Inhibition of noradrenaline release by neuropeptide Y in mouse atria does not involve inhibition of adenylate cyclase or a pertussis toxin-susceptible G protein

Naunyn Schmiedebergs Arch Pharmacol. 1989 Dec;340(6):658-65. doi: 10.1007/BF00717741.

Abstract

Neuropeptide Y (30-1000 nmol/l) significantly inhibited the fractional stimulation-induced outflow of radioactivity from mouse atria preincubated with [3H]-noradrenaline. The inhibitory effect of neuropeptide Y was observed at all frequencies tested (2, 5 and 10 Hz) as well as after alpha-adrenoceptor blockade with phentolamine (1 mumol/l). A combination of 8-bromo adenosine cyclic-3'-5'-monophosphate (90 or 270 mumol/l) with the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (100 mumol/l) was used to saturate maximally the adenylate cyclase system and these drug combinations significantly enhanced the stimulation-induced outflow of radioactivity. However, neuropeptide Y inhibited the stimulation-induced outflow in the presence of these drugs, suggesting that the inhibitory effect of neuropeptide Y was not due to decreasing endogenous cyclic AMP formation. Finally, atria from mice treated with pertussis toxin were used. In this case, the inhibitory effect of neuropeptide Y on the stimulation-induced outflow of radioactivity was still observed suggesting that inhibitory prejunctional neuropeptide Y receptors are not coupled to a pertussis toxin-susceptible G protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 1-Methyl-3-isobutylxanthine / pharmacology
  • 8-Bromo Cyclic Adenosine Monophosphate / pharmacology
  • Adenylate Cyclase Toxin*
  • Adenylyl Cyclases / metabolism*
  • Animals
  • GTP-Binding Proteins / metabolism*
  • Heart / drug effects
  • Heart Rate / drug effects
  • In Vitro Techniques
  • Mice
  • Myocardium / enzymology
  • Myocardium / metabolism*
  • Neuropeptide Y / pharmacology*
  • Norepinephrine / metabolism*
  • Pertussis Toxin*
  • Virulence Factors, Bordetella / pharmacology*

Substances

  • Adenylate Cyclase Toxin
  • Neuropeptide Y
  • Virulence Factors, Bordetella
  • 8-Bromo Cyclic Adenosine Monophosphate
  • Pertussis Toxin
  • GTP-Binding Proteins
  • Adenylyl Cyclases
  • 1-Methyl-3-isobutylxanthine
  • Norepinephrine