Research Article

Metformin Improves Fertility in Obese Males by Alleviating Oxidative Stress-Induced Blood-Testis Barrier Damage

Figure 4

Metformin repairs the disruption of BTB integrity induced by a high-fat diet. (a) Transmission electron micrographs of the seminiferous epithelia of mice on the 16th week of feeding; the lower images are magnified views of each of the paired sections above. Red arrowhead 1 shows the cracked BTB between two adjacent Sertoli cells constituted by cellular tight junctions. Red arrowheads 2 and 3 indicate the increase in protein along both sides of the BTB. The red arrows represent expanded endoplasmic reticula. The corresponding scale bar is marked in the lower left corner of each image. for each group. (b) On the 16th week of feeding, testes were injected with 50 μl of EZ-Link Sulfo-NHS-LC-Biotin (red), and cell nuclei were stained with DAPI (blue). In the sections of testes from NN mice, the red fluorescence of the biotin tracer was observed only in the interstitial spaces and basal compartment. In the HH + MET group, a small amount of red fluorescence was seen in the lumina of the seminiferous tubules (white arrow), whereas in the HH group mice, abundant red fluorescence was evident in the lumina of the seminiferous tubules (white arrows) beside the interstitial space and basal compartment. for the magnified images, and for the other images. for each group. All of the above micrographs are representative of 3 independent experiments. (c) Count of positive staining of biotin in seminiferous tubules. The results are presented as the mean ± SD. vs. the corresponding NN group; ## vs. the corresponding HH group.
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