Structural alterations in early myocardial anoxia

1983 ◽  
Vol 41 ◽  
pp. 792-793
Author(s):  
M. Ashraf ◽  
P.M. Rahamatulla
Keyword(s):  
Electron Microscopy ◽  
Osmium Tetroxide ◽  
Time Interval ◽  
Sprague Dawley ◽  
Structural Alterations ◽  
Sprague Dawley Rats ◽  
Rat Hearts ◽  
Major Coronary Artery ◽  
Temporal Basis ◽  
Isolated Rat

Occlusion of a major coronary artery in a canine results in heterogenous infarct that makes the study of sequential subcellular changes on a temporal basis difficult. In this investigation, global anoxia was induced in isolated rat hearts in order to produce uniform anoxic changes. The hearts removed from Sprague-Dawley rats were perfused with Krebs-Henseleit (KH) medium saturated with 95% O2, 5% CO2 for 30 minutes (control). The ingredients of the anoxic medium were the same except glucose was replaced by mannitol to adjust osmolarity. The anoxic medium was bubbled with 95% N2 and 5% CO2. The perfusion was changed to anoxic medium for 5, 10, 15, 20, 25, and 30 minutes. Six rats were used for each time interval. At the end of experiments, the hearts were perfused with 3% buffered glutaraldehyde, pH 7.3, postfixed with 1% buffered osmium tetroxide for 1 1/2 hours, dehydrated in ethanol and processed for electron microscopy.

Ultrastructural investigation of spontaneous pituitary gonadotroph cell adenomas in aging Sprague-Dawley rats

1983 ◽  
Vol 41 ◽  
pp. 702-703
Author(s):  
D. J. McComb ◽  
J. Beri ◽  
F. Zak ◽  
K. Kovacs
Keyword(s):  
Electron Microscopy ◽  
Animal Model ◽  
Epoxy Resin ◽  
Immunoelectron Microscopy ◽  
Tumor Type ◽  
Gonadal Function ◽  
Sprague Dawley ◽  
Male And Female ◽  
Reticulin Fibers ◽  
Sprague Dawley Rats

Gonadotroph cell adenomas of the pituitary are infrequent in human patients and are not invariably associated with altered gonadal function. To date, no animal model of this tumor type exists. Herein, we describe spontaneous gonadotroph cell adenomas in old male and female Sprague-Dawley rats by histology, immunocytology and electron microscopy.The material consisted of the pituitaries of 27 male and 38 female Sprague Dawley rats, all 26 months of age or older, removed at routine autopsy. Sections of formal in-fixed, paraffin-embedded tissue were stained with hematoxylin-phloxine-saffron (HPS), the PAS method and the Gordon-Sweet technique for the demonstration of reticulin fibers. For immunostaining, sections were exposed to anti-rat β-LH, anti-ratβ-TSH, anti-rat PRL, anti-rat GH and anti-rat ACTH 1-39. For electron microscopy, tissue was fixed in 2.5% glutaraldehyde, postfixed in 1% OsO4 and embedded in epoxy-resin. Tissue fixed in 10% formalin, embedded in epoxy resin without osmification, was used for immunoelectron microscopy.

Ultrastructural changes in isolated rat liver perfused with cyclic heptapeptide toxins from norwegian freshwater cyanobacteria (blue-green algae)

1987 ◽  
Vol 45 ◽  
pp. 858-859
Author(s):  
A.S. Dabholkar ◽  
W.W. Carmichael ◽  
K. Berg ◽  
J. Wyman
Keyword(s):  
Ultrastructural Changes ◽  
Sprague Dawley ◽  
Isolated Rat Liver ◽  
Blue Green Algae ◽  
Sprague Dawley Rats ◽  
Cyclic Heptapeptide ◽  
Intracellular Changes ◽  
Oscillatoria Agardhii ◽  
Rat Livers ◽  
Isolated Rat

