BACKGROUND: Opioids and nitric oxide (NO) are functionally linked in the regulation of intestinal motility. OBJECTIVES: To investigate the role of NO in the opium induced bowel dysfunction in mice. METHODS: Sixty-six male mice received incrementally doses of the following treatments in six groups for 5 consecutive days: 1) Opium (0.2, 0.3, 0.4, 0.5 and 0.6mg/30g/day), 2) N-nitro-L-arginine methyl ester (L-NAME, 5,7.5,10,15 and 20mg/kg/day), 3) L-arginine (5-20mg/kg/day), 4) Opium+L-NAME, 5) Opium+L-arginine and 6) distilled water. At the end of the treatment, the abdomen was opened; some pieces of duodenal and proximal colon were taken to determine NO synthase (NOS) expression and nitrite levels, and some isolated rings from those parts of small and large intestine were prepared and transferred to the organ bath system to study intestinal motility. RT-PCR was used to determine the NOS gene expression. To determine the small intestinal transit, 30 mice in six groups, were used for oral administration of charcoal+gum in vivo. RESULTS: Opium decreased amplitude of the duodenum and ileum contractions, but increased frequency of duodenal and mid colon contractions (P<0.05). While the gene expression of inducible, neuronal and endothelial NOS was increased in colon (P<0.05), a reduced neuronal and endothelial NOS gene expression was shown in duodenum. The charcoal+gum transit was decreased in opium-treated animals compared to the control group (19.9%). However, L-arginine increased this transit while L-NAME decreased it. CONCLUSIONS: Opium induced intestinal smooth muscle spasms, which result in the decreased intestinal movements. The alterations in NOS gene expression may be a compensation mechanism against opium-induced intestinal dysfunction.

BACKGROUND: Doxorubicin is one of the most widely used anticancer chemotherapeutic agents in small animal practice. The use of doxorubicin can cause cardiotoxicity, hepatotoxicity, neurotoxicity, and nephrotoxicity. OBJECTIVES: This study was carried out to evaluate the effects of ascorbic acid on doxorubicin hepatotoxicity in mice. METHODS: Twenty-four Balb/c mice were randomly divided into four groups. Group one received normal saline, group two received 100 mg/kg ascorbic acid, group three received 8 mg/kg doxorubicin and group four received ascorbic acid and doxorubicin intraperitoneally, with the same doses of groups 2 and 3. Twenty-one days after injection, the mice were euthanized. The activities of ALP, ALT, AST enzymes and total bilirubin levels in the serum samples were measured. Liver samples were evaluated histopathologically. RESULTS: The activities of ALP, ALT, AST, and total bilirubin levels and histopathologic scores of hepatotoxicity were significantly lower in the group that received ascorbic acid + doxorubicin in comparison to those of the doxorubicin group. CONCLUSIONS: Ascorbic acid may be useful in the prevention of doxorubicin hepatotoxicity in mice. Further studies are recommended for evaluation of the use of ascorbic acid in small animals.

BACHGROUND: Epilepsy is a chronic neurological disorder. Despite discovery of effective antiepileptic drugs (AEDs), more than 30% of patients are still resistant to AEDs. OBJECTIVES: Evaluation the effect of acute administration of Docosahexaenoic acid (DHA) in mice resistant to antiepileptic drugs in 6Hz model of epilepsy. METHODS: at first we evaluted intracerebroventricularly (i.c.v) injection and oral consumption of DHA alone and intrapritoneal (i.p.) injection of drugs in separate groups. In test groups LTG 25mg/kg or PHT 25mg/kg were injected i.p. 105 min after injection of PHT, 45 min after injection of LTG, DHA (1mM) was injected i.c.v. In control groups drugs solvent or DHA solvent was injected DHA. 15 min after injection of DHA or DHA solvent, in all groups 6 Hz stimulation was exerted and occurrence of limbic seizures was registered. In oral test groups PHT 25mg/kg or LTG 25mg/kg were injected i.p. 60 min after injection of PHT and simultaneous injection of LTG, DHA (0.1 ml) was gavaged. 60 minutes after injection of DHA 6 Hz stimulation was exerted. RESULTS: Acute administration of DHA alone via i.c.v injection or oral gavage had no protective effect on inhibiting seizures. Administration of DHA with LTG or PHT also couldn’t inhibit drug resistance. 6-Hz seizures when administered chronically. However, chronically administered DHA inhibited limbic seizures resistant to LTG and PHT. CONCLUSIONS: Acute administration of DHA couldn’t inhibits resistance to LTG and phenytoin in 6-Hz model of epilepsy. Also consumption of single dose of DHA with anticonvulsant drugs don’t have any effect on prevention of drug resistance in epileptic patients.

BACKGROUND: In traditional medicine in some Asian countries, including Iran, there is a belief that camphor is a suppressor of sexual activity. Not only has the validity of this hypothesis not been established, but also studies in this field are very limited.  OBJECTIVES: In this study, we investigated the effects of camphor on sperm quality in mice, and to protect sperm damage vitamin E as an antioxidant was used. METHODS: This study was conducted on 30 adult male mice (balb/c) with weight range 20-25 gr in 5 groups. First group was control (CO) and treated with normal saline,  groups  2 and 3 were sham groups treated respectively with Olive oil (OL) and the combination of olive oil and vitamin E (OL+E), and finally, two experimental groups were treated using camphor (CA) and camphor with vitamin E (CA+E). Camphor at doses of 30 mg/kg/day and vitamin E at doses of 100 mg/kg/day were prepared. All materials were administered orally (gavage). After 35 days semen were collected from tail of epididymis, and then total count, motility, viability, nuclear maturity, and DNA damage were examined. RESULTS: Results showed significant reduction in sperm total count, percentage of viability, increase in  the number of immature sperms and  no significant difference in rate of motile sperms and sperms with damaged DNA in groups that received Camphor was observed. Vitamin E as a strong antioxidant administered lightly was able to reduce the effects of  Camphor on viable and mature sperms (p<0.05). CONCLUSIONS: It can be concluded that Camphor could affect on mice sperm quality and vitamin E as an antioxidant,  was able to slightly reduce Camphor effects in sperm quality.

