HOME HELP CONTACT US SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by HOVE, K. Articles by TOLLMAN, R. Search for Related Content PubMed Articles by HOVE, K. Articles by TOLLMAN, R.

Hourly secretion of calcium and magnesium by goat mammary glands was studied following infusions of bovine parathyroid hormone (PTH) into the mammary artery in amounts (6–15 ng/kg per min) giving rise to levels of PTH in mammary venous blood commonly observed during spontaneous hypocalcaemia (2·4–13 µg/l). In two series of experiments a 3 h infusion of PTH was given. The first series was carried out at a normal level of plasma calcium, while the availability of calcium was increased by a 20 h infusion of CaCl₂ in the other series. No changes in mammary secretion of calcium or magnesium could be observed during the hormone infusions. A decrease in the urinary excretion of calcium occurred, thus demonstrating the activity of the infused PTH.

In a third experiment an 18·5 h infusion of PTH (6 ng/kg per min) into the mammary artery was given to study possible effects of a more prolonged increase of PTH concentrations. This infusion caused a gradual increase in plasma levels of calcium. Average concentrations of calcium in milk increased slightly (about 5% in both glands (P<0·05). The hourly yield of milk was not significantly changed in the infused gland after 18·5 h of PTH infusion. A small but significant increase occurred in the non-infused gland. Yields of magnesium were not influenced by the infusion of PTH. It was concluded that losses of calcium into milk are independent of the PTH concentration in the circulation.