Rincón Joao Alveiro Alvarado, Mion Bruna, Acosta Diego Andres Velasco, Gasperin Bernardo Garziera, Rovani Monique Tomazele, Pegoraro Lígia Margareth Cantarelli, Corrêa Marcio Nunes, Schneider Augusto
Faculdade de Veterinária, Universidade Federal de Pelotas, Pelotas, RS, Brasil.
Corporación Colombiana de Investigación Agropecuaria, Mosquera, Cundinamarca, Colombia.
Anim Reprod. 2019 Nov 18;16(4):914-922. doi: 10.21451/1984-3143-AR2018-0118.
The aim of this study was to evaluate the long-term effects of recombinant bovine somatotropin (rbST) on follicle population and ovulatory follicle development in non-lactating dairy cows. Twenty-one Jersey cows were allocated in rbST (n=11) or control (n=10) groups. On day -60, cows in rbST group received 500 mg of somatotropin (s.c. Lactotropin®, Elanco). On day 0, control and rbST cows received an intravaginal progesterone-releasing device (1.9 g, CIDR, Zoetis) and GnRH (100 mg, IM, Factrel, Zoetis). On day 8, cows received PGF2α (25 mg, IM, Lutalyse®, Zoetis) and the CIDR was removed. Twelve hours after device removal (D8), serum, follicular fluid and granulosa cells samples were collected. Serum and follicular concentration of estradiol (E2) and progesterone (P4) were analyzed. Total RNA was extracted from granulosa cells to measure gene expression of , , , , , , and by real-time PCR. Ultrasonography was performed on days -60, -53, -46, -14, -7, 0 and 8 for antral follicle count. Results were analyzed by repeated measures ANOVA and t-test. There was no effect of rbST treatment on the number of follicles during the 60 days period, as well as no effect on serum and follicular fluid E2 and follicular fluid P4 at the moment of follicle aspiration. There was a reduction in ( = 0.006), ( = 0.04) and ( = 0.002) mRNA levels in granulosa cells of the pre-ovulatory follicle of rbST treated cows. In conclusion, a single dose of rbST did not have long-term effects on antral follicle population, serum and follicular E2/P4 concentrations in non-lactating dairy cows. Despite that, rbST injection decreased granulosa cell expression of genes related to steroidogenesis in the pre-ovulatory follicle.
本研究的目的是评估重组牛生长激素（rbST）对非泌乳奶牛卵泡数量和排卵卵泡发育的长期影响。将21头泽西奶牛分为rbST组（n = 11）或对照组（n = 10）。在第-60天，rbST组的奶牛皮下注射500 mg生长激素（Lactotropin®，伊兰科公司）。在第0天，对照组和rbST组的奶牛均放入阴道内孕酮释放装置（1.9 g，CIDR，硕腾公司）并注射促性腺激素释放激素（100 mg，肌肉注射，Factrel，硕腾公司）。在第8天，奶牛注射前列腺素F2α（25 mg，肌肉注射，Lutalyse®，硕腾公司）并取出CIDR。取出装置（第8天）12小时后，采集血清、卵泡液和颗粒细胞样本。分析血清和卵泡中雌二醇（E2）和孕酮（P4）的浓度。从颗粒细胞中提取总RNA，通过实时PCR测定 、 、 、 、 、 、 和 的基因表达。在第-60天、-53天、-46天、-14天、-7天、0天和8天进行超声检查以计数窦卵泡数量。结果通过重复测量方差分析和t检验进行分析。rbST处理在60天期间对卵泡数量没有影响，在卵泡抽吸时对血清和卵泡液中的E2以及卵泡液中的P4也没有影响。rbST处理奶牛的排卵前卵泡颗粒细胞中 （ = 0.006）、 （ = 0.04）和 （ = 0.002）的mRNA水平有所降低。总之，单剂量的rbST对非泌乳奶牛的窦卵泡数量、血清和卵泡中的E2/P4浓度没有长期影响。尽管如此，注射rbST会降低排卵前卵泡中与类固醇生成相关基因的颗粒细胞表达。
