Department of Veterinary Medicine, Università degli Studi di Milano, Via Celoria, 10, Milan, Italy.
Department of AgriFood, Environmental and Animal Sciences, University of Udine, Via Sondrio, 2/a, Udine, Italy.
Anim Reprod Sci. 2020 Mar;214:106313. doi: 10.1016/j.anireprosci.2020.106313. Epub 2020 Feb 6.
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.
本研究旨在评估出生时、30 日龄和 60 日龄幼犬爪趾尖部 17β-雌二醇(E2)和睾酮(T)的浓度,评估与年龄和幼犬性别、阿普加评分、出生体重、“窝效应”、窝产仔数以及母犬年龄相关的变化。将 89 只体重正常且无畸形的幼犬(46 只雄性和 43 只雌性)分配到研究中。出生后 12 小时内剪下爪趾尖,30 日龄和 60 日龄时采集爪趾再生组织。使用放射免疫分析法进行类固醇定量分析。结果表明,与出生时相比,30 日龄和 60 日龄时两种激素的浓度均较低(P<0.001),且 30-60 日龄时浓度相似。雄性 T 浓度高于雌性(P<0.001),且性别与采样时间之间存在交互作用(P<0.01)。阿普加评分与出生时爪趾尖 T 浓度呈正相关(P<0.001)。体重与 T 浓度呈正相关(P<0.05),且幼犬性别、体重和采样时间之间存在交互作用(P<0.05)。本研究结果证实了爪趾尖作为研究犬围产期激素变化的基质的有用性。研究结果还表明,与 30 日龄和 60 日龄相比,出生时 E2 和 T 的浓度更高,这可能是这些产前类固醇影响胎儿发育的结果。