Ls. Sun et al., CHARACTERIZATION OF THE ALPHA(1)-ADRENERGIC CHRONOTROPIC RESPONSE IN NEUROPEPTIDE Y-HEATED CARDIOMYOCYTES, European journal of pharmacology, 349(2-3), 1998, pp. 377-381
The cardiac alpha(1)-adrenergic chronotropic response changes from sti
mulatory to inhibitory post-natally. The mature inhibitory response is
mediated by the alpha(1B)-adrenoceptor and a pertussis toxin sensitiv
e G protein. In vivo and in vitro studies identify sympathetic innerva
tion as critical for the maturation of this inhibitory response. Addit
ional experiments in a culture model indicate the effect of innervatio
n is dependent on neurally released neuropeptide Y. The present study
establishes that the individual signaling elements in the neuropeptide
Y induced alpha(1)-adrenergic cascade are the same as those appearing
during normal in vivo development. In addition, the data demonstrate
that the effect of neuropeptide Y does not result from activation of t
he putative cardiac Y-3 neuropeptide Y receptor subtype, since it is r
eproduced by the peptide fragment neuropeptide Y-(13-36) but not by [L
eu(31), Pro(34)]neuropeptide Y. (C) 1998 Elsevier Science B.V. All rig
hts reserved.