Release of noradrenaline from the ligated cat hypogastric nerve.
After in vivo ligation for 24 of the cat hypogastric nerve, large amounts of noradrenaline (NA) and dopamine beta-hydroxylase (DBH) accumulated in the nerve segment immediately proximal to the ligature (P 1). In vitro incubation of 24-h-ligated nerves ((segments P1 and P2) in oxygenated Krebs solution at 37 degrees C in the presence of the ionophore X537A or high K+ concentrations caused a marked release of endogenously accumulated NA into the incubation medium. High-K+-evoked release was entirely dependent on extracellular Ca2+. Electrical nerve stimulation caused an 80% tissue NA loss, but the transmitter could not be found in the medium as intact NA. These results suggest that the in vivo ligated cat hypogastric nerve may serve as a useful model of adrenergic nerve terminals free of effector cells.
D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002415:Cats; D004299:Dopamine beta-Hydroxylase / Q000032:analysis; D004558:Electric Stimulation; D007001:Hypogastric Plexus / Q000502:physiology; D066298:In Vitro Techniques; D008026:Ligation; D008959:Models, Neurological; D009638:Norepinephrine / Q000378:metabolism*; D011188:Potassium / Q000494:pharmacology; D013564:Sympathetic Nervous System / Q000502:physiology*; D013997:Time Factors
D004299:Dopamine beta-Hydroxylase; D011188:Potassium; D002118:Calcium; D009638:Norepinephrine