Intracellular changes in the hepatocytes of isolated rat livers perfused with cyclic heptapeptide toxins are described. The toxins used are 1) -Ala-Leu- β-methyl isoAsp-Arg-ADDA-isoGlu-mdha (M.W. 944) from Microcystis aeruginosa- Lake Akersvatn, Norway; 2) -Ala-Arg-isoAsp-Arg-ADDA-isoGlu-mdha (M.W. 1023) from Oscillatoria agardhii var. - Lake Kolbatnvatn, Norway; 3) -Ala-Arg-isoAsp-Arg-ADDA-isoGlu-dha (M.W. 1009) from Oscillatoria agardhii var. isothrix - Lake Froylandsvatn, Norway. Approximate LD intraperitoneal mouse for the toxins is 50, 500 and 1000 μg/kg respectively.Livers were removed from male Sprague Dawley rats and perfused for 15 min with a blood-free perfusate (50 ml) followed by 60 min with perfusate containing i) 25, 50, or 200 μg of M. aeruginosa toxin ii) 50, 250, 500 or 1000 μg of O. agardhii var. toxin and iii) 1000, 2000, 2500 or 5000 μg of O. agardhii var. isothrix toxin. Control livers were perfused for 75 min with the blood-free perfusate.

Postjunctional supersensitivity of the rat vas deferens and gap junctions

1976 ◽  
Vol 54 (3) ◽  
pp. 412-416 ◽  
Author(s):  
D. M. Paton ◽  
J. Buckland-Nicks ◽  
A. Johns
Keyword(s):  
Electron Microscopy ◽  
Gap Junctions ◽  
Spontaneous Activity ◽  
Vas Deferens ◽  
Rat Vas Deferens ◽  
Sprague Dawley ◽  
Glutaraldehyde Fixation ◽  
Sprague Dawley Rats

Tissues from the duodenum and vas deferens of Sprague–Dawley rats were examined of the rat vas deferens and gap junctions. Can. J. Physiol. Pharmacol. 54, 412–416. by electron microscopy after glutaraldehyde fixation and postosmication. Gap junctions (nexuses) were readily demonstrated in the duodenum in both control and reserpine treated animals (1.0 mg/kg per day for 7 days). However, gap junctions could not be demonstrated in vas deferens. It is concluded that the postjunctional supersensitivity and spontaneous activity induced by reserpine in vas deferens, does not result from the formation of gap junctions.

Effect of acute and chronic caloric restriction and metabolic glucoprivation on spontaneous physical activity in obesity-prone and obesity-resistant rats

2009 ◽  
Vol 297 (1) ◽  
pp. R176-R184 ◽  
Author(s):  
J. A. Teske ◽  
C. M. Kotz
Keyword(s):  
Physical Activity ◽  
Caloric Restriction ◽  
Phenotypic Traits ◽  
Time Interval ◽  
Sprague Dawley ◽  
Orexin A ◽  
Time Period ◽  
Sprague Dawley Rats ◽  
Spontaneous Physical Activity

Caloric restriction (CR) and metabolic glucoprivation affect spontaneous physical activity (SPA), but it's unknown whether these treatments similarly affect SPA in selectively bred obesity-prone (OP) and -resistant (OR) rats. OR rats have greater basal SPA and are more responsive to treatments that modulate SPA, such as orexin A administration. We hypothesized that OR rats would be more sensitive to other treatments modulating SPA. To test this, continuous 24-h SPA was measured before and during acute (24 h) and chronic (8 wk) CR in OR, OP, and Sprague-Dawley rats. Pharmacological glucoprivation was produced by injection of 2-deoxyglucose (2-DG), and SPA was measured 5 h postinjection. Acute CR increased SPA in all groups; however, the effect was dependent on the index of SPA and time interval during the 24-h time period. In contrast to OR rats, chronic CR increased distance traveled, ambulatory episodes, and time spent in ambulation and stereotypy during the time interval preceding anticipation of food in OP and Sprague-Dawley rats. Although the effects of 2-DG treatment on SPA were minimal, OR rats had significantly greater SPA than OP and Sprague-Dawley rats independent of treatment. That chronic CR failed to result in significant changes in SPA in OR rats suggests that these rats may be especially unresponsive to treatments modulating feeding. This insensitivity coupled with elevated basal SPA levels may in part mediate phenotypic traits of lean rats.

