Isolated adipose tissue cells were prepared from subcutaneous samples obtained from nine morbidly obese subjects weighing from 187 to 306% of ideal body weight. The responsiveness of these adipocytes to a number of test substances was determined by measuring cellular cyclic AMP concentration at one-half hour and glycerol release at four hours. Theophylline (10(-3) M) and epinephrine (10(-5) M) stimulated lipolysis; theophylline stimulated an increase in cyclic AMP, while epinephrine failed to prompt a significant change in the nucleotide. Neither the alpha blocker, phentolamine (10(-5) M), nor the beta blocker, propranolol (3 X 10(-5) M), affected lipolysis or cyclic AMP; when these agents were incubated in combination with epinephrine, changes occurred indicative of the presence of both alpha and beta adrenergic receptor sites. Insulin significantly reduced both basal and stimulated lipolysis but failed to affect cyclic AMP. With minor exceptions, adipocytes from hyperobese subjects behaved similarly to cells from unselected donors; at the concentration used, there was no evidence of resistance to insulin.

Download full-text PDF

Source
http://dx.doi.org/10.2337/diab.26.7.657DOI Listing

Publication Analysis

Top Keywords

cyclic amp
16
isolated adipose
8
adipose tissue
8
tissue cells
8
hyperobese subjects
8
stimulated lipolysis
8
in-vitro observations
4
observations isolated
4
cells hyperobese
4
subjects isolated
4

Similar Publications

Cell-free assays reveal that the HIV-1 capsid protects reverse transcripts from cGAS immune sensing.

PLoS Pathog

January 2025

Division of Microbiology and Immunology, Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah, United States of America.

Retroviruses can be detected by the innate immune sensor cyclic GMP-AMP synthase (cGAS), which recognizes reverse-transcribed DNA and activates an antiviral response. However, the extent to which HIV-1 shields its genome from cGAS recognition remains unclear. To study this process in mechanistic detail, we reconstituted reverse transcription, genome release, and innate immune sensing of HIV-1 in a cell-free system.

View Article and Find Full Text PDF

Structural and evolutionary insights into the functioning of glycoprotein hormones and their receptors.

Andrology

January 2025

Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York, USA.

The neuroendocrine system that comprises the glycoprotein hormones (GpHs) and their receptors is essential for reproduction and metabolism. Each GpH hormone is an αβ heterodimer of cystine-knot proteins and its cognate receptor is a G-protein coupled receptor (GPCR) distinguished by a large leucine-rich-repeat (LRR) extracellular domain that binds the hormone and a class A GPCR transmembrane domain that signals through an associating heterotrimeric G protein. Hence, the receptors are called LRR-containing GPCRs-LGRs.

View Article and Find Full Text PDF

Platinum drugs upregulate CXCR4 and PD-L1 expression via ROS-dependent pathways, with implications for novel combined treatment in gastric cancer.

J Pathol Clin Res

January 2025

State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers and National Clinical Research Center for Digestive Diseases, Xijing Hospital of Digestive Diseases, Fourth Military Medical University, Xi'an, PR China.

CXC chemokine receptor 4 (CXCR4) and programmed cell death-ligand 1 (PD-L1) are two critical molecules involved in the tumor immune microenvironment. However, the impact of platinum drugs, such as cisplatin, on CXCR4 or PD-L1 expression and the underlying mechanisms in gastric cancer (GC) remain unknown. Moreover, the correlation between their expression levels in GC remains elusive.

View Article and Find Full Text PDF

Facile integration of a binary nano-prodrug with αPD-L1 as a translatable technology for potent immunotherapy of TNBC.

Acta Biomater

January 2025

Hengyang Medical School, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, School of Pharmaceutical Science, MOE Key Lab of Rare Pediatric Disease, University of South China, Hengyang 421001, China. Electronic address:

Immune checkpoint blockers (ICBs)-based immunotherapy is a favorable approach for efficient triple-negative breast cancer (TNBC) treatment. However, the therapeutic efficacy of ICBs is greatly compromised by immunosuppressive tumor microenvironments (TMEs) and low expression levels of programmed cell death ligand-1 (PD-L1). Herein, we constructed an amphiphilic prodrug by linking a hydrophobic STING agonist, MSA-2 and a hydrophilic chemotherapeutic drug, gemcitabine (GEM) via an ester bond, which can self-assemble into GEM-MSA-2 (G-M) nanoparticles (NPs) with a tumor growth inhibition (TGI) value of 87.

View Article and Find Full Text PDF

Cuproptosis is a newly discovered mode of cell death, which is caused by excess copper and results in cell death via the mitochondrial pathway. However, the complex tumor microenvironment (TME) is characterized by many factors, including high levels of glutathione and lack O, limit the application of traditional cuproptosis agents in antitumor therapy. Herein, we report a hyaluronic acid modified copper-manganese composite nanomedicine (CMCNs@HA) to remodel the TME and facilitate efficient cuproptosis in tumor.

View Article and Find Full Text PDF

Want 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!