Changes in noradrenergic vesicle markers of rabbit oviducts during progesterone treatment.
The effect of progesterone (P) on norepinephrine (NE), [3H] norepinephrine ([3H]NE) and dopamine beta-hydroxylase (DBH) in noradrenergic vesicles from rabbit oviducts was studied after daily injections of the hormone during different periods (4, 7 and 15 days). Progesterone induced a concomitant increase in NE and DBH activity and [3H]NE uptake. To study the mechanism involved in such effects, 4 tissue fractions were obtained by differential centrifugation of the oviducts of which the vesicular fraction was applied over continuous sucrose gradients (0.3-2 M). The changes induced by P in markers of tissue and gradient fractions showed an increase of the NE storage capacity which could be ascribed to an increase in the number of storage vesicles, and/or to a higher extravesicular storage capacity. The occurrence of these mechanisms during pregnancy or after P treatment could account for the (long-lasting) high levels of NE observed in such instances.
D000818:Animals; D004299:Dopamine beta-Hydroxylase / Q000032:analysis; D005187:Fallopian Tubes / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D009638:Norepinephrine / Q000032:analysis / Q000378:metabolism*; D011374:Progesterone / Q000494:pharmacology*; D011817:Rabbits
D011374:Progesterone; D004299:Dopamine beta-Hydroxylase; D009638:Norepinephrine