This study was conducted to assess concentrations of 17β-estradiol (E2) and testosterone (T) in toe claws of puppies collected at birth, at 30 and at 60 days of age, evaluating changes relating to age and effect of puppy sex, Apgar score, bodyweight at birth, "litter effect", litter size, and maternal age. Puppies (n = 89), 46 males and 43 females, with normal weight and without malformations, were assigned for the study. Within 12 h of birth tips of toe claws were clipped, and the re-growth tissue of the claws was collected at 30 and 60 days of age. Steroid quantifications occurred using a radioimmunoassay. The results indicated there were lesser concentrations (P < 0.001) of both hormones at 30 and 60 days of age than at birth and that concentrations were similar at 30-60 days of age. There were greater (P < 0.001) T concentrations in males than females, with there being an interaction between sex and sampling time (P < 0.01). The Apgar score was positively (P < 0.001) related to T concentrations in toe claws at birth. The bodyweight was positively correlated (P < 0.05) with T concentrations, with an interaction among puppy sex, bodyweight and sampling time (P < 0.05). Results of the present study confirmed the usefulness of toe claws as a matrix for study of hormonal changes in perinatology of dogs. Results of the study also indicate there are greater E2 and T concentrations at birth compared with 30 and 60 days of age that could be the result of these prenatal steroids affecting fetal development.

中文翻译：

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从出生到成年60天，雌性和雄性狗脚趾爪中的围产期17β-雌二醇和睾丸激素浓度。

这项研究旨在评估出生时，30岁和60天时收集的幼犬脚趾爪中17β-雌二醇（E2）和睾丸激素（T）的浓度，评估与年龄和幼犬性别，Apgar得分有关的变化，出生时的体重，“产仔效应”，产仔数和产妇年龄。分配了体重正常但无畸形的幼犬（n = 89），46例男性和43例女性。在出生的12小时内，脚趾爪被剪断，并在30和60天龄时收集了爪的再生长组织。使用放射免疫测定法进行类固醇定量。结果表明，在出生30和60天时，两种激素的浓度均低于出生时（P <0.001），并且在30至60天时的浓度相似。有更大（P <0。001）男性中的T浓度要高于女性中的T浓度，性别与采样时间之间存在相互作用（P <0.01）。Apgar评分与出生时脚趾爪中的T浓度呈正相关（P <0.001）。体重与T浓度呈正相关（P <0.05），并且与小狗性别，体重和采样时间之间存在相互作用（P <0.05）。本研究的结果证实了脚趾爪作为研究狗围手术期激素变化的基质的有用性。研究结果还表明，与30和60天年龄相比，出生时的E2和T浓度更高，这可能是这些产前类固醇影响胎儿发育的结果。001）与出生时脚趾爪中的T浓度有关。体重与T浓度呈正相关（P <0.05），并且与小狗的性别，体重和采样时间之间存在相互作用（P <0.05）。本研究的结果证实了脚趾爪作为研究狗围病期荷尔蒙变化的基质的有用性。研究结果还表明，与30和60天年龄相比，出生时的E2和T浓度更高，这可能是这些产前类固醇影响胎儿发育的结果。001）与出生时脚趾爪中的T浓度有关。体重与T浓度呈正相关（P <0.05），并且与小狗的性别，体重和采样时间之间存在相互作用（P <0.05）。本研究的结果证实了脚趾爪作为研究狗围病期荷尔蒙变化的基质的有用性。研究结果还表明，与30和60天年龄相比，出生时的E2和T浓度更高，这可能是这些产前类固醇影响胎儿发育的结果。本研究的结果证实了脚趾爪作为研究狗围病期荷尔蒙变化的基质的有用性。研究结果还表明，与30和60天年龄相比，出生时的E2和T浓度更高，这可能是这些产前类固醇影响胎儿发育的结果。本研究的结果证实了脚趾爪作为研究狗围病期荷尔蒙变化的基质的有用性。研究结果还表明，与30和60天年龄相比，出生时的E2和T浓度更高，这可能是这些产前类固醇影响胎儿发育的结果。