Enzymatic histamine catabolism in vertebrate ontogenesis. A comparative study

Proteomic analysis of liver development of lean Pekin duck (Anas platyrhynchos domestica)

The liver plays vital roles in digestion, metabolism and immune defense. To elucidate the molecular mechanism of nutrient metabolism and antioxidation of lean Pekin duck liver from hatching to slaughter, the proteome changes were investigated using 2-DE, MS, quantitative real-time PCR and bioinformatics. A total of 59 differentially expressed proteins were identified. Proteins involved in transportation were highly up-regulated in newborn ducks whereas 37 proteins associated with metabolism, defense and antioxidation were up-regulated in adult ducks. The over-expression of proteins at the last developmental stage presumably occurs to fulfill the needs of multiple functions of the liver. However, the over-expressed proteins related to transportation during the first developmental stage are involved in maintaining the high basal metabolism of newborn ducks. The functional enrichment analysis also confirmed these results. Furthermore, the protein interaction network predicted 28 proteins acting as key nodes for liver development. The validated expression between proteins and genes provides us target genes for future genetic analyses to improve the health and performance of these ducks. These significant advanced proteome data expand our knowledge on the physiology of the duck liver, thereby providing a potentially valuable foundation for molecular breeding to enhance feed efficiency and immunity and for optimizing the feeding strategy.

Decreased histamine content and metabolism in mammary cancer tissue from C3H mice

Histamine (HA) level and its metabolism in adenocarcinoma mammae, spontaneously growing cancer in C3H mice, were examined in relation to the type of tumor, intensity of tumor vascularization and the presence or absence of a secretory function. Histamine concentration being in mammary gland one of the highest among mammalian organs (418 nmol/g) was decreased by 90% in tumor (34 nmol/g). Similarly, histidine decarboxylase (HDC) activity dropped from approximately 7.6 pmol/min/g in normal gland to an undetectable level in adenocarcinoma mammae. Of the two main HA degrading enzymes, namely, diamine oxidase and histamine N-methyl-transferase (HMT), only HMT could be detected in mammary gland, either healthy or neoplastic, and its activity was about 5-fold lower in tumor than in the control tissue (1 nmol/g/min vs. 5.2 nmol/g/min). The pattern of changes in histaminergic parameters evoked by the tumor was similar irrespective of the morphological type it represented, characteristics of its vascular bed or whether or not it showed secretory activity.

Histamine in C3H/W mice carrying spontaneous tumors of the mammary gland

Adenocarcinoma mammae, a spontaneously growing mammary cancer in C3H/W mice, contrary to many transplanted tumors does not evoke any rise in histamine level either in the tumor or in distant tissues. On the other hand, the histamine level is reduced by 90% in the tumor in comparison with the healthy gland. This seems to be a consequence of the fall of histidine decarboxylase activity to below a detectable level. There is also a significant reduction in histamine N-methyltransferase activity to one-fifth of the control level. The healthy mammary gland contains a high concentration of histamine and catabolizes it exclusively through the methylation pathway.

Histamine catabolism in proliferating skin

The histamine (HI) content and the activities of the enzymes involved in its degradation have been studied in guinea pig skin after stimulation of epidermal proliferation. As compared with unstimulated skin the HI content and histamine N-methyltransferase (HMT) activity in the stripped skin were reduced at the time of increased epidermal proliferation and were higher than the normal when the epidermis becomes hyperplastic. Diamine oxidase (DAO) followed an inverse pattern.