Ontogenesis of physiological responsiveness and guanine nucleotide sensitivity of cardiac muscarinic receptors during chick embryonic development.

@article{Halvorsen1984OntogenesisOP,
  title={Ontogenesis of physiological responsiveness and guanine nucleotide sensitivity of cardiac muscarinic receptors during chick embryonic development.},
  author={Stanley W. Halvorsen and Neil M. Nathanson},
  journal={Biochemistry},
  year={1984},
  volume={23 24},
  pages={5813-21}
}
Atria isolated from 4-day chick embryos were much less responsive to the negative chronotropic effect of muscarinic agonists than were atria from 5- or 8-day embryos, even though the density of muscarinic acetylcholine receptors (mAChR) was similar at all these ages. The mAChR in hearts from 4-day embryos were also significantly less susceptible to regulation of receptor number by in vivo agonist treatment and required a 2-5-fold greater dose of the muscarinic agonist carbachol to achieve a… CONTINUE READING