Ultrastructural effects of exogenous hydrogen peroxide on the myocardium

1989 ◽  
Vol 47 ◽  
pp. 1102-1103
Author(s):  
T. Oguro ◽  
K. Aida ◽  
T. Onodera ◽  
M. Ashraf
Keyword(s):  
Hydrogen Peroxide ◽  
Superoxide Anion ◽  
Osmium Tetroxide ◽  
Structure And Function ◽  
Ultrastructural Changes ◽  
Superoxide Anions ◽  
Isolated Hearts ◽  
Rat Hearts ◽  
And Function ◽  
Isolated Rat

It has been suggested that hydrogen peroxide (H2O2) is indirectly associated with postischemic-reperfusion injury of the heart. Previously, we reported that the heart was not damaged when perfused with exogenously generated superoxide anions. However, H2O2, a dismutation product of superoxide anion severely affected the heart structure and function. In this study, we evaluated the ultrastructural changes of the cel1 membranes in isolated rat hearts and cultured myocytes follow-ing treatment with exogenous H2O2.In the isolated hearts, 300 μM of H2O2, a concentration which was based on our earlier study was perfused for 5 minutes. For the last 2 minutes, 100 mg (2200 U/mg) of horseradish peroxidase was perfused to see the permeability of the cell membranes. In the isolated cultured myocytes, 300 μM of H2O2 was added to the medium for 30 minutes. Both the hearts and the isolated myocytes were fixed with 2.5% buffered glutaraldehyde, postfixed with 1% osmium tetroxide and were processed for electron microscopy.

Sarcolemmal KATP channel triggers delayed ischemic preconditioning in rats

2005 ◽  
Vol 288 (1) ◽  
pp. H445-H447 ◽  
Author(s):  
Hemal H. Patel ◽  
Eric R. Gross ◽  
Jason N. Peart ◽  
Anna K. Hsu ◽  
Garrett J. Gross
Keyword(s):  
Infarct Size ◽  
Ischemic Preconditioning ◽  
Size Reduction ◽  
Sprague Dawley ◽  
Area At Risk ◽  
Sprague Dawley Rats ◽  
Rat Hearts ◽  
Opioid Administration ◽  
Infarct Size Reduction ◽  
Prior Administration

Previous work from our laboratory has shown that the sarcolemmal KATP channel (sKATP) is required as a trigger for delayed cardioprotection upon exogenous opioid administration. We also established that the mitochondrial KATP (mKATP) channel is not required for triggering delayed δ-opioid-induced infarct size reduction. Because mechanistic differences have been found among δ-opioids and that due to ischemic preconditioning (IPC), we determined whether the triggering mechanism of delayed IPC-induced infarct size reduction involves either the sKATP or mKATP. Male Sprague-Dawley rats received either sham surgery or IPC (3- to 5-min cycles of ischemia and reperfusion) 24 h before being subjected to 30 min of ischemia and 2 h of reperfusion. Infarct size was determined and expressed as a percentage of the area at risk, with significance compared with sham reported at P ≤ 0.001. A subset of both sham and IPC-treated rats received either the selective sKATP channel antagonist, HMR-1098 (6 mg/kg), or the selective mKATP channel antagonist, 5-hydroxydeconoic acid (5-HD; 10 mg/kg), given 5 min before IPC. Rats subjected to IPC demonstrated a significant reduction in infarct size compared with sham (29.2 ± 4.7 vs. 59.3 ± 2.5%, respectively; P ≤ 0.001). Prior administration of HMR-1098, but not 5-HD, abolished IPC-induced infarct size reduction (48.8 ± 2.9 and 28.8 ± 4.0%, respectively; P ≤ 0.001). Furthermore, administration of HMR 24 h after IPC, before index ischemia, did not abrogate IPC-induced infarct size reduction (33.0 ± 5.0 vs. 29.2 ± 4.7%, respectively; P ≤ 0.001). These data suggest that the sKATP channel is required as a trigger but not a mediator for delayed IPC-induced infarct size reduction in rat hearts.

