effects of l-arginine on the hippocampus of male rat fetuses under maternal stress

Introduction: Prenatal stress has deleterious effects on the development of the brain and is associated with behavioral and psychosocial problems in childhood and adulthood. This study aimed to determine the protective effect of L-arginine on fetal brain under maternal stress

Methods: Twenty pregnant Wistar rats [weighting 200-230 g] were randomly divided into 4 groups [n=5 for each group]. The first nonstress and stress groups received 2 mL of normal saline and the other nonstress and stress two groups received L-arginine [200 mg/kg, IP] from their 5[th] to 20[th] days of pregnancy. The pregnant rats were killed on 20[th] day and the brain fetuses removed and prefrontal cortical thickness, total neurons in the prefrontal cortex and in the areas of CA1, CA2, and CA3 of the hippocampus were measured and counted. Nitrite levels in the brain were measured as an indicator for nitric oxide [NO] level

Results: There was a significant decrease of mean number of pyramidal cells in the CA1 in prenatal stress group compared to nonstress and nonstress plus arginine groups. The NO level in brain tissue increased significantly in the stress plus arginine [3.8 +/- 0.4 nmol/mg] and in nonstress rats [2.9 +/- 0.3 nmol/mg] compared to the stress group [1.8 +/- 0.1 nmol/mg]. Prefrontal cortical thickness decreased significantly in stress rats [1.2 +/- 0.09 mm] compared to the nonstress plus arginine [1.7 +/- 0.15 mm] and nonstress [1.6 +/- 0.13 mm] groups

Discussion: Results indicated that prenatal stress could lead to neurodegeneration of hippocampus and prefrontal cortex of rat fetuses. L-arginine as a precursor of NO synthesis had neuroprotective effect during prenatal stress and could be used an effective treatment for stress

effect of hydro alcoholic extract of Juglans regia leaves in streptozotocin-nicotinamide induced diabetic rats

Phytotherapy has been achieved to maintain glycemic control in patients with diabetes mellitus. The present study was conducted to evaluate the antihyperglycemic properties of the Juglans regia leaf extract in streptozotocinnicotinamide induced diabetic rats. Nicotinamide was injected intraperitonealy [i.p.] 15 min before the injection of Streptozotocin [i.p.]. One week after induction of diabetes, oral treatment started with extract of Juglans regia and Metformin and continued for 4 weeks. Fasting blood sugar, body weight, serum lipids and insulin level were measured in different groups. A significant reduction of glucose, HbA1c, total cholesterol and serum triglycerides were detected after 4 weeks in rats treated with Juglans regia leaves compared to the control groups. Thus, Juglans regia extract treatment showed potential hypoglycemic and hypolipidemic effects in type 2 diabetic rats

effects of cyclosporin-A on functional outcome and axonal regrowth following spinal cord injury in adult rats

It has been shown that the immunophilin ligands have the special advantage in spinal cord repair. In this study, the effects of cyclosporine A [CsA] on functional recovery and histological outcome were evaluated following spinal cord injury in rats. After spinal cord hemisection in thirty six adult female Sprague-Dawley rats [200- 250 g], treatment groups received CsA [2.5 mg/kg i.p.] at 15min and 24h after lesion [CsA 15min group and CsA 24h group] daily, for 8 weeks. Control and sham groups received normal saline and in sham operated animals the spinal cord was exposed in the same manner as treatment groups, but was not hemisected. Hindlimb motor function was assessed in 1, 3, 5 and 7 weeks after lesion, using locomotive rating scale developed by Basso, Bresnahan and Beattie [BBB]. Motor neurons were counted within the lamina IX of ventral horn and lesion size was measured in 5 mm of spinal lumbar segment with the epicenter of the lesion site. The mean number of motor neurons and the mean BBB scale in 3, 5 and 7 weeks in CsA 15min groups significantly increased compared to the control group. Although, the lesion size reduced in rats with CsA treatment compared to the control group, no significant difference was observed. Thus, it can be concluded that CsA can improve locomotor function and histological outcome in the partial spinal cord injury

