Ethanol-induced dopamine elevation in the rat — Modulatory effects by subchronic treatment with nicotinic drugs

Abstract Objectives Dexamethasone is used experimentally to induce insulin resistance and type 2 diabetes. However, data concerning the dose, the duration of treatment, and the associated comorbidities are inconsistent. The aim of this study was to compare the effects of different doses of dexamethasone and the duration of treatment necessary for the development of a model of insulin resistance that mimics the clinical condition with the associated comorbidities. Methods Dexamethasone was administered intramuscularly to male Wistar rats, at doses of 500 and 1,000 µg/kg/day for the subchronic treatment (eight consecutive days) and at doses of 5, 25, 50, and 100 µg/kg/day in chronic treatment (28 consecutive days). Effects on body weight, metabolism, hemodynamics, renal function, and redox status were evaluated. Results Both treatments induced a progressive body weight loss that was drastic in subchronic treatment, improved glucose tolerance without affecting fasting glycemia. Doses of 1,000 and 100 µg/kg were associated with hypertriglyceridemia, hypertension, and increased heart rate, cardiac and renal hypertrophy. Increased creatinemia associated with reduced creatinuria were observed in sub-chronic treatment while increased proteinuria and reduced creatinuria were noticed in chronic treatment. 1,000 µg/kg dexamethasone caused an increase in hepatic, and renal malondialdehyde (MDA) and glutathione (GSH) coupled with a reduction in catalase activity. The dose of 100 µg/kg induced a rise in GSH and catalase activity but reduced MDA levels in the kidney. Conclusions Doses of 1,000 µg/kg for subchronic and 100 µg/kg for chronic treatment exhibited similar effects and are the best doses to respective time frames to induce the model.

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Changes in sensitivity of dopamine autoreceptors in rat striatum after subchronic treatment with methamphetamine

European Journal of Pharmacology ◽

10.1016/0014-2999(91)90768-l ◽

1991 ◽

Vol 205 (1) ◽

pp. 43-47 ◽

Cited By ~ 12

Author(s):

Yamada Shigeto ◽

Yokoo Hideyasu ◽

Nishi Syogoro

Keyword(s):

Rat Striatum ◽

Dopamine Autoreceptors ◽

Subchronic Treatment

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Genotoxic and mutagenic effects of vigabatrin, a γ-aminobutyric acid transaminase inhibitor, in Wistar rats submitted to rotarod task

Human & Experimental Toxicology ◽

10.1177/0960327115611970 ◽

2016 ◽

Vol 35 (9) ◽

pp. 958-965 ◽

Cited By ~ 5

Author(s):

VR Coelho ◽

K Sousa ◽

TR Pires ◽

DKM Papke ◽

CG Vieira ◽

...

Keyword(s):

Acute Treatment ◽

Wistar Rats ◽

Micronucleus Test ◽

Repeated Administration ◽

Saline Group ◽

Aminobutyric Acid ◽

Subchronic Treatment ◽

Motor Activities ◽

Male Wistar Rats ◽

Mutagenic Effects

Vigabatrin (VGB) is an antiepileptic drug thatincreases brain γ-aminobutyric acid (GABA) levels through irreversible inhibition of GABA transaminase. The aim of this study was to evaluate neurotoxicological effects of VGB measuring motor activity and genotoxic and mutagenic effects after a single and repeated administration. Male Wistar rats received saline, VGB 50, 100, or 250 mg/kg by gavage for acute and subchronic (14 days) treatments and evaluated in the rotarod task. Genotoxicity was evaluated using the alkaline version of the comet assay in samples of blood, liver, hippocampus, and brain cortex after both treatments. Mutagenicity was evaluated using the micronucleus test in bone marrow of the same animals that received subchronic treatment. The groups treated with VGB showed similar performance in rotarod compared with the saline group. Regarding the acute treatment, it was observed that only higher VGB doses induced DNA damage in blood and hippocampus. After the subchronic treatment, VGB did not show genotoxic or mutagenic effects. In brief, VGB did not impair motor activities in rats after acute and subchronic treatments. It showed a repairable genotoxic potential in the central nervous system since genotoxicity was observed in the acute treatment group.

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The effects of acutely and subchronically applied DL-methionine on plasma oxidative stress markers and activity of acetylcholinesterase in rat cardiac tissue

Vojnosanitetski pregled ◽

10.2298/vsp171213055m ◽

2020 ◽

Vol 77 (2) ◽

pp. 165-173

Author(s):

Zarko Micovic ◽

Sanja Kostic ◽

Slavica Mutavdzin ◽

Aleksa Andrejevic ◽

Aleksandra Stamenkovic ◽

...

Keyword(s):

Oxidative Stress ◽

Antioxidant Enzymes ◽

Ache Activity ◽

Cardiac Tissue ◽

Heart Function ◽

Antioxidant Defense System ◽

Rat Plasma ◽

Physiological Solution ◽

Control Group ◽

Subchronic Treatment

Background/Aim. Chronically induced hypermethioninemia leads to hyperhomocysteinemia which causes oxidative stress, atherogenesis, neurodegeneration and cancer. However, little is known about the acute and subchronic effects of DL-methionine (Met). The aim of study was to assess the effects of acutely and subchronically applied Met on oxidative stress parameters in rat plasma [enzymes: catalase (CAT), glutathione peroxidise (GPx), superoxide dismutase (SOD) and index of lipid peroxidation, malondialdehyde (MDA)], and acetylcholinesterase (AChE) activity in rat cardiac tissue. Methods. The enzymes activities, as well as MDA concentration were evaluated following acute (n = 8) and subchronic (n = 10) application of Met [i.p. 0.8 mmoL/kg body weight (b.w.) in a single dose in the acute overload or daily during three weeks in the subchronic overload]. The same was done in the control groups following application of physiological solution [i.p. 1 mL 0.9% NaCl (n = 8) in the acute overload and 0.1?0.2 mL 0.9% NaCl, daily during three weeks (n =10) in the subchronic overload]. Tested parameters were evaluated 60 minutes after application in acute experiments and after three weeks of treatment in subchronic experiments. Results. There were no difference in homocysteine values between the groups treated with Met for three weeks and the control group. Met administration significantly increased the activity of CAT and GPx after 1 h compared to the control group (p = 0.008 for both enzymes), whereas the activity of SOD and MDA concentrations were unchanged. Subchronically applied Met did not affect activity of antioxidant enzymes and MDA level. AChE activity did not show any change in rat cardiac tissue after 1 h, but it was significantly decreased after the subchronic treatment (p = 0.041). Conclusion. Results of present research indicate that Met differently affects estimated parameters during acute and subchronic application. In the acute treatment Met mobilizes the most part of antioxidant enzymes while during the subchronic treatment these changes seems to be lost. On the contrary, the acute Met overload was not sufficient to influence on the AChE activity, while longer duration of Met loading diminished function of the enzyme. These findings point out that methionine can interfere with antioxidant defense system and cholinergic control of the heart function.

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Investigation of Aronia Melanocarpa Fruit Juice for Sedative-Hypnotic Effects in Rats

Journal of Biomedical and Clinical Research ◽

10.2478/jbcr-2018-0012 ◽

2018 ◽

Vol 11 (1) ◽

pp. 77-82

Author(s):

Miroslav Ts. Eftimov ◽

StefkaV. Valcheva-Kuzmanova

Keyword(s):

Locomotor Activity ◽

Acute Treatment ◽

Fruit Juice ◽

Open Field Test ◽

Treatment Control ◽

Aronia Melanocarpa ◽

Subchronic Treatment ◽

Male Wistar Rats ◽

The Central Nervous System ◽

Time Test

Summary Aronia melanocarpa fruit juice (AMFJ) has been intensively studied for effects on the central nervous system. The study aimed to investigate AMFJ for possible sedative-hypnotic effects in rats after acute and subchronic administration. Male Wistar rats were treated orally with three doses of AMFJ (2.5, 5.0 and 10.0 ml/kg) either once (acute treatment) or in 30 days (subchronic treatment). Control rats were similarly treated with distilled water. The tests were performed 1 hour after the last AMFJ administration. The possible sedative-hypnotic effects of the juice were investigated in the open field test (OFT) and thiopental-induced sleeping time test. Substances with sedative-hypnotic effects decrease locomotor activity in the OFT and prolong the time of thiopental-induced sleep. The results from the OFT showed that neither the acute, nor the subchronic treatment of rats with all AMFJ doses affected the horizontal and vertical locomotor activity significantly. The two patterns of administration of AMFJ (acute and subchronic) had no significant effect on the duration of thiopental-induced sleep. The lack of effect of AMFJ on locomotor activity and the lack of prolongation of thiopental-induced sleep showed that AMFJ did not display sedative-hypnotic effects in rats.

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