85 research outputs found
Pozne morfoloŔke promene u pulpi zuba molara Wistar pacova sa aloksanskim diabetesom
The aim of this study was examination of late changes in the dental pulp of rats with experimental diabetes. The experiment involved 36 male albino rats, initially 35 days old and 89.45Ā±9.95 g body wight. The animals were separated into 6 equal groups. The first (T1), third (T2) and fifth (T3) groups of animals were given a single dose of alloxan tetrahydrate approximately 80 mg/ kg body weight. Just before the application, the substance was dissolved in physiological saline, and each animal was given 1 ml in the tail vein. The second (C1), fourth (C2), and sixth (C3) group of animals were used as appropriate control groups and received 1 ml of physiological saline injection. Body weights were measured and glycemia was checked weekly. The animals in groups T1 and C1 were sacrificed on the 63rd day, groups T2 and C2 on the 95th day and groups T3 and C3 on the 125th day by decapitation. The block of mandibular molars was taken for histological examination. The results of histological examinations showed stasis, in microcirculation, as well as in large blood vessels of the pulp, and necrosis of the pulp tissue in animals after 63 days of experimental diabetes. Pulps of the animals killed after 95 days showed, besides massive pulp necrosis, abscess forms localized in the mesial horn of the pulp. This evidence was not present in every animal from group T2. Pulps of the animals sacrificed after 125 days showed hydropic degeneration of the pulp with massive and diffuse presence of vacuoles in odontoblasts.Cilj ovog rada je bio ispitivanje poznih promena na pulpi zuba pacova sa eksperimentalnim dijabetom. Eksperiment je izveden na 36 muÅ”kih albino pacova, starih 35 dana, telesne mase 89.45 Ā± 9.95 g. Životinje su bile podeljene u 6 grupa. Prva (T1), treÄa (T2) i peta (T3) grupa životinja primila je jednokratnu dozu aloksan tetrahidrata, približno oko 80 mg/kg mase tela. Neposredno pre aplikacije, supstanca je rastvorena u fizioloÅ”kom rastvoru i svakoj životinji je dat 1 ml rastvora u repnu venu. Druga (C1) Äetvrta (C2) i Å”esta (C3) grupa životinja bile su kontrolne grupe i dobijale su 1 ml Äistog fizioloÅ”kog rastvora. Jednom nedeljno merena je telesna masa i glikemija. Životinje grupe T1 i C1 su žrtvovane 63-eg dana, životinje grupe T2 i C2 95-og dana a životinje grupe T3 i C3 125-og dana eksperimenta dekapitacijom. Za histoloÅ”ka ispitivanja uzeti su iseÄci mandibularnih molara. Rezultati histoloÅ”kih ispitivanja pokazuju stazu kako u mikrocirkulaciji tako i u velikim krvnim sudovima pulpe kao i nekrozu tkiva pulpe kod životinja žrtvovanih 63-Äeg dana eksperimentalnog dijabeta. Kod nekih životinja žrtvovanih 95-og dana pored masivne nekroze pulpe, u uoÄavaju se abscesi lokalizovani na mezijalnom rogu. Pulpe životinja žrtvovanih 125-og dana ukazuju na hidropsnu degeneraciju pulpe sa masovnom i difuznom pojavom vakuola u odontoblastima
Uticaj endotelina i L-NAME na koncentraciju mokraÄne kiseline i uree u plazmi kod Wistar pacova
Effects of endothelins, which include vasoconstriction and vasodilatation are possible by different molecular mechanisms. Endothelins induce increased synthesis of nitric oxide which in turn inhibits the synthesis of endothelin. Changes in biochemical parameters connected with the increased and decreased synthesis of nitric oxide are not thoroughly examined yet. In a series of experiments we compared the effects of endothelin (ET-1) on the inhibition of nitric oxide synthase (NOS), as well as the effects of L-nitro arginin metal estar (L-NAME) on plasma urea and uric acid concentration. Experiments were performed on anesthetized female adult Wistar rats. The experimental groups received an i. v. bolus of ET-1, L-NAME or saline. All parameters, heamodynamic and biochemical, were measured before the animals were sacrificed. L-NAME increased the mean arterial pressure, decreased renal blood flow and increased vascular resistance in carotid and renal arteries and increased in plasma uric acid and urea concentrations. ET- 1 significantly decreased uric acid