scholarly journals Structural dermis remodeling in a skin expansion rat model

2021 ◽  
Vol 10 (2) ◽  
pp. 50-56
Author(s):  
E.S. Mishina ◽  
◽  
M.A. Zatolokina ◽  
M.V. Mnikhovich ◽  
◽  
...  
Keyword(s):  
Skin Flap ◽  
Light And Electron Microscopy ◽  
Fold Increase ◽  
Type Iii Collagen ◽  
Fiber Types ◽  
Cellular Mechanisms ◽  
Skin Expansion ◽  
Male Wistar Rats ◽  
Expansion Model ◽  
Epidermal Cell Layer

Introduction. Skin expansion is known to be the most effective way to obtain skin for alloplastic closing of large defects, and it has proven to be successfully used in various fields of surgery, cosmetology, and traumatology. At the same time, the issues of skin flap restructuring when it is stretched and possible range of its application are still relevant. In this regard, the aim was to study the adaptive skin rearrangements of the fibrous skeleton in a murine skin expansion model. Materials and methods. We used the skin of mature male Wistar rats (N=30) after a 2-week stretching. We utilized a complex morphological light and electron microscopy approach as well as an immunohistochemi-cal method to determine the types of collagen and to study the alterations in skin samples. Results. We revealed pronounced reactive changes in the skin structural components in the skin expansion area. On day 14, we observed a decrease in the epidermal cell layer thickness as well as stretching, partial disorganization, and damage of dermal fibrous structure. At the same time, cellular mechanisms of regen-eration and activation of collagen synthesis were launched, the morphological substrate of which was (1) a significant 2.7-fold increase in the number density of fibroblasts, which produce substances for building fibrous structures, (2) a five-fold increase in macrophages, which are a catalyst for the fibroblast functional activity and (3) a collagen fiber types’ redistribution s with Type III collagen structures’ predominance. Conclusion. The results indicate, first of all, the restructuring of the dermal fibrous component, which im-plies reparative and restorative processes. These must be taken into account in clinical practice to achieve not only an esthetic effect but also the subsequent adequate functioning and vital activity of the skin flap. Keywords: skin expansion, fibrous dermis, remodeling, skin, hyperextension

Structural Organization and Distribution of Fiber Types in Extraocular Muscles of Cats

1972 ◽  
Vol 30 ◽  
pp. 34-35
Author(s):  
Asish C. Nag ◽  
Lee D. Peachey
Keyword(s):  
Fiber Type ◽  
Light And Electron Microscopy ◽  
Small Diameter ◽  
Extraocular Muscles ◽  
Fiber Types ◽  
Distinctive Features ◽  
Superior Rectus ◽  
Adult Cats ◽  
Different Diameters ◽  
Orbital Region

Cat extraocular muscles consist of two regions: orbital, and global. The orbital region contains predominantly small diameter fibers, while the global region contains a variety of fibers of different diameters. The differences in ultrastructural features among these muscle fibers indicate that the extraocular muscles of cats contain at least five structurally distinguishable types of fibers.Superior rectus muscles were studied by light and electron microscopy, mapping the distribution of each fiber type with its distinctive features. A mixture of 4% paraformaldehyde and 4% glutaraldehyde was perfused through the carotid arteries of anesthetized adult cats and applied locally to exposed superior rectus muscles during the perfusion.

Biodegradable polyester neuroprostheses promote the reconnection of separated peripheral nerve stubs

1992 ◽  
Vol 50 (2) ◽  
pp. 1094-1095
Author(s):  
Beverly L. Giammara ◽  
Jennifer S. Stevenson ◽  
Peggy E. Yates ◽  
Robert H. Gunderson ◽  
Jacob S. Hanker
Keyword(s):  
Image Analysis ◽  
Basement Membrane ◽  
Periodic Acid ◽  
Light And Electron Microscopy ◽  
Computer Assisted ◽  
Type Iii Collagen ◽  
Image Analysis System ◽  
Biodegradable Polyester ◽  
Adult Rats ◽  
Type Iv

