Insensitivity to insulin of human arterial tissue in vitro

1979 ◽  
Vol 106 (4) ◽  
pp. 493-494 ◽  
Author(s):  
H. J. ARNQVIST ◽  
R. BERGLIND ◽  
H. H. DAHLKVIST ◽  
E. VARENHORST
Keyword(s):  
Arterial Tissue

Differential modulation of caffeine- and IP3-induced calcium release in cultured arterial tissue

1999 ◽  
Vol 276 (5) ◽  
pp. C1115-C1120 ◽  
Author(s):  
Karl Dreja ◽  
Per Hellstrand
Keyword(s):  
Calcium Release ◽  
Cyclopiazonic Acid ◽  
Differential Modulation ◽  
Transient Responses ◽  
Inositol 1,4,5 Trisphosphate ◽  
Arterial Tissue ◽  
Intracellular Ca ◽  
Rat Tail

To investigate the Ca2+-dependent plasticity of sarcoplasmic reticulum (SR) function in vascular smooth muscle, transient responses to agents releasing intracellular Ca2+ by either ryanodine (caffeine) ord- myo-inositol 1,4,5-trisphosphate [IP3; produced in response to norepinephrine (NE), 5-hydroxytryptamine (5-HT), arginine vasopressin (AVP)] receptors in rat tail arterial rings were evaluated after 4 days of organ culture. Force transients induced by all agents were increased compared with those induced in fresh rings. Stimulation by 10% FCS during culture further potentiated the force and Ca2+ responses to caffeine (20 mM) but not to NE (10 μM), 5-HT (10 μM), or AVP (0.1 μM). The effect was persistent, and SR capacity was not altered after reversible depletion of stores with cyclopiazonic acid. The effects of serum could be mimicked by culture in depolarizing medium (30 mM K+) and blocked by the addition of verapamil (1 μM) or EGTA (1 mM) to the medium, lowering intracellular Ca2+ concentration ([Ca2+]i) during culture. These results show that modulation of SR function can occur in vitro by a mechanism dependent on long-term levels of basal [Ca2+]iand involving ryanodine- but not IP3 receptor-mediated Ca2+release.

scholarly journals Non-human primate platelets and arterial tissue cannot convert preformed [14C]lanosterol into[14C]cholesterol in vivo

1976 ◽  
Vol 158 (1) ◽  
pp. 157-159 ◽  
Author(s):  
A Derksen ◽  
M M Meguid ◽  
P Cohen
Keyword(s):  
Mevalonic Acid ◽  
Arterial Tissue ◽  
Methyl Sterol ◽  
Prevailing View ◽  
Human Primate

In contrast with the prevailing view, we report the inability of non-human primate platelets or arterial tissue to complete the biosynthesis of [14C]cholesterol from [14C]mevalonic acid in vitro or in vivo, or from performed [14C]lanosterol in vivo. The latter observation suggests that these tissues lack one or more components of the methyl sterol demethylase system.

Short-term exercise training increases ACh-induced relaxation and eNOS protein in porcine pulmonary arteries

2001 ◽  
Vol 90 (3) ◽  
pp. 1102-1110 ◽  
Author(s):  
Lynelle R. Johnson ◽  
James W. E. Rush ◽  
James R. Turk ◽  
Elmer M. Price ◽  
M. Harold Laughlin
Keyword(s):  
Pulmonary Artery ◽  
Pulmonary Arteries ◽  
Fold Increase ◽  
Immunoblot Analysis ◽  
Short Term ◽  
Miniature Swine ◽  
Lung Lobe ◽  
Arterial Tissue ◽  
Enos Protein

We tested the hypothesis that short-term exercise (STEx) training and the associated increase in pulmonary blood flow during bouts of exercise cause enhanced endothelium-dependent vasorelaxation in porcine pulmonary arteries and increased expression of endothelial cell nitric oxide synthase (eNOS) and superoxide dismutase-1 (SOD-1) protein. Mature, female Yucatan miniature swine exercised 1 h twice daily on a motorized treadmill for 1 wk (STEx group, n = 7); control pigs (Sed, n = 6) were kept in pens. Pulmonary arteries were isolated from the left caudal lung lobe, and vasomotor responses were determined in vitro. Arterial tissue from the distal portion of this pulmonary artery was processed for immunoblot analysis. Maximal endothelium-dependent (ACh-stimulated) relaxation was greater in STEx (71 ± 5%) than in Sed (44 ± 6%) arteries ( P < 0.05), and endothelium-independent (sodium nitroprusside-mediated) responses did not differ. Sensitivity to ACh was not altered by STEx training. Immunoblot analysis indicated a 3.9-fold increase in eNOS protein in pulmonary artery tissue from STEx pigs ( P < 0.05) with no change in SOD-1 or glyceraldehyde-3-phosphate dehydrogenase protein levels. We conclude that STEx training enhances ACh-stimulated vasorelaxation in pulmonary arterial tissue and that this adaptation is associated with increased expression of eNOS protein.

