Related Experiment Video

Updated: Sep 22, 2026

Coculture Analysis of Extracellular Protein Interactions Affecting Insulin Secretion by Pancreatic Beta Cells
05:51

Coculture Analysis of Extracellular Protein Interactions Affecting Insulin Secretion by Pancreatic Beta Cells

Published on: June 15, 2013

Insulin-like peptides in the lobster Homarus americanus. I. Insulin immunoreactivity

B Sanders

    General and Comparative Endocrinology
    |June 1, 1983
    PubMed

    Experiments were conducted to determine if insulin-like peptides are present in the lobster Homarus americanus. Peptides were found that bind specifically to bovine insulin antibodies in a modified vertebrate radioimmunoassay. Extracts of whole hepatopancreas, gut, and hemolymph contained insulin immunoreactivity (IRI) concentrations of 67.5, 14.0, and 11.0 ng, respectively, per 700-g lobster. No insulin immunoreactivity was detected in neurosecretory cells of the eyestalk. The highest immunoreactivity was measured in the hepatopancreas, in the same fractions of eluate which contained the highest immunoreactivity when a bovine insulin standard was passed through the same chromatographic column.

    More Related Videos

    Measuring Relative Insulin Secretion using a Co-Secreted Luciferase Surrogate05:58

    Measuring Relative Insulin Secretion using a Co-Secreted Luciferase Surrogate

    Published on: June 25, 2019

    Precise Visualization of Insulin Receptors A and B in Murine Brain with an RNA In Situ Hybridization Assay08:34

    Precise Visualization of Insulin Receptors A and B in Murine Brain with an RNA In Situ Hybridization Assay

    Published on: July 15, 2025

    Related Concept Videos

    Insulin Secretory Vesicles01:05

    Insulin Secretory Vesicles

    Insulin secretory vesicles release insulin to stimulate blood glucose uptake and regulate carbohydrate metabolism. When the blood glucose levels increase, glucose enters the pancreatic β-islet cells through glucose transporters. Once inside, glucose is metabolized through glycolysis, the citric acid cycle, and the electron transport chain, producing ATP. This increase in ATP concentration closes ATP-sensitive potassium channels, leading to depolarization of the membrane and the opening of...
    Glucose Homeostasis: Pancreatic Islets and Insulin Secretion01:27

    Glucose Homeostasis: Pancreatic Islets and Insulin Secretion

    The pancreatic islets comprising only 1%-2% of the volume are highly vascularized and innervated mini-organs. They contain five endocrine cell types, including β cells that secrete insulin, which is synthesized as a single polypeptide chain, preproinsulin, processed to proinsulin, and finally to insulin and C-peptide. This process is complex and regulated, involving the Golgi complex, the endoplasmic reticulum, and the secretory granules of the β cell.
    Insulin and C-peptide are co-secreted in...
    Insulin: The Receptor and Signaling Pathways01:28

    Insulin: The Receptor and Signaling Pathways

    Insulin action is mediated through a receptor tyrosine kinase, akin to the IGF-1 receptor. The number of receptors per cell varies significantly, from 40 on erythrocytes to 300,000 on adipocytes and hepatocytes. The insulin receptor consists of linked α/β subunit dimers, forming a heterotetramer glycoprotein with two extracellular α subunits and two β subunits spanning the membrane. The α subunits inhibit the inherent tyrosine kinase activity of the β subunits, but this inhibition is released...
    Insulin: Biosynthesis, Chemistry, and Preparation01:25

    Insulin: Biosynthesis, Chemistry, and Preparation

    The endoplasmic reticulum (ER) of pancreatic β-cells synthesizes preproinsulin, which consists of a signal peptide, A and B chains, and a C-peptide. Preproinsulin is then cleaved and folded into proinsulin, which translocates to the Golgi apparatus for sorting and packaging into secretory granules. In these granules, enzymatic clipping generates insulin and C-peptide.
    Damage or functional impairment of β-cells inhibits insulin production, leading to diabetes. Diabetes treatment primarily uses...
    Glucagon-like Receptor Agonists01:24

    Glucagon-like Receptor Agonists

    Incretins include glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), which stimulate insulin secretion post-meals. In type 2 diabetes, GIP's efficacy is reduced, making GLP-1 a viable drug target. GIP originates from preproGIP.
    GLP-1, when administered in high doses intravenously, triggers insulin secretion, inhibits glucagon release, slows gastric emptying, reduces food intake, and restores normal insulin secretion. However, its rapid inactivation by the...