Showing papers by "Pallu Reddanna published in 2000"

Lipoxygenase Metabolites of α-linolenic Acid in the Development of Resistance in Pigeonpea, Cajanus cajan (L.) Millsp, Seedlings Against Fusarium udum Infection

Abstract: Lipoxygenase (LOX) activity was measured in germinating pigeonpea Cajanus cajan seedlings, resistant (ICP-8863) and susceptible (ICP-2376) to wilt fungus, before and after infection with Fusarium udum. LOX activity was significantly higher in the resistant than in the susceptible cultivars of pigeonpea and was enhanced further in response to infection with Fusarium udum. This increase in LOX activity in the resistant cultivars of pigeonpea appears to be due to the induction of lipoxygenase isozymes in response to infection. Analysis of the endogenous LOX metabolites in pigeonpea seedlings revealed the predominant formation of 13-hydroperoxyoctadecadienoic acid (13-HPODE) in healthy seedlings and 13-hydroperoxyoctadecatrienoic acid (13-HPOTrE) in infected seedlings. Further studies on the effects of LOX metabolites on the growth and multiplication of Fusarium udum showed that HPOTrEs, LOX metabolites of α-linolenic acid, are more anti-fungal compared to HPODEs, LOX metabolites of linoleic acid.

Xenoesterogens and male infertility: myth or reality?

Abstract: Aim: To evaluate the role of polychlorinated biphenyls (PCBs) as a potential environmental hazard in the deterioration of male fertility. Methods: Fifty-three males were studied. After a thorough case history evaluation and relevant clinical and laboratory investigations, PCBs were estimated in the seminal plasma of 21 infertile men with “Unexplained Male Factor” and 32 fertile controls. Peak retention times of the eluants were compared with those of the commercially available standard PCB Mix, and the results confirmed spectrophotometrically. Seminal PCB concentrations were compared between i) fertile and infertile men and ii) men from different areas and diets. The relationship between PCB concentrations and measures of sperm quality such as the total motile sperm count, was assessed. Results: PCBs were detected in seminal plasma of infertile men but absent from controls. Sperm quantity and quality were significantly lower in infertile men compared to controls. The highest average PCB concentrations were found in fish-eating urban dwellers, and followed in succession by fish-eating rural dwellers, non fish-eating urban dwellers and non fish-eating rural dwellers. The total motile sperm counts were inversely proportional to the PCB concentrations and were significantly lower than those of the respective controls. Conclusion: PCBs may be instntmental in the deterioration of sperm quantity and quality, a contaminated fish diet being the main source of exposure.(Asian J Androl 2000 Dec;2:263-269)

Purification and characterization of rat testicular glutathione S-transferases : role in the synthesis of eicosanoids

Abstract: Aim: Purification of glutathione S-transferases (GSTs) from rat testis; separation and identification of various subunits and their role in eicosanoid biosynthesis. Methods: Purification of rat testicular GSTs by affinity chromatography, employing S-hexylglutathione-linked epoxy-activated Sepharose 6B column and separation of individual subunits by reverse phase-high pressure liquid chromatography (RP-HPLC). Characterization of affinity purified GSTs by Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis. The role of testicular GSTs in eicosanoid biosynthesis was determined by incubating GSTs with 5, 6-Leukotriene A4Me (LTA 4 -Me) and prostaglandin H 2 (PGH 2 ) and analyzing the products formed on HPLC/TLC. Results: The present study reveals that majority of rat testicular GSTs are of Y b size (60%) with molecular weight of 27 kDa. The most predominant subunits, however, are GST Y n2 (27%), followed by GST Y c (24%) and GST Y n1 (20%). These testicular GSTs showed very high Leukotriene C 4 (LTC 4 ) synthase activity with 5, 6-Leukotriene A 4 Me(LTA 4 Me) as the substrate and prostaglandin D (PGD) synthase activity with prostaglandin H 2 (PGH 2 ) as the substrate. Conclusion: Majority of rat testicular GSTs are Y b sized and are involved in the synthesis of eicosanoids like LTC 4 and PGD 2 .