ABSTRACT
Fermentation experiments with Streptomyces toxytricini were performed using (5Z,8Z)-[10,11,12,12-(2)H]tetradeca-5,8-dienoic acid or a mixture of [2,2-(2)H(2)]- and [8,8,8-(2)H(3)]octanoic acid as supplements. (2)H NMR and mass spectroscopy confirmed the incorporation of (5Z,8Z)-[10,11,12,12-(2)H]tetradeca-5,8-dienoic acid into the C(13) side chain as well as into the C(6) side chain of lipstatin. Moreover, deuterium was incorporated into the C(6) side chain of lipstatin from the 8-position but not from the 2-position of octanoate. The data establish that the beta-lactone moiety of lipstatin is formed by condensation of a C(8) and a C(14) fatty acid with a concomitant exchange of the H-2 atoms of the C(8) fatty acid.
Subject(s)
Caprylates/metabolism , Fatty Acids, Unsaturated/metabolism , Lactones/metabolism , Streptomyces/metabolism , Deuterium , Fermentation , Magnetic Resonance SpectroscopyABSTRACT
A group of 1,052 C578L/6J mice -- 296 males and 756 females - was kept under well defined, clean, conventional conditions from the age of 6 weeks until natural death. At regular time intervals several hematological values were examined from 50 to 60 randomly selected animals of each sex and statistically evaluated. The hematological investigations did not reveal any important sex-related differences. A significant gradual decrease of the RBC counts and hemoglobin content was observed during the life-span. Lymphocyte and total WBC counts were subject to considerable variation. They decreased in the first two-thirds of life and increased in the last third. Neutrophils remained rather stable and exhibited an increasing trend in the higher age. The relative level of lymphocytes decreased signficantly in favour of neutrophils during natural aging.
Subject(s)
Aging , Blood Cell Count , Animals , Erythrocyte Count , Female , Hemoglobinometry , Leukocyte Count , Lymphocytes , Male , Mice , Mice, Inbred C57BL , NeutrophilsABSTRACT
A group of 1,052 C57BL/6J mice (296 males and 756 females) was kept under well-defined, clean laboratory conditions from the age of 6 weeks until natural death. The survival curves of males and females (computer-produced 3, 4, and 5 parameter curves, Gompertz curve histogram) were established and shown to follow a logistic function. The average life-span amounted to 878 plus or minus 10 days for males and 794 plus or minus 6 days for females. These values distinctly exceed comparable values given in the literature. They are attributed to favorable conditions of animal care and to supposed alterations in genetic background. A genetic drift in sex-dependent mean survival time occurred in the genetically unstable C57BL/6J strain between 1966 and 1970. Before this drift, the males died sooner; after it, they lived longer.
