Enhancement of Chemotactic Response of Polymorphonuclear Leukocytes into the Mammary Gland and Isolation from Milk

• Published in: Journal of dairy science 1977-01, Vol.60 (1), p.53-62
• Main Authors: Paape, M.J., Pearson, R.E., Wergin, W.P., Guidry, A.J.
• Format: Article
• Language: English
• Subjects: Animals; Cattle - immunology; Chemotaxis, Leukocyte - drug effects; Female; Glycogen - pharmacology; Lactation; Mammary Glands, Animal - drug effects; Mammary Glands, Animal - immunology; Milk - cytology; Neutrophils - ultrastructure; Phagocytosis; Pregnancy; Sodium Chloride - pharmacology; Staphylococcus aureus
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.S0022-0302(77)83828-9

Intramammary infusion of saline containing .1% glycogen resulted in diapedesis of numerous leukocytes (93% polymorphonuclear leukocytes) into milk. Direct microscopic somatic cell counts of primary milk 11h after infusion with 100ml of either saline containing .1% glycogen, saline, distilled water, or noninfused averaged 4.17, 1.06, .05, and .10×106 cells/ml of milk. Four times more polymorphonuclear leukocytes were isolated from residual milk (6.1×109 cells) collected 11h following infusion than from primary milk (1.5×109). The polymorphonuclear leukocytes isolated from either the primary or residual milk collected 11h after infusion of saline containing .1% glycogen phagocytosed Staphylococcus aureus with great avidity. Sixty-eight percent of a culture of heatkilled phosphorus-32-labeled Staphylococcus aureus (400×106) were phagocytosed within 60min by 25×106 polymorphonuclear leukocytes. When isolated polymorphonuclear leukocytes were incubated with live Staphylococcus aureus, 98% of the ingested organisms were killed. Isolation of polymorphonuclear leukocytes from residual milk 11h after intramammary infusion of saline containing .1% glycogen will provide large numbers of polymorphonuclear leukocytes for in vitro studies of the cellular defense of the mammary gland.