scholarly journals Fluorescence demonstration of cathepsin B activity in skeletal, cardiac, and vascular smooth muscle.

1981 ◽  
Vol 29 (7) ◽  
pp. 866-869 ◽  
Author(s):  
W T Stauber ◽  
S H Ong
Keyword(s):  
Skeletal Muscle ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Cathepsin B ◽  
Extensor Digitorum Longus ◽  
Histochemical Demonstration ◽  
Extensor Digitorum ◽  
Lysosomal Protease ◽  
Muscle Tissues ◽  
Muscle Types

Histochemical demonstration of cathepsin B activity was performed for the soleus, extensor digitorum longus, cardiac and vascular smooth muscle tissues of the rat using CBZ-Arg-Arg-4-methoxy-beta-naphthylamide or CBZ-Ala-Arg-Arg-4-methoxy-beta-naphthylamide as the substrate. The enzyme varied in its apparent activity but was localized in discrete granules in all muscle types. Cathepsin B was most active in cardiac muscle and least active in extensor digitorum longus muscles in between these extremes similar to another lysosomal protease, dipeptidyl peptidase II. However, in both types of skeletal muscle, the granules were observed more frequently at the periphery of the muscle cell just beneath the sarcolemma. Since cathepsin B is found only in lysosomes, this subsarcolemmal predominence may indicate that only one population of lysosomes in muscle contains active cathepsin B. All cathepsin B activity was abolished in the presence of the protease inhibitor, leupeptin.

scholarly journals Fluorescence demonstration of dipeptidyl peptidase II in skeletal, cardiac, and vascular smooth muscles.

1981 ◽  
Vol 29 (5) ◽  
pp. 672-677 ◽  
Author(s):  
W T Stauber ◽  
S H Ong
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Extensor Digitorum Longus ◽  
Smooth Muscles ◽  
Dipeptidyl Peptidase ◽  
Extensor Digitorum ◽  
Vascular Smooth Muscles ◽  
Normal Muscle ◽  
Muscle Tissues ◽  
Muscle Types

Dipeptidyl peptidase II (Dpp II) was demonstrated histochemically in soleus, extensor digitorum longus, cardiac, and vascular smooth muscle tissues using Lys-Ala-4-methoxy-beta-naphthylamide or Lys-Pro-4-methoxy-beta-naphthylamide as the substrate. The enzyme was found to be localized in discrete granules in all muscle types, but varied in its apparent activity. Dpp II activity was greatest in cardiac and least in extensor digitorum longus muscles with activity in soleus and vascular smooth muscles in between these extremes. Since Dpp II is localized only in lysosomes, the relative amounts and locales of lysosomes can be easily observed in normal muscle cells by the techniques described in this study.

scholarly journals Fluorescence demonstration of dipeptidyl peptidase I (cathepsin C) in skeletal, cardiac, and vascular smooth muscles.

1982 ◽  
Vol 30 (2) ◽  
pp. 162-164 ◽  
Author(s):  
W T Stauber ◽  
S H Ong
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Extensor Digitorum Longus ◽  
Smooth Muscles ◽  
Muscle Cells ◽  
Dipeptidyl Peptidase ◽  
Extensor Digitorum ◽  
Cathepsin C

Dipeptidyl peptidase I (cathepsin C) was demonstrated histochemically in soleus, extensor digitorum longus, and cardiac muscles but not in vascular smooth muscle cells of the caudal artery of the rat. The enzyme using Pro-Arg-4-methoxy-beta-naphthylamide as the substrate was found in discrete granules in the striated muscles. The activity was greatest in the soleus muscle, with less activity observed in cardiac tissue, and only a few reactive sites observed in the extensor digitorum longus muscle. Under identical conditions no activity was observed associated with vascular smooth muscle cells. Dipeptidyl peptidase I activity was inhibited completely by 1mM HgCl2 in the incubation solutions and not preserved following conventional chemical fixation techniques.

Human growth hormone treatment of hypophysectomized rats increases the proportion of type-1 fibres in skeletal muscle

1989 ◽  
Vol 123 (3) ◽  
pp. 429-NP ◽  
Author(s):  
C. M. Ayling ◽  
B. H. Moreland ◽  
J. M. Zanelli ◽  
D. Schulster
Keyword(s):  
Skeletal Muscle ◽  
Fibre Type ◽  
Extensor Digitorum Longus ◽  
Human Growth ◽  
Hormone Treatment ◽  
Pituitary Hormones ◽  
Extensor Digitorum ◽  
Replacement Treatment ◽  
Hypophysectomized Rats

ABSTRACT The studies describe alterations after hypophysectomy in the proportion of the type-1 and type-2 fibres in rat skeletal muscles, and the effects of replacement treatment with pituitary human (h) GH. Cytochemical analysis of myosin ATPase, succinate dehydrogenase and lactate dehydrogenase activities in sections of rat hind limb muscles were used as markers of fibre type and revealed that hypophysectomy reduced the proportion of type-1 fibres by 50% in soleus and in extensor digitorum longus muscles. This reduction in the proportion of type-1 fibres was accompanied by the appearance of transitional fibres (type 2C/1B). Following seven daily injections of hGH (60 mIU/day) to hypophysectomized rats, the proportion of type-1 fibres in both soleus and in extensor digitorum longus was increased with a concomitant reduction in the number of transitional fibres. After 11 days of treatment, all these transitional fibres had reverted back to type-1 fibres. Only hGH was observed to elicit this effect; injections of other pituitary hormones had no effect on the proportions of these transitional fibres. These alterations in fibre type occurred more rapidly than the changes reported after prolonged electrical stimulation of muscle or following extended exercise. These findings suggest that hypophysectomy and GH injection can result in a rapid alteration in the fibre composition of skeletal muscle, which may have important implications in terms of the resistance to fatigue and speed of contraction of the muscle. Journal of Endocrinology (1989) 123, 429–435

scholarly journals Identification in skeletal muscle of a distinct extracellular pool of amino acids, and its role in protein synthesis

