Alpha-adrenergic regulation of angiotensin II receptors in neuronal cultures from rat brain

Journal Article · Wed Mar 05 00:00:00 EST 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:7035117

Sumners, C; Watkins, L L; Raizada, M K

Our previous studies have suggested that endogenous catecholamine (CA) levels are important regulators of angiotensin II receptors (AngII-R) in neuronal cultures. The present study was undertaken to determine the possible mechanisms by which CA exert their effects on AngII-R. Incubation of neuronal cultures with norepinephrine (NE) resulted in time and dose dependent decreases in (/sup 125/I)-AngII specific binding. A maximal effect of 60-70% was observed between 4-8 hours at 1..mu..M NE, which was the result of a decrease in Bmax (104 +/- 16.3 fmol/mg protein in controls vs 41.4 +/- 9.3 fmol/mg protein in NE treated) and little change in Kd. Similar effects were observed when neuronal cultures were incubated with dopamine (DA) or phenylephrine, but serotonin, epinephrine and isoproterenol had no effect. The NE and DA stimulated decrease in AngII-R appears to be an ..cap alpha../sub 1/=adrenergic receptor mediated phenomenon because it is abolished by coincubation with prazosin (..cap alpha../sub 1/-antagonist) and not by ..cap alpha../sub 2/- or ..beta..-antagonists. Similar incubations of neuronal cultures with NE also caused a time and dose dependent downregulation of ..cap alpha../sub 1/-adrenergic receptors. Taken together these observations indicate that the NE induced downregulation of AngII-R is mediated by ..cap alpha../sub 1/-receptors, and suggest that one possible mechanism may be the cointernalization of both ..cap alpha../sub 1/- and AngII-R stimulated by ..cap alpha../sub 1/-adrenergic agonists.

• Research Organization: Unvi. of Florida, Gainesville
• OSTI ID: 7035117
• Report Number(s): CONF-8604222-; TRN: 87-010353
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:4; Conference: 70. annual meeting of the Federation of American Society for Experimental Biology, St. Louis, MO, USA, 13 Apr 1986
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ANGIOTENSIN
BIOCHEMICAL REACTION KINETICS
RECEPTORS
CATECHOLAMINES
BIOLOGICAL EFFECTS
BRAIN
DOPAMINE
DOSE-RESPONSE RELATIONSHIPS
IODINE 125
NERVE CELLS
NORADRENALINE
RATS
SEROTONIN
TIME DEPENDENCE
TRACER TECHNIQUES
ADRENAL HORMONES
AMINES
ANIMAL CELLS
ANIMALS
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
AZAARENES
AZOLES
BETA DECAY RADIOISOTOPES
BODY
CARDIOTONICS
CARDIOVASCULAR AGENTS
CENTRAL NERVOUS SYSTEM
DAYS LIVING RADIOISOTOPES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
GLOBULINS
HETEROCYCLIC COMPOUNDS
HORMONES
HYDROXY COMPOUNDS
INDOLES
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MAMMALS
MEMBRANE PROTEINS
NERVOUS SYSTEM
NEUROREGULATORS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PHENOLS
POLYPHENOLS
PROTEINS
PYRROLES
RADIOISOTOPES
RADIOPROTECTIVE SUBSTANCES
REACTION KINETICS
RODENTS
SOMATIC CELLS
STEROID HORMONES
SYMPATHOMIMETICS
TRYPTAMINES
VASOCONSTRICTORS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques