ABSTRACT
Context: Alzheimer's disease is strongly associated with brain insulin signalling.Objective: Investigating the effect of amylin as a novel treatment in streptozotocin (STZ) rat model of AD.Materials and methods: Alzheimer's disease (AD) was induced in albino rats by intracerebroventricular injection of STZ (3 mg/kg). Rats received either amylin analogue (Pramlintide 200 µg/kg/day) or Metformin (30 mg/kg/day) for 5 weeks.Results: Both Pramlintide and Metformin improve learning and memory through enhancing insulin signalling (p-IR and p-PI3K) which lead to lowering level of CSF glucose, phosphorylated tau proteins, and amyloid-ß peptide (Aß) in hippocampus.Conclusions: Insulin sensitisers as Metformin and Pramlintide can improve learning and memory and decrease the pathological changes in STZ induced rat model of AD. However, Pramlintide is superior to Metformin in some memory tests which related to its action as an amylin analogue. Amylin improves learning and memory through an independent effect other than insulin sensitisation.
Subject(s)
Alzheimer Disease/metabolism , Insulin Resistance , Islet Amyloid Polypeptide/pharmacology , Memory/drug effects , Alzheimer Disease/physiopathology , Animals , Avoidance Learning/drug effects , Cognition/drug effects , Disease Models, Animal , Gene Expression Regulation, Enzymologic/drug effects , Glucose/cerebrospinal fluid , Hippocampus/drug effects , Hippocampus/metabolism , Islet Amyloid Polypeptide/blood , Male , Maze Learning/drug effects , Phosphatidylinositol 3-Kinase/metabolism , Phosphorylation/drug effects , Rats , Receptor, Insulin/metabolismABSTRACT
BACKGROUND: Irisin is an exercise-induced myokine that could play a role in post-myocardial infarction (MI) cardiac rehabilitation. AIM OF THE STUDY: We investigated the ability of dihydromyricetin to mimic the effects of exercise on raising serum irisin and on enhancing cardiac function and remodeling following MI in rats. METHODS: MI was induced in albino rats by subcutaneous injection of isoproterenol (85 mg/kg) for 2 consecutive days at an interval of 24 h. One week post-MI, rats either underwent physical exercise by running on a motor-driven treadmill at 25 m/min, 30 min/d, 5 d/week or received orally dihydromyricetin 100 mg/kg/d, for 8 weeks. RESULTS: Exercise and dihydromyricetin raised serum irisin 1.8 and 1.9 folds as compared to sedentary rats (p <0.001) with no difference between both regimens (p = 0.992). There was an improvement of cardiac remodeling where ß-myosin heavy chain level was not different in exercise and dihydromyricetin groups from normal group (p = 0.695, p = 0.470). The heart rate variability domains increased back to normal. However, exercise was superior to dihydromyricetin in improving cardiac contractility by increasing carotid blood flow, stroke volume and cardiac output to be insignificant from normal rats (p = 0.899, p = 0.850, p = 0.912). Meanwhile, treatment with dihydromyricetin showed reduction by 29% of carotid blood flow, 24% of stroke volume and 25% of cardiac output compared to normal rats (p <0.001). CONCLUSIONS: DHM could mimic the effect of exercise in stimulating irisin secretion but it is not as effective as exercise in improving myocardial contractility.
Subject(s)
Cardiac Rehabilitation/methods , Fibronectins/blood , Flavonols/pharmacology , Myocardial Infarction/rehabilitation , Physical Conditioning, Animal/physiology , Animals , Humans , Male , Myocardial Contraction/drug effects , Myocardial Infarction/blood , Myocardium/pathology , Rats , Ventricular Remodeling/drug effectsABSTRACT
Background: Preeclampsia (PE) is a disorder of pregnancy associated with vitamin D (VD) deficiency. Chemerin is an adipokine significantly increased in preeclampsia and is regulated by VD. Objectives: To determine whether VD supplementation would protect against development of PE through Chemerin reduction Methods: PE was induced in albino rats by injection of 12.5 mg of deoxycorticosterone (DOCA). Rats were randomly divided into normal pregnant, PE group, VD supplemented PE group. Results: VD supplementation decreased systolic blood pressure, proteinuria and decreased serum Chemerin level. Conclusion: VD treatment reduced Chemerin level, and blood pressure in DOCA rat model of PE.
Subject(s)
Blood Pressure/drug effects , Chemokines/blood , Pre-Eclampsia/drug therapy , Proteinuria/drug therapy , Vitamin D/therapeutic use , Animals , Dietary Supplements , Disease Models, Animal , Female , Pre-Eclampsia/blood , Pregnancy , Proteinuria/blood , Rats , Vitamin D/administration & dosageABSTRACT
AIMS: Cerium oxide nanoparticles (CeO2NPs) have been recently introduced into the medical field for their antioxidant properties. The ability of CeO2NPs alone or in combination with spironolactone (SP) to attenuate monocrotaline (MCT)-induced pulmonary hypertension and associated right ventricular hypertrophy was studied in rats. A special emphasis was given to endothelin-1 pathway. MATERIALS AND METHODS: Pulmonary hypertension was induced in albino rats by a single subcutaneous injection of MCT (60â¯mg/kg). Rats received either single CeO2NPs therapy or combined therapy with SP for 2â¯weeks. KEY FINDINGS: CeO2NPs improved pulmonary function tests with concomitant decrease in serum endothelin-1 and pulmonary expression of endothelin-1 and its receptor ETAR. Besides, CeO2NPs diminished MCT-induced right ventricular hypertrophy and reduced cardiac oxidative stress and apoptosis. SIGNIFICANCE: CeO2NPs could improve pulmonary hypertension and associated right ventricular hypertrophy with no additive value for SP. Besides being an antioxidant, CeO2NPs work through endothelin-1 pathway to improve pulmonary hypertension.
