Glucose-6-phosphatase and age: biochemical and histochemical studies

The effect of protein-xanthophyll concentrate (PX) from alfalfa (Medicago sativa L.) on the activity of selected enzymes in the liver cells of fattening pigs

The available Polish and foreign literature contains few reports on the activity of indicator enzymes, especially marker enzymes, which characterize the work of specific cell organelles. Information on enzyme changes induced by experimental dietary factors is also scarce. We postulated that proteinxanthophyll PX alfalfa concentrate would have a positive effect on metabolism in fattening pigs, resulting in improved performance parameters. Therefore the aim of the study was to test the possibility of using enzymes that have not previously been used to assess the biochemical processes taking place following administration of PX. We evaluated the activity of enzymes associated with key biological transformations taking place in the cell, as this makes it possible to assess whether these processes are proceeding normally and to evaluate the response of the body to external factors. The experiment was conducted on 288 finishers (gilts and barrows), all of which were crossbreds (Polish Large White x Neckar), divided into 4 groups according to the dosage and duration of administration of proteinxanthophyll PX concentrate from alfalfa (Medicago sativa L.). The alfalfa concentrate was introduced to the compound feed in place of soybean extraction meal. We analysed the activity of selected marker enzymes: lactate dehydrogenase (LDH), malate dehydrogenase (MDH), succinate hydrolase (SDH), and glucose-6-phosphate hydrolase (G6PC). We found a decrease in the activity of the enzymes in the liver cells of the pigs receiving the PX concentrate as compared to the control, which suggests that the product had a favourable effect on their metabolism. The results confirm the benefit of using proteinxanthophyll PX in pig feed, particularly at a continuous dose of 3%.

Immunolocalization and expression of kinin B1R and B2R receptors in human inflammatory bowel disease

Bradykinin is a mediator of inflammation, responsible for pain, vasodilation, and capillary permeability. Bradykinin receptor 1 (B(1)R) and bradykinin receptor 2 (B(2)R) are G protein-coupled receptors that mediate kinin effects. The latter is constitutive and rapidly desensitized; the former is induced by inflammatory cytokines and resistant to densensitization. The distribution of bradykinin receptors in human intestinal tissue was studied in patients with inflammatory bowel disease (IBD), namely ulcerative colitis (UC) and Crohn's disease (CD). Both B(2)R and B(1)R proteins are expressed in the epithelial cells of normal and IBD intestines. B(1)R protein is visualized in macrophages at the center of granulomas in CD. B(2)R protein is normally present in the apexes of enterocytes in the basal area and intracellularly in inflammatory tissue. In contrast, B(1)R protein is found in the basal area of enterocytes in normal intestine but in the apical portion of enterocytes in inflamed tissue. B(1)R protein is significantly increased in both active UC and CD intestines compared with controls. In patients with active UC, B(1)R mRNA is significantly higher than B(2)R mRNA. However, in inactive UC patients, the B(1)R and B(2)R mRNA did not differ significantly. Thus bradykinin receptors in IBD may reflect intestinal inflammation. Increased B(1)R gene and protein expression in active IBD provides a structural basis of the important role of bradykinin in chronic inflammation.

Genomic effect of glucocorticoids on enzymes of intermediary metabolism in Oreochromis mossambicus

The present study examined the effect of long-term treatment with cortisol and corticosterone on enzymes of intermediary metabolism, namely malic enzyme (ME), glucose-6-phosphate dehydrogenase (G6PDH), isocitrate dehydrogenase (ICDH), glucose 6 phosphatase (G-6-Pase), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) in Oreochromis mossambicus. Cortisol and corticosterone regulate intermediary metabolism in the liver of O. mossambicus as evidenced by changes in the activity pattern of gluconeogenic and lipogenic enzymes and amino-transferases. The long-term in vivo ip administration of glucocorticoids (GCs) suggests hyperglycemic, gluconeogenic, and antilipogenic roles of the hormones in O. mossambicus. The genomic mode of action of GCs is well established in the present study since the long-term treatment is sensitive to the action of transcription and translation inhibitors.

Liver disease in the elderly

Despite several morphologic and functional changes that have been described in the aging liver, most relevant studies fail to identify a significant age-related deficit in liver function in humans. One of the important age-related changes is a decrease in regenerative capacity, which may partly explain the impaired recovery after severe viral and toxic injury in the elderly. Nevertheless, livers from older subjects are used successfully for transplantation. Substantial morbidity and mortality in the elderly is attributable to liver diseases, and the number of patients older than 65 years of age with chronic liver disease is increasing rapidly. Although there are no liver diseases specific to advanced age, the presentation, clinical course and management of liver diseases in the elderly may differ in important respects from those of younger individuals.