Local control of mammary involution: is stanniocalcin-1 involved?

Area of Science:

• Veterinary Science
• Endocrinology
• Cell Biology

Background:

• Local control mechanisms of mammary gland involution are not fully understood.
• Stanniocalcin-1 (STC-1), a mammalian hormone, is potentially involved in lactation and involution.

Purpose of the Study:

• To investigate the role of STC-1 in mammary gland involution.
• To measure changes in STC-1 levels in milk and serum during the drying-off period in dairy cows.

Main Methods:

• Holstein cows underwent unilateral drying off for 14 days.
• Milk, serum, and mammary biopsies were collected at various time points.
• STC-1 concentrations, milk proteinase activity, albumin, and mammary epithelial apoptosis were quantified.
• In vitro studies assessed the effects of milk from involuting glands on mammary epithelial cells.

Main Results:

• STC-1 and proteinase activity increased in non-milked quarters, while milk production in milked quarters rose by 30%.
• Mammary epithelial apoptosis was significantly higher in non-milked quarters by day 2.
• Milk from involuting quarters induced higher apoptosis and reduced metabolic activity in mammary epithelial cells in vitro.
• Milk STC-1 concentration negatively correlated with metabolic activity.

Conclusions:

• STC-1 levels in milk increase with milk stasis during mammary gland involution.
• STC-1 may contribute to the regulation of mammary epithelial cell apoptosis and metabolic activity during involution.
• Further research is needed to elucidate the precise role of STC-1 in the involution process.