HISTAMINE IN MAMMARY-GLAND - PREGNANCY AND LACTATION

1. Histamine concentration, kistidine decarboxylase (HDC), histamine N -methyltransferase (HMT) and transglutaminase (TG ase) activities have been followed in mouse and guinea pig mammary gland during pregnancy and lactation. 2. The most significant changes concerned histidine dec arboxylase (HDC) activity and their pattern was similar for the two sp ecies. In either species 2nd trimester of pregnancy was associated wit h stimulation whereas early lactation was associated with reduction of the tissue HDC activity. 3. Hormonal control of HDC is suggested on t he basis of Variations in the enzyme activity and histamine concentrat ion in mammary gland during estrous cycle. 4. The circumstantial evide nce is provided indicating that histamine might be involved in pregnan cy associated growth of mammary gland and in excretory activity of lac tating gland. Copyright (C) 1996 Elsevier Science Inc.