A Astragalus Improved Cardiac Function of Adriamycin-Injured Rat Hearts by Upregulation of SERCA2a Expression

2009 ◽  
Vol 37 (03) ◽  
pp. 519-529 ◽  
Author(s):  
Dan Su ◽  
Han-Yi Li ◽  
Hao-Ran Yan ◽  
Peng-Fei Liu ◽  
Liu Zhang ◽  
...  
Keyword(s):  
Cardiac Function ◽  
Significant Inhibition ◽  
Heart Weight ◽  
High Dose ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Rat Hearts ◽  
Protein Expressions ◽  
Cardioprotective Effects ◽  
Traditional Chinese Medical

The traditional Chinese medical herb Astragalus, the dried root of Astragalus membranaceus (Fisch.) Bge., has been widely applied to treat patients with cardiovascular disease in China and has profound cardioprotective effects. This study investigated the effect of Astragalus on hemodynamic changes in adriamycin (ADR)-injured rat hearts and its underlying molecular mechanism. Sprague-Dawley rats were divided into four groups: control, ADR only, ADR + low dose of Astragalus and ADR + high dose of Astragalus. Rats were injected intraperitoneally with 6 equal doses of ADR (cumulative dose, 12 mg/kg) over a period of 2 weeks. Treatment of Astragalus began 1 day before the onset of ADR injection and was given orally once a day for 50 days (3.3 or 10 g/kg/day). Five weeks after the final injection of ADR, rats treated with ADR only showed a significant inhibition of cardiac diastolic function accompanied by the presence of ascites, a remarkable reduction in body weight and heart weight as well as survival rate compared to the controls. Moreover, SERCA2a mRNA and protein expressions in hearts were obviously downregulated by ADR. However, this impaired cardiac function was significantly improved in both doses of Astragalus feeding groups. The amount of ascites was also reduced in a similar extent in these 2 groups. Only the high dose treatment of Astragalus significantly attenuated the changes of SERCA2a expression in injured hearts and improved survival. These results indicated that Astragalus could improve cardiac function of ADR-injured rat hearts, which was partly mediated by upregulation of SERCA2a expression.

Acid Phosphatase Localization in the Cataractous Rat Lens

1977 ◽  
Vol 35 ◽  
pp. 436-437
Author(s):  
N.J. Unakar ◽  
J. Tsui ◽  
J.R. Reddan
Keyword(s):  
Electron Microscopy ◽  
Wound Healing ◽  
Acid Phosphatase ◽  
Tissue Repair ◽  
Lysosomal Enzymes ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Probable Role

Lysosomal enzymes seem to play an important role in wound healing and tissue repair (1,2, and 3). In the present investigation we have shown the existence of acid phosphatase and lysosomes in lenticular tissue and have examined the probable role of this enzyme in the induction of galactose cataract. Experiments were performed on Sprague-Dawley rats (50g) fed for 4 days on a diet consisting of equal proportions (by wt.) of Purina Rat Chow and D-galactose. Animals fed Purina Rat Chow alone served as controls. Acid phosphatase was localized by two separate procedures (4 and 5). Lenses were processed for electron microscopy as previously described (3). Lenticular tissue of both controls (Figs. 1 and 2) and galactose fed animals exhibits the reaction product of acid phosphatase. However, the group fed galactose showed a much stronger reaction product compared to controls.

