Pharmaceutical Sciences
Volume:16 Issue: 2, 2010

The cardiotoxic effects of isoproterenol (ISO) are associated with, and possibly due to, lipid peroxidation in heart tissue. In this study, the effect of exercise against lipid peroxidation and injuries due to isoproterenol was investigated in rat heart. 50 Wistar rats were divided into 5 groups: control rats (C), saline (S), Exercise (E), ISO injected (150 mg/kg) (ISO), Exercise + ISO (E+ISO), at the end of the experiment all animals anesthetized and heart tissue were collected for biochemical and histological examinations. Exercise increased GSH (Glutathione), GSSG (Oxidized Glutathione) and decreased TBARS (Thiobarbituric Acid Reactive Substances) levels in ISO group (p<0.05). Also, exercise reduced the rate of edema, inflammatory cells infiltration and degree of necrosis compared with control group. Our results show exercise by reduction of lipid peroxidation and intensity of myocardial injuries may have beneficial protective effects against injuries due to isoproterenol.

Quercetin and hesperetin are natural flavonoids with many important therapeutic properties. The interaction of these polyphenolic compounds with bovine milk xanthine oxidase as one of their major target proteins was studied using fluorescence quenching method for the first time. ThisEnzyme (3.0710-8M) incubated with varying concentrations of hesperetin and quercetin (0-100 μM) for 5 min and the fluorescence spectra were recorded at 296, 303 and 310 K. It was found that these compounds quenched the fluorescence of XO. The binding constants and the number of binding sites of quercetin and hesperetin with XO were obtained.It was shown that the fluorescence quenching of quercetin and hesperetin with xanthine oxidase occur through a static, static and dynamic mechanism, respectively. The thermodynamic parameters (enthalpy and entropy changes) were also calculated at different temperatures. Both hydrogen and hydrophobic binding are involved in the interaction of quercetin with xanthine oxidase and hydrophobic binding exists in the interaction of hesperetin with xanthine oxidase.

Physical exercises induce many biochemical changes including hyperkalmia and increasing of catecholamines in blood circulation. The purpose of this study is to investigate the heart electrical changes induced by hyperkalmia occurring during exercise and also study the protective effects of catecholamines against hyperkalmia. 12 healthy male volunteers (23 - 19 years) were selected for this study. Each individual performed an exercise using Ergometer to complete exhaustion (increasing 20 watts workload every two minutes) twice, with one week interval. In the first instance they took a placebo, in the second instance, they took 80 mg propranolol, one and half hours before starting the exercise. Before the exercise and in the last 20 seconds of each increment in the workload, electrocardiogram was recorded in all the 12 leads. With each increment in workload heart rate and plasma potassium was increased in both protocols. In protocol of propranolol administration increase in HR was less than of placebo and enhancement of potassium was more. Comparison of two protocols together in ECG changes showed no significant differences. Increase in potassium levels in muscles during exercise can not have toxic effects on heart. Probably catecholamines do not have a main role in defense against hyperkalmia due to exercise. As a result we suggest administration of propranolol can not be limiting factor for the individual physical exercise.

Reliable findings indicate that lipid profile, oxidative stress and inflammatory factors disorders has the main role in pathogeneses of diabetes and its complications. Traditionally plant extracts have been used for diabetes control. This study was aimed to recognition of the most components in the most effective hydromethanolic fraction of Iranian black orthodox tea on lipid profile, oxidative stress and inflammatory factors in type I Diabetic rats. This study was conducted on 35 rats which were randomly divided into 5 groups (7 rats in each group). The weight of rats was 200 – 250 gr. Total of groups was diabetic, and diabetes was induced by intraperitoneal injection of streptozotocin 60mg/kg. Groups 1 to 5 were received: carrier, methanol fractions of 20%, 40%, 60%, 80% plus 100% respectively. In the end of study biochemical factors was measured. Data were analyzed by using one ways ANOVA, SPSS statistic methods. Analytical, Preparative and NMR were used to recognize of components in the most effective fraction. In this study concluded that the effective fraction on biochemical factors was 20%. The main component of 20% fraction were caffeine, epicatechingallat, quercetin and kaempferol. It can be concluded that injection of 20% fraction of black tea had positive effect on the prevention of incidence and develop of diabetes complications.

