Metformin improves epididymal sperm quality and antioxidant function of the testis in diet-induced obesity rats / 中华男科学杂志

<p><b>OBJECTIVE</b>To observe the effects of metformin on epididymal sperm quality and antioxidant function of the testis in diet-induced obesity rats.</p><p><b>METHODS</b>Thirty-two male SD rats were fed on high-fat food for 8 weeks to make obesity models, and another 8 were included as normal controls. Twenty-four of the model rats were equally randomized into a model control group to be fed continuously on high-fat food, a metformin group to be fed on normal food with metformin, and a normal food group. By the end of the 12th week, all the rats were killed for the determination of Lee's index, the organ coefficients of the testis and epididymis, epididymal sperm concentration, sperm motility, grade a + b sperm percentage, and the contents of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) in the testicular homogenate.</p><p><b>RESULTS</b>Lee's index was significantly increased in the model control group (P < 0.01) as compared with the other three. Lee's index was markedly higher in the normal control than in the metformin group (P < 0.05). The organ coefficients of the testis and epididymis were significantly decreased in the model control group (P < 0.01) as compared with the other three. Sperm concentration and motility and the percentage of a + b sperm were significantly decreased in the model control in comparison with the other three groups (P < 0.05 or P < 0.01). Sperm concentration was remarkably higher in the normal control than in the metformin and normal food groups (P < 0.05). The content of SOD (U/mg prot) was significantly lower in the model control (90.92 +/- 4.06) than in the normal control and metformin groups (101.69 +/- 8.49 and 102.04 +/- 10.67) (P < 0.05); that of GSH-Px (U) obviously higher in the normal control (28.32 +/- 2.28) than in the model control (23.49 +/- 1.08, P < 0.01), the metformin (25.73 +/- 2.14, P < 0.05) and the normal food group (25.77 +/- 2.19, P < 0.05), but evidently lower in the model control than in the metformin group (P < 0.05); and that of MDA (nmol/mg prot) significantly higher in the model control (2.68 +/- 0.76) than in the normal control (1.84 +/- 0.31, P < 0.01), the metformin (1.88 +/- 0.33, P < 0.01), and the normal food group (2.14 +/- 0.35, P < 0.05).</p><p><b>CONCLUSION</b>Metformin therapy and improved diet could improve sperm quality and promote the antioxidant ability of the testis in diet-induced obesity rats.</p>

Relationship of nitric oxide and nitric oxide synthase with varicocele infertility / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the relationship of nitric oxide (NO) and nitric oxide synthase (NOS) with varicocele (VC) infertility.</p><p><b>METHODS</b>Fifty-three infertile men, 21 with varicocele and 32 with subvaricocele, were enrolled as Group 1, 29 infertile patients with oligoasthenozoospermia but without varicocele as Group 2 and 28 normal fertile controls as Group 3. The NO content and NOS activity in the seminal plasma and peripheral blood were measured by nitric acid reductase method, and the semen parameters of VC determined by computer-assisted semen analysis (CASA).</p><p><b>RESULTS</b>Significant differences were noted between Group 1 and the other two in the NO content and NOS activity in the seminal plasma (P < 0.05) but not in the peripheral blood (P > 0.05). In Group 1, the NO content and NOS activity were increased in both the seminal plasma and peripheral blood with the enhanced diameter of the varicose spermatic vein, with a significant difference only in the seminal plasma between the varicocele and subvaricocele patients (P < 0.05), and the same increase was observed with decreased sperm concentration (> or = 20 x 10(6)/ml and < or = 10 x 10(6)/ml) and motility (> or = 50% and < or = 25%), with significant differences (P < 0.05).</p><p><b>CONCLUSION</b>NO plays an important role in the VC-induced decrease of seminal quality. For the diagnosis of VC, the determination of the NO content and NOS activity in the seminal plasma is of more significance than that in the peripheral blood, and the earlier the determination, the greater its clinical value for both the diagnosis and treatment of VC.</p>

Cloning, Sequence Analysis and Expression of Glutamate Dehydrogenase in Brevibacterium flavum GDK-9 / 微生物学通报

The glutamate dehydrogenase (EC.1.4.1.4) gene which amplified from the genome of Brevibacterium flavum GDK-9 by polymerase chain reaction was linked with pUCm-T for sequence alignment. Analysis of gdh sequences revealed that the whole sequence is 1927 bp, only one ORF existed, which used ATG as the initiation codon and coded a peptide of 448 amino acids with a calculated molecular weight of 48 kD. The comparability between the cloned gdh sequence to the reported sequence is high to 99.55%. Only the 1190th base mutation (C→A) lead to the change of amino acid sequence (Thr→Asn), the others are not. The recombinant plasmid pXG was then transformed into E. coli XL-Blue and Brevibacterium flavum GDK-9 which was induced by IPTG. SDS-PAGE analysis revealed that there was a clear induced protein band with molecular mass of 48.7 kD on expected position. Standard glutamate fermentations indicated that although the level of GDH increases the intracellular glutamate pool, the level of GDH has no influence on glutamate secretion.