This study was undertaken to characterise the protein phosphatases in bovine adrenal chromaffin cells acting on tyrosine hydroxylase. Cells were pre-labelled with 32Pi and permeabilized with digitonin. The extent of dephosphorylation of Ser-8, Ser-19, Ser-31 and Ser-40 on tyrosine hydroxylase was found to be 30%, 38%, 37% and 71% respectively over 5 min. For Ser-19, Ser-31 and Ser-40 the dephosphorylation was entirely due to protein phosphatase 2A, as the dephosphorylation could be completely blocked by microcystin, but not by the protein phosphatase I inhibitory peptide. Permeabilization did not change the distribution of protein phosphatase 2A or tyrosine hydroxylase, or the activity of PP2A, from that occurring in intact cells. The dephosphorylation of Ser-8 was not altered by any inhibitor, suggesting the involvement of other protein phosphatases. The method developed here can be used to determine the protein phosphatases acting on substrates in conditions closely approximating those in situ, including the endogenous state of substrate phosphorylation and phosphatase location.
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http://dx.doi.org/10.1023/a:1014880403970 | DOI Listing |
J Pediatr Endocrinol Metab
January 2025
Department of Rare Diseases, Institute of Graduate Studies in Health Sciences, Istanbul University, Istanbul, Türkiye.
Objectives: Phenylketonuria (PKU) and tyrosinemia type 3 (HT3) are both rare autosomal recessive disorders of phenylalanine-tyrosine metabolism. PKU is caused by a deficiency in phenylalanine hydroxylase (PAH), leading to elevated phenylalanine (Phe) and reduced tyrosine (Tyr) levels. HT3, the rarest form of tyrosinemia, is due to a deficiency in 4-hydroxyphenylpyruvate dioxygenase (HPD).
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Federal University of Technology, Akure, Ondo, Nigeria.
Background: In recent decades, epidemiological and experimental studies have looked into the role of pesticides, particularly the herbicide paraquat, in the development of Parkinson's disease. Horseradish tree (Moringa oleifera) is an ethnobotanical plant with lots of therapeutic potential, but there is a dearth of information on the bioactive properties of the seed alkaloid extracts.
Method: This study examined the modulatory effects of various concentrations of an alkaloid extract from the seeds of Horseradish Tree (Moringa oleifera) on the survival rate of flies exposed to paraquat, as well as certain biochemical and molecular markers related to Parkinson's disease in the heads of the flies.
Andrology
January 2025
Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, Brazil.
Background: 6-Nitrodopamine (6-ND) released from rat vas deferens acts an endogenous modulator of vas deferens contractility.
Objectives: To investigate whether rat isolated seminal vesicles (RISV) releases 6-ND, the mechanisms involved in the release, and the modulatory role of 6-ND on tissue contractility.
Methods: Rat seminal vesicles were removed and placed in Krebs-Henseleit's solution at 37°C for 30 min, and an aliquot was used to analyze the concentrations of 6-ND, dopamine, noradrenaline, and adrenaline by liquid chromatography with tandem mass spectrometry (LC-MS/MS).
J Vet Res
December 2024
Department of Biophysics, Faculty of Environmental Biology, University of Life Sciences in Lublin, 20-950 Lublin, Poland.
Introduction: This study explored the effects of prenatal exposure to fumonisins B (FB) on bone innervation in newborn Wistar rats.
Material And Methods: Pregnant dams (n = 6 per group) were assigned to either the control or one of two FB-exposed groups (60 mg or 90 mg/kg body weight) from the 7 day of gestation until parturition. On the day of parturition, one male pup from each litter (n = 6 per group) was randomly selected and euthanised, and their femurs were dissected for analysis.
NPJ Parkinsons Dis
January 2025
Université de Bordeaux, Institut des Maladies Neurodégénératives, Bordeaux, France.
Parkinson's disease arises from the degeneration of dopaminergic neurons in the substantia nigra pars compacta, leading to motor symptoms such as akinesia, rigidity, and tremor at rest. The non-motor component of Parkinson's disease includes increased neuropathic pain, the prevalence of which is 4 to 5 times higher than the general rate. By studying a mouse model of Parkinson's disease induced by 6-hydroxydopamine, we assessed the impact of dopamine depletion on pain modulation.
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