[Metformin effect on the mouse pancreatic langerhans islets volume]

Metformin is a widely used medicine for treatment of type 2 diabetes. In this study, the effect of various doses of metformin on the mouse islets of langerhans volume was investigated. Twenty four C57BL/6 adult male mice weighting 30 +/- 5 gr were randomly divided into 4 groups. Normal saline was given to the control group [group 4] and the experimental groups [groups 1-3] received 75, 150 and 300 mg/kg metformin daily by intraperitoneal injection for seven days. One day after the last injection the mice were sacrificed by cervical dislocation and their pancreases were fixed in 10% formalin for histological studies. The volume of the islets of langerhans was estimated by using Cavalieri method. Volume of the islets of langerhans in doses of 75 and 150 mg/kg Metformin showed a nonsignificant difference in comparison to control group [P>0.05]. 300 mg/kg metformin treated mice showed a significant increase in islets of langerhans volume compared to the control group [P<0.05]. Metformin increases in the islets of langerhans volume in a dose-dependent manner. Increasing effects of Metformin on the islets of langerhans volume may be due to proliferation or hypertrophy of beta cells

[Effect of metformin on the Pdx-1 gene expression during development of mouse pancreas]

Metformin, an oral medicine used to treat type 2 diabetes, is a Glucagon-Like Peptide-1 [GLP-1] analogue, which has been demonstrated to stimulate the expression of Pancreatic duodenal homeobox-1 [Pdx-1], Insulin and Glucose transporter 2 [Glut-2] genes. In this study, the regulatory effect of metformin on beta cells function through the expression of Pdx-1, Insulin and Glut-2 genes was investigated. Pregnant C57BL/6 mice were randomly divided into 2 groups. Normal saline was given to the control group and the experimental group received 75, 150 and 250 mg/kg metformin daily by intraperitoneal injection from day 8.5 of pregnancy. Half the pregnant animals were then sacrificed by cervical dislocation or day 19.5 of pregnancy and the pancreases of embryos were dissected. The other half of pregnant animals were allowed to deliver their pups and the pancreases of one day old mice were dissected. The dissected pancreases were then used for assessment of Pdx-1, Insulin and Glut-2 genes expression by semi-quantitative RT-PCR method. Results showed that the administration of various doses of metformin caused no changes in the expression of Pdx-1, Insulin and Glut-2 genes compared to the control group [P>0.05]. The regulatory effect of metformin on beta cells function might not be related to the expression of Pdx-1, Insulin and Glut-2 genes and may be related to the expression of gloconeogenesis pathway genes

Pituitary primary cell culture of Common carp [Cyprinus Carpio] and evaluation of its secretion effect on endocrine activity of incubated ovarian follicles

In this study, five carp pituitary glands were collected and dispersed enzymatically and mechanically. Then, the cells were cultivated as monolayer in MEM [minimum essential medium Eagle]. The culture media were collected after 72 h and frozen at -20°C. Carp ovarian follicles also were separated mechanically and incubated in BSS [basic salt solution] Cortland medium in 24-well microplates for 48 h at 20°C. Then, they were divided into two groups: control group which were incubated in BSS medium and experimental group which subdivided into three subgroups according to treatment with different concentration of collected pituitary secretion [50, 100 and 200 micro 1/ml]. Follicles culture media were collected 24 h later and were analyzed for 17-beta-oestradiol [E[2]] and 17-alpha-hydroxy progesterone [P[4]] content by radioimmunoassay [RIA]. The results showed that adding low concentration [50 micro 1/ml] of collected pituitary secretion [CPS] increased steroid hormones [E[2] and P[4]] secretion of incubated ovarian follicles significantly [P<0.05] but the high concentration of CPS [200 micro 1/ml] significantly decreased the secretion of E[2] and P[4] [P<0.05]. Collected pituitary secretion at the concentration of 100 micro 1/ml had no significant effect on steroid hormones [P>0.05]

[ study of Bax protein expression in dexamethasone induced apoptosis in spermatogenic cells in mice]

Some studies have shown that glucocorticoids affect testis homeostasis by decreasing testosterone level. In this study the influence of dexamehasone [Dex], a widely used glucocorticoid drug, was evaluated on expression of Bax protein in mice testicular germ cells and spermatogenesis process. In this experimental study thirty five adult male mice randomly divided into 5 groups. Test groups [T1-T4] received 2, 4, 7 and 10 mg/kg Dex per day for 7 days, respectively. Control group received only saline daily for 7 days. Then the mice were sacrificed and their testes were incubated in formalin for immunohistochemistry and histology studies. T1 and T2 groups, which received 7 and 10 mg/kg Dex, showed significant decrease in the number of germ cells and somatic cells of testes, and also in the maturity of spermatogenesis [p<0.05]. Immunohistochemical studies showed that Dex with doses of 7 and 10 mg/kg significantly increased Bax expression at all stages of spermatogenesis cycle except stage IX. It seems that glucocorticoid drugs such as Dex induce apoptosis in testicular germ cells by affecting proapoptotic proteins and causing defect in spermatogenesis process

[Effect of dexamethasone on Fas ligand expression in mouse testicular germ cells]

