Apr 1, 1976

Dissociation constants and relative efficacies of agonists acting on alpha adrenergic receptors in rabbit aorta

The Journal of Pharmacology and Experimental Therapeutics
J C Besse, R F Furchgott


The dissociation constants (KA values) of l-norepinephrine (l-NE) and seven other agonists acting on alpha adrenergic receptors in rabbit aorta strips were determined by analysis of concentration-response data before and after fractional inactivation of receptors with Dibenamine. In experiments to determine KA values, propranolol was added to block activation of beta receptors and cocaine to block the neuronal uptake mechanism. The KA of l-NE and the KA of a second agonist, when determined on paired strips from the same aorta, were used to calculate the relative affinity and the relative efficacy (er) of the second agonist as compared to l-NE. The validity of the method used for determining KA and er values was supported by the following findings. 1) The dissociation constant (KB) of the competitive antagonist, phentolamine, determined with each of the agonists, was the same as that determined with l-NE. 2) The KA determined for l-NE was independent of the fraction of active receptors remaining (q) after pretreatment with different concentrations of Dibenamine. 3) The KB of phentolamine determined with l-NE as the agonist was the same before and after fractional inactivation of receptors. 4) After inactivation in paired strips ...Continue Reading

  • References
  • Citations


  • We're still populating references for this paper, please check back later.
  • References
  • Citations


  • This paper may not have been cited yet.

Mentioned in this Paper

Adrenergic beta-Agonists
Norepinephrine, (+, -)-Isomer
Adrenergic alpha-Agonists
Norepinephrine Receptors
Descending Aorta

About this Paper

Trending Feeds


Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Bone Marrow Neoplasms

Bone Marrow Neoplasms are cancers that occur in the bone marrow. Discover the latest research on Bone Marrow Neoplasms here.

IGA Glomerulonephritis

IgA glomerulonephritis is a chronic form of glomerulonephritis characterized by deposits of predominantly Iimmunoglobin A in the mesangial area. Discover the latest research on IgA glomerulonephritis here.

Cryogenic Electron Microscopy

Cryogenic electron microscopy (Cryo-EM) allows the determination of biological macromolecules and their assemblies at a near-atomic resolution. Here is the latest research.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

LRRK2 & Immunity During Infection

Mutations in the LRRK2 gene are a risk-factor for developing Parkinson’s disease. However, LRRK2 has been shown to function as a central regulator of vesicular trafficking, infection, immunity, and inflammation. Here is the latest research on the role of this kinase on immunity during infection.

Antiphospholipid Syndrome

Antiphospholipid syndrome or antiphospholipid antibody syndrome (APS or APLS), is an autoimmune, hypercoagulable state caused by the presence of antibodies directed against phospholipids.

Meningococcal Myelitis

Meningococcal myelitis is characterized by inflammation and myelin damage to the meninges and spinal cord. Discover the latest research on meningococcal myelitis here.

Alzheimer's Disease: MS4A

Variants within membrane-spanning 4-domains subfamily A (MS4A) gene cluster have recently been implicated in Alzheimer's disease by recent genome-wide association studies. Here is the latest research.