Showing papers by "Pallu Reddanna published in 1989"

The role of vitamin E and selenium on arachidonic acid oxidation by way of the 5-lipoxygenase pathway.

Abstract: Arachidonic acid, the most abundant Go polyunsaturated fatty acid found in the phospholipids of mammalian tissues, is a biosynthetic precursor of several families of compounds that exert diverse biological effects. Once the action of phospholipases releases arachidonic acid from phospholipids, it is metabolized by one of the two pathways shown in FIGURE 1. The cyclooxygenase pathway produces prostaglandins (PG), thromboxanes (TX), and prostacyclins (PGI), whereas the lipoxygenase pathway leads to the formation of leukotrienes (LT) and lipoxins. The enzymic oxidation of arachidonic acid by way of the cyclooxygenase and lipoxygenase pathways to produce a spectrum of biologically active compounds is collectively referred to as the arachidonic acid cascade. Recent attention has focused on those factors that can regulate the concentration of these biologically active eicosanoids, especially in relation to their possible role in several pathological conditions including arteriosclerosis, arthritis, asthma, and anaphylactic reactions.'-3 One area of particular interest has been the effect of fatty acid hydroperoxides (FAHP) on lipoxygenase and cyclooxygenase activities. For example, both cyclooxygenase and lipoxygenase exhibit an obligatory requirement for FAHP ( < 1 pM) as an activator; however, these enzymes are inhibited by higher concentrations (> 10 pM) of FAHP.\"' The interest in FAHP, as modulators of the arachidonic acid cascade, probably reflects the implication of lipid peroxidation, one of the possible sources of FAHP formation, in many pathological and nonpathological in vivo processes.

In vitro effects of gossypol and lactic acid on rat uterus and ovary during implantation and antiimplantation.

Abstract: ATPase activity of uterus and ovary was markedly elevated in presence of gossypol and decreased in presence of lactic acid indicating activation and inhibition of energy metabolism by gossypol and lactic acid respectively. The elevated levels of glycogen in uterus indicate inhibition of glycogenolysis as supported by phosphorylase activity. Whereas in ovary the glycogen depletion indicates activation of glycogenolysis supported by phosphorylase activity. The activity levels of aldolase and G-6-PDH decreased in the uterus in presence of gossypol and increased in presence of lactic acid. The same were elevated in ovary indicating the activation of hexose mono and diphosphate pathways. Lactic acid accumulated in presence of both gossypol and lactic acid with a depletion in level of pyruvic acid in both the tissues. This situation in the uterus indicates the condition of anti-implantation in presence of both gossypol and lactic acid. The NAD-LDH activity was inhibited in presence of gossypol and activated in presence of lactic acid in both tissues.