Apoptosis [programmed cell death] is an important regulatory event in spermatogenesis. Abnormally accelerated apoptosis in germ cells, may lead to an imbalance between cell proliferation and death, resulting in impairment in spermatogenic. Some studies have shown that glucocorticoids affect testialar homeostasis by decreasing of testosterone level. In the present study, the influence of dexametasone [Dex], a widely used glucocorticoid agent, on expression of FasL [Fas-Ligand] protein [a proapoptotic protein] in mouse testicular germ cells is investigated. Twenty-four adult male [6-8 weeks] mice were randomly divided into 3 groups. The first and second test groups received 2 and 7 mg/kg Dex per day, respectively, for 7 days. The control group received only saline daily for 7 days. One day after the final injection, the mice were sacrificed and the test groups were placed in formalin solution for immunohistochemistry studies. Positive immunoreactivity was calculated by H-score method. The results revealed that expression of FasL in seminiferous epithelium is spermatogenic stage dependent, and the stage VII was the most susceptible to Dex. FasL expression was observed only at stages VII-VIII of spermatogenic cycle in 2 mg/kg Dex treated group [P < 0.05]. H-score was significantly increased in all stages of 7 mg/kg Dex treated group [P < 0.05]. The number of spermatocytes decreased significanhy in this group. It appears that glucocorticoid agents such as Dex, induces apoptosis by affecting proapoptotic proteins

[ evaluation of the survival rate and motility of freeze-thawed mouse sperm -frozen in and out of the epididym]

Direct contact between a sperm cell and cryopreservation solution has detrimental effects on the cell. In this study the role of the epididymal tissue in the preservation of direct contact between sperm cell and cryopreservation solution during a freeze-thaw process was studied by assessing motility and vitality of the sperm. About 30 male mice were killed and the right caudal epididymis were removed and placed in cryo-preservation solution for two minutes. The samples were exposed to liquid nitrogen vapor for ten minutes and then immersed in liquid nitrogen. The left caudal epididymis were similarly removed and placed in T6 medium. In order to extract sperm, samples were needled and incubated for 1 hour at 37°C. Subsequently, sperm motility and vitality were assessed as control group and then the remaining solution was transmitted into a tube containing cryopreservation solution. For thawing, samples were picked up from a liquid nitrogen tank and kept in room temperature for 20 seconds and then immersed in warm water [37°C] for 2 minutes. Thereafter, sperm motility and vitality were assessed. The survival rates of the three groups [control, outer and inner epididym] were 78.75 +/- 13.01, 34.67 +/- 7.86 and 9.97 +/- 7.08, respectively. The statistical analysis has shown that the difference between the inner and outer epididym was significant [P<0.05]. The progressive motility of sperms in the three groups was 30.29 +/- 15.33, 3.29 +/- 3.55 and 0.00 +/- 0.00, respectively. The progressive motility of sperms in the inner and outer epididym was less than the control group [P<0.05], but there was no significant difference between the inner and outer groups [P=0.344]. The non-progressive motility of sperms in the three groups was 34.72 +/- 12.21, 29.21 +/- 10.37 and 6.78 +/- 4.94, respectively. The statistical analysis has shown that the difference between the control and outer groups and also between the control and inner groups was significant [P<0.05] but the difference between the inner and outer groups was not significant. The quality of cryopreserved-thawed sperm in the outer epididym group was significantly better than in the inner epididym group. In this study we can conclude that the epididym has no protective effect on sperm during cryopreserved processing

How to decrease the emotional impact of cadaver dissection in medical students

Teaching of anatomy is based on cadaver dissection. Working with cadavers whether through active dissection or by examination of prosected specimens, constitutes a potential stressor in medical education. To reduce the anxiety level by mentally preparing the student before going to the dissection hall. Two questionnaires were distributed among 68 medical students. The pre-dissection questionnaire No.1 comprised questions relating to demographics and first encounter with a cadaver.Then all the students were randomly divided into experimental and control groups.The experimental group was prepared psychologically prior to dissection but the control group had no such preparation. After the first dissection class all the students were surveyed by questionnaire No.2 which included physical and cognitive symptoms of anxiety, resulting from exposure to the dissection room at the first visit and six weeks later. There was a significant difference p<0.05 in the rate of anxiety between experimental and control group in the initial visit. The difference in the rate of anxiety between the first exposure and six weeks later was significant in control group [p<0.008], while it was not significant in experimental group. The initial preparation could relatively reduce the rate of stress, so that the experimental group experience less emotional effects during dissection compared to control group

How to decrease the emotional impact of cadaver dissection in medical students

Teaching anatomy is based on cadaver dissection. Working with cadavers, whether through active dissection or by examination of prosected specimens, constitutes a potential stressor in medical education. To reduce the anxiety of the medical students by mentally preparing them before going to the dissection room. The questionnaires were distributed among 68 medical students. The pre-dissection questionnaire comprised questions related to demographic data and the first encounter with a cadaver. The students were randomly divided into experimental and control groups. The experimental group was prepared psychologically prior to dissection, but the control group entered the dissection room without any preparation. After the first dissection class, all students were surveyed by the second questionnaire which surveyed physical and cognitive symptoms of anxiety, resulting from exposure to the dissection room at the first visit and six weeks later. There was a significant difference [p<.05] in the rate of anxiety between experimental and control group in the initial visit. The difference in the rate of anxiety between the first exposure and six weeks later was significant in control group [p<.008], while it was not significant in the experimental group. The initial preparation could relatively reduce the rate of stress, so that the experimental group experienced less emotional effects during dissection compared to control group