concentration in the plasma but did not effect plasma urea concentration compared to the control group. These differences show complex relations of nitric oxide with cellular signalization compared to the basic NO-cGMP pathway.Efekti endotelina koji ukljuÄuju vazokonstrikciju I vazodilataciju ostvaruju se razliÄitim molekularnim mehanizmima. Endotelin indukuje poveÄanu sintezu azotnog oksida za koji se smatra da povratno inhibira sintezu endotelina. Promene biohemijskih parametara vezanih za poveÄanu i smanjenu sintezu NO nisu dovoljno prouÄene. U ovom radu su uporeÄeni efekti endotelina (ET-1) i inhibitora NOS-a, L-NAME na koncentraciju mokraÄne kiseline i uree u plazmi. Eksperimenti su izvedeni na anesteziranim odraslim NW pacovima, ženskog pola. Eksperimentalne životinje su u i.v. bolusu primale ET-1, L-NAME ili fizioloÅ”ki rastvor. Svi hemodinamski i biohemijski parametri su mereni pre žrtvovanja. L-NAME dovodi do poveÄanja srednjeg arterijskog pritiska smanjenja renalnog protoka i poveÄanja vaskularnog otpora u karotidnoj i renalnoj arteriji i poveÄanja koncentracije mokraÄne kiseline i uree u plazmi. ET-1 znaÄajno smanjuje koncentraciju mokraÄne kiseline u plazmi ali ne utiÄe na koncentraciju uree u odnosu na kontrolu. Ove razlike pokazuju kompleksnije relacije NO-a sa Äelijskom signalizacijom u odnosu na osnovni NO-cGMP put
Effects of high dose olive leaf extract on the hemodynamic and oxidative stress parameters in normotensive and spontaneously hypertensive rats
The antihypertensive activity of olive leaf extract (OLE), a natural antioxidant is recognized, but its influence on the cardiovascular system when administered in a high dose has not yet been investigated. The aim of the present study was to determine the acute effects of excessive intake of standardized OLE on blood pressure, heart rate and oxidative status in both spontaneously hypertensive rats and normotensive Wistar rats. The systolic arterial pressure and heart rate were measured using a tail-cuff and pneumatic pulse detector before and 60 and 120 min after intragastric OLE administration. The activities of catalase, glutathione peroxidase, superoxide dismutase (SOD) and glutathione reductase in erythrocytes, as well as lipid peroxidation in plasma (pTBARS) were measured spectrophotometrically at the same time points. A high-dose of OLE did not influence blood pressure, heart rate or pTBARS in normotensive rats, while the SOD, catalase and glutathione reductase activities were significantly increased. The same dose significantly decreased blood pressure in hypertensive rats, but increased the pTBARS and SOD activity. Excessive oral intake of OLE induced moderate hypotensive effects only in spontaneously hypertensive rats, suggesting the absence of harmful hemodynamic effects after an oral overdose in both rat strains. However, its pro-oxidative role when given in a high dose in hypertensive organisms should not be neglected
Uticaj hroniÄne promene vrednosti hematokrita na krvni pritisak i glomerulsku filtraciju kod pacova sa uroÄenom hipertenzijom
Many studies in hypertensive humans and animals have shown that increased blood viscosity is in direct relation with essential hypertension. The aim of our studies was to investigate the effects of chronic hematocrit value changes on arterial blood pressure and kidney function in genetically induced hypertension. To this end, we studied the effects of several interventions, designed to increase/decrease hematocrit, on hemodynamic parameters, vascular reactivity, glomerular filtration and renal function curve in spontaneously hypertensive rats (SHR). Results of our study show that chronic hematocrit value elevation increases blood pressure and peripheral vascular resistance in SHR. On the other hand, chronic hematocrit lowering elucidates blood pressure and peripheral vascular resistance decrease followed by cardiac output rising. Both hematocrit value changes significantly reduce vasodilatory vascular response. Hematocrit lowering induces acute renal failure. Sodium excretion is shifted to higher blood pressure values in high hematocrit value animals and opposite - lower blood pressure values in low hematocrit value animals. Repeated transfusions develop salt sensitive malignant hypertension in SHR. Further studies are necessary to evaluate the degree of kidney damage after chronic hematocrit value changes in SHR.Brojna ispitivanja izvedena na životinjama i ljudima su ukazala da je poveÄanje viskoznosti krvi u direktnoj vezi sa hipertenzijom. Cilj naÅ”e studije je bio da se istraži uticaj promene vrednosti hematokrita (Hct) na krvni pritisak i funkciju bubrega u uroÄenoj hipertenziji. U tom cilju, istraživan je uticaj hroniÄnog poveÄanja ili smanjenja vrednosti Hct na hemodinamske parametre, vaskularnu reaktivnost, glomerulsku filtraciju i krivu bubrežne funkcije kod pacova sa uroÄenom hipertenzijom (SHR). Rezultati naÅ”e studije su ukazali da hroniÄno poveÄanje vrednosti Hct dovodi do poveÄanja arterijskog krvnog pritiska (AKP) i perifernog vaskularnog otpora (PVO) kod SHR . Nasuprot tome, hroniÄno smanjenje vrednosti Hct dovodi do smanjenja AKP i PVO, praÄenih poveÄanjem minutnog volumena srca. Obe promene vrednosti Hct dovode do smanjenja vaskularne reaktivnosti. HroniÄno smanjenje vrednosti Hct izaziva nastanak akutne bubrežne insuficijencije. Ekskrecija natrijuma je pomerena ka veÄim vrednostima krvnog pritiska kod pacova sa poveÄanim vrednostima Hct, a ka nižim kod pacova sa sniženim vrednostima Hct. HroniÄno poveÄanje vrednosti Hct dovodi do razvoja maligne hipertenzije kod SHR. Potrebne su dalje studije da bi se utvrdio taÄan stepen i priroda oÅ”teÄenja bubrega nakon hroniÄne promene vrednosti Hct
Optimization of the extraction of antioxidants from stinging nettle leaf using response surface methodology
The aim of this study was to optimize the parameters for the extraction of total flavonoids from stinging nettle leaf. Comparison of the effects of different solvents on total flavonoid content showed that, regardless of extraction time, aqueous methanolicextracts had higher total flavonoid content than did aqueous ethanolic extracts. So, full factorial design and response surface methodology (RSM) were em-ployed to estimate the effects of methanol content (50, 75and 100%) and extraction time (30, 60and 90 min) on the total flavonoid content and antioxidant capacities of the extracts. RSM analysis showed that methanol content in the solvent influenced significantly total flavonoid content and FRAP (ferric-reducing antioxidant power) antioxidant capacity, while extraction time had no significant effect on either of these responses. Extraction parameters for maximal total flavonoid content were estimated to be 69% aqueous methanol and 67 min, and 65% aqueous methanol and 83 min for maximal FRAPantioxidantcapacity. DPPH (2,2-diphenyl-1-picrylhydrazyl) antioxidant capacity was not significantly affected by extraction time or methanol percentage in the solvent
Resveratrol Protects Cardiac Tissue in Experimental Malignant Hypertension Due to Antioxidant, Anti-Inflammatory, and Anti-Apoptotic Properties
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-Ī² 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
Uticaj blokade receptora tip 1 za angotenzin II udružene sa uklanjanjem superoksidnog anjona na postishemiÄni bubreg kod pacova sa uroÄenom hipertenzijom
Ischemic acute kidney injury is characterized by renal vasoconstriction, filtration failure, tubular obstruction, tubular backleak and overproduction of angiotensin II and reactive oxygen species. Considering this complexity, the aim of our study was to investigate the effects of angiotensin II type-1 receptor blocker - Losartan and superoxide anion scavenger - Tempol, in a combined treatment on acute kidney injury in postischemic hypertensive rats. The experiment was performed in anesthetized, adult male spontaneously hypertensive rats. The right kidney was removed and the left renal artery was occluded for 40 minutes. Experimental groups received combined treatment (Losartan + Tempol) or saline in the femoral vein 5 minutes before, during and 175 minutes after clamp removal. Hemodynamics and biochemical parameters were measured and kidney specimens were collected 24h after