Repair of peripheral nerve defects using a polyvinylidene fluoride channel containing nerve growth factor and collagen gel in adult rats

As effectiveness of the autologous graft in the repair of long nerve defects is very limited an effective substitute is needed. This study was conducted to determine the poled polyvinylidene fluoride [PVDF] tube as an alternative to nerve autograft. The left sciatic nerve was transected in 45 male Wistar rats. The animals were then divided randomly into three groups: in an epineural group the nerve was sutured end to end; in an autograft group a 10 mm piece of sciatic nerve was cut, rotated 180[degree sign] and sutured in the nerve gap; and in a nerve guidance channel group [NGC], PVDF, tube containing nerve growth factor [NGF] and collagen gel was placed in the gap. In a control [n=15] group the sciatic nerve was exposed but not transected. To determine axonal regeneration, retrograde DiI tracer was injected into the gastrocnemius muscle. One week later, retrograde-labeled neurons were counted in the L4-L6 spinal segments and one way ANOVA analysis was performed to compare groups. Neuronal morphology changes were studied by electron microscopy. Significant statistical decreases in the mean number of labeled motoneurons were observed in all surgical groups compared to the control group; and in the autograft and the NGC groups compared to epinural suture group [p<0.01]. No significant difference in the mean number of motoneurons was observed between the autograft and NGC groups. Chromatin condensation, dilated endoplasmic reticulum and large vacuoles were observed in the autograft and NGC groups. Regarding the positive effects of PVDF tube containing NGF and Collagen gel on the sciatic nerve regeneration, authors suggest that it may be useful in peripheral nerve repair

Immcinohistochemical study of spinal motor neurons following sciatic nerve repair in fldult rat

Epineural suture and autologous graft are two routine techniques in peripheral nerve surgery. However, their efficiency can be highly limited depending on the type of lesion and the gap between two nerve stumps and because of deficient proper nerve donors. So much interest has been focused on the development of alternative instruments for bridging the nerve gaps. In the present study, we have used charged polyvinelidene fluoride [PVDF] tube filled with nerve growth factor [NGF] and collagen gel as a substitute for nerve autograft and compared the results with other current surgical techniques. We studied the changes of spinal motoneurons to evaluate the effect of repairing techniques. In this study, 30 male Wistar rats weighing 200-250 g were divided randomly in five groups: axotomy, epineural suture, autograft, nerve guidance channel, and sham operation. In all experimental groups, the left sciatic nerve was transected at mid-thigh level. The nerve was not repaired in axotomy group. In epineural suture group, it was sutured end-to-end. In autograft group, a 10 mm piece of nerve was rotated 180° and sutured again in the nerve gap. Finally, in nerve guidance channel group, a piece of PVDF tube containing NGF7s [100 ng/ml] and collagen gel [1.28 mg/ml] was replaced in the gap. After one week, one month, and two months, L4-6 segments of spinal cord were removed and 5 urn paraffin sections were prepared for bax immunohistochemical study. In all groups contralateral spinal cord was used as the control. The proportion of Bax-positive apoptotic motoneurons was studied in all groups to evaluate the efficiency of different repairing techniques. Mean percentage of Bax-positive neurons to the total number of motor neurons in left side was analyzed. One way ANOVA showed significant difference after two months. LSD post hoc test showed that mean percentage of Bax-positive neurons in axotomized group was significantly higher compared to other surgical groups [p<0.05]. The number of apoptotic neurons after one week, one month and two months in each type of surgical approach showed no significant difference between one week and one month and between one month and two months. Comparison of motoneuron population in left side [experimental] with right side [control] showed no significant differences after one week, but significant differences were seen [p<0.01] after one month and two months. In sham group, no Bax-positive neuron was found after one week, one month, and two months. A PVDF tube filled with NGF and collagen gel can be used as a proper substitute for autografts and protect motoneurons following peripheral nerve injury