ENZYME ACTIVITY OF HUMAN MILK DURING THE FIRST MONTH OF LACTATION
Gordana Kocić, Ljiljana Bjelaković, Tatjana Cvetković, Zoran Pop-Trajković, Marina Jonović, Bojko Bjelaković, Dušan Sokolović, Tatjana Jevtović and Dušica Stojanović
The dynamic of enzyme activities in human colostrum and milk changes, depending on the lactation stimulation. The aim of the study was to study the activity of alkaline phosphatase, amylase, transaminases (ALT and AST) and lactate dehydrogenase (LDH) in the samples of human colostrum and mature milk obtained by manual squeezing. The study involved 35 women, 18-39 years of age, who had given birth at the Clinic for Gynecology and Obstetrics, Faculty of Medicine in Niš, with normal delivery, without any complications reported. The samples of colostrum and milk were collected by mechanical squeezing of milk during three intervals: the first sample of colostrum was obtained immediately after the appearance of the first drops of milk after childbirth; the second sample was obtained after 24 hours, and the third after one month. The samples were collected in the morning, and kept in sterile test tubes in the freezer until the performance of analysis. The activity of these enzymes was reduced (statistically significant for amylase) in the period after one month, which means that it corresponded to the amount of protein. The activity of transaminases (ALT and AST) and alkaline phosphatase activity showed a tendency to fall after a month, but statistically significant difference was obtained with AST. The dynamic of alkaline phosphatase activity showed statistically significant decrease after one month. Enzyme activity in human milk represents an important field of research, from the aspect of functional importance and benefits of human milk compared to the cow’s milk, in which enzymes are generally destroyed by pasteurization. On the other hand, increased activity of certain enzymes may be a useful and valid diagnostic marker of mechanical tissue irritation, epithelial desqamation and increase of the concentration of inflammatory cells during mastitis. Acta Medica Medianae 2010;49(2):20-24.
Key words: human milk, colostrum, alkaline phosphatase, amylase, transaminase, lactate-dehydrogenase