New role of nerve growth factor--an inhibitory neuromodulator of adrenergic transmission.
In the present study, we investigated the effects of nerve growth factor (NGF) on norepinephrine (NE) release from peripheral sympathetic nerve endings of rat mesenteric artery. We made isolated mesenteric artery-intestinal loop preparations, by the modified method of Castelluci et al., from 4- and 8-week-old Wistar rats. NGF produced a dose-dependent inhibition of NE overflow from sympathetic nerve endings evoked by electrical nerve stimulation in the range of 0.1-10 ng/ml. Inhibition of NE overflow also occurred in the presence of a neuronal uptake blocker, desipramine (5 x 10(-8) M). NGF showed no effect on pressor response to exogenous NE (1 micrograms). These results suggest that NGF inhibits NE release from sympathetic nerve endings, in other words, NGF acts as an inhibitory neuromodulator of adrenergic transmission. This function of NGF might be considered as an inhibitory feedback mechanism against catecholamine-stimulated NGF synthesis.
Department of Medicine, Wakayama Medical College, Japan.
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T
Ueyama
T
T
Hano
M
M
Hamada
I
I
Nishio
Y
Y
Masuyama
D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D003891:Desipramine / Q000494:pharmacology; D004558:Electric Stimulation; D008297:Male; D008638:Mesenteric Arteries / Q000294:innervation / Q000502:physiology; D009411:Nerve Endings / Q000187:drug effects / Q000378:metabolism; D009414:Nerve Growth Factors / Q000502:physiology*; D018377:Neurotransmitter Agents / Q000502:physiology*; D009638:Norepinephrine / Q000378:metabolism / Q000494:pharmacology; D010477:Perfusion; D051381:Rats; D011919:Rats, Inbred Strains; D013564:Sympathetic Nervous System / Q000502:physiology*; D009435:Synaptic Transmission / Q000502:physiology*
D009414:Nerve Growth Factors; D018377:Neurotransmitter Agents; D003891:Desipramine; D009638:Norepinephrine