Correlation of Bovine Serum Macroglobulin and Calcium at Parturition
- Resource Type
- Authors
- L.B. Barnett; D.G. Doherty; J.R. Vercellotti; R.G. Cragle
- Source
- Journal of Dairy Science. 57:41-48
- Subject
- medicine.medical_specialty
animal structures
Globulin
Cattle Diseases
Ice calving
chemistry.chemical_element
Calcium
fluids and secretions
Pregnancy
Macroglobulins
Internal medicine
Lactation
Methods
Genetics
medicine
Animals
Paralysis
Magnesium
Bovine serum albumin
skin and connective tissue diseases
Labor, Obstetric
Hypocalcemia
biology
Chemistry
Milk fever
Puerperal Disorders
medicine.disease
Centrifugation, Zonal
Macroglobulin
medicine.anatomical_structure
Endocrinology
biology.protein
Cattle
Electrophoresis, Polyacrylamide Gel
Female
Animal Science and Zoology
Ultracentrifugation
circulatory and respiratory physiology
Food Science
- Language
- ISSN
- 0022-0302
Serum globulin varied little in cows sampled over a physiological cycle of 1 yr except at parturition and onset of lactation. The 19S macroglobulin peak in parturient cows was elevated 75% shortly before calving with a return to normal (4.8±.7% of serum protein) within 18 days after birth. Serum protein remained constant. A drop in serum calcium at birth accompanied the macroglobulin changes from 3.0mM to 1.9mM calcium. The elevated 19S macroglobulin component was α 2 -macroglobulin by preparative fractionation of macroglobulin samples followed by electrophoresis and by analytical ultracentrifuge studies. Eight cows with parturient hypocalcemia developed the same serum macroglobulin patterns as normal cows during parturition, but serum calcium dropped to .92mM with inorganic phosphate also decreasing significantly. We isolated, identified, and physically and chemically characterized bovine α 2 -macroglobulin to ascertain its function in physiological adjustments to parturition and lactation. Elevated α 2 -macroglobulin in parturient or milk fever cows and the diminished serum calcium of these animals were uncorrelated.