Stretch-induced release of proctolin from the dendrites of a lobster sense organ.
Reversed-phase high-performance liquid chromatography coupled with a sensitive bioassay was used to quantify the content of proctolin in the peripheral sensory endings of a crustacean mechanoreceptor, the oval organ, and to examine for its release in response to the physiological stimulus of stretch. Material co-eluting with proctolin and showing proctolin-like bioactivity was present in the oval organ and in the nerve trunks containing the 3 sensory axons. Repetitive stretch stimulation, in which the dendrites were exposed to physiological stretch amplitudes, resulted in a significant increase in the release of proctolin from the oval organ in vitro. Approximately 11.7% of the total proctolin stored in the oval organ was released during a 5 min stimulation period. The stretch-evoked release of proctolin was calcium dependent. Since a previous study has shown that proctolin has excitatory effects upon these primary afferents, the present results imply that endogenous proctolin may function to self-modulate the sensory transduction mechanism of these sensory terminals.
Pasztor
V M
VM
Biology Department, McGill University, Montreal, Canada.
Lange
A B
AB
Orchard
I
I
D000818:Animals; D002118:Calcium / Q000494:pharmacology; D003712:Dendrites / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D008465:Mechanoreceptors / Q000502:physiology*; D008121:Nephropidae; D009479:Neuropeptides; D018377:Neurotransmitter Agents / Q000378:metabolism*; D009842:Oligopeptides / Q000378:metabolism*; D012016:Reference Values
D009479:Neuropeptides; D018377:Neurotransmitter Agents; D009842:Oligopeptides; C011536:proctolin; D002118:Calcium