Effect of irradiation on the properties of pollen in austrian and scotch pines

Zusammenfassung Kohlenhydrate, amylolytische Aktivität und Aminosäuren wurden in nicht bestrahlten und bestrahlten Pollen der gemeinen Kiefer und Schwarzkiefer bestimmt. Die Bestrahlung bis zu 1200 r hatte keinen signifikanten Einfluss auf den Gehalt an Aminosäuren, doch kann die Bestrahlung die Menge der reduzierenden Zucker bedeutend verändern. So kam es zur Ausgleichung des Zuckergehalts des unbestrahlten gemeinen Kieferpollens mit dem Zuckergehalt der bestrahlten Schwarzkiefer bei 1000 r. Unter diesen ähnlichen Bedingungen gelang die Befruchtung der genannten Kiefern.

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This investigation was supported partly by grants from the Yugoslav Federal Nuclear Energy Commission and the Federal Research Work Fund.     

Zinc,copper and selenium in reproduction

Of the nine biological trace elements, zinc, copper and selenium are important in reproduction in males and females. Zinc content is high in the adult testis, and the prostate has a higher concentration of zinc than any other organ of the body. Zinc deficiency first impairs angiotensin converting enzyme (ACE) activity, and this in turn leads to depletion of testosterone and inhibition of spermatogenesis. Defects in spermatozoa are frequently observed in the zinc-deficient rat. Zinc is thought to help to extend the functional life span of the ejaculated spermatozoa. Zinc deficiency in the female can lead to such problems as impaired synthesis/secretion-of (FSH) and (LH), abnormal ovarian development, disruption of the estrous cycle, frequent abortion, a prolonged gestation period, teratogenicity, still-births, difficulty in parturition, pre-eclampsia, toxemia and low birth weights of infants. The level of testosterone in the male has been suggested to play a role in the severity of copper deficiency. Copper-deficient female rats are protected against mortality due to copper deficiency, and the protection has been suggested to be provided by estrogens, since estrogens alter the subcellular distribution of copper in the liver and increase plasma copper levels by inducing ceruloplasmin synthesis. The selenium content of male gonads increases during pubertal maturation. Selenium is localized in the mitochondrial capsule protein (MCP) of the midpiece. Maximal incorporation in MCP occurs at steps 7 and 12 of spermatogenesis and uptake dereases by step 15. Selenium deficiency in females results in infertility, abortions and retention of the placenta. The newborns from a selenium-deficient mother suffer from muscular weakness, but the concentration of selenium during pregnancy does not have any effect on the weight of the baby or length of pregnancy. The selenium requirements of a pregnant and lactating mother are increased as a result of selenium transport to the fetus via the placenta and to the infant via breast milk.     

Investigations on the turnover of adrenocortical mitochnodria. VII. Effects of ACTH on the half-life of mitochondria from the zona reticularis of the rat adrenal cortex.

The half-life of mitochondria from the zona reticularis of the rat adrenal was calculated by determining the radioactivity decay curves of the mitochondrial compartment of 3H-thymidine-injected animals, using autoradiographic methods. ACTH was found to enchance significantly the half-life of the organelles.