An 11mm length of sciatic nerve was removed from 10 anesthetized adult rats and replaced by a biodegradable polyester Vicryl™ mesh sleeve which was then injected with the basement membrane gel, Matrigel™. It was noted that leg sensation and movement were much improved after 30 to 45 days and upon sacrifice nerve reconnection was noted in all animals. Epoxy sections of the repaired nerves were compared with those of the excised segments by the use of a variation of the PAS reaction, the PATS reaction, developed in our laboratories for light and electron microscopy. This microwave-accelerated technique employs periodic acid, thiocarbohydrazide and silver methenamine. It stains basement membrane or Type IV collagen brown and type III collagen (reticulin), axons, Schwann cells, endoneurium and perineurium black. Epoxy sections of repaired and excised nerves were also compared by toluidine blue (tb) staining. Comparison of the sections of control and repaired nerves was done by computer-assisted microscopic image analysis using an Olympus CUE-2 Image Analysis System.

scholarly journals Adrenergic control of vascular resistance varies in muscles composed of different fiber types: influence of the vascular endothelium

2011 ◽  
Vol 301 (3) ◽  
pp. R783-R790 ◽  
Author(s):  
Bradley J. Behnke ◽  
Robert B. Armstrong ◽  
Michael D. Delp
Keyword(s):  
Blood Flow ◽  
Vascular Resistance ◽  
Vascular Endothelium ◽  
Fold Increase ◽  
Male Rats ◽  
Type I ◽  
Fiber Types ◽  
Fast Twitch Muscle ◽  
Dose Responses ◽  
Fast Twitch

The influence of the sympathetic nervous system (SNS) upon vascular resistance is more profound in muscles comprised predominately of low-oxidative type IIB vs. high-oxidative type I fiber types. However, within muscles containing high-oxidative type IIA and IIX fibers, the role of the SNS on vasomotor tone is not well established. The purpose of this study was to examine the influence of sympathetic neural vasoconstrictor tone in muscles composed of different fiber types. In adult male rats, blood flow to the red and white portions of the gastrocnemius (GastRed and GastWhite, respectively) and the soleus muscle was measured pre- and postdenervation. Resistance arterioles from these muscles were removed, and dose responses to α1-phenylephrine or α2-clonidine adrenoreceptor agonists were determined with and without the vascular endothelium. Denervation resulted in a 2.7-fold increase in blood flow to the soleus and GastRed and an 8.7-fold increase in flow to the GastWhite. In isolated arterioles, α2-mediated vasoconstriction was greatest in GastWhite (∼50%) and less in GastRed (∼31%) and soleus (∼17%); differences among arterioles were abolished with the removal of the endothelium. There was greater sensitivity to α1-mediated vasoconstriction in the GastWhite and GastRed vs. the soleus, which was independent of whether the endothelium was present. These data indicate that 1) control of vascular resistance by the SNS in high-oxidative, fast-twitch muscle is intermediate to that of low-oxidative, fast-twitch and high-oxidative, slow-twitch muscles; and 2) the ability of the SNS to control blood flow to low-oxidative type IIB muscle appears to be mediated through postsynaptic α1- and α2-adrenoreceptors on the vascular smooth muscle.

scholarly journals Mitochondrial Biogenesis and Remodeling during Adipogenesis and in Response to the Insulin Sensitizer Rosiglitazone

2003 ◽  
Vol 23 (3) ◽  
pp. 1085-1094 ◽  
Author(s):  
Leanne Wilson-Fritch ◽  
Alison Burkart ◽  
Gregory Bell ◽  
Karen Mendelson ◽  
John Leszyk ◽  
...  
Keyword(s):  
Mitochondrial Biogenesis ◽  
Gradient Centrifugation ◽  
Light And Electron Microscopy ◽  
Fold Increase ◽  
Mitochondrial Proteins ◽  
Whole Body ◽  
Brown Adipocyte ◽  
Insulin Sensitizer ◽  
Adipose Differentiation ◽  
Whole Body Metabolism

ABSTRACT White adipose tissue is an important endocrine organ involved in the control of whole-body metabolism, insulin sensitivity, and food intake. To better understand these functions, 3T3-L1 cell differentiation was studied by using combined proteomic and genomic strategies. The proteomics approach developed here exploits velocity gradient centrifugation as an alternative to isoelectric focusing for protein separation in the first dimension. A 20- to 30-fold increase in the concentration of numerous mitochondrial proteins was observed during adipogenesis, as determined by mass spectrometry and database correlation analysis. Light and electron microscopy confirmed a large increase in the number of mitochondrion profiles with differentiation. Furthermore, mRNA profiles obtained by using Affymetrix GeneChips revealed statistically significant increases in the expression of many nucleus-encoded mitochondrial genes during adipogenesis. Qualitative changes in mitochondrial composition also occur during adipose differentiation, as exemplified by increases in expression of proteins involved in fatty acid metabolism and of mitochondrial chaperones. Furthermore, the insulin sensitizer rosiglitazone caused striking changes in mitochondrial shape and expression of selective mitochondrial proteins. Thus, although mitochondrial biogenesis has classically been associated with brown adipocyte differentiation and thermogenesis, our results reveal that mitochondrial biogenesis and remodeling are inherent to adipose differentiation per se and are influenced by the actions of insulin sensitizers.

