Nerve growth factor NT-5 induce increased thermal sensitivity of cutaneous nociceptors in vitro.
1. Perfusion of the receptive field (RF) of C- or A delta-fiber nociceptors with nerve growth factor (NGF) in an in vitro preparation of the rat saphenous nerve with functionally attached skin induced a significant decrease in heat threshold without changing mechanical or cold sensitivity. 2. NGF-induced thermal sensitization was absent after saline perfusion and in skin taken from mast-cell depleted animals, hence confirming a role for mast cells in NGF-induced thermal hyperalgesia. 3. Neurotrophin-5 (NT-5) also induced a small but significant reduction in heat threshold without affecting mechanical sensitivity. It is speculated that NT-5 exerts its action either directly on the trkA receptor, as with NGF or alternatively through trkB receptors located on sympathetic efferents or on small diameter afferents.
Rueff
A
A
Department of Neurobiology and Behavior, State University of New York, Stony Brook 11794-5230, USA.
Mendell
L M
LM
D000818:Animals; D005260:Female; D066298:In Vitro Techniques; D009414:Nerve Growth Factors / Q000494:pharmacology*; D009619:Nociceptors / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D013696:Temperature
D009414:Nerve Growth Factors; C071951:neurotrophin 5