de Souza Diogo B, Silva Dilson, Cortez Celia M, Costa Waldemar S, Sampaio Francisco J B
Urogenital Research Unit, State University of Rio de Janeiro, Av 28 de Setembro, 87, Fundos, Vila Isabel, Rio de Janeiro, RJ, Brazil.
J Androl. 2012 Jul-Aug;33(4):735-9. doi: 10.2164/jandrol.111.014225. Epub 2011 Sep 22.
The objective of this study was to investigate structural changes in the penile corpus cavernosum of prepubertal chronically stressed rats. Eight Wistar rats were assigned into the stress group (SG) and were submitted to 2 hours of tube restraint daily, from the fourth to the ninth week of life. Another 7 rats were used as the control group (CG). All animals were weighed weekly. At day 64, animals were sacrificed by anesthetic overdose, blood was collected for testosterone concentration by radioimmunoassay, and penis and adrenal were collected. Adrenal mass index and testosterone serum levels were used to assess the efficacy of the stress stimulus. The surface density of connective tissue and smooth muscle fibers of corpus cavernosum were measured on Masson trichromic-stained slices. Picrosirius red-stained slices were assessed under polarized light for different types of collagen. The Student's t test was applied for mean comparisons, with P < .05 considered significant. Testosterone serum concentrations decreased and adrenal mass index increased, confirming the effectiveness of the stress protocol. Smooth muscle fibers of corpus cavernosum decreased from 14.07% (CG) to 8.98% (SG) (P = .02), and connective tissue increased from 53.66% (CG) to 64.47% (SG) (P = .01). Also, there was a higher level of type I collagen in the SG animals compared with the CG. Stress stimuli induced structural changes in the corpus cavernosum of rats suggestive of penile fibrosis, which may play a role in erection dysfunction.
本研究的目的是调查青春期前长期应激大鼠阴茎海绵体的结构变化。将8只Wistar大鼠分为应激组（SG），从出生后第4周开始至第9周，每天对其进行2小时的束缚应激。另外7只大鼠作为对照组（CG）。每周对所有动物称重。在第64天，通过过量麻醉处死动物，采集血液用放射免疫分析法检测睾酮浓度，并采集阴茎和肾上腺。用肾上腺质量指数和血清睾酮水平评估应激刺激的效果。在Masson三色染色切片上测量海绵体结缔组织和平滑肌纤维的表面密度。在偏振光下评估天狼星红染色切片中不同类型的胶原蛋白。采用Student's t检验进行均值比较，P <.05认为具有统计学意义。血清睾酮浓度降低，肾上腺质量指数升高，证实了应激方案的有效性。海绵体平滑肌纤维从14.07%（CG）降至8.98%（SG）（P = 0.02），结缔组织从53.66%（CG）增至64.47%（SG）（P = 0.01）。此外，与CG组相比，SG组动物的I型胶原蛋白水平更高。应激刺激导致大鼠海绵体结构发生变化，提示阴茎纤维化，这可能在勃起功能障碍中起作用。
