ABSTRACT
Background and Aim: Endogenous opioids and addictive opiate drugs change many body functions. Previous studies have referred to the effects of morphine on smooth and pulmonary muscles, but the effects of opioids on skeletal muscles is not known well. Thus, the current study aimed at assessing the effect of a single dose of morphine on muscle fatigue in male rats
Materials and Methods: In this experimental study, 40 male Wistar rats weighing 220-270 g were randomly divided into four equal groups: control [the mice were kept in their cages and received food and water], morphine receiving group, fatigue group [the mice in this group were kept running on a treadmill. for120 minutes at a rate of 20 meters per minute], and morphine plus fatigue group. At the end of the experiments, blood samples were obtained from the corner of their eyes and were sent to the laboratory for measurement of muscle fatigue indexes including lactate dehydrogenase [LDH] and creatine phosphokinase [CPK]
Results: Administration of morphine to the fatigue group decreased running time compared with the control group [P=0.009]. Furthermore, administration of morphine to the fatigue group significantly increased serum levels of LDH [P=0.009] and CPK [P=0.008]
Conclusion: The present study showed that administration of a single dose of morphine in rats increases muscle fatigue biomarkers [LDH, CPK]
ABSTRACT
Background and Aim: Oxidative stresses are involved in neuronal degeneration of substantia nigra and thereby induction of Parkinson's disease. It is reported that Foeniculum Vulgare L. can affect lactating and modulating dopaminergic system activity and antioxidant activity as well. In the present study, the effects of methanolic extract of Foeniculum Vulgare seeds on a Parkinson's disease model induced by ICV injection of 6-hydroxydopamin [6-OHDA] in female rats were investigated
Materials and Methods: In this experimental study, 60 female rats were randomly divided into 6 equal groups including saline, Parkinson's disease and Parkinson's groups which were treated by different doses of the extract. Parkinson's disease was induced by i.c.v injection of 6-OHDA. Methanolic extract of Foeniculum Vulgare seeds [100 and 200 mg/kg] was gavaged through two ways including repeated gavage [14 days before and 14 days after 6-OHDA injection] and acute gavage [once every day for 14 days after 6-OHDA injection]. The induced Parkinson`s disease was evaluated using Rotarod and Wire grasping tests on the day 14[th] after 6-OHDA injection
Results: The findings of the study demonstrated that repeated gavage of Foeniculum Vulgare extract improved motility and muscle tone in Parkinson's animals [p<0.05]. However, acute gavage of the extract had no significant effect on the performance of Parkinson's animals
Conclusion: Results of the current study showed that chronic administration of Feoniculum Vulgare extract may improve Parkinson's symptoms in female rats
ABSTRACT
Introduction: Lower level of estrogen hormone is considered as an important factor for loss of learning and memory in postmenopausal women. Although estrogen replacement therapy is used for compensation, but long-term usage of estrogen is associated with a higher risk of hormone-dependent cancers. Phytoestrogens, due to fewer side effects, have been proposed to prevent menopause-related cognitive decline
Methods: 24 female Wistar rats weighing 180-220 g were used in this study. The animals were ovariectomized and randomly divided into four groups including, control and two groups which received 8 and 80 mg/kg Vitex agnus castus [VAC] ethanolic extract orally. The last groups were treated with 40 micro g/kg of estradiol valerat. Step-through passive avoidance [STPA] test was used for the evaluation of learning and memory. The hippocampal estrogen receptor alpha [ERalpha] expression was measured using Real-Time PCR
Results: The results demonstrated that VAC extract or estradiol had better performance on step-through passive avoidance test than control group [all P<0.05]. Moreover, administration of either estradiol or VAC extract increased the hippocampal mRNA level of ER alpha and prevented the decrease in uterine weight of ovariectomized rats
Discussion: Based on our data, VAC extract improves learning and memory in ovariectomized rats. The positive effect of VAC extract on learning and memory is possibly associated with an increase in ER alpha gene expression in the hippocampal formation
ABSTRACT
Background: Chronic use of opioids usually results in physical dependence. The underlying mechanisms for this dependence are still being evaluated. Transient receptor potential vanilloid type 1 [TRPV1] are important receptors of pain perception. Their role during opioid dependence has not been studied well. The aim of this study was to evaluate the effect of morphine-dependence on the expression of TRPV1 receptors in the amygdala and CA1 region of the hippocampus
Methods: This study used four groups of rats. Two groups of rats [morphine and morphine+naloxone] received morphine based on the following protocol: 10 mg/kg [twice daily, 3 days] followed by 20, 30, 40 and 50 mg/kg [twice daily], respectively, for 4 consecutive days. Another group received vehicle [1 ml/ kg] instead of morphine given using the same schedule. The morphine+naloxone group of rats additionally received naloxone [5 mg/kg] at the end of the protocol. The control group rats received no injections or intervention. The amygdala and CA1 regions of the morphine, saline-treated and intact animals were isolated and prepared for real-time PCR analysis
Results: Administration of naloxone induced withdrawal signs in morphine-treated animals. The results showed a significant decrease in TRPV1 gene expression in the amygdala [P<0.05] but not the CA1 region of morphine dependent rats
Conclusion: TRPV1 receptors may be involved in morphineinduced dependence
ABSTRACT