scholarly journals Antigoitrogenic effect of combined supplementation with dl-alpha-tocopherol, ascorbic acid and beta-carotene and of dl-alpha-tocopherol alone in the rat

1998 ◽  
Vol 156 (3) ◽  
pp. 551-561 ◽  
Author(s):  
JF Mutaku ◽  
MC Many ◽  
I Colin ◽  
JF Denef ◽  
MF van den Hove
Keyword(s):  
Endothelial Cells ◽  
Ascorbic Acid ◽  
Vitamin E ◽  
Beta Carotene ◽  
Iodine Content ◽  
Fold Increase ◽  
Alpha Tocopherol ◽  
Free Radical Scavengers ◽  
Rate Of Increase ◽  
Male Wistar Rats

The effects of the vitamins dl-alpha-tocopherol, ascorbic acid and beta-carotene, free radical scavengers and lipid peroxidation inhibitors, were analyzed in male Wistar rats made goitrous by feeding a low iodine diet (< 20 micrograms iodine/kg) and perchlorate (1% in drinking water) for 4, 8, 16, and 32 days. Groups of control or goitrous rats received for at least 16 days before killing a diet containing 0.6% vitamin E (as dl-alpha-tocopherol acetate), 1.2% vitamin C (ascorbic acid) and 0.48% beta-carotene, either simultaneously (vitamin cocktail) or separately. This treatment led to a 5-fold increase of vitamin E in the thyroid gland, a 24-fold increase in the liver and a 3-fold increase in the plasma. In control rats, vitamin cocktail administration increased slightly the thyroid weight with little changes in thyroid function parameters. During iodine deficiency, administration of the vitamin cocktail or vitamin E alone reduced significantly the rate of increase in thyroid weight, and DNA and protein contents, as well as the proportion of [3H]thymidine labeled thyroid follicular cells, but not that of labeled endothelial cells. Plasma tri-iodothyronine, thyroxine, TSH levels, thyroid iodine content and concentration as well as relative volumes of glandular compartments were not modified. The proportion of necrotic cells rose from 0.5% in normal animals to about 2% after 16 days of goiter development. No significant protective effect of the vitamins was observed. These results suggest that these vitamins, particularly vitamin E, modulate one of the regulatory cascades involved in the control of thyroid follicular cell growth, without interfering with the proliferation of endothelial cells.

scholarly journals Apoptosis and Caspase-3 in Experimental Anti-Glomerular Basement Membrane Nephritis

2001 ◽  
Vol 12 (3) ◽  
pp. 485-495
Author(s):  
BIN YANG ◽  
TIMOTHY S. JOHNSON ◽  
GRAHAM L. THOMAS ◽  
PHILIP F. WATSON ◽  
BART WAGNER ◽  
...  
Keyword(s):  
Basement Membrane ◽  
Glomerular Basement Membrane ◽  
Cell Apoptosis ◽  
Caspase 3 ◽  
Light And Electron Microscopy ◽  
Fold Increase ◽  
Northern Blotting ◽  
Nuclear Antigen ◽  
Tubular Atrophy ◽  
Wistar Kyoto

