Oxytocin stimulates oxytocin release from isolated nerve terminals of rat neural lobes.
Nerve endings from rat neural lobes isolated by homogenization were placed on a filter and constantly superfused. The effects of exogenous oxytocin and vasopressin (both added at 1 nM concentration) on basal and stimulated release of oxytocin and vasopressin were investigated. Stimulated release was evoked by 30 mM potassium and a simultaneous increase in osmolarity. A stimulatory effect of oxytocin on basal and evoked release of oxytocin was found while there was no effect on vasopressin release. The addition of vasopressin did not induce any change in the release of either hormone. The positive feedback mechanism observed with oxytocin might be active during the discharge of oxytocin which is known to occur in bursts.
Falke
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Sektion Elektronenmikroskopie, Universität Ulm, FRG.
D000818:Animals; D001127:Arginine Vasopressin / Q000378:metabolism / Q000494:pharmacology*; D008297:Male; D009489:Neurosecretion / Q000187:drug effects*; D010121:Oxytocin / Q000378:metabolism / Q000494:pharmacology*; D010904:Pituitary Gland, Posterior / Q000294:innervation*; D051381:Rats; D013997:Time Factors
D001127:Arginine Vasopressin; D010121:Oxytocin