reperfusion. Histological examination was performed by optical microscopy. Combined treatment improves renal haemodynamics parameters which were exacerbated due to acute kidney injury. Acute kidney injury significantly decreased creatinine and urea clearance and increased lipid peroxidation in the plasma. Treatment with Losartan and Tempol induced a significant increase of creatinine and urea clearance. Lipid peroxidation in the plasma decreased and glutathione peroxidase enzyme activity in the erythrocytes increased after Losartan + Tempol treatment. This combined treatment reduced cortico-medullary necrosis and tubular dilatation in the kidney. Our results indicate that synergism of Losartan and Tempol treatment could have beneficial effects on blood pressure and kidney function, during postischemic acute kidney injury development in experimental hypertension.Glavne karakteristike ishemiÄne akutne bubrežne slabosti su: renalna vazokonstrikcija, pad glomerulske filtracije, tubularna opstrukcija, vraÄanje glomerulskog filtrata u intersticijum tubula i prekomerna produkcija angiotenzina II i reaktivnih vrsta kiseonika. UzimajuÄi u obzir kompleksnost ovog poremeÄaja, cilj ove studije je bio da istraži efekte kombinovanog tretmana blokatora angiotenzin II receptora tip 1 - Losartana i sakupljaÄa superoksidnog anjona - Tempola u modelu ishemiÄne bubrežne slabosti kod hipertenzivnih pacova. Eksperiment je uraÄen na odraslim anesteziranim mužjacima hipertenzivnih pacova. Desni bubreg je uklonjen, dok je na levoj renalnoj arteriji uraÄena okluzija u trajanju od 40 minuta. Eksperimentalne grupe su primile kombinovani tretman (Losartan+Tempol) ili fizioloÅ”ki rastvor u femoralnu venu, 5 minuta pre i 175 minuta nakon uklanjanja kleme sa renalne arterije. Hemodinamski i biohemijski parametri su izmereni, a uzorci bubrega uzimani su 24 Äasa nakon reperfuzije. HistoloÅ”ka ispitivanja su raÄena pomoÄu svetlosnog mikroskopa. Kombinovani tretman poboljÅ”ava renalnu hemodinamiku, poremeÄenu usled ishemiÄne akutne bubrežne slabosti. U ovom modelu bubrežne slabosti dolazi do pada klirensa kreatinina i uree, i poveÄanja lipidne peroksidacije u plazmi.Tretman Losartanom i Tempolom dovodi do znaÄajnog poveÄanja klirensa kreatinina i uree. Lipidna peroksidacija je smanjena, a aktivnost glutation peroksidaze u eritrocitima je poveÄana nakon kombinovanog tretmana sa Losartanom i Tempolom. TakoÄe, ovakav kombinovan tretman smanjuje kortiko-medularnu nekrozu i tubularnu dilataciju u bubregu. NaÅ”i rezultati ukazuju na to da sinergizam Losartana i Tempola može imati povoljan efekat na krvni pritisak i bubrežnu funkciju tokom razvoja postishemiÄne akutne bubrežne slabosti u eksperimentalnoj hipertenziji
Acute Superoxide Radical Scavenging Reduces Blood Pressure but Does Not Influence Kidney Function in Hypertensive Rats with Postischemic Kidney Injury
Acute kidney injury (AKI) is associated with significant morbidity and mortality in hypertensive surroundings. We investigated superoxide radical molecules influence on systemic haemodynamic and kidney function in spontaneously hypertensive rats (SHR) with induced postischemic AKI. Experiment was performed in anesthetized adult male SHR. The right kidney was removed, and left renal artery was subjected to ischemia by clamping for 40 minutes. The treated group received synthetic superoxide dismutase mimetic TEMPOL in the femoral vein 5 minutes before, during, and 175 minutes after the period of reperfusion, while the control AKI group received the vehicle via the same route. All parameters were measured 24 h after renal reperfusion. TEMPOL treatment significantly decreased mean arterial pressure and total peripheral resistance (P lt 0.05) compared to AKI control. It also increased cardiac output and catalase activity (P lt 0.05). Lipid peroxidation and renal vascular resistance were decreased in TEMPOL (P lt 0.05). Plasma creatinine and kidney morphological parameters were unchanged among TEMPOL treated and control groups. Our study shows that superoxide radicals participate in haemodynamic control, but acute superoxide scavenging is ineffective in glomerular and tubular improvement, probably due to hypertension-induced strong endothelial dysfunction which neutralizes beneficial effects of O-2(-) scavenging