BACKGROUND: Oxidative stress is involved in pathogenesis of Polycystic Ovary Syndrome (PCOS). Lutein is a herbal compounds with antioxidant properties. OBJECTIVES: The current research aimed to evaluate the effect of lutein on body weight and histomorphometry of uterus in experimental PCOS induced with Dehydroepiandrosterone (DHEA) in mouse models. METHODS: Twenty-four female NMRI mice aged 20 days and weighing 14-17 g were randomly assigned to four equal groups: control, experimental PCOS, and PCOS treated groups with 125 and 250 mg/kg lutein. The induction period of PCOS with oral administration of DHEA (6 mg/100 g, daily) was 21 days and lutein treatment was followed by the induction period of 28 days. The mean body weight of the groups was evaluated on day 0, day 21 (at the end of DHEA treatment), and day 49 (at the end of treatment period) with lutein. The mean diameter of the uterine wall, the mean overall thickness of the uterine wall, the average thickness of the endometrium, myometrium and uterine epithelium, along with the number of endometrial gland branches were measured utilizing light microscope. RESULTS: The results revealed that body weight in the PCOS group was significantly higher than that in the control group on days 21 and 49. Treatment with 125 and 250 mg/kg of lutein reduced body weight in the lutein treated groups compared with PCOS (p < /em><0.01). The mean uterine wall diameter, mean total uterine wall thickness, mean thickness of endometrium, myometrium, and uterine epithelium with the number of uterine endometrial branching were significantly lower in the control and lutein treated groups compared to those in the PCOS group (p < /em><0.05). The use of both doses of lutein (125 and 250 mg / kg) significantly improved uterine histopathological indices, particularly the mean uterine wall diameter (p < /em>=0.0001) compared to the PCOS group. CONCLUSIONS: Lutein could improve the side effects of induced PCOS by DHEA on body weight and uterine parameters.

BACKGROUND: The main part of ovary is consisted of follicles which certain drugs may cause change in them. OBJECTIVES: The purpose of this study was to investigate the effects of Methylphenidate on ovarian follicle of mice, treated by Ritalin before puberty. METHODS: 40 immature female mice at 3 weeks of age were divided into 4 groups, consisting of one control and 3 experimental groups. The experimental groups were gavaged by 2, 5 and 10 mg/kg methylphenidate respectively and the control group received only distilled water with the same method for 60 days. At the end of the experiment, the mice were weighed and then the serum levels of FSH and LH were assessed and structural changes of ovarian follicles and corpora lutea were studied. RESULTS: The mean difference of body weight in experimental groups compared with the control group which showed a significant reduction (p<0.05). In experimental groups compared with the control group, a significant reduction in pre enteral, enteral follicles, corpora lutea and a significant increase in atretic follicles were observed (p<0.05). CONCLUSIONS: Ritalin intake for a long period may increase the number of atretic follicles and decrease corpora lutea, so subsequently results in reduction of the growth of follicles and oocytes as well as inducing the atypical appearance of the cells in the luteinized cells.

Polyclonal rabbit antiserum to human T-cell CD3 was used to study its reactivity in lymphoid tissues (lymph nodes, spleen, aggregated lymphoid follicles [Peyer's patches], thymus) of several animal species (cattle, sheep, goats, rats, and mice). Using a peroxidase-antiperoxidase technique on formalin-fixed and paraffin-embedded tissues, immunoreactive cells were detected in T cell-dependent areas of the lymphoid tissues. Reactivity was high in all species tested, but mouse tissues had reduced reactivity, compared with the other species. To obtain a reaction, it was necessary to digest tissues with pronase before application of the immunocytochemical technique. Our results indicate that CD3 antiserum may specifically recognize T-lymphoid cells as it does in human lymphoid tissues and can be used as a marker to study physiologic and pathologic conditions of the lymphoid system of these species.

Immunogenicity of the lipid A component of Haemophilus somnus lipooligosaccharide in cattle and mice was examined after purification, detoxification, and covalent conjugation to a protein carrier. After 2 inoculations, a substantial antibody response was induced in most cattle to lipid A and the protein carrier. To determine whether antibodies to lipid A would be protective, 5 X 10(7) colony-forming units of H somnus strain 649 were administered IV to endotoxin-responsive (C3H/HEN) mice. In one study, 8 of 13 C3H/HEN mice aborted when inoculated. In contrast, abortion did not result when mice were inoculated with the same dose of an isolate of H somnus normally found in the prepuce or with the rough mutant Escherichia coli J5. In addition, endotoxin-nonresponsive (C3H/HeJ) mice were significantly (P = 0.03) more resistant to abortion by strain 649 than were C3H/HeN mice, but inoculated C3H/HeN mice were only slightly more resistant to H somnus abortion, compared with control mice. Although a large antibody response to lipid A was detected, there was no significant difference in the immunized group between mice that aborted and mice that delivered normally. Thus, lipooligosaccharide and other properties of virulent H somnus strains may contribute to abortion in mice.