Xanthine oxidoreductase exists in two functionally distinct forms, xanthine dehydrogenase (XDH, D-form) and xanthine oxidase (XOX, O-form). Under normal conditions, the larger part of the enzyme occurs in an NAD+-dependent dehydrogenase form that produces NADH and urate. The dehydrogenase can be transformed under various (patho)physiological conditions to an oxygen-dependent oxidase which produces reactive oxygen species [...]
Maf is a family of oncogenes originally identified in an avian oncogenic retrovirus, AS42, encoding bZIP transcription factors. Recently, two maf-related clones, c-maf (maf-2) and mafB (maf-1), were isolated from genes of the rat liver complementary DNA library. It has been reported that genes of the maf family have essential roles in embryonic development and [...]
Androgens are essential in males for the development and maintenance of specific reproductive organs such as testes, prostate, and epididymis. The biochemical aspects of androgen metabolism are now of special interest since recent data imply that estrogens play an important role in modulating the function of the male gonad, especially in germ cell development. The [...]
Methylxanthines induce bronchospasmolytic effects in asthmatic patients due to their nonspecific inhibition of phosphodiesterases and a subsequent increase in intracellular levels of the second messenger cAMP. Methylxanthines also increase ciliary beat frequency and stimulate mucociliary transport. Previous studies have demonstrated overstimulation and damage to tracheal goblet cells as well as a substantial decrease in the [...]
Sildenafil citrate has been shown to be highly effective in the treatment of erectile dysfunction and it is used to treat impotence of various etiologies with good tolerance.
The penis is composed of three columns of erectile tissue each enclosed by its own dense fibrous connective tissue. Corpora cavernosa, two of the three columns of erectile [...]
The pineal secretory product melatonin was recently shown to have free radical scavenging properties. Melatonin also activates several antioxidative enzymes including glutathione (GSH) peroxidase, modulates gene expression for several protective enzymes and reduces lipid peroxidation. Additionally, the antioxidant effects of melatonin are probably based on its stimulatory effect on the expression of superoxide dismutase, GSH [...]
Caveolin-1 is an integral membrane protein, with both the N- and C-terminal domains being cytoplasmic, and is the principal component of caveolar membranes. Caveolae are specialised vesicular microdomains of the plasma membrane that are formed by localised accumulation of cholesterol, glycosphingolipids, and caveolin. Caveolae can be found individually or in clusters and are found in [...]
Number and volume of peroxisomes are increased and peroxisomal ?-oxidation enzymes such as acyl-CoA oxidase (AOX) are induced when responsive animals are exposed to peroxisome proliferators. This phenomenon is known as peroxisome proliferation and it has been observed in several fish species after treatment with fibrate hypolipidemic drugs and a diverse array of environmental organic [...]
Many molecules and biochemical cascades that mediate sperm–egg interactions and egg activation have been discovered, but much still remains to be understood. Studies in the past were often focused on the identification of specific molecules such as egg and sperm receptors and egg activation and transduction pathways, but relatively few studies dealt with more general [...]
The grass lizard, Takydromus wolteri Fischer, belonging to the Laceridae in the order of Lacertinae, lives in eastern part of Russia, China and Korea and is considered to be a primitive palearctic lacertid, most closely related to Lacerta vivipara. They have a distinct white ventrolateral band running from the tip of the snot to the [...]