The videos, shown with minimal information and often without sound or music, are meant to provide a sort of scientific cinéma vérité.
Image courtesy of Nipam Patel (University of California, Berkeley, CA).
New Research In
Physical Sciences
Featured Portals
Articles by Topic
Biological Sciences
Featured Portals
Articles by Topic
Abstract
The binding properties of two alpha-adrenergic radioligands, [3H]epinephrine (an agonist) and [3H]dihydroergocryptine (an antagonist), were compared in two model systems--membranes derived from human platelets and membranes from rat liver. The platelet contains exclusively alpha 2 and the liver mostly (approximately 80%) alpha 1 receptors. Agonists induce the formation of a guanine nucleotide-sensitive high-affinity state of alpha 2 but not alpha 1 receptors. [3H]Dihydroergocryptine labels all the alpha receptors, whereas [3H]epinephrine at low concentrations labels predominantly the high-affinity form of the alpha 2 receptor in both platelet and liver. However, in the liver, alpha-adrenergic effects such as glycogen phosphorylase activation are shown to be mediated via alpha 1 receptors. Thus, in liver membranes the endogenous "physiological" agonist may not label the physiologically relevant alpha 1 receptors in typical radioligand binding assays using low concentrations of [3H]epinephrine.
Agonist versus antagonist binding to alpha-adrenergic receptors
More Articles of This Classification
Related Content
Cited by...
- No citing articles found.
Similar Articles
You May Also be Interested in
Victoria Orphan and Elizabeth Trembath-Reichert discuss microbial life in the deep subseafloor.
PNAS Profile with NAS member and anthropologist Michael Tomasello
Researchers report an early monumental burial site near Lake Turkana in Kenya that may have served as a stable landmark for mobile herders in a changing physical environment and as a social anchor point to foster communal identity and interaction among mobile herders.
A study reports evidence of water ice on the moon’s surface, discerned via a signature in the near-infrared reflectance spectra that suggests the ice was formed by slow condensation due to impact or water migration through the lunar exosphere.
Image courtesy of Pixabay/Ponciano.
