Understanding the physiology of penile spicules in guinea pigs (Cavia porcellus) may improve their management in large-scale production guinea systems. Here we examined whether penis spicule development depends on testosterone and whether exogenous testosterone can reverse penile spicule atrophy in castrated guinea pigs. The relationship between total testosterone (TT) and the development of penile spicules (DPS) in guinea pigs was explored in two experiments. The first experiment described the TT and DPS curves in non-castrated guinea pigs (E1-G1) and guinea pigs castrated on day 35 (E1-G2). In the second experiment, the dose-dependent effect of the administration of exogenous testosterone (ET) was evaluated during DPS in Group 1 (E2-G1; castrated guinea pigs + 125 μg ET on days 65 and 80 of age), Group 2 (E2-G2; castrated guinea pigs + 250 μg ET on days 65 and 80 of age), Group 3 (E2-G3; non-castrated guinea pigs), and Group 4 (E2-G4; castrated guinea pigs without ET). Analysis of variance using a General Linear Model (GLM) was performed. TT increased from day 20 to day 35 in both groups in the first experiment (P > 0.05). This increase in TT was maintained in E1-G1 on days 50, 65, and 80; however, TT fell to basal values in E1-G2 after castration. DPS guinea was directly related to TT level. In Experiment 2, guinea E2-G1 and E2-G2 animals that received ET showed an increase in TT, significantly differing from E2-G4 (P < 0.05). Nevertheless, ET administration in E2-G1 and E2-G2 was not sufficient to reach the TT levels in E2-G3. DPS was closely related to TT levels, such that when testicles were removed, the spicules began to atrophy without disappearing. Our results suggest that TT in guinea pigs increases steadily until puberty completes, after which it decreases and stabilizes and shows an association with DPS. Furthermore, 12-35% of TT produced by guinea pigs is testicle-independent. Finally, ET administration can stop and reverse the spicule atrophy process in castrated males. These results will help to manage guinea pigs in a more sustainable way in countries where this species is of utmost relevance to provide the population with the meat of high quality.

中文翻译：

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豚鼠（Cavia porcellus）睾酮与阴茎骨针的关系

了解豚鼠（Cavia porcellus）阴茎针状体的生理学可以改善它们在大规模生产豚鼠系统中的管理。在这里，我们检查了阴茎骨针的发育是否取决于睾酮以及外源性睾酮是否可以逆转去势豚鼠的阴茎骨针萎缩。在两个实验中探讨了总睾酮 (TT) 与豚鼠阴茎针 (DPS) 发育之间的关系。第一个实验描述了未阉割的豚鼠 (E1-G1) 和第 35 天阉割的豚鼠 (E1-G2) 的 TT 和 DPS 曲线。在第二个实验中，在第 1 组（E2-G1；去势的豚鼠 + 65 天和 80 天龄的 125 μg ET）、第 2 组（ E2-G2；去势豚鼠 + 250 μg ET，第 65 天和 80 天），第 3 组（E2-G3；未阉割的豚鼠）和第 4 组（E2-G4；没有 ET 的去势豚鼠）。使用一般线性模型 (GLM) 进行方差分析。在第一次实验中，两组的 TT 从第 20 天增加到第 35 天（P > 0.05）。在第 50、65 和 80 天，这种 TT 的增加在 E1-G1 中得以保持；然而，阉割后 TT 在 E1-G2 中降至基础值。DPS几内亚与TT水平直接相关。在实验 2 中，接受 ET 的几内亚 E2-G1 和 E2-G2 动物显示 TT 增加，与 E2-G4 显着不同（P < 0.05）。然而，E2-G1 和 E2-G2 中的 ET 管理不足以达到 E2-G3 中的 TT 水平。DPS 与 TT 水平密切相关，因此当睾丸被移除时，针状体开始萎缩而不消失。我们的结果表明，豚鼠的 TT 稳定增加，直到青春期结束，之后它会下降并稳定下来，并显示出与 DPS 的关联。此外，豚鼠产生的 TT 中有 12-35% 不依赖睾丸。最后，ET 给药可以阻止和逆转去势雄性的骨针萎缩过程。这些结果将有助于以更可持续的方式管理豚鼠，在这些国家中，豚鼠与为人口提供高质量的肉最相关。ET 给药可以阻止和逆转去势雄性的骨针萎缩过程。这些结果将有助于以更可持续的方式管理豚鼠，在这些国家中，豚鼠与为人口提供高质量的肉最相关。ET 给药可以阻止和逆转去势雄性的骨针萎缩过程。这些结果将有助于以更可持续的方式管理豚鼠，在这些国家中，豚鼠与为人口提供高质量的肉最相关。