Effect of cord factor, a toxic glycolipid from Mycobacterium tuberculosis, on mouse liver drug metabolizing enzymes.

Cord factor (a mycobacterial toxin) treatment of mice for 72 hr resulted in decreased activities of hepatic drug metabolizing enzymes. The toxin treated animals exhibited reduced levels of liver cytochrome P-450 and cytochrome b5, accompanied by significant lowering of NADPH-cytochrome c reductase and NADH-cytochrome b5 reductase activities. The hepatic activities of aminopyrine N-demethylase and aniline hydroxylase were diminished, while liver cytosolic glutathione S-transferase activity was inhibited in mice receiving the toxin. Earlier studies from this laboratory (J. K. Batra, Ph.D. Thesis, Delhi University, India, 1982) on the effects of experimental tuberculosis on hepatic drug metabolism revealed changes similar to the presently reported influence of cord factor on mouse liver microsomal monooxygenases. Thus, the action of cord factor (on hepatic drug metabolism) largely mimics the effects of tuberculosis infection.

Simultaneous determination of adreno-ovarian steroids from a single aliquot.

PIP: A standardized technique for simultaneous fractionation and estimation of samples of progesterone, estrone, 17alpha-estradiol, 17beta-estradiol, estriol, corticosterone, cortisone, and cortisol obtained from guinea-pigs during mid-pregnancy is presented. The hormones were separated on a single TLC plate using a single solvent system, and were measured on a single biphasic column on the basis of a single aliquot. The technique affords considerable utility in the inves tigation of the complexities of the adreno-genital syndrome. Progesterone content in the ovaries and plasma showed an increase of 77% during pregnancy, while plasma levels of estrone were increased by 34%. Urinary estradiol levels were also markedly increased. Plasma estradiol and estriol and placental estriol could not be detected by the technique. Adrenal cortisone levels and plasma cortisone and cortisol were considerably higher during pregnancy. An initial overlap was found between cortisol and estriol on the TLC plate, though subsequent estimation by GLC overcome the problem.^ieng

Pyridine nucleotides and redox state regulation of aflatoxin biosynthesis in Aspergillus parasiticus NRRL 3240.

In vivo regulation of lipid and aflatoxin biosynthesis by pyridine nucleotides and their derived functions was studied in Aspergillus parasiticus NRRL 3240. Aflatoxins, total lipids and pyridine nucleotide content were estimated under different growth conditions. Aflatoxin formation was highest in cultures grown in sucrose-low salts medium followed by asparagine- and zinc-deficient media. The lipid content of the cultures followed an inverse pattern. The levels of oxidized nucleotides decreased with age under all culture conditions employed. Concentrations of NADPH peaked before the onset of aflatoxin biosynthesis. For each medium used, the estimated catabolite reduction charge was constant at all stages of growth whereas the anabolic reduction charge varied. A direct relationship between the level of extracellular ammonium ions and anabolic reduction charge was established. A high anabolic reduction charge was associated with increased lipid biosynthesis rather than aflatoxin biosynthesis.