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Effects of receptor‐selective neurokinin agonists and a neurokinin antagonist on the electrical activity of spinal cord neurones in culture
Author(s) -
Wienrich M.,
Reuss K.,
Harting J.
Publication year - 1989
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1989.tb14621.x
Subject(s) - neurokinin b , neurokinin a , substance p , tachykinin receptor 1 , tachykinin receptor , depolarization , tetrodotoxin , antagonist , receptor , medicine , endocrinology , receptor antagonist , chemistry , spinal cord , nk1 receptor antagonist , biology , neuropeptide , neuroscience
1 Rat spinal cord neurones grown in tissue culture were used to examine the electrophysiological effects of the neurokin in (NK)‐selective agonists (pGlu 6 , Pro 9 ) substance P(6–11) (septide; NK 1 , 10 −6 m .) and (pGlu 5 , MePhe 8 , MeGly 9 )SP(1–7) (DiMe‐C7; NK 3 , 10 −6 m .). In addition, the effect of the neurokinin antagonist (D‐Arg 1 , D‐Pro 2 , D‐Trp 7,9 , Leu 11 )SP (10 −5 m .) on the neurokinin‐evoked responses was investigated. 2 Neurokinin‐evoked responses consisted of an increase in neuronal activity with or without long‐lasting (mean: 50s) depolarizations of the membrane potential of up to 25mV. The latter also occurred in the presence of tetrodotoxin (10 −7 m .) (direct response). 3 In a number of spinal cord neurones ( n = 17) only septide induced a membrane depolarization while DiMe‐C7 elicited no response. On the other hand, in 2 neurones a response was exclusively evoked by DiMe‐C7. 4 The neurokinin antagonist (D‐Arg 1 , D‐Pro 2 , D‐Trp 7,9 , Leu 11 )SP had no effect of its own but blocked the septide‐ and DiMe‐C7‐induced depolarizations. It had no effect on the glutamate (10 −5 m .)‐evoked depolarization. 5 It is concluded that by the use of neurokinin receptor‐selective agonists, subpopulations of spinal cord neurones in primary dissociated cell culture can be differentiated which express the NK 1 or the NK 3 receptor. Cells expressing only the NK 1 receptor outnumber those expressing only the NK 3 receptor subtype. Both receptors can be blocked by the neurokinin antagonist (D‐Arg 1 , D‐Pro 2 , D‐Trp 7,9 , Leu 11 )SP.