Vasopressin increases the permeability of collecting ducts to water. Administration of this hormone is also associated with an increase in intramembranous particle clusters in rat collecting duct luminal membrane (CDLM) as revealed by freeze-fracture electron microscopy. To determine whether this morphologic alteration of CDLM is quantitatively related to the dose of vasopressin, anesthetized Brattleboro homozygous rats were given the hormone at different doses. CDLM from kidneys removed before and during infusion were examined by freeze-fracture electron microscopy. The frequency of CDLM clusters as well as the area of membrane occupied by them was related to the dose of vasopressin. In a separate experimental protocol, a decrease in intramembranous particle clusters accompanied a decrease in urinary osmolality when vasopressin was stopped. We conclude that CDLM intramembranous particle clusters represent a specific structural change related to the action of vasopressin. Accordingly, quantitation of CDLM clusters may serve as an end point for the study of vasopressin-induced water permeability.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1152/ajprenal.1980.239.6.F560 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Plasmonic nano-bowls for monitoring intra-membrane changes in liposomes, and DNA-based nanocarriers in suspension.
Biomed Opt Express
April 2024
Bio-photonics and Green Photonics Laboratory, Indian Institute of Technology Delhi, Hauz-Khas, New Delhi 110016, India.
Programmable nanoscale carriers, such as liposomes and DNA, are readily being explored for personalized medicine or disease prediction and diagnostics. The characterization of these nanocarriers is limited and challenging due to their complex chemical composition. Here, we demonstrate the utilization of surface-enhanced Raman spectroscopy (SERS), which provides a unique molecular fingerprint of the analytes while reducing the detection limit.
View Article and Find Full Text PDFMature gametocytes of Plasmodium falciparum display a banana (falciform) shape conferred by a complex array of subpellicular microtubules (SPMT) associated with the inner membrane complex (IMC). Microtubule-associated proteins (MAPs) define MT populations and modulate interaction with pellicular components. Several MAPs have been identified in Toxoplasma gondii, and homologues can be found in the genomes of species, but the function of these proteins for asexual and sexual development of malaria parasites is still unknown.
View Article and Find Full Text PDFFreeze-Fracture Electron Microscopy for Extracellular Vesicle Analysis.
J Vis Exp
September 2022
Faculty of Medicine, Institute of Cell Biology, University of Ljubljana;
Extracellular vesicles (EVs) are membrane-limited structures released from the cells into the extracellular space and are implicated in intercellular communication. EVs consist of three populations of vesicles, namely microvesicles (MVs), exosomes, and apoptotic bodies. The limiting membrane of EVs is crucially involved in the interactions with the recipient cells, which could lead to the transfer of biologically active molecules to the recipient cells and, consequently, affect their behavior.
View Article and Find Full Text PDFFirst Responders to Hyperosmotic Stress in Murine Astrocytes: Connexin 43 Gap Junctions Are Subject to an Immediate Ultrastructural Reorganization.
Biology (Basel)
December 2021
Department of Anatomy and Cell Biology, Saarland University, 66421 Homburg/Saar, Germany.
In a short-term model of hyperosmotic stress, primary murine astrocytes were stimulated with a hyperosmolar sucrose solution for five minutes. Astrocytic gap junctions, which are mainly composed of Connexin (Cx) 43, displayed immediate ultrastructural changes, demonstrated by freeze-fracture replica immunogold labeling: their area, perimeter, and distance of intramembrane particles increased, whereas particle numbers per area decreased. Ultrastructural changes were, however, not accompanied by changes in Cx43 mRNA expression.
View Article and Find Full Text PDFUltrastructural and Functional Analysis of a Novel Extra-Axonemal Structure in Parasitic Trichomonads.
Front Cell Infect Microbiol
January 2022
Departamento de Microbiologia, Instituto Aggeu Magalhães, FIOCRUZ, Recife, Brazil.
and are extracellular flagellated parasites that inhabit humans and other mammals, respectively. In addition to motility, flagella act in a variety of biological processes in different cell types, and extra-axonemal structures (EASs) have been described as fibrillar structures that provide mechanical support and act as metabolic, homeostatic, and sensory platforms in many organisms. It has been assumed that and do not have EASs.
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!