Diarrhea is one of the world's health problems as the most common causes of death in children. In this study, the effect of Teucrium Polium [TP] extract on diarrhea induced by castor oil has been studied. 30 male rats were divided into five equal groups containing extract with doses of 100, 200 and 600 mg/kg; diphenoxylate [5 mg/kg]; and control group or vehicle [normal saline] groups. One hour after feeding the drugs or vehicle in the volume of 10 ml/kg, 2 ml of castor oil were fed to each animal through an oral-gastric catheter. Then excrements of animals were separately observed in the cages for 4 hours and their quality, frequency and stool weight were determined. Data analysis was performed using one-way ANOVA and Tukey post-test and p<0.05 was considered as significant. Diphenoxylate and 600 mg/kg dose of TP reduced the percentage of the weight loss of animals, their excretion frequency and defecation index [p< 0.001]. The 600 mg/kg dose of TP decreased the fecal water content compared to the control group [p< 0.01]. Based on our data, essential oil of TP has an effect similar to diphenoxylate on the reduction of osmotic diarrhea symptoms and also reduces the volume of excreted water
ABSTRACT
Background and purpose: Morphine addiction and morphine withdrawal syndrome are of main problems in human societies. In the present study, effect of nicotine on the strength of physical and psychological dependency, produced by single and repeated doses of morphine, was investigated
Material and method: Male wistar rats were dependent to morphine with single and repeated dose protocols. In the single dose protocol, rats received only one dose of morphine and 24h later were given Naloxone. In the repeated dose protocol, rats received incremental doses of morphine for 7 days and 24h after the last dose [8th day] were given Naloxone. In the single dose protocol, rats were given one dose of nicotine 30 min before Naloxone. However in the repeated doses they received nicotine 15 min before morphine for 4 days from 4th day to 7th day. 5 min after Naloxone each rat?s behavior was captured for 30 min. then physical and psychological signs of withdrawal syndrome were recorded
Results: Results showed that injection of repeated and even single dose of morphine can produce dependency. Nicotine consumption attenuated strength of withdrawal syndrome signs, specially increasing weight excrement and total withdrawal score in single dose protocol and weight excrement increasing, weight decreasing, place aversion, and total withdrawal score in repeated dose treatment
Conclusion: Based on our data, even a single dose of morphine can produce dependency in rats. Conversely, Nicotine consumption attenuates strength of withdrawal syndrome signs
ABSTRACT
Morphine addiction and morphine withdrawal syndrome are the two main problems of today's human society. The present study has investigated the effects of nicotine on the strength of physical and psychological dependency in single and repeated doses morphine administrated rats. Male Wistar rats were subjected to morphine consumption with single or frequent dose protocols. In the single dose protocol, rats received only one dose of morphine and 24hrs later they also received one dose of nicotine 30 min prior to injection of naloxone. In the repeated dose protocol, rats received incremental doses of morphine for 7 days and 24hr after the last dose [the 8th day] were given naloxone. However, the nicotine regimen of this group was injected 15 min before the morphine injection, for 4 days, from the 4th to the 7th day. Five minutes after naloxone injection, each rat's behavior was captured for 30 min, and then physical and psychological signs of withdrawal syndrome were recorded. Data were analyzed by ANOVA followed by Tukey tests and p<0.05 was considered as significant difference. Results showed that the injection of frequent and single doses of morphine lead to morphine dependency. In single dose protocol, nicotine consumption attenuated the signs of withdrawal syndrome, especially weight of excrement and total withdrawal score. In frequent dose protocol, in addition to these effects, nicotine induced weight loss and place aversion. The inhibitory effects of nicotine on signs of withdrawal syndrome may involve a dopaminergic portion of the central nervous system and is mediated by central nicotinic receptors. There is also a cross-dependence between nicotine and morphine
ABSTRACT
Opioid abuse is still remained a major mental health problem, a criminal legal issue and may cause ischemic brain changes including stroke and brain edema. In the present study, we investigated whether spontaneously withdrawal syndrome might affect stroke outcomes. Addiction was induced by progressive incremental doses of morphine over 7 days. Behavioral signs of withdrawal were observed 24, 48 and 72 hr after morphine deprivation and total withdrawal score was determined. Cerebral ischemia was induced 18-22 hr after the last morphine injection by placing a natural clot into the middle cerebral artery [MCA]. Neurological deficits were evaluated at 2, 24 and 48 hr after ischemia induction, and infarct size and brain edema were determined at 48 hr after stroke. Morphine withdrawal animals showed a significant increase in total withdrawal score and decrease of weight gain during the 72 hr after the last morphine injection. Compared to the addicted and control animals, infarct volume and brain edema were significantly increased in the morphine deprived animals [P< 0.05] at 48 hr after cerebral ischemia. Also, neurological deficits were higher in the morphine-withdrawn rats at 48 hr after stroke [P< 0.05]. Our data indicates that spontaneous withdrawal syndrome may worsen stroke outcomes. Further investigations are necessary to elucidate mechanisms of opiate withdrawal syndrome on stroke
Subject(s)
Male , Animals, Laboratory , Morphine/adverse effects , Brain Ischemia , Rats, Wistar , Stroke , Morphine Dependence , Brain Edema , Body Weight ChangesABSTRACT
Previous studies have demonstrated that pretreatment with alpha-tocotrienol [a-TCT] can reduce ischemic damage in mice following middle cerebral artery [MCA] occlusion. It is also reported to decrease stroke dependent brain tissue damage in 12-Lox-deficient mice and spontaneously hypertensive rats. In the present study, the neuroprotective effects of a-TCT and rosiglitazone [RGZ] at 3 hr after cerebral ischemia were investigated. Stroke was induced by embolizing a preformed clot into the MCA. Rats were assigned to vehicle, a-TCT [1 or 10 mg/kg], RGZ and sham-operation. Compared to the control group, only RGZ decreased infarct volume [P<0.05], neurological deficits [P<0.05] and sensory impairments [P<0.01] but low and high doses of a-TCT did not show any significant neuroprotective effect. Our data showed that a-TCT was not neuroprotective at 3 hr after the embolic model of stroke. Further studies should be undertaken to clarify the neuroprotective effects of a-TCT after stroke