Studies on Certain Aspects of the Dynamics of Cholesterol Deposition in Rabbit Arterial Tissue

1979 ◽  
Author(s):  
S. Mukherjee ◽  
C. Mukherjee
Keyword(s):  
Thoracic Aorta ◽  
Free Cholesterol ◽  
Gradual Increase ◽  
In Vitro Study ◽  
Vitro Study ◽  
Low Density ◽  
Cholesterol Diet ◽  
Efflux Rate ◽  
Arterial Tissue

Rabbits were maintained on a 1% cholesterol diet for 30, 60 and 90 days and jsotope labeling of aorta and serum was attained by feeding 100 mc of 4-14C-cholesterolduring the last 4 days before sacrifice of each group. Labeled aorta and low-density lipoprotéine (LDL) isolated from sera of the various diet regimens were employed for in vitro study of rates of flux of free and esterifiedcholesterol by incubating respectively with LDL and aorta of a rabbitmaintained for similar periods on above diet but given no radiocholesterol. Influx of free and ester cholesterol into thoracic aorta of hypercholesterolemia rabbit were respectively 6 and 11 times that obtained with tissues isolated from norraocholesterolemic animals. With progressive Ingestion of hypercholesterolemia diet, a gradual increase in rate of influx with concomitant lowering of efflux rate was noticed for both free and ester cholesterol. Studies on percentage clearance of labeled cholesterol from aorta of hypercholesterolemic rabbits into serum LDL indicate that 25 to 30 percent of radioactivity of free cholesterol is removed by LDL as against 2 to 4.5 percent of ester cholesterol radioactivity. Experiments carried out with partially de-lipidated LDL of sera hypercholesterolemic rabbits reveal that efflux of cholesterol from aorta is markedly increased.

Ultrastructural Investigations of the Contractile Filaments of Amoebae

1974 ◽  
Vol 32 ◽  
pp. 188-189
Author(s):  
P.L. Moore
Keyword(s):  
Cytoplasmic Streaming ◽  
Three Dimensional ◽  
Freeze Fracture ◽  
Amoeboid Movement ◽  
Different Types ◽  
Chemical Conditions ◽  
Complete Interpretation

Previous freeze fracture results on the intact giant, amoeba Chaos carolinensis indicated the presence of a fibrillar arrangement of filaments within the cytoplasm. A complete interpretation of the three dimensional ultrastructure of these structures, and their possible role in amoeboid movement was not possible, since comparable results could not be obtained with conventional fixation of intact amoebae. Progress in interpreting the freeze fracture images of amoebae required a more thorough understanding of the different types of filaments present in amoebae, and of the ways in which they could be organized while remaining functional.The recent development of a calcium sensitive, demembranated, amoeboid model of Chaos carolinensis has made it possible to achieve a better understanding of such functional arrangements of amoeboid filaments. In these models the motility of demembranated cytoplasm can be controlled in vitro, and the chemical conditions necessary for contractility, and cytoplasmic streaming can be investigated. It is clear from these studies that “fibrils” exist in amoeboid models, and that they are capable of contracting along their length under conditions similar to those which cause contraction in vertebrate muscles.

In Vitro Induction of Crystals of MT Protein by Vinblastine-Colcemid in Mouse Spermatids

1974 ◽  
Vol 32 ◽  
pp. 132-133
Author(s):  
John J. Wolosewick ◽  
John H. D. Bryan
Keyword(s):  
Endoplasmic Reticulum ◽  
Smooth Endoplasmic Reticulum ◽  
Nuclear Ring ◽  
Rough Er ◽  
Distal Direction ◽  
In Vitro Induction

Early in spermiogenesis the manchette is rapidly assembled in a distal direction from the nuclear-ring-densities. The association of vesicles of smooth endoplasmic reticulum (SER) and the manchette microtubules (MTS) has been reported. In the mouse, osmophilic densities at the distal ends of the manchette are the organizing centers (MTOCS), and are associated with the SER. Rapid MT assembly and the lack of rough ER suggests that there is an existing pool of MT protein. Colcemid potentiates the reaction of vinblastine with tubulin and was used in this investigation to detect this protein.

Induction and Differentiation of Dental Epithelium in Vivo and in Vitro

1982 ◽  
Vol 40 ◽  
pp. 142-145
Author(s):  
E. J. Kollar
Keyword(s):  
Connective Tissue ◽  
Oral Mucosa ◽  
Basal Lamina ◽  
Functional Derivatives ◽  
Specific Source ◽  
Dental Epithelium ◽  
Connective Tissue Stroma

The differentiation and maintenance of many specialized epithelial structures are dependent on the underlying connective tissue stroma and on an intact basal lamina. These requirements are especially stringent in the development and maintenance of the skin and oral mucosa. The keratinization patterns of thin or thick cornified layers as well as the appearance of specialized functional derivatives such as hair and teeth can be correlated with the specific source of stroma which supports these differentiated expressions.

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