The present study evaluated the possible role of α1-adrenergic receptors of the dorsal hippocampus on WIN55, 212-2 induced amnesia and WIN55, 212-2 state-dependent memory in adult male Wistar rats. In this study Phenylephrine as agonist and prazosin as antagonist of α1-adrenergic receptor, WI 55, 212-2 as agonist of cannabinoid receptor was used. The animals were bilaterally implanted with chronic cannulae in the CA1 regions of the dorsal hippocampus, trained in a step-down type inhibitory avoidance task, and tested 24 h after training to measure step-down latency. post-training intra-CA1 administration of WIN55, 212-2 (0.25 and 0.5 μg/rat) impaired the memory retrieval. Amnesia produced by post-training WIN55, 212-2 (0.5 μg/rat) was reversed by pre-test administration of the same dose of WIN55, 212-2 that is due to a state-dependent effect. Pre-test intra-CA1 injection of phenylephrine (0.5 and 0.75 μg/rat) improved post-training WIN55, 212-2 (0.5 μg/rat) induced retrieval impairment. On the other hand, pre-test injection of prazosin prevented the restoration of memory by pre-test WIN55, 212-2. It is important to note that pre-test intra-CA1 administration of the same doses of prazosin or phenylephrine, alone did not affect memory retrieval. These results suggest that α1-adrenergic receptors of the dorsal hippocampal CA1 regions may play an important role in WIN55, 212-2 state-dependent memory.

The perinatal effects of antidepressants on the central nervous system (CNS) due to its common usage are important issues in neuroscience researches. Bupropion is an atypical antidepressant that is widely used for smoking cessation. The study of synaptic effects of bupropion can reveal its mechanism for nicotine dependence cessation. In this study the effects of long term administration bupropion during perinatal period on synaptic plasticity (Long Term Potentiating or LTP) in neonatal hippocampus slices were evaluated. Hippocampus slices from 19-25 day old rat pups by using standard brain slices techniques were prepared. Slices preparation were accomplished from three groups, control, normal saline and bupropion-treated (40 mg/Kg, i.p) according to maternal perinatal treatments. To produce LTP, the PB stimulation paradigm was applied and evoked responses were recorded from strata pyramidal of area CA1 following stimulation of Schaffer collaterals. Analysis of data showed that LTP induction parameter (PS amplitude) between normal saline and control groups had no significant difference, however there were significant difference between control and treated groups p<0.05, as well as normal saline and treated groups p <0.01. Long term perinatal administration of bupropion decreased induction and maintenance of LTP in strata pyramidal of area CA1. It seems that the loss of LTP maintenance in bupropion-treated animals is more likely the result of the disruption of cellular processes that they contribute following LTP induction.

The aim of this project was determination of intestinal absorption of furosemide in the presence of anionic macromolecules. In the present study the SPIP technique was used for permeability determination in rat intestine. We conduct the experiment on a 10 cm cannulated jejunal segment of anesthetized rats. The segment was filled with perfusion solution. Perfusion rate was 0.2 ml/min and lasted for 90 minutes.Outlet tubing samples were gathered in defined time intervals (every 10 min) and the remaining drug was measured in samples. Samples were analyzed by HPLC system. The calculation of Peff was based on outlet perfusate steady-state concentrations and the initial concentration of drug solution. Obtained data indicated that the intestinal permeability increased by increasing the NaCMC concentration (P <0.001). The increasing could be explained by donnan equilibrium and influence of anionic polymer on tight junctions. Poly electrolytes (like NaCMC) enhance the transport rate of ionic drugs with same electrical charge. Anionic polymers could be used as absorption enhancers for anionic drugs like furosemide in defined concentrations.