Vibroacustic microvibrations enhance kidney blood supply, glomerular filtration and glutathione peroxidase activity in spontaneously hypertensive rats
Limited numbers of studies include research of microvibration therapy in experimental models. We examined effects of chronic vibroacustic-microvibration treatment on haemodynamics and anti-oxidative defense in experimental hypertension. Study was performed on chronically treated hypertensive and normotensive Wistar rats. Mean arterial pressure (MAP), cardiac output (CO), renal blood flow (RBF), glomerular filtration and activity of anti-oxidative enzymes were determined after three weeks treatment. Vibroacustic treatment had no influence on MAP and CO, but RBF was increased in both groups of treated rats. Additionally, vibroacustic treatment enhanced diuresis and increased glomerular filtration in hypertensive rats. Glutathione peroxidase (GSH-Px) activity was elevated in both treated rat strains, but activity of superoxide dismutase was unchanged. We conclude that microvibration treatment doesn't ameliorate hypertension but improves renal blood supply (trough diminished renal vascular resistance), glomerular filtration, diuresis, and enhances glutathione dependent anti-oxidant defense with more important beneficials in hypertensive animals
Usporavaenje progresije hroniÄne insuficijencije bubrega kaptoprilom kod pacova sa spontanom arterijskom hipertenzijom i adriamicinskom nefropatijom
In SHRs with ADR nephropathy treatment with captopril normalized systemic blood pressure, and slowed down CRF progression in their early stage. These functional changes correlate with significant slowing of glomerular and interstitial changes.Uticaj arterijske hipertenzije na progresiju hroniÄne insuficijencije bubrega opisan je u brojnim eksperimentalnim i kliniÄkim studijama. Samim tim uticaj razliÄitih antihipertenzivnih lekova ka regulisanju pritiska krvi i usporavaju progresne hroniÄne insuficijencije bubrega joÅ” uvek je predmet rasprava i neslaganja mnogih nauÄnika. Cilj ovog rada bio je da se ispita uticaj kaptoprila na kliniÄke, biohemijske i morfoloÅ”ke promene kod pacova sa spontanom arterijskom hipertenzijom i nefropatijom izazvanom adriamicinom. Å ezdeset i devet ženki pacova sa spontanom arterijskom hipertenzijom (stare 24 nedelje) svrstane su u tri grupe: 1. kontrolna grupa - 12; 2. grupa s nefropatijom izazvanom adriamicinom - 27 sa spontanom arterijskom hipertenzijom koja je tretirana adriamicinom (2 mg/kg i.V. dva puta u 20 dana); 3. grupa s nefropatijom izazvanom adriamicinom - grupa S: 30 sa spontanom arterijskom hipertenzijom tretirana adriamicinom i kaptoprilom (60 mg/kg dnevno). Sistolni pritisak krvi meren je na dve nedelje, a analize seruma i urina na poÄetku studije i u 6-oj, 12. i 18. nedele posle druge injekcije adriamicina. Životinje su žrtvovane 6-e, 12. i 18. nedelje od poÄetka tretiranja kaptoprilom. PatomorfoloÅ”ke promene prikazane su semikvantitativno izraÄunavanjem indeksa glomerula vaskularnog indeksa, kao i indeksa fibroze intersticijuma i infiltracije, i atrofije tubula. Kaptopril je normalizovao sistemski pritisak krvi, ali nije smanjio proteinuriju kod pacova sa spontanom arterijskom hipertenzijom. Ureja i kreatinin u serumu progresivno su rasli u svim ispitivanim grupama pacova, ali brže kod pacova koji su tretirani adriamicinom. Klirens kreatinina najbrže je opadao u grupi kod pacova s nefropatijom izazvanom adriamicmom. Kaptopril smanjuje promene u glomerulima kod pacova sa spontanom arterijskom hipertenzijom i nefropatijom izazvanom adriamicinom s visokom statistiÄkom znaÄajnoÅ”Äu u 18-oj nedelji studije. Promene u intersticijumu kod pacova sa spontanom arterijskom hipertenzijom koji su tretirani adriamicinom uveÄavaju ce u toku ogleda, ali statistiÄki znaÄajno sporije u svim nedeljama studije u grupi pacova s nefropatijom izazvanom adriamicinom (grupa C) Kaptopril nije uticao na promene u tubulima kod ovih životinja
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