1971 ◽  
Vol 121 (5) ◽  
pp. 817-827 ◽  
Author(s):  
R. C. Hider ◽  
E. B. Fern ◽  
D. R. London
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Incubation Medium ◽  
Extensor Digitorum Longus ◽  
Extensor Digitorum ◽  
Longus Muscle ◽  
Kinetics Of

1. The kinetics of radioactive labelling of extra- and intra-cellular amino acid pools and protein of the extensor digitorum longus muscle were studied after incubations with radioactive amino acids in vitro. 2. The results indicated that an extracellular pool could be defined, the contents of which were different from those of the incubation medium. 3. It was concluded that amino acids from the extracellular pool, as defined in this study, were incorporated directly into protein.

The role of globins in cardiovascular physiology

2021 ◽  
Author(s):  
T.C. Steven Keller ◽  
Christophe Lechauve ◽  
Alexander S Keller ◽  
Steven Brooks ◽  
Mitchell J Weiss ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Central Nervous System ◽  
Nervous System ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Cell Types ◽  
Specific Cell ◽  
In Cells

Globin proteins exist in every cell type of the vasculature, from erythrocytes to endothelial cells, vascular smooth muscle cells, and peripheral nerve cells. Many globin subtypes are also expressed in muscle tissues (including cardiac and skeletal muscle), in other organ-specific cell types, and in cells of the central nervous system. The ability of each of these globins to interact with molecular oxygen (O2) and nitric oxide (NO) is preserved across these contexts. Endothelial α-globin is an example of extra-erythrocytic globin expression. Other globins, including myoglobin, cytoglobin, and neuroglobin are observed in other vascular tissues. Myoglobin is observed primarily in skeletal muscle and smooth muscle cells surrounding the aorta or other large arteries. Cytoglobin is found in vascular smooth muscle but can also be expressed in non-vascular cell types, especially in oxidative stress conditions after ischemic insult. Neuroglobin was first observed in neuronal cells, and its expression appears to be restricted mainly to the central and peripheral nervous systems. Brain and central nervous system neurons expressing neuroglobin are positioned close to many arteries within the brain parenchyma and can control smooth muscle contraction and, thus, tissue perfusion and vascular reactivity. Overall, reactions between NO and globin heme-iron contribute to vascular homeostasis by regulating vasodilatory NO signals and scaveging reactive species in cells of the mammalian vascular system. Here, we discuss how globin proteins affect vascular physiology with a focus on NO biology, and offer perspectives for future study of these functions.

Spaceflight on STS-48 and earth-based unweighting produce similar effects on skeletal muscle of young rats

1993 ◽  
Vol 74 (5) ◽  
pp. 2161-2165 ◽  
Author(s):  
M. E. Tischler ◽  
E. J. Henriksen ◽  
K. A. Munoz ◽  
C. S. Stump ◽  
C. R. Woodman ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Extensor Digitorum Longus ◽  
Space Shuttle ◽  
Weight Bearing ◽  
Similar Rate ◽  
Extensor Digitorum ◽  
Hindlimb Suspension ◽  
Albino Rats ◽  
Sprague Dawley ◽  
Ambient Temperatures

Our knowledge of the effects of unweighting on skeletal muscle of juvenile rapidly growing rats has been obtained entirely by using hindlimb-suspension models. No spaceflight data on juvenile animals are available to validate these models of simulated weightlessness. Therefore, eight 26-day-old female Sprague-Dawley albino rats were exposed to 5.4 days of weightlessness aboard the space shuttle Discovery (mission STS-48, September 1991). An asynchronous ground control experiment mimicked the flight cage condition, ambient shuttle temperatures, and mission duration for a second group of rats. A third group of animals underwent hindlimb suspension for 5.4 days at ambient temperatures. Although all groups consumed food at a similar rate, flight animals gained a greater percentage of body mass per day (P < 0.05). Mass and protein data showed weight-bearing hindlimb muscles were most affected, with atrophy of the soleus and reduced growth of the plantaris and gastrocnemius in both the flight and suspended animals. In contrast, the non-weight-bearing extensor digitorum longus and tibialis anterior muscles grew normally. Earlier suspension studies showed that the soleus develops an increased sensitivity to insulin during unweighting atrophy, particularly for the uptake of 2-[1,2–3H]deoxyglucose. Therefore, this characteristic was studied in isolated muscles within 2 h after cessation of spaceflight or suspension. Insulin increased uptake 2.5- and 2.7-fold in soleus of flight and suspended animals, respectively, whereas it increased only 1.6-fold in control animals. In contrast, the effect of insulin was similar among the three groups for the extensor digitorum longus, which provides a control for potential systemic differences in the animals.

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