title: Ontogeny of mammalian cardiac alpha 1-adrenergic receptors.
abstract: We find a similar number of alpha 1-adrenergic receptors in fetal mouse hearts of 15--20 day gestational age as compared to adult mouse hearts, and a significantly greater number of alpha 1-adrenoceptors in the early neonate (7--21 days) hearts. Cardiac norepinephrine (NE) concentrations were extremely low in the fetus and increased continuously after birth to reach adult levels at about 21 days of age. The cardiac alpha 1-adrenergic receptors mature prior to the development of a presynaptic component (NE) and show a dramatic increase in density without a change in affinity in the early neonate which then decreases with innervation.
mesh_terms: D000818:Animals; D001665:Binding Sites; D005318:Fetal Heart / Q000294:innervation*; D006321:Heart / Q000294:innervation*; D066298:In Vitro Techniques; D051379:Mice; D009206:Myocardium / Q000032:analysis; D009638:Norepinephrine / Q000032:analysis; D011941:Receptors, Adrenergic / Q000502:physiology*; D011942:Receptors, Adrenergic, alpha / Q000502:physiology*; D013564:Sympathetic Nervous System / Q000254:growth & development
chemical_list: D011941:Receptors, Adrenergic; D011942:Receptors, Adrenergic, alpha; D009638:Norepinephrine