Veterinar, Vol. 59. No. 2., 2021.
Pregledni rad
Hormonal Regulation of the Development of the Mammary Gland and Milk Synthesis
Kristian Nikolić
Filip Čoklo
Lana Pađen
; Veterinarski fakultet Sveučilišta u Zagrebu, Zagreb, Hrvatska
Jasna Aladrović
; Veterinarski fakultet Sveučilišta u Zagrebu, Zagreb, Hrvatska
Sažetak
The growth and development of the mammary gland starts before the animal is born, and it is especially fast during puberty and gestation. The endocrine system coordinates the development of the mammary gland with the reproductive system and the metabolic needs of offspring. Before it starts producing milk, the development of the mammary gland is known as mammogenesis. The crucial hormones for mammogenesis are: growth hormones, insulin-like growth factor 1, glucocorticoids, thyroid gland hormones and sex hormones. Progesterone, estrogen, prolactin, growth hormone, placental lactogen, insulin and corticosteroids are of great importance for mammary gland development during pregnancy. Lactogenesis is the beginning of milk production. The first milk that the mammary gland produces is called colostrum. The process of maintaining milk production is called galactopoiesis, and the number of epithelial cells and milk production are in correlation during this process. Lactogenesis is primarily controlled by prolactin, and milk ejection is dependent on oxytocin. Prolactin has many biological functions inside the organism, and is released by the anterior lobe of the pituitary gland. Its main function is the gene expression necessary for milk protein synthesis. Oxytocin is crucial for myoepithelial cell contraction. These cells are found on the surface of the alveoli and milk ducts. Other hormones that are important for lactogenesis are: cortisol, progesterone, growth hormone and estrogens. Most of the organic milk compounds are synthetized only in the epithelial cells of the mammary gland. The four main constituents of milk are proteins, fats, lactose and minerals. If the udder is not emptied properly, milk production will drop due to alveoli and secretory tissue involution. After weaning of their young, the mammary gland goes through involution.
Ključne riječi
mammary gland; oxytocin; prolactin; milk; lactation
Hrčak ID:
274018
URI
Datum izdavanja:
20.1.2022.
Posjeta: 1.385 *