The role of biotransformation–detoxication in acetone-, 2-butanone-, and 2-hexanone-potentiated chloroform-induced hepatotoxicity

1987 ◽  
Vol 65 (11) ◽  
pp. 2313-2318 ◽  
Author(s):  
L. Arthur Hewitt ◽  
Céline Valiquette ◽  
Gabriel L. Plaa
Keyword(s):  
Rank Order ◽  
Time Interval ◽  
Monooxygenase System ◽  
Reactive Intermediate ◽  
Sprague Dawley ◽  
System P ◽  
Sprague Dawley Rats ◽  
Hepatic Glutathione ◽  
Metabolite Generation ◽  
Polysubstrate Monooxygenase

The hepatotoxicity of chloroform (CHCl3) is thought to require biotransformation, by the polysubstrate monooxygenase system (P-450), to a reactive intermediate(s). Therefore, the potentiation of CHCl3-induced hepatotoxicity, which occurs following exposure to certain ketones, may hypothetically be explained by a reduced capacity of the cell to form glutathione conjugates (detoxicate the intermediate) and (or) by an increased rate of reactive intermediate(s) generation secondary to a modification of the P-450 system. To test these hypotheses, liver damage, as indicated by elevation in plasma alanine aminotransferase and ornithine carbamyl transferase activities, was modulated in male Sprague-Dawley rats by varying the time interval (10, 18, 24, 48, 72, 96 h) between acetone, 2-butanone, or 2-hexanone (15 mmol/kg, p.o.) pretreatment and CHCl3 (0.5 mL/kg, p.o.) administration. These data were compared with hepatic glutathione and with various parameters of the polysubstrate monooxygenase system: cytochrome P-450, cytochrome c reductase, cytochrome b5, and microsomal binding of 14CHCl3-derived radiolabel. Reduced detoxication capacity does not appear to be involved as hepatic glutathione levels were not reduced. Globally, a relationship between modifications to the polysubstrate monooxygenase system and potentiation of CHCl3-induced hepatotoxicity appears to exist. The rank order of each ketone's ability to modify P-450 parameters was the same in most instances as that based on peak ability to potentiate CHCl3-induced hepatotoxicity: 2-hexanone > 2-butanone ≥ acetone. Therefore, these results suggest that a general relationship exists between the ketone-induced potentiation of CHCl3-induced hepatotoxicity and increased CHCl3 reactive metabolite generation. However, other factors may also contribute to the phenomenon.

scholarly journals Dietary n-6 and n-3 PUFA alter the free oxylipin profile differently in male and female rat hearts

2019 ◽  
Vol 122 (03) ◽  
pp. 252-261 ◽  
Author(s):  
Afroza Ferdouse ◽  
Shan Leng ◽  
Tanja Winter ◽  
Harold M. Aukema
Keyword(s):  
Dietary Treatment ◽  
Interactive Effects ◽  
Female Rats ◽  
Female Rat ◽  
Sprague Dawley ◽  
Oil Composition ◽  
American Institute ◽  
Sprague Dawley Rats ◽  
Rat Hearts ◽  
Health And Disease

AbstractOxylipins are bioactive lipid mediators synthesised from PUFA. The most well-known oxylipins are the eicosanoids derived from arachidonic acid (ARA), and many of them influence cardiac physiology in health and disease. Oxylipins are also formed from other n-3 and n-6 PUFA such as α-linolenic acid (ALA), EPA, DHA and linoleic acid (LA), but fundamental data on the heart oxylipin profile, and the effect of diet and sex on this profile, are lacking. Therefore, weanling female and male Sprague–Dawley rats were given American Institute of Nutrition (AIN)-93G-based diets modified in oil composition to provide higher levels of ALA, EPA, DHA, LA and LA + ALA, compared with control diets. After 6 weeks, free oxylipins in rat hearts were increased primarily by their precursor PUFA, except for EPA oxylipins, which were increased not only by dietary EPA but also by dietary ALA or DHA. Dietary DHA had a greater effect than ALA or EPA on reducing ARA oxylipins. An exception to the dietary n-3 PUFA-lowering effects on ARA oxylipins was observed for several ARA-derived PG metabolites that were higher in rats given EPA diets. Higher dietary LA increased LA oxylipins, but it had no effect on ARA oxylipins. Overall, heart oxylipins were higher in female rats, but this depended on dietary treatment: the female oxylipin:male oxylipin ratio was higher in rats provided the ALA compared with the DHA diet, with other diet groups having ratios in between. In conclusion, individual PUFA and sex have unique and interactive effects on the rat heart free oxylipin profile.

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