The divalent cation barium was used to study the role of calcium in coupling neuropeptide secretion and biosynthesis following secretagogue stimulation of bovine chromaffin cells. Barium chloride (0.1-2.5 mM) stimulated in a dose-dependent manner the secretion of met-enkephalin (up to 20% of intracellular peptide content) and increased the total amount (cell plus medium content) of met-enkephalin and vasoactive intestinal polypeptide (VIP) 2- to 3-fold after 72 hours. A greater than six-fold increase in proenkephalin mRNA (mRNA(enk)) was observed by 24 hours following barium stimulation. The voltage-sensitive calcium channel blocker D600 inhibited the barium-stimulated secretion of enkephalin and blocked the stimulation of VIP biosynthesis and mRNA(enk). Reducing calcium in the medium resulted in an enhancement of barium-stimulated release of both peptides, but blocked the induction of their biosynthesis. The data indicate that calcium targets involved in secretion can be activated by barium or calcium while calcium targets involved in biosynthesis specifically require calcium. It is therefore proposed that pathways leading to peptide secretion and biosynthesis in the adrenal diverge just after secretagogue-stimulated calcium influx.
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http://dx.doi.org/10.1016/0143-4179(88)90026-1 | DOI Listing |
Exp Hematol Oncol
January 2025
Department of Hematology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
Myelodysplastic Syndromes (MDS) represent a group of heterogeneous myeloid clonal diseases derived from aberrant hematopoietic stem/progenitor cells. Enhancer of zeste homolog 2 (EZH2) is an important regulator in gene expression through methyltransferase-dependent or methyltransferase-independent mechanisms. Herein, we found EZH2 inhibition led to MDS cell pyroptosis through RNA Helicase A (RHA) down-regulation induced overexpression of S100A9, a key regulator of inflammasome activation and pyroptosis.
View Article and Find Full Text PDFActa Neuropathol Commun
January 2025
Department of Physiology and Pharmacology, Sapienza University of Rome, 00185, Rome, Italy.
The generation of retinal models from human induced pluripotent stem cells holds significant potential for advancing our understanding of retinal development, neurodegeneration, and the in vitro modeling of neurodegenerative disorders. The retina, as an accessible part of the central nervous system, offers a unique window into these processes, making it invaluable for both study and early diagnosis. This study investigates the impact of the Frontotemporal Dementia-linked IVS 10 + 16 MAPT mutation on retinal development and function using 2D and 3D retinal models derived from human induced pluripotent stem cells.
View Article and Find Full Text PDFBMC Pharmacol Toxicol
January 2025
Department of Anatomy, College of Health Sciences, University of Ilorin, Ilorin, 240003, Nigeria.
Background: Glia mediated neuroinflammation and degeneration of inhibitory GABAergic interneurons are some of the hall marks of pyrethroid neurotoxicity. Here we investigated the sex specific responses of inflammatory cytokines, microglia, astrocyte and parvalbumin positive inhibitory GABAergic interneurons to λ-cyhalothrin (LCT) exposures in rats.
Methods: Equal numbers of male and female rats were given oral corn oil, 2 mg/kg.
Biochem Genet
January 2025
Department of Physiology, University of Louisville School of Medicine, Louisville, KY, 40202, USA.
Although DNA methyltransferase 1 (DNMT1) and RNA editor ADAR triplications exist in Down syndrome (DS), their specific roles remain unclear. DNMT methylates DNA, yielding S-adenosine homocysteine (SAH), subsequently converted to homocysteine (Hcy) and adenosine by S-adenosine homocysteine (Hcy) hydrolase (SAHH). ADAR converts adenosine to inosine and uric acid.
View Article and Find Full Text PDFSci Rep
January 2025
College of Hydraulic and Civil Engineering, Xinjiang Agricultural University, Urumqi, 830052, Xinjiang, People's Republic of China.
Aiming at the problem that it is difficult to realize low-cost, high-performance and large-scale utilization of cementitious materials prepared from bulk solid wastes, this paper constructs a set of composite cementitious system based on alkaline activation of slag and fly ash (FA) by calcium carbide slag (CCS) and synergistic activation of sodium sulfate (NaSO) as a chemical dopant. The influence of factors such as solid waste type, mixing ratio, and NaSO content on the mechanical properties of composite cementitious systems was investigated by assessing compressive strength and analyzing microstructure using XRD, SEM-EDS, and FTIR. The test results indicate that CCS and NaSO exert significant influences on the strength of the composite cementitious system.
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