Effects of chronic restraint stress in the prostate of prepubertal and adult rats.

PURPOSE: To investigate the effects of chronic stress in the prostate of prepubertal and adult rats. METHODS: Thirty-two male rats were assigned into four groups depending on the type of treatment (control or stressed) and the age at which stress was initiated (prepubertal or adult). Restraint stress stimuli were applied for six weeks. Stressed prepubertal and adult rats evaluated immediately after the last stress stimuli were named SP and SA groups, respectively. Age-matched rats were used as control groups (CP and CA). At the end of the experiment, the rats were euthanized, and prostate morphological parameters were evaluated and statistically compared. RESULTS: Application of stress stimuli to the SP group resulted in reduced body weight, but no prostate morphological modification was noted. The SA group showed reduced testosterone level and prostatic epithelium surface density, in comparison to CA group. Further, the prostatic lumen surface density was increased in adult stressed animals, in comparison to adult controls. CONCLUSIONS: The stress stimuli promoted changes in hormonal and morphological parameters in the prostate of adult stressed rats. Prepubertal stressed animals did not presented modifications of prostate morphology.

Effects of chronic restraint stress in the prostate of prepubertal and adult rats

Purpose: To investigate the effects of chronic stress in the prostate of prepubertal and adult rats. Methods: Thirty-two male rats were assigned into four groups depending on the type of treatment (control or stressed) and the age at which stress was initiated (prepubertal or adult). Restraint stress stimuli were applied for six weeks. Stressed prepubertal and adult rats evaluated immediately after the last stress stimuli were named SP and SA groups, respectively. Age-matched rats were used as control groups (CP and CA). At the end of the experiment, the rats were euthanized, and prostate morphological parameters were evaluated and statistically compared. Results: Application of stress stimuli to the SP group resulted in reduced body weight, but no prostate morphological modification was noted. The SA group showed reduced testosterone level and prostatic epithelium surface density, in comparison to CA group. Further, the prostatic lumen surface density was increased in adult stressed animals, in comparison to adult controls. Conclusions: The stress stimuli promoted changes in hormonal and morphological parameters in the prostate of adult stressed rats. Prepubertal stressed animals did not presented modifications of prostate morphology.

Evaluation of the effects of chronic stress applied from the prepubertal to the adult stages or only during adulthood on penile morphology in rats.

The present study aimed to evaluate the effects of chronic stress from the prepubertal to the adult stages or during adulthood on penile morphology in rats. The animals were immobilized in a cylinder for 2 h daily for a total of six weeks to simulate stress. Ten rats were exposed to stress stimulus beginning from the prepubertal age, while nine rats were exposed to stress stimulus only during adulthood. Animals were killed at 24 h after the last stress session for short-term evaluation (SP-S and SA-S), while other age-matched rats were sacrificed at 6 weeks after the last stress session for long-term evaluation (SP-L and SA-L). Age-matched animals were used as controls (CP-S, CA-S, CP-L and CA-L). After treatment, serum testosterone levels and areas of cavernosum structures were evaluated. We observed no changes in serum testosterone levels after stress treatment. Results revealed that the area of the corpus cavernosum without the tunica albuginea in animals in the SA-S group was 16% lower than that in the CA-S group. The smooth muscle was 31% lower in the SP-L group than in the SP-S group and 42% lower in the SA-S group than in the CA-S group. The elastic fiber system was 48% lower in the SP-L group than in the CP-L group and 59% lower in the SA-S group than in the CA-S group. Chronic stress promoted morphological changes in the rat penis and was significantly more pronounced when the stress occurred throughout the adulthood. Chronically applied single stress stimulus caused greater damage to the penis when induced directly during adulthood than when introduced before puberty to adulthood and could be associated with erectile dysfunction.

Immediate and Late Effects of Stress on Kidneys of Prepubertal and Adult Rats.

BACKGROUND/AIMS: Stress had been related to physiological and morphological alterations in different organs, however kidney morphology and function after stress conditions are not well-known. To evaluate the effects of chronic stress on renal morphology in prepubertal and adult rats, and to investigate if the effects of induced stress remain stable or worsen following removal of the stress stimuli. METHODS: Forty prepubertal rats (4 weeks old) and thirty six adult rats (10 weeks old) were used. Each age group was divided a into control group and a stressed group. Stressed animals were restrained in rigid tubes 2 hours per day for 6 weeks. Animals were euthanized 24 hours after the last stress stimulus for immediate evaluation (50% of the groups), and 6 weeks after the last stress stimulus for late evaluation (50% of the groups). Kidney weight and volume, cortical-medullar ratio, glomerular volumetric density, volume-weighted glomerular volume, and number of glomeruli per kidney were evaluated using the Image J software. RESULTS: Prepubertal stressed animals showed reduced kidney weight and volume, and increased cortical-medullar ratio in comparison to its control group when evaluated immediately. Furthermore, stressed prepubertal and adult animals evaluated immediately had reduced glomerular volumetric density. Most importantly, all stressed groups exhibited reduced number of glomeruli per kidney. Other analyzed parameters did not difeer significantly the groups. CONCLUSION: Chronic stress induced before and after puberty led to irreversible glomerular loss, however, renal impairment was interrupted by removal of the stress stimuli.

Pneumoperitoneum induces morphological alterations in the rat testicle.

PURPOSE: To investigate the seminiferous tubule histological morphology after an 8 mmHg pneumoperitoneum in the rat model. METHODS: Fourteen rats were divided into two groups: a Sham group submitted to anesthesia and a pneumoperitoneum (Pp) group submitted to abdominal insufflation at 8 mmHg during three hours, followed by desuflation. All rats were killed after six weeks, testicles were collected and evaluated for the tubule diameter, germinative epithelium height and Johnsen´s score. Means were compared by using the Student's-t-test. RESULTS: The seminiferous tubule diameter was diminished by 11.3% in the group submitted to pneumoperitoneum (p<0.05). No significant difference was found among the groups when analyzing the epithelium height and Johnsen´s score. CONCLUSION: In the rat model, the seminiferous tubules present structural alterations when subjected to pneumoperitoneum of 8 mmHg during three hours.

Pneumoperitoneum induces morphological alterations in the rat testicle

PURPOSE:To investigate the seminiferous tubule histological morphology after an 8 mmHg pneumoperitoneum in the rat model. METHODS: Fourteen rats were divided into two groups: a Sham group submitted to anesthesia and a pneumoperitoneum (Pp) group submitted to abdominal insufflation at 8 mmHg during three hours, followed by desuflation. All rats were killed after six weeks, testicles were collected and evaluated for the tubule diameter, germinative epithelium height and Johnsen´s score. Means were compared by using the Student's-t-test. RESULTS:The seminiferous tubule diameter was diminished by 11.3% in the group submitted to pneumoperitoneum (p<0.05). No significant difference was found among the groups when analyzing the epithelium height and Johnsen´s score. CONCLUSION:In the rat model, the seminiferous tubules present structural alterations when subjected to pneumoperitoneum of 8 mmHg during three hours.