Development of the linkage of beta-adrenergic receptors to cardiac hypertrophy and heart rate control: neonatal sympathectomy with 6-hydroxydopamine.

Journal Article

Presynaptic neural projections are thought to participate in the maturation of postsynaptic sensitivity to neurotransmitters. In the current study, we have examined the effects of sympathectomy with 6-hydroxydopamine on the ontogeny of the linkage of beta-adrenergic receptors to cardiac growth and heart rate control in the rat. Destruction of sympathetic projections at birth compromised the ability of beta-receptor stimulation to evoke cardiac hypertrophy, a defect which persisted into young adulthood. The chronotropic response to beta-receptor activation, assessed by acute challenge with a submaximally-effective dose of isoproterenol, also exhibited a slowed development, but did eventually achieve normal sensitivity. In contrast, neonatal sympathectomy had only minor effects on resting heart rate, basal heart rate (the intrinsic rate in the absence of autonomic input) or maximal heart rate; these animals also showed beta-receptor desensitization of chronotropic action in response to chronic isoproterenol treatment. Chronic isoproterenol treatment itself lowered the basal heart rate, regardless of whether animals were normal or sympathectomized. Thus, during critical developmental periods, sympathetic input to beta-receptors selectively programmes the linkage between postsynaptic receptors, tissue growth and heart rate.

Full Text

Duke Authors

Cited Authors

  • Hou, QC; Seidler, FJ; Slotkin, TA

Published Date

  • May 1989

Published In

Volume / Issue

  • 11 / 5

Start / End Page

  • 305 - 311

PubMed ID

  • 2533225

International Standard Serial Number (ISSN)

  • 0141-9846

Language

  • eng

Conference Location

  • England