Stress Hormone Corticosterone Controls Metabolic Mitochondrial Performance and Inflammatory Signaling of In Vitro Cultured Sertoli Cells.

Stress, as a physiological response, is a major factor that affects several processes, including reproductive functions. The main hormonal players of stress are cortisol (humans) and corticosterone (rodents). Sertoli cells (SCs), as key contributors for the testicular homeostasis maintenance, are extensively challenged by different hormones, with glucocorticoid corticosterone being the signaling modulator that may impact these cells at different levels. We aimed to characterize how corticosterone modulates SCs energy balance, putting the mitochondrial performance and signaling output in perspective as the cells can disperse to the surroundings. TM4 mouse SCs were cultured in the absence and presence of corticosterone (in nM: 20, 200, and 2000). Cells were assessed for extracellular metabolic fluxes, mitochondrial performance (cell respirometry, mitochondrial potential, and mitochondrial complex expressions and activities), and the expression of androgen and corticosteroid receptors, as well as interleukine-6 (IL-6) and glutathione content. Corticosterone presented a biphasic impact on the extracellular fluxes of metabolites. Low sub-physiological corticosterone stimulated the glycolytic activity of SCs. Still, no alterations were perceived for lactate and alanine production. However, the lactate/alanine ratio was decreased in a dose-dependent mode, opposite to the mitochondrial complex II activity rise and concurrent with the decrease of IL-6 expression levels. Our results suggest that corticosterone finely tuned the energetic profile of mouse SCs, with sub-physiological concentrations promoting glycolytic expenditure, without translating into cell redox power and mitochondrial respiratory chain performance. Corticosterone deeply impacted the expression of the pro-inflammatory IL-6, which may alter cell-to-cell communication in the testis, in the last instance and impact of the spermatogenic performance.

Immediate and late effects of chronic stress in the testes of prepubertal and adult rats.

The objective of this study was to investigate the effects of chronic stress on the testes of prepubertal and adult rats and to evaluate whether any alterations could be reversed when stress induction is ended. Seventy-six male rats were assigned to eight groups depending on the type of treatment (control or stressed), the age at which stress was initiated (prepubertal or adult), and the time of evaluation (immediate or late). Stress stimuli were applied for 6 weeks. Stressed prepubertal and adult rats evaluated immediately after the last stress stimulus were included in SP-I and SA-I groups, respectively. The late prepubertal (SP-L) and adult (SA-L) groups of stressed rats were evaluated 6 weeks after the last stress stimulus. Age-matched rats were used as controls (CP-I, CA-I, CP-L, and CA-L groups). Application of stress stimuli to rats in the SP-I group resulted in body weight and seminiferous tubule diameter reduction. The rats in the SA-I group also showed several functional (testosterone level and sperm parameter) and morphological (testicular weight and seminiferous tubule diameter) reductions. The rats in the SP-L group showed increased body weight and intertubular compartment volumetric and absolute densities and reduced tubular compartment volumetric density. The rats in the SA-L group presented only reduced sperm viability. Stress stimuli promoted changes in the rats in all the study groups. The testes of the adult rats were the most affected by chronic stress. However, the stressed adult rats recovered well from the testicular alterations.

Effects of testicular transfixation on seminiferous tubule morphology and sperm parameters of prepubertal, pubertal, and adult rats.

Orchiopexy is performed as part of cryptorchidism and testicular torsion treatment. The inflammation caused by the needle and suture penetration has been suggested to be one of the possible causes of subfertility after parenchymal transfixation of the testicles. The purpose of the present study was to investigate testicular alterations after parenchymal transfixation sutures at different ages in rats. Prepubertal, pubertal, and adult rats were submitted to parenchymal suturing (without tying the knots, thus avoiding local ischemic injury) of the right testicle, which was maintained for 4 hours. All animals were subjected to euthanasia on completion of 14 weeks of life. The right testicles were studied as the sutured testicles, whereas the left organs were studied as contralateral. One age-matched control group of rats that was not submitted to any procedure was used for comparison. During euthanasia, sperm were collected from the tail of the epididymal and evaluated for concentration, motility, and viability. Samples from testicular tissue were collected for morphologic analysis. Sperm analysis indicated that only the adult operated animals presented reductions in motility (38.2% of adult vs. 54.1% of control; P = 0.02) and viability (16.6% of adult vs. 24.6% of control; P = 0.003). Several morphologic alterations were noted both in sutured and in contralateral testes at all ages. For instance, the seminiferous epithelium volumetric density of right testicles was reduced from 50.4% in controls to 32.3% in prepubertal operated animals, 45.3% in pubertal operated animals, and 39.4% in adult operated animals (P < 0.05). The seminiferous epithelium volumetric density was also reduced to 39.9% and 39.0% in contralateral testicles of animals operated before and after puberty, respectively (P < 0.05). The animals operated on before puberty and in adulthood showed more testicular morphologic alterations, as seminiferous tubule volumetric density, seminiferous tubule length, and tubular diameter were reduced only in prepubertal and/or adult operated animals. Testicular transfixation in rats led to important morphologic modifications in the ipsilateral and contralateral organs. These alterations were observed regardless of the age when surgery was performed, but they were milder in animals operated on during puberty. Orchiopexy techniques that do not involve the application of testicular transfixation sutures should be recommended.

Effect of antioxidants on outcome of testicular torsion in rats of different ages.

PURPOSE: We assessed reproductive and testicular function in adult rats after testicular torsion created before, during and after puberty, and with vs without resveratrol or arginine treatment. MATERIALS AND METHODS: Age matched rats were divided into groups, including simulated surgery without testicular torsion, 720-degree testicular torsion for 4 hours, testicular torsion with resveratrol treatment and testicular torsion with arginine treatment. To study reproductive function at age 12 weeks each rat mated with 3 females. The males were sacrificed at age 14 weeks. Spermatozoids were collected from the epididymal tail and evaluated for concentration, motility and viability. Testicular samples were collected for morphological analysis. RESULTS: Reproductive function was not altered by testicular torsion but antioxidants improved potency. Compared to sham operated and contralateral samples all spermatozoid parameters from testicular torsion samples were inferior. Resveratrol and arginine did not improve spermatozoid quality or quantity in torsed testes but contralateral samples were improved by each drug. The seminiferous epithelium of rats submitted to testicular torsion during puberty was least affected. Each antioxidant partially to totally prevented the morphological alterations found in rats with untreated testicular torsion. Rats submitted to testicular torsion before puberty that were treated with antioxidants showed the fewest changes. CONCLUSIONS: Testicular morphology was altered less in rats when torsion occurred earlier in life, that is during puberty. Treatment with antioxidants improved contralateral spermatozoid production and some fertility parameters. Each antioxidant also prevented testicular morphology alterations after testicular torsion. Prepubertal rats benefited most from antioxidant treatment.