Effects of insulin and ascorbic acid on inhibition of the apoptosis in hippocampus of STZ-lnduced diabetic rats

The aim of this study was to investigate effects of insulin and ascorbic acid on rate of Caspase - 3 activity and DNA Laddering in hippocampus of STZ-induced diabetic rats. Thirty male Wistar rats in five groups, 6 in each group: one control group [group C] and four diabetic groups [diabetic control [group D], treatment with insulin [group I], with ascorbic acid [group AA] and with insulin plus ascorbic acid [group I+AA]] were used in this study. Diabetes was induced by injection of 60 mg/kg STZ IP. After six weeks, rats in group I were treated with insulin [4-6 U/kg/day Sc.], rats in group AA treated with ascorbic acid [200 mg/kg/day, IP] and rats in group I+AA treated with equal dosage of both insulin and ascorbic acid for two weeks. Rats in group D were treated with saline and considered as the diabetic control group. Two weeks after treatment, animals were anesthetized and hippocampus was dissected from hemispheres. Caspase-3 activity was assessed by Fluorometry, and finally, DNA fragmentation due to apoptosis was determined by DNA laddering Assay. Caspase-3 activity in group D significantly increased compared to group C [6.7 fold], whereas it decreased after treatment with insulin, ascorbic acid or both [2.6, 4.2 and 5.1 fold, respectively]. DNA laddering was observed in group D, but not in three treated groups. Conclusions: From this survey it was concluded that treatment of STZ-induced diabetic rats with insulin and/or L-ascorbic acid could possibly inhibit apoptosis in hippocampal tissues using decrease of Caspase -3 activity and prevention of DNA Laddering

[Effect of demineralized bone matrix on induction and conduction of osteogenesis in alveolar bone of type I diabetic rats]

There are few studies on application of Demineralized Bone Matrix [DBM] in presence of a disease, such as type I diabetes. The aim of this study was to determine the osteoinductive and osteoconductive effects of DBM on the repair of alveolar bone in diabetic rats treated with insulin. This experimental study was carried out on 50 adult male [8 weeks old] rats [200-250g body weight]. The animals were divided into four groups as follow: first group, containing 8 animals, as control group and second, third and fourth groups, containing 14 animals [in each group], were diabetic groups. Diabetes was induced by alloxan. Among the diabetic groups, only group 4 received 1 unit of Insulin NPH daily. After 10 days, the upper right incisor tooth was extracted and the socket was filled with DBM in groups 3 and 4. At the end of the first and second weeks, half of the rats in each group were decapitated. The specimens were prepared and stained with H and E [Hematoxylin-Eozine] method. The histological changes around the DBM particle showing osteoblastic activity were studied. In group 4, at the end of first week, osteoblastic activity and formation of bone trabecula and collagen fibers[5 from 7 animals], and at the end of second week, osteogenesis with formation of more and thicker bone trabecula in vicinity of DBM was observed. In group 3, at the end of first week, osteoinductivity and osteoconductive effects were seen in some area around DBM Particles [3 from 7 animales], meanwhile degeneration of bone matrix were seen by osteoclastic activity. At the end of second week, osteogenesis was dispersly seen. In group 2, hematom and inflammation were the dominant features at the end of first week and at the end of second week, osteogenesis was seen weakly. In group 1, histological findings at the end of first and second weeks, were osteogenesis around periodental ligament [PDL] and osteogenesis with formation of bone trabecula respectively. Our results indicated that DBM particles can stimulate undifferentiated cells to start differentiate to pro-osteoblast and osteoblast in control diabetic rats, so osteogenesis in this group, was better in comparison with other diabetic groups and it is a good mater for graft

[ study of effects of insulin and ascorbic acid on Bcl-2 family expression in hippocampus of streptozotocin -induced diabetic rats]

Diabetes is a metabolic disorder that has been shown to adversely affect both the central and peripheral nervous system by increasing basal neuronal apoptosis. Since Bcl-2 protein family is considered to play a key role in the regulation of apoptosis, in the present study we have examined the effects of insulin and ascorbic acid on expression of Bcl-2 family members including Bax [pro-apoptotic] and Bcl-2 and Bcl-x[L] [anti-apoptotic] on hippocampus of STZ-induced diabetic rats. Five groups of six Wistar rats including one control group [C] and four diabetic groups [D, I, AA and I+AA] were used in this study. Diabetes was induced by injection of 60 mg/kg STZ [IP]. After six weeks, rats in group I were treated with insulin [4-6 U/kg/day Sc], rats in group AA were treated with ascorbic acid [200 mg/kg/day IP] and rats in group I+AA were treated with equal dosage of both insulin and ascorbic acid for two weeks. Rats in group D were treated with normal saline and considered as diabetic control group. Two weeks after treatment, expression of Bcl-2, Bcl-x[L] and Bax genes were measured at both mRNA and protein levels. In diabetic control rats [group D], Bax increased whereas Bcl-2 and Bcl-x[L] decreased at both mRNA and protein levels compared to group C [P<0.01, P<0.001 respectively]. Interestingly, treatment with insulin [group I], ascorbic acid [group AA] and insulin plus ascorbic acid [group I+AA] could reverse these changes both at mRNA and protein levels [p<0.001 for I and AA+I groups, p<0.05 [Bcl-2] and p<0.01 [Bcl-x[L]] for AA group]. It is concluded that insulin and ascorbic acid alone or together can inhibit apoptosis in STZ-induced diabetic rats' hippocampus through increasing the ratio of Bcl-2/Bax and Bcl-x[L]/Bax expressions. We suggest that inhibition of apoptosis may prevent cognitive dysfunctions induced by hippocampal damage in diabetic patients as well. In addition, further experimental studies will need to be performed to confirm such effects

