Pancreatic islets contain calmodulin. This protein activates adenylate cyclase in a subcellular fraction of rat islets in a calcium-dependent fashion. The Km for calmodulin was close to 0.1 microM, well below the concentration of endogenous calmodulin. Trifluoperazine and the trifluoromethylphenothiazine derivative of domperidone inhibited glucose-stimulated insulin release without affecting glucose oxidation by the islets. When insulin release was inhibited by 30% or more, this inhibition coincided with a reduction in the 45Ca net uptake by the islets. Both drugs suppressed the increment in adenylate cyclase activity evoked by calmodulin in a particulate fraction derived from the islets. However, the drugs also decreased basal and NaF-stimulated adenylate cyclase activities. Within limits, these data are compatible with the participation of endogenous calmodulin in the normal process of insulin release.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1210/endo-108-4-1305 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Growth Hormone Increase Induced by Oral Administration of Melatonin in a Young Woman With Sleep Disturbances.
JCEM Case Rep
February 2025
Clinica Medica 3, Department of Medicine-DIMED, University Hospital of Padova, Padova 35128, Italy.
Growth hormone (GH) secretion by the pituitary is regulated by stimulatory and inhibitory pathways such as growth hormone releasing hormone (GHRH) and somatostatin, respectively, being also modulated by different neurotransmitters acting at the hypothalamic/pituitary level. The pineal gland hormone melatonin regulates GH secretion in many mammals, including humans, although its role in modulating GH secretion has been debated. We describe the case of a young woman chronically taking melatonin for sleep disturbances, referring to her general practitioner for flushing that appeared just after starting melatonin intake.
View Article and Find Full Text PDFOxylipin dynamics in dairy cows during clinical ketosis and after treatment with niacin and flunixin meglumine.
JDS Commun
January 2025
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824.
Dairy cows with clinical ketosis (CK) exhibit metabolic changes, including intense adipose tissue (AT) lipolysis and systemic insulin resistance, that increase plasma BHB and free fatty acids (FFA). Cows with CK also have systemic inflammation, predisposing them to inflammatory and infectious diseases. This inflammatory process is modulated in part by oxidized fatty acids (oxylipins) that regulate all aspects of inflammation.
View Article and Find Full Text PDFThe neurohormone tyramine stimulates the secretion of an insulin-like peptide from the Caenorhabditis elegans intestine to modulate the systemic stress response.
PLoS Biol
January 2025
Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB) CCT UNS-CONICET, Bahía Blanca, Argentina.
The DAF-2/insulin/insulin-like growth factor signaling (IIS) pathway plays an evolutionarily conserved role in regulating reproductive development, life span, and stress resistance. In Caenorhabditis elegans, DAF-2/IIS signaling is modulated by an extensive array of insulin-like peptides (ILPs) with diverse spatial and temporal expression patterns. However, the release dynamics and specific functions of these ILPs in adapting to different environmental conditions remain poorly understood.
View Article and Find Full Text PDFBiphasic glucose-stimulated insulin secretion over decades: a journey from measurements and modeling to mechanistic insights.
Life Metab
February 2025
New Cornerstone Science Laboratory, State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, National Biomedical Imaging Center, The Beijing Laboratory of Biomedical Imaging, Peking-Tsinghua Center for Life Sciences, School of Future Technology, Peking University, Beijing 100871, China.
Glucose-stimulated insulin release from pancreatic β-cells is critical for maintaining blood glucose homeostasis. An abrupt increase in blood glucose concentration evokes a rapid and transient rise in insulin secretion followed by a prolonged, slower phase. A diminished first phase is one of the earliest indicators of β-cell dysfunction in individuals predisposed to develop type 2 diabetes.
View Article and Find Full Text PDFChronic cold exposure reprograms feeding-regulated LPL activity in white adipose tissues through hepatic ANGPTL3 and ANGPTL8.
Life Metab
February 2025
Hubei Key Laboratory of Cell Homeostasis, Department of Biochemistry, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, Hubei 430072, China.
Graphical Abstract Lipoprotein lipase (LPL) mediates peripheral tissue triglyceride (TG) uptake. Hepatic ANGPTL3 (A3) and ANGPTL8 (A8) form a complex and inhibit LPL activity in the white adipose tissue (WAT) via systematic circulation. ANGPTL4 (A4) is expressed in WAT and inhibits LPL activity locally.
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!