A study of 5-HT-receptors associated with afferent nerves located in normal and inflamed rat ankle joints.
Neural recordings were made from sensory fibres in a nerve supplying the ankle joint in normal rats and in rats with a novel monoarticular arthritis. The responses of mechanically and chemically sensitive units to intra-arterial injections of 5-HT were measured. In most cases the mechanosensitivity of sensory receptors in the ankle joint was not altered by 5-HT. However, 5-HT produced an increase in afferent activity in units which were identified as C-fibres on the basis of action potential amplitude and duration. The receptive fields of these chemosensitive units were not located. The responses of these units to 5-HT were dose dependent and were abolished by the 5-HT2-antogonist, ketanserin, but not by the 5-HT3-receptor antagonist, MDL 72222. The responses of chemosensitive units to injections of 5-HT were similar in normal and arthritic rats although the response was slightly prolonged in arthritic animals.
Grubb
B D
BD
Department of Preclinical Veterinary Sciences, S.V.S. University of Edinburgh, Summerhall, UK.
McQueen
D S
DS
Iggo
A
A
Birrell
G J
GJ
Dutia
M B
MB
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D000843:Ankle Joint / Q000294:innervation*; D001168:Arthritis / Q000473:pathology / Q000503:physiopathology*; D007650:Ketanserin / Q000494:pharmacology; D009475:Neurons, Afferent / Q000502:physiology*; D051381:Rats; D011985:Receptors, Serotonin / Q000502:physiology*; D012701:Serotonin / Q000494:pharmacology*; D012702:Serotonin Antagonists / Q000494:pharmacology; D014326:Tropanes / Q000494:pharmacology
D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D014326:Tropanes; D012701:Serotonin; D007650:Ketanserin; C042253:bemesetron