The Experts below are selected from a list of 72453 Experts worldwide ranked by ideXlab platform

S O Osanyintuyi - One of the best experts on this subject based on the ideXlab platform.

Tahia H. Saleem - One of the best experts on this subject based on the ideXlab platform.

Stephen R. Max - One of the best experts on this subject based on the ideXlab platform.

  • Androgen-estrogen synergy in rat levator ani muscle Glucose-6-Phosphate Dehydrogenase
    Molecular and Cellular Endocrinology, 2003
    Co-Authors: Stephen R. Max
    Abstract:

    Abstract The effects of castration and hormone administration on the activity of Glucose-6-Phosphate Dehydrogenase in the rat levator ani muscle were studied. Castration caused a decrease in enzyme activity and in wet weight of the levator ani muscle. Chronic administration of testosterone propionate increased Glucose-6-Phosphate Dehydrogenase activity in the levator ani muscle of castrated rats; the magnitude of the recovery of enzyme activity was related to the length of time of exposure to testosterone propionate after castration as well as to the length of time the animals were castrated. The longer the period of castration before exposure to testosterone propionate, the greater the effect. This result may be related to previously reported castration-mediated increases in androgen receptor binding in muscle. Dihydro-testosterone was less effective than testosterone propionate in enhancing Glucose-6-Phosphate Dehydrogenase activity in the levator ani muscle from castrated rats; estradiol-17β alone was ineffective. Combined treatment with estradiol-17β and dihydrotestosterone, however, was as effective as testosterone alone. Thus, androgens and estrogens may exert synergistic effects on levator ani muscle.

Kamran Moradkhani - One of the best experts on this subject based on the ideXlab platform.

  • Molecular characterization of Glucose-6-Phosphate Dehydrogenase deficiency in Jeddah, Kingdom of Saudi Arabia
    BMC Research Notes, 2011
    Co-Authors: Soad Al-jaouni, Jummanah Jarullah, Essam Azhar, Kamran Moradkhani
    Abstract:

    ABSTRACT: BACKGROUND: The development of polymerase chain reaction (PCR)-based methods for the detection of known mutations has facilitated detecting specific red blood cell (RBC) enzyme deficiencies. We carried out a study on Glucose-6-Phosphate Dehydrogenase (G6PD) deficient subjects in Jeddah to evaluate the molecular characteristics of this enzyme deficiency and the frequency of nucleotide1311 and IVS-XI-93 polymorphisms in the Glucose-6-Phosphate Dehydrogenase gene. RESULTS: A total of 1584 unrelated Saudis (984 neonates and 600 adults) were screened for Glucose-6-Phosphate Dehydrogenase deficiency. The prevalence of Glucose-6-Phosphate Dehydrogenase deficiency was 6.9% (n=110). G6PD Mediterranean mutation was observed in 98 (89.1%) cases, G6PD Aures in 11 (10.0%) cases, and G6PD Chatham in 1 (0.9%) case. None of the samples showed G6PD A mutation. Samples from 29 deficient subjects (25 males and 4 females) were examined for polymorphism. The association of two polymorphisms of exon/intron 11 (c.1311T/IVS XI 93C) was observed in 14 (42.4%) of 33 chromosomes studied. This association was found in 9 (31.0%) carriers of G6PD Mediterranean and in 4 (13.8%) carriers of G6PD Aures. CONCLUSIONS: The majority of mutations were G6PD Mediterranean, followed by G6PD Aures and

Carlos Severo Dutra-filho - One of the best experts on this subject based on the ideXlab platform.

  • Phenylpyruvic Acid Decreases Glucose-6-Phosphate Dehydrogenase Activity in Rat Brain
    Cellular and Molecular Neurobiology, 2012
    Co-Authors: Andrea Pereira Rosa, Carlos Eduardo Dias Jacques, Tarsila Barros Moraes, Ângela Mattos Dutra, Clovis Milton Duval Wannmacher, Carlos Severo Dutra-filho
    Abstract:

    Phenylketonuria is a recessive autosomal disorder that is caused by a deficiency in the activity of phenylalanine-4-hydroxylase, which converts phenylalanine to tyrosine, leading to the accumulation of phenylalanine and its metabolites phenyllactic acid, phenylacetic acid, and phenylpyruvic acid in the blood and tissues of patients. Phenylketonuria is characterized by severe neurological symptoms, but the mechanisms underlying brain damage have not been clarified. Recent studies have shown the involvement of oxidative stress in the neuropathology of hyperphenylalaninemia. Glucose-6-Phosphate Dehydrogenase plays an important role in antioxidant defense because it is the main source of reduced nicotinamide adenine dinucleotide phosphate (NADPH), providing a reducing power that is essential in protecting cells against oxidative stress. Therefore, the present study investigated the in vitro effect of phenylalanine (0.5, 1, 2.5, and 5 mM) and its metabolites phenyllactic acid, phenylacetic acid, and phenylpyruvic acid (0.2, 0.6, and 1.2 mM) on the activity of enzymes of the pentose phosphate pathway, which is involved in the oxidative phase in rat brain homogenates. 6-Phosphogluconate Dehydrogenase activity was not altered by any of the substances tested. Phenylalanine, phenyllactic acid, and phenylacetic acid had no effect on Glucose-6-Phosphate Dehydrogenase activity. Phenylpyruvic acid significantly reduced Glucose-6-Phosphate Dehydrogenase activity without pre-incubation and after 1 h of pre-incubation with the homogenates. The inhibition of Glucose-6-Phosphate Dehydrogenase activity caused by phenylpyruvic acid could elicit an impairment of NADPH production and might eventually alter the cellular redox status. The role of phenylpyruvic acid in the pathophysiological mechanisms of phenylketonuria remains unknown.