Morphological changes of tight junctions in the rat liver after chronic administration of N-nitrosomorpholine (NNM) as revealed by freeze-fracturing

1980 ◽  
Vol 70 (1) ◽  
pp. 82-91 ◽  
Author(s):  
Horst Robenek ◽  
Margarete Döldissen ◽  
Hermann Themann
Keyword(s):  
Tight Junctions ◽  
Rat Liver ◽  
Morphological Changes ◽  
Chronic Administration ◽  
Freeze Fracturing

scholarly journals In vivo induction of tight junction proliferation in rat liver.

1976 ◽  
Vol 68 (3) ◽  
pp. 793-798 ◽  
Author(s):  
R Montesano ◽  
G Gabbiani ◽  
A Perrelet ◽  
L Orci
Keyword(s):  
Cell Membrane ◽  
Tight Junction ◽  
Tight Junctions ◽  
Rat Liver ◽  
Chronic Administration ◽  
Rat Hepatocytes ◽  
Bile Canaliculi ◽  
Parallel Orientation ◽  
In Vivo Induction

The chronic administration of phalloidin induces an extensive development of tight junctions between rat hepatocytes. The junctional strands lose their predominantly parallel orientation with respect to the canalicular lumen and extend abluminally in irregular patterns which cover large membrane areas at considerable distance from the bile canaliculi. These changes indicate both proliferation and provide further evidence that these junctions are not permanent differentiations of the cell membrane.

scholarly journals Resveratrol Protects Cardiac Tissue in Experimental Malignant Hypertension Due to Antioxidant, Anti-Inflammatory, and Anti-Apoptotic Properties

2021 ◽  
Vol 22 (9) ◽  
pp. 5006
Author(s):  
Jelica Grujić-Milanović ◽  
Vesna Jaćević ◽  
Zoran Miloradović ◽  
Djurdjica Jovović ◽  
Ivica Milosavljević ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cardiovascular Diseases ◽  
Cardiac Tissue ◽  
Morphological Changes ◽  
Chronic Administration ◽  
Heart Tissue ◽  
Severe Form ◽  
Malignant Hypertension ◽  
Experimental Hypertension ◽  
Resveratrol Treatment

Hypertension is one of the most prevalent and powerful contributors of cardiovascular diseases. Malignant hypertension is a relatively rare but extremely severe form of hypertension accompanied with heart, brain, and renal impairment. Resveratrol, a recently described grape-derived, polyphenolic antioxidant molecule, has been proposed as an effective agent in the prevention of cardiovascular diseases. This study was designed to examine chronic resveratrol administration on blood pressure, oxidative stress, and inflammation, with special emphasis on cardiac structure and function in two models of experimental hypertension. The experiments were performed in spontaneously (SHRs) and malignantly hypertensive rats (MHRs). The chronic administration of resveratrol significantly decreased blood pressure in both spontaneously and malignant hypertensive animals. The resveratrol treatment ameliorated morphological changes in the heart tissue. The immunohistochemistry of the heart tissue after resveratrol treatment showed that both TGF-β and Bax were not present in the myocytes of SHRs and were present mainly in the myocytes of MHRs. Resveratrol suppressed lipid peroxidation and significantly improved oxidative status and release of NO. These results suggest that resveratrol prevents hypertrophic and apoptotic consequences induced by high blood pressure with more pronounced effects in malignant hypertension.

Glucocorticoid effects on respiration and metabolism by rat liver homogenates

1962 ◽  
Vol 202 (2) ◽  
pp. 343-346 ◽  
Author(s):  
Dennis D. Goetsch ◽  
L. E. McDonald
Keyword(s):  
Lactic Acid ◽  
Oxygen Uptake ◽  
Rat Liver ◽  
Inorganic Phosphate ◽  
Chronic Administration ◽  
Glucocorticoid Treatment ◽  
Carbohydrate Utilization ◽  
Protein Levels ◽  
Liver Homogenates ◽  
And Control

The effects of glucocorticoid administration on oxygen uptake, glucose and glycogen disappearance, lactic acid formation, and inorganic phosphate and protein levels in rat liver homogenates have been studied. A single injection of hydrocortisone, prednisolone, or 9 α-fluoroprednisolone 5 hr before sacrifice resulted in a highly significant increase in oxygen uptake by rat liver homogenates, whereas chronic administration of prednisolone daily for 7 days caused a marked inhibition in homogenate respiration. Glycolytic rate did not appear to be affected by single injections since endogenous carbohydrate utilization was similar in liver homogenates prepared from control and treated animals. Incubation of liver homogenates under aerobic conditions disclosed that inorganic phosphate levels were decreased in homogenates from corticoid-treated rats, whereas these levels were similar in treated and control liver homogenates incubated under nitrogen. Under anaerobic conditions, liver homogenates from treated rats accumulated lactic acid more rapidly than untreated liver homogenates. Glucocorticoid treatment did not appear to affect protein disappearance since no differences between protein levels in treated and untreated rat liver homogenates were detected following incubation.

Induction of rat liver DNA alterations by chronic administration of peroxisome proliferators as detected by 32P-postlabeling

1991 ◽  
Vol 247 (1) ◽  
pp. 65-76 ◽  
Author(s):  
Erika Randerath ◽  
Kurt Randerath ◽  
Ranjani Reddy ◽  
Tracy F. Danna ◽  
M. Sambasiva Rao ◽  
...  
Keyword(s):  
Rat Liver ◽  
Chronic Administration ◽  
Peroxisome Proliferators ◽  
Dna Alterations

Morphological Changes of Intercellular Junctions in the Rat Submandibular Gland Treated by Long-term Repeated Administration of Isoproterenol

1987 ◽  
Vol 66 (8) ◽  
pp. 1303-1309 ◽  
Author(s):  
T. Inoue ◽  
H. Yamane ◽  
T. Yamamura ◽  
M. Shimono
Keyword(s):  
Gap Junctions ◽  
Tight Junctions ◽  
Morphological Changes ◽  
Freeze Fracture ◽  
Acinar Cells ◽  
Intercellular Junctions ◽  
Repeated Administration ◽  
Experimental Conditions ◽  
Significant Difference

Long-term repeated administration of isoproterenol (lPR) 2 mg/100 g bw, once daily for ten days, resulted in morphological changes in the intercellular junctions of rat submandibular glands, which were investigated by means of the freeze fracture technique. A significantly increased number of tight-junctional strands was present. These junctional strands extended much deeper toward the basal membrane than those in normal acinar cells. The basal frontier strands that branched from the networks of tight junctions were elongated and had either free-endings or terminal loops, which were more frequently observed in the IPR-treated acinar cells than in untreated acinar cells. Some of the strands of tight junctions were connected to small gap junctions. The diameters of gap junctions were not significantly different from those of control acinar cells. However, smooth areas devoid of particles were found intermingling with the usual packed particles in irregularly shaped small gap junctions. There was no significant difference between the desmosomes of IPR-treated and untreated acinar cells, in terms of either morphology or distribution. These changes in junctional morphology in the IPR-treated acinar cells resemble those seen in salivary glands during development, and in some experimental conditions including tumorous changes.

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