Barrington G M, Besser T E, Gay C C, Davis W C, Reeves J J, McFadden T B, Akers R M
Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164, USA.
J Endocrinol. 1999 Oct;163(1):25-31. doi: 10.1677/joe.0.1630025.
Induction of colostrogenesis in non-pregnant cows was used to evaluate the relationship between prolactin (PRL) and mammary immunoglobulin G1 (IgG1) receptor expression. Six of eleven non-pregnant, non-lactating Holstein cattle responded to a standard lactation induction protocol by development of elevated IgG1 concentrations in mammary secretions. In order to increase the diversity in PRL concentrations, two of the six cattle were treated with bromocriptine, and two others were treated with recombinant bovine PRL. Serum alpha-lactalbumin, serum PRL and mammary secretion IgG1 concentrations were measured throughout the experiment. Biopsies of mammary tissue were collected after induction of lactation, and after treatments to alter serum PRL. Immunohistochemistry was used to evaluate IgG1 receptor expression. Administration of recombinant bovine (rbPRL) was associated with increased lactogenic activity, decreased secretion IgG1 concentrations, and decreased IgG1 receptor expression. Decreased serum PRL, due to bromocriptine, was associated with decreased lactogenic activity and maintenance of IgG1 receptor expression. Results of this experiment are consistent with an effect of PRL in decreasing the expression of the bovine mammary IgG1 receptor at the onset of lactogenesis.
通过诱导非妊娠母牛产生初乳来评估催乳素（PRL）与乳腺免疫球蛋白G1（IgG1）受体表达之间的关系。11头非妊娠、非泌乳的荷斯坦奶牛中有6头对标准泌乳诱导方案有反应，乳腺分泌物中IgG1浓度升高。为了增加PRL浓度的多样性，6头牛中的2头用溴隐亭治疗，另外2头用重组牛PRL治疗。在整个实验过程中测量血清α-乳白蛋白、血清PRL和乳腺分泌物IgG1浓度。在诱导泌乳后以及在改变血清PRL的处理后采集乳腺组织活检样本。采用免疫组织化学法评估IgG1受体表达。给予重组牛PRL（rbPRL）与泌乳活性增加、分泌的IgG1浓度降低以及IgG1受体表达降低有关。溴隐亭导致血清PRL降低与泌乳活性降低和IgG1受体表达维持有关。本实验结果与PRL在泌乳起始时降低牛乳腺IgG1受体表达的作用一致。
