Improvement of tissue survival of skin flaps by 5α-reductase inhibitors: Possible involvement of nitric oxide and inducible nitric oxide synthase

Background: Skin flap grafting is a popular approach for reconstruction of critical skin and underlying soft tissue injuries. In a previous study, we demonstrated the beneficial effects of two 5α-reductase inhibitors, azelaic acid and finasteride, on tissue survival in a rat model of skin flap grafting. In the current study, we investigated the involvement of nitric oxide and inducible nitric oxide synthase (iNOS) in graft survival mediated by these agents. Methods: A number of 42 male rats were randomly allocated into six groups: 1, normal saline topical application; 2, azelaic acid (100 mg/flap); 3, finasteride (1 mg/flap); 4, injection of L-NG-nitroarginine methyl ester (L-NAME) (i.p., 20 mg/kg); 5, L-NAME (20 mg/kg, i.p.) + azelaic acid (100 mg/flap, topical); 6, L-NAME (20 mg/kg, i.p.) + finasteride (1 mg/flap, topical). Tissue survival, level of nitric oxide, and iNOS expression in groups were measured. Results: Our data revealed that azelaic acid and finasteride significantly increased the expression of iNOS protein and nitric oxide (NO) levels in graft tissue (P < 0.05). These increases in iNOS expression and NO level were associated with higher survival of the graft tissue. Conclusion: It appears that alterations of the NO metabolism are implicated in the azelaic acid- and finasteride-mediated survival of the skin flaps. © 2015, Pasteur Institute of Iran. All rights reserved

Cryopreservation of rainbow trout (Onchorhynchus mykiss) semen

Breeding has moved beyond the point of simply propagating random stock. Genetic potential can be improved by establishing and crossing genetically defined strains, crossing species and manipulating gametes. Some of these activities require cryopreservation of semen. Cryopreserved sperm could also be a means of exchange of genetic material between locations and populations when transportation of live fish is restricted. In this study we had a survey on rainbow trout sperm quality in Genetic and Breeding Center for Coldwatwr Fishes, Shahid Motahari, Yasouj. Then Cryopreservation trials on rainbow trout (Oncorhynchus mykiss) sperm were carried out using six basic extenders. Egg batches of 25 g were inseminated with semen frozen in five 0.5-ml straws. Thowing temperature of cryopreserved sperm also was tested. In anather trial we investigate different cryoprotectant. The result showd that the best period for sperm collection in this center was from Novamber to January. The best extender based on sperm motility parameters were extender 2 and 1 with 57.2 and 56.9% fertilisatin rates, respectively. So this two extender were used in the further experiments. The best thowing temperathre was 25°C in 30s. Testing different cryoprotectant, adding 10% methanol to extender 1 gave the highest fertilization rate (64.6%) among cryoprotectant that used with this extender. In the other extender (2) adding 5% DMSO and mixture of 5% DMSO and 1% glycerol gave the highest fertilization rates (64.8% and 67.0%, respectively). In conclusion using extender 1 and 2 with mentioned cryoprotectant and thowing rate of 25°C in 30 s was recammended for rainbow trout sperm cryopreservation

Evaluation of sperm quality and different nutrient levels on sperm efficiency in male rainbow trout

Considering the importance of rainbow trout (Oncorhynchus mykiss) in supplying required protein of people and effort to increase the efficiency of these fish reproduction, some related factors such as sperm quality and potential fertility of male are necessary. The aim of this study was to find out the effects of different dosages of Arginine on the biochemical parameters (including LDH, AST, ALT, ALP, iron, magnesium, phosphorous, chloride, calcium, sodium, Potassium, cholesterol, uric acid, urea, fructose, glucose, total protein and pH) of rainbow trout seminal plasma. For this purpose, five practical diets (each consisting of 3 triplicates) were supplemented with Arginine at 0.00 (Control), 0.50, 1.00, 1.50 and 2.00%. Broodstock feed last for 90 days. At the end of the feeding period one fish was captured from each replicate in order to collect their semen. Results indicate that there were no significant differences in LDH, ALP, Fe^2+ and P content among different treatments. The lowest level of AST and ALT and the highest level of Ca^2+ and Mg^2+ ions were observed in the treatment fed with 1.50% of Arginine which showed significant differences with other treatments (p<0.05). Moreover, the amount of Cl^-, Na^+ and K^+ ions were significantly increased in the seminal plasma in fish which were fed on diets containing arginine in comparison to control. As the amount of Arginine were increased, the levels of uric acid stepped up significantly in contrast to the urea and glucose. The highest amounts of cholesterol, fructose and total protein were observed in the treatments fed on 2.00, 0.50 and 1.00% of Arginine, respectively, that showed significant differences with other treatments (p<0.05). The highest pH value was assayed in the 1.50% of Arginine treatment. The results of the Pearson correlation coefficient showed a significant positive correlation between Ca^2+ and Mg^2+ ions and Na^+ with K^+ and Clions (r=0.750, r=0.769 and r= 0.938, p<0.01), respectively. On the other hand, a significant negative correlation between cholesterol with Cl^-, Na^+, K^+, ALT and LDH (r=- 0.764, r=-0.724 and r=-0.728, p<0.01) and (r=-0.531 and r=-0.560, p<0.05) and also a significant positive correlation between K^+ and Clions (r=0.836, p<0.01) were observed. Finally, it can be expressed that the levels of most of the ions were increased and there was a reduction in the levels of enzymes in seminal plasma of fish which were fed with practical diet including 1.5% of Arginine. So it can be recommended that adding this value of Arginine to the diets of rainbow trout broodstock, would improve the sperm quality which results in the enhancement of efficiency in rainbow trout reproduction