Effects of extracellular Ca2+ on phagocytosis and intracellular Ca2+ concentrations in polymorphonuclear leukocytes of postpartum dairy cows

Res Vet Sci. 2003 Aug;75(1):27-32. doi: 10.1016/s0034-5288(03)00038-9.


The aim of this study was to determine the effects of extracellular Ca(2+) concentration ([Ca(2+)](e)) on phagocytosis and intracellular Ca(2+) concentration ([Ca(2+)](i)) in bovine polymorphonuclear leukocytes (PMNs). The experiments were performed by using blood samples from parturient paretic and clinically normal parturient cows and manipulating the [Ca(2+)](e) in vitro. Phagocytosis by PMNs (with and without stimulation with phorbol myristate acetate and inhibition with cytochalasin B) and resting [Ca(2+)](i) were significantly lower in parturient paretic cows. Repletion of Ca(2+) in the extracellular media for the samples from these animals increased phagocytosis and resting [Ca(2+)](i). In the blood of clinically normal parturient cows, decreasing the [Ca(2+)](e) decreased phagocytosis and resting [Ca(2+)](i) in PMNs, but increasing the [Ca(2+)](e) did not affect phagocytosis. These results suggest that the hypocalcemic condition of parturient paretic cows in vivo causes decreased phagocytosis and resting [Ca(2+)](i) in PMNs, which may partly contribute to greater susceptibility to infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adjuvants, Immunologic / metabolism
  • Animals
  • Calcium / administration & dosage
  • Calcium / blood
  • Calcium / metabolism*
  • Cattle
  • Cattle Diseases / blood
  • Cattle Diseases / immunology*
  • Cytochalasin B / metabolism
  • Female
  • Neutrophils / immunology*
  • Neutrophils / metabolism
  • Parturient Paresis / blood
  • Parturient Paresis / immunology
  • Phagocytosis / immunology*
  • Postpartum Period / blood
  • Postpartum Period / immunology
  • Pregnancy
  • Tetradecanoylphorbol Acetate / metabolism


  • Adjuvants, Immunologic
  • Cytochalasin B
  • Tetradecanoylphorbol Acetate
  • Calcium