Onda Ken, Sato Aiko, Yamaguchi Maiko, Matsuki Naoaki, Ono Kenichiro, Wada Yasunori
Laboratory of Internal Medicine III, Azabu University School of Veterinary Medicine, Kanagawa, Japan.
J Vet Med Sci. 2006 Jul;68(7):709-13. doi: 10.1292/jvms.68.709.
To investigate the roles of mammary PTHrP in calcium uptake and/or release in the mammary gland of cows, plasma PTHrP and Ca levels, and their arterial-venous differences were examined in a Jersey cow during the periparturient period. Levels of Ca in both abdominal aorta and abdominal subcutaneous vein blood slightly decreased around the parturition and at 24 days after the parturition, however, no remarkable arterial-venous differences were observed. Plasma PTHrP levels in both arterial and venous samples were below the detection limit (0.57 pmol/l) during the experimental period. Milk PTHrP and Ca levels were measured in 9 Holstein dairy cows. Although plasma PTHrP levels in all arterial and venous samples were also below the detection limit, milk PTHrP and Ca levels were remarkably high, ranging from 14,900 pmol/l to 41,200 pmol/l and from 772 mg/l to 1,200 mg/l, respectively. In addition, a significant positive correlation (P<0.01) was observed between milk PTHrP and Ca levels. These results suggested that mammary PTHrP is closely related to Ca concentration in the milk.
为研究乳腺甲状旁腺激素相关蛋白（PTHrP）在奶牛乳腺钙摄取和/或释放中的作用，在围产期对一头泽西奶牛的血浆PTHrP和钙水平及其动静脉差异进行了检测。腹主动脉和腹皮下静脉血中的钙水平在分娩前后及分娩后24天略有下降，然而，未观察到明显的动静脉差异。在实验期间，动脉和静脉样本中的血浆PTHrP水平均低于检测限（0.57 pmol/l）。对9头荷斯坦奶牛的牛奶PTHrP和钙水平进行了测定。尽管所有动脉和静脉样本中的血浆PTHrP水平也低于检测限，但牛奶PTHrP和钙水平显著升高，分别为14,900 pmol/l至41,200 pmol/l和772 mg/l至1,200 mg/l。此外，牛奶PTHrP和钙水平之间存在显著正相关（P<0.01）。这些结果表明，乳腺PTHrP与牛奶中的钙浓度密切相关。
