Department of Advanced Pathobiology, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Izumisano, Osaka, Japan.
Theriogenology. 2012 Feb;77(3):550-7. doi: 10.1016/j.theriogenology.2011.08.030. Epub 2011 Oct 19.
The objectives were to: (1) develop a time-resolved fluorescence immunoassay (TRFIA) to measure insulin-like peptide 3 (INSL3) in canine plasma; (2) investigate changes of plasma concentrations of INSL3 and testosterone with age in normal male dogs; and (3) compare hormonal concentrations among cryptorchid, normal, and castrated dogs to evaluate endocrine function of the Leydig cell component in retained testes. Blood samples were taken from normal male dogs from prepubertal age to advanced age (4 mo to 14 y, n = 89), and from unilateral cryptorchid (n = 31), bilateral cryptorchid (n = 7), and castrated dogs (n = 3). Canine plasma INSL3 was measured with a newly developed TRFIA. The minimum detection limit of the INSL3 assay was 0.02 ng/ml and the detection range was 0.02 to 20 ng/ml. Plasma INSL3 concentrations increased (P < 0.05) from prepubertal age (4-6 mo) to pubertal age (6-12 mo), and then declined (P < 0.05) from pubertal age to post-pubertal age (1-5 y), reaching a plateau. Plasma testosterone concentrations increased (P < 0.0001) dramatically from prepubertal to pubertal ages, and then seemed to plateau. Concentrations of both INSL3 and testosterone were lower (P < 0.0001 for each) in bilateral cryptorchid dogs than in normal and unilateral cryptorchid dogs. The INSL3 (range: 0.05-0.43 ng/ml) and testosterone (range: 0.10-0.94 ng/ml) concentrations were readily detected in bilateral cryptorchids, but not in castrated dogs (INSL3 < 0.02 ng/ml; testosterone < 0.04 ng/ml). In conclusion, plasma INSL3 concentrations in male dogs measured by a newly developed TRFIA had a transient surge at a pubertal age, whereas testosterone did not. Lower plasma concentrations of INSL3 and testosterone in bilateral cryptorchid dogs suggest impaired endocrine functions of Leydig cell component in paired retained testes. Therefore, peripheral plasma INSL3 and testosterone concentrations have potential diagnostic value in predicting the presence of bilaterally retained testes in male dogs.
(1)建立一种时间分辨荧光免疫分析(TRFIA)方法来检测犬血浆中的胰岛素样肽 3 (INSL3);(2)研究正常雄性犬中 INSL3 和睾酮随年龄的变化;(3)比较隐睾、正常和去势犬的激素浓度,以评估保留睾丸中莱迪希细胞成分的内分泌功能。从青春期前(4 月龄至 14 岁,n = 89)到老年的正常雄性犬,以及单侧隐睾(n = 31)、双侧隐睾(n = 7)和去势犬(n = 3)采集犬血浆。用新开发的 TRFIA 测量犬血浆 INSL3。该 INSL3 检测的最小检测限为 0.02 ng/ml,检测范围为 0.02 至 20 ng/ml。INSL3 浓度从青春期前(4-6 月龄)到青春期(6-12 月龄)升高(P < 0.05),然后从青春期到青春期后(1-5 岁)下降(P < 0.05),达到一个平台。睾酮浓度从青春期前到青春期急剧升高(P < 0.0001),然后似乎达到一个平台。双侧隐睾犬的 INSL3 和睾酮浓度均较低(P < 0.0001)。双侧隐睾犬的 INSL3(范围:0.05-0.43 ng/ml)和睾酮(范围:0.10-0.94 ng/ml)浓度可检测到,但去势犬的浓度不可检测到(INSL3 < 0.02 ng/ml;睾酮 < 0.04 ng/ml)。结论:用新开发的 TRFIA 测量的雄性犬血浆 INSL3 浓度在青春期时短暂升高,而睾酮没有升高。双侧隐睾犬血浆 INSL3 和睾酮浓度较低提示双侧保留睾丸中莱迪希细胞成分的内分泌功能受损。因此,外周血浆 INSL3 和睾酮浓度在预测雄性犬双侧保留睾丸的存在方面具有潜在的诊断价值。