Activation of alpha-1 adrenergic receptors modulates the control of left/right sidedness in rat embryos.
Presomite stage rat embryos were cultured for 45-49 hr with medium containing various adrenergic agonists and antagonists. L-Norepinephrine but not D-norepinephrine (several orders of magnitude less potent than the L-isomer at alpha-1 adrenergic receptors) resulted in a dose-dependent increase of situs inversus similar to that found for phenylephrine, an alpha-1 adrenergic agonist. Prazosin, an alpha-1 adrenergic antagonist, inhibited phenylephrine-induced situs inversus in a dose-dependent manner. Neither dexmedetomidine, an alpha-2 adrenergic agonist, nor isoproterenol, a beta adrenergic agonist, caused situs inversus. These results provide pharmacological evidence that stimulation of alpha-1 but not of alpha-2 and beta adrenergic receptors modulates the control of left/right sidedness in rat embryos.
Department of Anesthesia, Stanford University School of Medicine, California 94305.
M
M
Fujinaga
M
M
Maze
B B
BB
Hoffman
J M
JM
Baden
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004622:Embryo, Mammalian / Q000502:physiology*; D007839:Functional Laterality / Q000187:drug effects*; D007093:Imidazoles / Q000494:pharmacology; D007536:Isomerism; D007545:Isoproterenol / Q000494:pharmacology; D020926:Medetomidine; D009638:Norepinephrine / Q000494:pharmacology*; D009924:Organ Culture Techniques; D010656:Phenylephrine / Q000494:pharmacology*; D011224:Prazosin / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000502:physiology*
D000316:Adrenergic alpha-Agonists; D007093:Imidazoles; D011942:Receptors, Adrenergic, alpha; D010656:Phenylephrine; D007545:Isoproterenol; D020926:Medetomidine; D009638:Norepinephrine; D011224:Prazosin