Abstract. The caspase family is central to the proteolytic events of apoptosis. In particular, caspase-3 plays a key role in the execution of apoptosis. However, the importance of caspase-3 in renal cell apoptosis during kidney scarring has not been established. Here, nephrotoxic nephritis (NTN) was induced in Wistar Kyoto rats by a single intravenous injection of rabbit anti-rat glomerular basement membrane serum, with analysis at days 7, 15, 30, and 45 after injection. Cell apoptosis (in situ end labeling of DNA, light and electron microscopy), proliferation (proliferating cell nuclear antigen-positive cells), and inflammation (ED1-positive cells) all increased in NTN kidneys, peaking early (day 7) in the glomeruli and later (days 30 to 45) in the tubules and interstititum. The expression of caspase-3 mRNA (Northern blotting) was increased in NTN kidneys on days 7, 30, and 45 (173.3%, 228%, and 241.7%, respectively; P < 0.05). Western blotting showed that a 24-kD protein band (caspase-3 active subunit) increased with time in NTN kidneys (P < 0.01) and reached a maximum on day 45 (6.08-fold increase). A 32 kD band (caspase-3 precursor) was also increased on day 45 (3.92-fold; P < 0.01). Elevated caspase-3 activity (two- to threefold) was observed in NTN kidneys at all time points (P < 0.01). Upregulated expression of caspase-3 at all levels positively correlated with apoptosis, whereas both correlated closely with inflammation, proliferation, and subsequent fibrosis in glomeruli, tubules, and interstitium (P < 0.05). Inhibition of caspase-3 during the course of experimental nephritis may offer a new therapeutic approach for the prevention of renal apoptosis and the associated renal tubular atrophy and fibrosis.

Fiber type specific glycogen utilization in rat diaphragm during treadmill exercise

1987 ◽  
Vol 63 (1) ◽  
pp. 75-83 ◽  
Author(s):  
H. J. Green ◽  
M. E. Ball-Burnett ◽  
M. A. Morrissey ◽  
M. J. Spalding ◽  
R. L. Hughson ◽  
...  
Keyword(s):  
Fiber Type ◽  
Vastus Lateralis ◽  
Work Of Breathing ◽  
Periodic Acid ◽  
Fiber Types ◽  
Periodic Acid Schiff ◽  
Glycogen Concentration ◽  
Male Wistar Rats ◽  
Glycogen Utilization ◽  
Continuous Running

To examine the significance of endogenous stores of glycogen in specific fiber types (I, IIa, IIb) of the costal region of the diaphragm, adult male Wistar rats performed continuous running (25 m/min, 8 degrees grade) exercise for either 30 min or until fatigue. At 30 min of exercise, glycogen loss, as measured microphotometrically using the periodic acid-Schiff technique averaged between 73 and 80% (P less than 0.05) in the different fiber types. When exercise was performed to exhaustion, representing an additional 94 min, no further reduction in glycogen was observed in any fiber type. Biochemical determinations of glycogen from the diaphragm confirmed the extensive reduction in glycogen concentration with exercise. Large reductions (P less than 0.05) in glycogen were also noted in the soleus, plantaris, and vastus lateralis red. Although significant depletion (P less than 0.05) occurred in the vastus lateralis white, it was not as pronounced as in these other muscles. Repletion to preexercise glycogen concentration was complete by 4 h of recovery in all muscles except the vastus lateralis white. It is concluded that endogenous glycogen is a significant substrate in all muscles sampled regardless of fiber composition. In the case of the costal region of the diaphragm, the increased work of breathing resulting from heavy exercise leads to the recruitment of all fiber types, and each fiber type depends on glycogen as a substrate at least early in the exercise.

scholarly journals Paravascular channels, cisterns, and the subarachnoid space in the rat brain: A single compartment with preferential pathways

2016 ◽  
Vol 37 (4) ◽  
pp. 1374-1385 ◽  
Author(s):  
Beatrice Bedussi ◽  
Nicole N van der Wel ◽  
Judith de Vos ◽  
Henk van Veen ◽  
Maria Siebes ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cerebrospinal Fluid ◽  
Rat Brain ◽  
Subarachnoid Space ◽  
Light And Electron Microscopy ◽  
Confocal Imaging ◽  
Brain Vasculature ◽  
Fluid Compartment ◽  
Male Wistar Rats ◽  
Preferential Pathways

