title: Parathyroid hormone-related protein (PTHrP) and Ca levels in the milk of lactating cows.
abstract: 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.
authors.affiliation: Laboratory of Internal Medicine III, Azabu University School of Veterinary Medicine, Kanagawa, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Onda
authors.forename: Aiko
authors.initials: A
authors.lastname: Sato
authors.forename: Maiko
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: Naoaki
authors.initials: N
authors.lastname: Matsuki
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Ono
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Wada
mesh_terms: D000818:Animals; D002118:Calcium / Q000032:analysis* / Q000097:blood; D002417:Cattle; D005260:Female; D008892:Milk / Q000737:chemistry*; D044162:Parathyroid Hormone-Related Protein / Q000097:blood / Q000737:chemistry / Q000378:metabolism*; D036801:Parturition / Q000097:blood / Q000378:metabolism; D011247:Pregnancy
chemical_list: D044162:Parathyroid Hormone-Related Protein; D002118:Calcium