Handbook of Vitamin C Research

xivHubert Kucharski and Julek Zajacor deficient ascorbate levels have been correlated with low sperm counts, increased numbersof abnormal sperm, reduced motility and agglutination. Decreased ascorbate concentrationsin semen are associated with poor breeding performance in bulls, while scorbutic guinea pigsdeveloped defective testicular germinal epithelium. Such studies suggest that ascorbatedeficiency can be harmful both to the structure and function of the male reproductive tract—in vitro loss of spermatozoa‘s motility in human sperm. This chapter attempts to examine thevarious causes of male and female infertility and the role of OS in various reproductivedisorders.Chapter XI - Epileptic seizures result from excessive discharge in a population ofhyperexcitable neurons. Excessive production of ROS (reactive oxygen species) is thought tocontribute to epilepsy, and there is a potential connection between ROS and mitochondrialdysfunction in epilepsy. Free radical generation can also induce seizure activity by directactivation of glutamine synthatase, thereby permitting an abnormal buildup of glutamic acid,the excitatory neurotransmitter. The brain is extremely susceptible to oxidative damageinduced by these ROS because it generates extremely high levels of ROS due to its very highaerobic metabolism and blood perfusion, and it has a relatively poor enzymatic antioxidantdefense. Recent research on vitamin C (ascorbic acid, or ascorbate) has pointed out novelmechanisms of its action such as that of neuromodulator in addition to its well-knownantioxidant activity. In the current study, the author reviews the dose-dependent effects ofascorbate in intracellular signaling pathways of oxidative stress in epilepsy, focusing on itsmodulation of neuronal survival.The author also focuses on ascorbic acid deficiency andtreatments in intracellular signaling pathways in the brain as well as in dietary requirements,and he discusses the effects of antiepileptic drugs on plasma ascorbate levels. The authorconcludes with a note on the putative protective role of vitamin C in the neurodegenerativeprocess as well as in epileptic diseases.Chapter XII - Physiological condition of Norway spruce (Picea abies (L.) Karst.) andconsequently vitality of forest ecosystems was intensively studied in the period 1991 – 2007in northern Slovenia, i.e., in an area influenced by the Šoštanj Thermal Power Plant (ŠTPP).ŠTPP, which is the largest Slovene thermal power plant, used to be the largest Sloveneemission source of gaseous pollutants (e.g., SO 2 , NO x ), and very important source of differentinorganic (e.g., heavy metals) as well as organic toxic substances (e.g., PAHs). However,extremely high SO 2 emission (up to 86,000 t in 1993, and > 120.000 in the 1980s,respectively) and dust emissions (up to 8,000 in 1993), have been dramatically reduced afterthe installation of desulphurization devices in the late 1990s. Indeed in comparison with1993, SO 2 emissions in 2007 were reduced more than 15-fold and dust emissions more than35-fold, respectively. These extreme exposures in the past as well as huge changes inenvironmental pollution during the last two decades have significantly influenced the vitalityof forest ecosystems including physiological conditions (e.g., contents of antioxidant) ofdifferent tree species in the study area. Therefore, vitamin C (ascorbic acid) as a sensitive,non-specific bioindicator of stress caused either by anthropogenic (e.g., air pollution) ornatural stressors (climatic conditions, diseases, altitude gradient, etc.) was included in apermanent survey of forest conditions in northern Slovenia. Atmospheric pollutants such asozone and sulphur dioxide cause formation of free radicals, which are involved in oxidationof proteins and lipids and injury of plant tissues. Plant cells have evolved a special