Recent evidence suggests an extensive exchange of fluid and solutes between the subarachnoid space and the brain interstitium, involving preferential pathways along blood vessels. We studied the anatomical relations between brain vasculature, cerebrospinal fluid compartments, and paravascular spaces in male Wistar rats. A fluorescent tracer was infused into the cisterna magna, without affecting intracranial pressure. Tracer distribution was analyzed using a 3D imaging cryomicrotome, confocal microscopy, and correlative light and electron microscopy. We found a strong 3D colocalization of tracer with major arteries and veins in the subarachnoid space and large cisterns, attributed to relatively large subarachnoid space volumes around the vessels. Confocal imaging confirmed this colocalization and also revealed novel cisternal connections between the subarachnoid space and ventricles. Unlike the vessels in the subarachnoid space, penetrating arteries but not veins were surrounded by tracer. Correlative light and electron microscopy images indicated that this paravascular space was located outside of the endothelial layer in capillaries and just outside of the smooth muscle cells in arteries. In conclusion, the cerebrospinal fluid compartment, consisting of the subarachnoid space, cisterns, ventricles, and para-arteriolar spaces, forms a continuous and extensive network that surrounds and penetrates the rat brain, in which mixing may facilitate exchange between interstitial fluid and cerebrospinal fluid.

scholarly journals A regulatory domain in the K2P2.1 (TREK-1) carboxyl-terminal allows for channel activation by monoterpenes

2020 ◽  
Author(s):  
Eden Arazi ◽  
Galit Blecher ◽  
Noam Zilberberg
Keyword(s):  
Pain Perception ◽  
Fold Increase ◽  
Cellular Mechanisms ◽  
Voltage Range ◽  
Temperature Changes ◽  
Regulatory Domains ◽  
Anionic Phospholipids ◽  
Part Time ◽  
Carboxyl Terminal ◽  
First Time

AbstractPotassium K2P (‘leak’) channels conduct current across the entire physiological voltage range and carry leak or ‘background’ currents that are, in part, time- and voltage-independent. K2P2.1 channels (i.e., TREK-1, KCNK2) are highly expressed in excitable tissues, where they play a key role in the cellular mechanisms of neuroprotection, anesthesia, pain perception, and depression. Here, we report for the first time that human K2P2.1 channel activity is regulated by monoterpenes (MTs). We found that cyclic, aromatic monoterpenes containing a phenol moiety, such as carvacrol, thymol and 4-IPP had the most profound effect on current flowing through the channel (up to a 6-fold increase). By performing sequential truncation of the carboxyl-terminal domain of the channel and testing the activity of several channel regulators, we identified two distinct regulatory domains within this portion of the protein. One domain, as previously reported, was needed for regulation by arachidonic acid, anionic phospholipids and temperature changes. Within a second domain, a triple arginine residue motif (R344-346), an apparent PIP2-binding site, was found to be essential for regulation by holding potential changes and important for regulation by monoterpenes.

scholarly journals Prolonged morphine exposure during adolescence alters the responses of lateral paragigantocellularis neurons to naloxone in adult morphine dependent rats

2021 ◽  
Vol 71 (1) ◽  
Author(s):  
Sara Sabuee ◽  
S. Mohammad Ahmadi-Soleimani ◽  
Hossein Azizi
Keyword(s):  
Adolescent Male ◽  
Neuronal Responses ◽  
Cellular Mechanisms ◽  
Unit Recording ◽  
Free Interval ◽  
Baseline Activity ◽  
Opioid Drugs ◽  
Male Wistar Rats ◽  
Excitatory Responses ◽  
Drug Free

Abstract Introduction Adolescence is a critical period in brain development, and it is characterized by persistent maturational alterations in the function of central nervous system. In this respect, many studies show the non-medical use of opioid drugs by adolescents. Although this issue has rather widely been addressed during the last decade, cellular mechanisms through which adolescent opioid exposure may induce long-lasting effects are not duly understood. The present study examined the effect of adolescent morphine exposure on neuronal responses of lateral paragigantocellularis nucleus to naloxone in adult morphine-dependent rats. Methods Adolescent male Wistar rats (31 days old) received increasing doses of morphine (from 2.5 to 25 mg/kg, twice daily, s.c.) for 10 days. Control subjects were injected saline with the same protocol. After a drug-free interval (20 days), animals were rendered dependent on morphine during 10 days (10 mg/kg, s.c., twice daily). Then, extracellular single-unit recording was performed to investigate neural response of LPGi to naloxone in adult morphine-dependent rats. Results Results indicated that adolescent morphine treatment increases the number of excitatory responses to naloxone, enhances the baseline activity and alters the pattern of firing in neurons with excitatory responses in adult morphine-dependent rats. Moreover, the intensity of excitatory responses is reduced following the early life drug intake. Conclusion It seems that prolonged opioid exposure during adolescence induces long-lasting neurobiological changes in LPGi responsiveness to future opioid withdrawal challenges.

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