[ rare variation of sciatic nerve]

Sciatic nerve, as the largest branch of the sacral plexus and the thickest nerve of the body, forms from the union of ventral branches of L[4]-S[3]. Then it leaves the pelvis via the greater sciatic foramen below the piriformis and descends between the greater trochanter and ischial tuberosity. Afterwards, it divides into the tibial and the common proneal nerves, most frequently at the level of the upper angle of the popliteal fossa. Bifurcation into its two major divisions may occur, anywhere, between the sacral plexus and the upper angle of the popliteal fossa. However, concurrent occurrence of these variations: dividing of the sciatic nerve into two terminal branches in pelvis, existence of piriformis with completely separated upper and lower parts, the common proneal nerve passing through the two parts of piriformis in which one part of inferior gluteal nerve fibers and tibial nerve passing under the lower part of this muscle in company with the other part of inferior gluteal nerve, is a rare and very important phenomenon. This phenomenon may be of great importance in view of both entrapment of these members between two parts of piriformis which can lead to "piriformis syndrome", and being next to the muscular injection site of the gluteal region. Furthermore, it might be of major significance for medical specialists in particular for anatomists and surgeons to reduce the postoperative complications

[Effect of mercuric chloride on intraventricular and spinal cord diameters of rat embroys]

Mercuric chloride [HgC12] is a white cristaline toxic poweder which is absorbed through gasterointentinal tract and skin, and excreted from kidney. Chronic poisoning with mercuric chloride causes sensorial and mobile disorders, behavioral and mental disorders. Mercuric chloride is teratogen for embryonic organs. The aim of the present study was to evaluate the effects of HgC12 on embryo's ventricles and spinal canal as a part of nervous system. In this study 24 female Sprague Dawley rats after scieng vaginal plague that considered at day zero of gestation were divided into four groups: One control group that injected normal saline solution and three experimental groups that injected mercuric chloride 2mg/kg [ip] in 8[th], 9[th] and 10[th] days of gestation. Emboryos were removed from uterus on day 15th and tissue process was done and measured and analyzed with LSD and Duncan tests. Ventricular and spinal cord diameters and coroidal branches in experimental groups were decreased significantly compared to control group [p<0.05]. In addition the spinal canal diameter in control group was significantly [p<0.001] more than experimental groups. The number of coroidal branches were significantly decreased[p<0.001] in experimental groups compare to control group. The results of this study indicated that HgC12 has toxic effect on nervous system including, decrease in ventricular and spinal cord diameters, and the number of coroidal branches

[Sexual dimorphism in volume and surface anatomical parameters of cingulate cortex in normal human brains - A stereologic and macroscopic study]

This study is designed to deteremine the sex differences in volume and surface anatomical parameters in the cingulate cortex of the left cerebral hemispheres in healthy right - handed subjects. This cross - sectional descriptive study was performed on 72 human brains [38 males, 34 females]. The brains belonged to right - handed subjects who had died of non - neurologic causes. The age of males and females was similar. The brains were removed from the cranium no longer than 24 hours postmortem and were fixed in 4% formaldehyde solution. The right hemisphere of each brain was used for neuropathologic examinations [to confirm the health of the brain] and the left one was used for stereologic analyses. The estimation of the volume, surface areas, and thickness of the cingulated cortex was performed on photographs of 5 mm serial coronal sections of the left hemispheres using unbiased stereological methods [with point and linear grids]. The results were analyzed by t- student test. The volumes of the left cingulate cortex in males and females were 10.92 +/- 3.06 and 10.5 +/- 2.30 cm[3], respectively. The outer surface area was 43.87 +/- 10.73 cm [2] in males and 43.74 8.68 cm[2] in females. The inner surface areas in males and females were 34.87 +/- 11.56 and 36.55 +/- 8.08 cm[2], respectively. There was no significant difference between two sexes in the volume and surface areas of the left cingulate cortex. The mean thickness of the left cingulate cortex in males and females were 2.88 +/- 0.5 and 2.51 +/- 0.3mm, respectively. The mean thickness of the left cingulate cortex in females was 12.85% smaller than males [P<0.05].Although the volume and outer and inner surface areas of the left cingulated cortex are similar between two sexes, the cortical thickness of this area in healthy right - handed females is significantly smaller than males. The functional significance of these sexual differences and similarities in human brain is not clear. However, scientists must be aware of them in their morphometrical studies on human brain

[Ultrastructural study of interestitial cells of cajal in hirschsprungs disease]

Introduction: This investigation was performed to study the anatomy and ultrastructure that is interstitial cells of cajal [ICC], of colon in Iranian patients with Hischsprung's disease [HD]

Material and Methods: Samples were obtained from healthy and pathologic segments of colon in 10 children under 10 years of age in which the distal part of colon was resected for surgical treatment of H.D. The specimens were prepared for electron microscopic studies and the ultrathin sections were obtained. Then the location and morphology of ICC in pathologic segments were compared with healthy ones

Results: In the affected segment, on ICC was detected among the smooth muscle cells and nerve endings, but the ultrastructural study showed mild differences with healthy parts

Conclusion: Lack of intermediate position of ICC in pathologic segments, considering it's inhibitory role on smooth muscle cell function, could be the reason for spasm in involved areas