (12) ◽  
pp. 996-1006 ◽  
Author(s):  
Michael I Lindinger ◽  
Thomas J Hawke ◽  
Lisa Vickery ◽  
Laurie Bradford ◽  
Shonda L Lipskie

The contributions of Na+/K+-ATPase, K+ channels, and the NaK2Cl cotransporter (NKCC) to total and unidirectional K+ flux were determined in mammalian skeletal muscle at rest. Rat hindlimbs were perfused in situ via the femoral artery with a bovine erythrocyte perfusion medium that contained either 86Rb or 42K, or both simultaneously, to determine differences in ability to trace unidirectional K+ flux in the absence and presence of K+-flux inhibitors. In most experiments, the unidirectional flux of K+ into skeletal muscle (JinK) measured using 86Rb was 8–10% lower than JinK measured using 42K. Ouabain (5 mM) was used to inhibit Na+/K+-ATPase activity, 0.06 mM bumetanide to inhibit NKCC activity, 1 mM tetracaine or 0.5 mM barium to block K+ channels, and 0.05 mM glybenclamide (GLY) to block ATP-sensitive K+ (KATP) channels. In controls, JinK remained unchanged at 0.31 ± 0.03 µmol·g–1·min–1 during 55 min of perfusion. The ouabain-sensitive Na+/K+-ATPase contributed to 50 ± 2% of basal JinK, K+ channels to 47 ± 2%, and the NKCC to 12 ± 1%. GLY had minimal effect on JinK, and both GLY and barium inhibited unidirectional efflux of K+ (JoutK) from the cell through K+ channels. Combined ouabain and tetracaine reduced JinK by 55 ± 2%, while the combination of ouabain, tetracaine, and bumetanide reduced JinK by 67 ± 2%, suggesting that other K+-flux pathways may be recruited because the combined drug effects on inhibiting JinK were not additive. The main conclusions are that the NKCC accounted for about 12% of JinK, and that KATP channels accounted for nearly all of the JoutK, in resting skeletal muscle in situ.Key words: sodium potassium chloride cotransporter, NKCC, Na+/K+-ATPase, potassium channels, potassium transport, in situ rat hindlimb.


2009 ◽  
Vol 96 (3) ◽  
pp. 127a
Author(s):  
M.L. Bang ◽  
M. Caremani ◽  
E. Brunello ◽  
R. Littlefield ◽  
R. Lieber ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document