Leucine-enkephalin- and neuropeptide Y-modulation of [3H]noradrenaline release in the oviduct of mature and juvenile rabbits.
1. The effects of leucine-enkephalin and neuropeptide Y (NPY) on [3H]noradrenaline release induced by electrical field stimulation were studied in the isthmic part of the oviduct of juvenile and mature rabbits. 2. [3H]noradrenaline and total tritium overflow in the presence of cocaine, corticosterone and hyoscine were determined by liquid scintillation spectrometry. 3. Tritium overflow evoked by electrical stimulation (1 or 4 Hz, 1 msec) was calcium dependent. [3H]noradrenaline content (measured by ion exchange chromatography) accounted for 85% of the total tritium overflow. 4. Leucine-enkephalin (1 microM) in the presence of the peptidase inhibitor bacitracin reduced the stimulation-evoked tritium overflow in mature rabbits by 26.1 +/- 1.6% and in juvenile rabbits by 11.9 +/- 1.9%. Naloxone (1 microM) antagonized the effect of leucine-enkephalin. 5. NPY (0.2 microM) reduced the evoked tritium overflow in mature rabbits by 23.4 +/- 2.4% and in juvenile rabbits by 17.2 +/- 4.3%. 6. It is concluded that leucine-enkephalin and NPY inhibited [3H]noradrenaline release in rabbit oviduct and the modulatory effect of leucine-enkephalin depends on maturity while NPY modulation is a more independent system.
Chernaeva
L
L
Institute of Physiology, Bulgarian Academy of Sciences, Sofia.
Charakchieva
S
S
D000375:Aging / Q000378:metabolism*; D000818:Animals; D004558:Electric Stimulation; D004743:Enkephalin, Leucine / Q000494:pharmacology*; D005187:Fallopian Tubes / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D005260:Female; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D009478:Neuropeptide Y / Q000494:pharmacology*; D009638:Norepinephrine / Q000378:metabolism*; D011817:Rabbits
D009478:Neuropeptide Y; D004743:Enkephalin, Leucine; D009638:Norepinephrine