Origin, utilization, and recycling of nucleosides in the central nervous system.
نویسنده
چکیده
The brain relies on the salvage of preformed purine and pyrimidine rings, mainly in the form of nucleosides, to maintain its nucleotide pool in the proper qualitative and quantitative balance. The transport of nucleosides from blood into neurons and glia is considered to be an essential prerequisite to enter their metabolic utilization in the brain. Recent lines of evidence have also suggested that local extracellular nucleoside triphosphate (NTP) degradation may contribute to brain nucleosides. Plasma membrane-located ectonucleotidases, with their active sites oriented toward the extracellular space, catalyze the successive hydrolysis of NTPs to their respective nucleosides. Apart from the well-established modulation of ATP, ADP, adenosine (the purinergic agonists), UTP, and UDP (the pyrimidinergic agonists) availability at their respective receptors, ectonucleotidases may also serve the local reutilization of nucleosides in the brain. After their production in the extracellular space by the ectonucleotidase system, nucleosides are transported into neurons and glia and converted back to NTPs via a set of purine and pyrimidine salvage enzymes. Finally, nucleotides are transported into brain cell vescicles or granules and released back into the extracellular space. The key teaching concepts to be included in a two-to three-lecture block on the molecular mechanisms of the local nucleoside recycling process, based on a cross talk between the brain extracellular space and cytosol, are discussed in this article.
منابع مشابه
Staying Current Origin, utilization, and recycling of nucleosides in the central nervous system
Ipata PL. Origin, utilization, and recycling of nucleosides in the central nervous system. Adv Physiol Educ 35: 342–346, 2011; doi:10.1152/advan.00068.2011.—The brain relies on the salvage of preformed purine and pyrimidine rings, mainly in the form of nucleosides, to maintain its nucleotide pool in the proper qualitative and quantitative balance. The transport of nucleosides from blood into ne...
متن کاملCentral Nervous System Tumors in Guilan, Iran: Epidemiological Features Over 10 Years
Background: Tumors of the central nervous system (CNS) are a heterogeneous group of neoplasms with different prevalence in different sex and age groups and various parts of CNS. Objectives: Determining the relative frequency of different types of CNS tumors in different ages, sex and CNS anatomical locations. Materials and Methods: This retrospective study was performed using pathological repor...
متن کاملEffect of recycling solid oxide fuel cell products on the performance of a SOFC-Gas turbine hybrid system
In this study, the effect of recycling fuel cell products on the performance of a solid oxide fuel cell and gas turbine (SOFC-GT) hybrid system was investigated. Three types of products recycling are considered: cathode products recycling (CPR), anode products recycling (APR), and both cathode and anode products recycling (BACPR). In the present work, operating temperature and limiting curre...
متن کاملReview of the Aspergillosis and Report A Case of its Central Nervous System
SUMMARY Because Aspergillus SP. are one of the most common airborne fungal contaminants in all parts of the world, the incidence of Aspergillosis is relatively high, but will not be diagnosed in some cases. In this survey we decided to review the importance of Aspergillosis and also to report a case of its Central Nervous system involvement in a patient without Immunodeficiency.
متن کاملEvaluation of changes in testosterone concentration of the rat central nervous system following progesterone administration
Neurosteroids are steroids that are produced in the central nervous system (CNS). While progesterone and dehydroepiandostendione (the precursors of testosterone) are among the identified neurosteroids, it is not clear that testosterone could be considered as a neurosteroid. The testosterone synthesis has been demonstrated in the brain of castrated frog, but not in the rat brain. In the present ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Advances in physiology education
دوره 35 4 شماره
صفحات -
تاریخ انتشار 2011