RESUMO
BACKGROUND: Leptin, as a 16 kDa adipokine, is a pleiotropic cytokine-like hormone that primarily secreted from adipose tissue. It also involves in the regulation of energy homeostasis, neuroendocrine function, immunity, lipid and glucose homeostasis, fatty acid oxidation, angiogenesis, puberty and reproduction. The aim of this study was to investigate the effects of in vitro addition of leptin to in vitro maturation (IVM) medium on buffalo oocyte maturation and apoptosis. MATERIALS AND METHODS: In this experimental study, Ovaries from apparently normal reproductive organs of slaughtered adult buffaloes (Bubalus bubalis) with unknown breeding history were collected from Urmia Abattoir, Urmia, Iran, and were transported immediately to the laboratory in a thermos flask containing sterile normal saline with added antibiotics. Oocytes were aspirated from 2-8 mm visible follicles of the ovaries using an 18-G needle attached to a 10 ml syringe. IVM medium included tissue culture medium-199 (TCM-199), 10% fetal bovine serum (FBS), 22 µg/ml sodium pyruvate, 0.5 IU/ml ovine follicle-stimulating hormone (oFSH), 0.5 IU/ml ovine luteinizing hormone (oLH), 1 µg/ml oestradiol, 50 µg/ml gentamycin, and leptin [0 (control), 10, 50, and 100 ng/ml]. The good quality buffalo oocytes (batches of 10 oocytes) were placed in a culture plate containing six 50 µl droplets of maturation medium, covered with sterilized mineral oil, and then incubated at 38.5ËC with 5% CO2 in air for 24 hours. The maturation of oocytes was evaluated under a stereomicroscope by detecting the first polar body extrusion of oocytes. FITC-Annexin V propidium iodide (PI) staining method was used to detect oocyte apoptosis. RESULTS: From a total of 115 collected ovaries, 1100 oocytes were recovered among which 283 oocyte were suitable for IVM. In the groups of leptin treated with 0 (control), 10, 50 and 100 ng/ml, the percentage of oocytes maturation was 74.65, 83.81, 77.85, and 75.40%, while the percentage of oocytes apoptosis was 9.83, 9.54, 9.93, and 10.42%, respectively. Our results showed that addition of 10 ng/ml leptin to buffalo IVM medium increased oocyte maturation, significantly, as compared with that in control group. However, addition of leptin to IVM medium had no significant influence on buffalo oocyte apoptosis. CONCLUSION: Our findings suggested that addition of 10 ng/ml leptin to IVM medium of buffalo oocyte can improve oocyte nuclear maturation. Furthermore, we showed that there is no relation between in vitro addition of leptin to buffalo oocyte IVM medium and oocyte apoptos. CONCLUSION: Our findings suggested that addition of 10 ng/ml leptin to IVM medium of buffalo oocyte can improve oocyte nuclear maturation. Furthermore, we showed that there is no relation between in vitro addition of leptin to buffalo oocyte IVM medium and oocyte apoptosis.
RESUMO
PURPOSE: To assess the local effect of triiodothyronine (T3) on peripheral nerve regeneration in a rat model of sciatic nerve transection. MATERIALS AND METHODS: Forty-five male healthy white Wistar rats were divided randomly into 3 experimental groups (n = 15): sham operation, control (CHIT), and T3 treatment (CHIT/T3). In the sham-operated group, the left sciatic nerve was exposed under anesthesia through a gluteal muscle incision and the muscle was sutured after homeostasis. In the CHIT group, the left sciatic nerve was exposed the same way and transected proximal to the tibioperoneal bifurcation, leaving a 10-mm gap. Each proximal and distal stump was inserted into a chitosan conduit, which was filled with phosphate buffered solution 10 µL. In the CHIT/T3 group, the defect was bridged using a chitosan conduit filled with T3 10 µL. Each group was subdivided into 3 subgroups of 5 animals each and studied 4, 8, and 12 weeks after surgery. Data were analyzed statistically by factorial analysis of variance and the Bonferroni test for pairwise comparisons. RESULTS: Behavioral testing and sciatic nerve function study confirmed a faster and better recovery of regenerated axons in the CHIT/T3 group than in the CHIT group (P < .05). Gastrocnemius muscle mass was significantly larger in the CHIT/T3 group than in the CHIT group. Morphometric indices of regenerated fibers showed that the number and diameter of the myelinated fibers were significantly larger in the CHIT/T3 group than in the CHIT group. Immunohistochemistry showed that the locations of reaction to S-100 were clearly more positive in the CHIT/T3 group than in the CHIT group. CONCLUSIONS: The response to local treatment showed that thyroid hormone influenced and improved the functional recovery of peripheral nerve regeneration.
