| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Dairy Sciences, AgResearch, Ruakura Research Centre, Private Bag 3123, Hamilton, New Zealand
Saanen goats were used to determine the effect of the alteration of the intramammary Na to K ratio on milk secretion. Udders were infused via the teat with an isosmotic solution that was high in Na or K to increase or decrease, respectively, the intramammary Na to K ratio. Control glands received an isosmotic sucrose solution. To ensure that the results were not confounded by a decrease in milk secretion as a result of enhanced permeability of mammary tight junctions, the latter was monitored throughout the experiments. An increase in the Na to K ratio caused a significant transient reduction in milk secretion. Therefore, an increase in Na and a decrease in K in milk, commonly observed as a result of the leakiness of tight junctions, may at least partially explain the reduction in milk secretion when the permeability of tight junctions was increased. These experiments further showed that the adverse effects on secretion were not due to a high intracellular concentration per se but were related to a change in the Na to K ratio because a reduction in the ratio also lowered milk secretion. These data support the evidence for activity of Na+-K+-ATPase in the basolateral secretory cell membranes and passive movement of these ions across the apical cell membranes.
Key Words: sodium • potassium • milk secretion • tight junction
Submitted on May 11, 1998
Accepted on September 1, 1998
This article has been cited by other articles:
|
|
 |
|
  F. Abeni, M. G. Terzano, M. Speroni, L. Migliorati, M. Capelletti, F. Calza, L. Bianchi, and G. Pirlo Evaluation of Milk Enzymes and Electrolytes, Plasma Metabolites, and Oxidative Status in Twin Cows Milked in an Automatic Milking System or Twice Daily in a Conventional Milking Parlor J Dairy Sci, September 1, 2008; 91(9): 3372 - 3384. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. O'Dowd, J. C. Kent, J. M. Moseley, and M. E. Wlodek Effects of uteroplacental insufficiency and reducing litter size on maternal mammary function and postnatal offspring growth Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2008; 294(2): R539 - R548. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. R. Quesnell, X. Han, and B. D. Schultz Glucocorticoids stimulate ENaC upregulation in bovine mammary epithelium Am J Physiol Cell Physiol, May 1, 2007; 292(5): C1739 - C1745. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. I. Nielsen, T. Larsen, M. Bjerring, and K. L. Ingvartsen Quarter Health, Milking Interval, and Sampling Time During Milking Affect the Concentration of Milk Constituents J Dairy Sci, September 1, 2005; 88(9): 3186 - 3200. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. N. Seagroves, D. Hadsell, J. McManaman, C. Palmer, D. Liao, W. McNulty, B. Welm, K.-U. Wagner, M. Neville, and R. S. Johnson HIF1{alpha} is a critical regulator of secretory differentiation and activation, but not vascular expansion, in the mouse mammary gland Development, April 15, 2003; 130(8): 1713 - 1724. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
