Phospholipase A2 activity (EC 3.1.1.4) was estimated in low-speed supernatants of human placenta by measuring the release of arachidonic acid from phosphatidylcholine, 1-stearoyl-2-[3H]arachidonyl and other phospholipids under alkaline conditions (pH 8). Activity was calcium dependent and followed Michaelis-Menten kinetics with an apparent Km of 0.19 (SD 0.04) mM and a Vmax of 486 (SD 52) pmol/mg protein per h. Placental phospholipase A2 activity was relatively high in early pregnancy (8-11 weeks gestation) and following spontaneous preterm labour (31-34 weeks), but decreased significantly towards term with no changes in relation to parturition. By contrast, activity in the fetal membranes (amnion and chorio-decidua) was low after preterm labour and increased significantly towards term. The placenta and fetal membranes have the capacity to contribute to the increased intra-uterine release of arachidonic acid and eicosanoids that occurs during term and preterm labour, but at present there is no evidence that this increase involves direct changes in phospholipase A2 activity.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/0028-2243(92)90172-u | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Metabolic pathways of eicosanoids-derivatives of arachidonic acid and their significance in skin.
Cell Mol Biol Lett
January 2025
Department of Analytical Chemistry, Medical University of Bialystok, Kilinskiego 1, 15-069, Bialystok, Poland.
The skin is a barrier that protects the human body against environmental factors (physical, including solar radiation, chemicals, and pathogens). The integrity and, consequently, the effective metabolic activity of skin cells is ensured by the cell membrane, the important structural and metabolic elements of which are phospholipids. Phospholipids are subject to continuous transformation, including enzymatic hydrolysis (with the participation of phospholipases A, C, and D) to free polyunsaturated fatty acids (PUFAs), which under the influence of cyclooxygenases (COX1/2), lipoxygenases (LOXs), and cytochrome P450 (CYPs P450) are metabolized to various classes of oxylipins, depending on the type of PUFA being metabolized and the enzyme acting.
View Article and Find Full Text PDFStructure-activity relationship expansion and microsomal stability assessment of the 2-morpholinobenzoic acid scaffold as antiproliferative phosphatidylcholine-specific phospholipase C inhibitors.
RSC Med Chem
January 2025
School of Chemical Sciences, University of Auckland Auckland 1010 New Zealand
Dysregulation of choline phospholipid metabolism and overexpression of phosphatidylcholine-specific phospholipase C (PC-PLC) is implicated in various cancers. Current known enzyme inhibitors include compounds based on a 2-morpholino-5--benzylamino benzoic acid, or hydroxamic acid, scaffold. In this work, 81 compounds were made by modifying this core structure to explore the pharmacophore.
View Article and Find Full Text PDFFurther Characterization of Lipase B from Ustilago maydis Expressed in Pichia pastoris: a Member of the Candida antarctica Lipase B-like Superfamily.
Appl Biochem Biotechnol
January 2025
Unidad de Biotecnología Industrial, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco A.C, 45019, Zapopan, Jal, Mexico.
Lipases from the basidiomycete fungus Ustilago maydis are promising but underexplored biocatalysts due to their high homology with Candida antarctica lipases. This study provides a comprehensive characterization of a recombinant CALB-like lipase from U. maydis, expressed in Pichia pastoris (rUMLB), and compares its properties with those of the well-studied recombinant lipase B from C.
View Article and Find Full Text PDFCirculating monocytes upregulate CD52 and sustain innate immune function in cirrhosis unless acute decompensation emerges.
J Hepatol
January 2025
Department of Biomedicine, University of Basel, Switzerland; University Centre for Gastrointestinal and Liver Disease Basel, Switzerland. Electronic address:
Background & Aims: Infectious complications determine the prognosis of cirrhosis patients. Their infection susceptibility relates to the development of immuneparesis, a complex interplay of different immunosuppressive cells and soluble factors. Mechanisms underlying the dynamics of immuneparesis of innate immunity remain inconclusive.
View Article and Find Full Text PDFMaternal exposure to deltamethrin during pregnancy and lactation impairs hippocampal learning and memory function of male offspring by ferroptosis.
Ecotoxicol Environ Saf
January 2025
Key Laboratory of Environmental Stress and Chronic Disease Control & Prevention (China Medical University), Ministry of Education, Shenyang, Liaoning, China; Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning, China. Electronic address:
Deltamethrin (DM), a broad-spectrum insecticide, is widely used in the world. It can exert direct action on the central nervous system to produce neurotoxicity. Exposure to DM can lead to iron metabolism disorder, oxidative stress and learning and memory dysfunction.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!