Concurrent releases of norepinephrine and purines by potassium from adrenergic melanosome-aggregating nerve in Tilapia.
Elevation of [K+]0 elicited pigment aggregation within melanophores, and, at the same time, release of both norepinephrine (NE) and purines from split fin preparations of the tilapia, Sarotherodon niloticus, doubly labeled with [14C]NE and [3H]adenosine. This concomitant release increased with the increase in [K+]0 up to 50 mM, although a further increase in [K+]0 caused a progressive decrease in the outputs. The release of either NE or purines was significantly reduced by bretylium. It was concluded that, upon stimulation of the nerve, both the true transmitter, NE, and the co-transmitter, adenine nucleotides, are liberated for an exquisite control of chromatophore movements.
D000320:Adrenergic Fibers / Q000378:metabolism*; D000818:Animals; D001949:Bretylium Compounds / Q000494:pharmacology; D005260:Female; D005399:Fishes / Q000378:metabolism*; D008297:Male; D008544:Melanocytes / Q000378:metabolism*; D008547:Melanophores / Q000187:drug effects / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism*; D011188:Potassium / Q000494:pharmacology*; D011687:Purines / Q000378:metabolism*
D001949:Bretylium Compounds; D011687:Purines; D011188:Potassium; D009638:Norepinephrine