Pharmacological characterization of the magnocellular neuroendocrine cells of the guinea pig supraoptic nucleus in vitro.
The effects of various agents which have been implicated in the regulation of vasopressin release, on the supraoptic neuroendocrine cells were studied intracellularly. L-glutamate (10(-4)M) and gamma-aminobutyric acid (10(-6) M) had potent excitatory and inhibitory actions, respectively. Acetylcholine (10(-6) M) depolarized the membrane and increased the membrane input resistance. Norepinephrine (10(-5) M) produced either excitatory or inhibitory action on the spontaneous firing rate depending on the cell impaled. Morphine (10(-8)-10(-6) M) strongly depressed the spontaneous firing rate whereas it has no noticeable effect on the membrane potential and input resistance. Angiotensin II (10(-5) M) had no effect on any of the cells tested.
D000109:Acetylcholine / Q000494:pharmacology; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D005998:Glycine / Q000494:pharmacology; D006168:Guinea Pigs; D009020:Morphine / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology; D012970:Sodium Glutamate / Q000494:pharmacology; D013495:Supraoptic Nucleus / Q000187:drug effects*; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
D000804:Angiotensin II; D005680:gamma-Aminobutyric Acid; D009020:Morphine; D000109:Acetylcholine; D005998:Glycine; D012970:Sodium Glutamate; D009638:Norepinephrine