The electrically evoked, tachykinin-mediated contractile response of the isolated rabbit iris sphincter muscle involves NK1 receptors only.
In the presence of atropine and guanethidine, the electrically evoked contractile response of the rabbit iris sphincter muscle is mediated by tachykinins. Two highly selective NK1 receptor antagonists, (+/-) CP-96,345 and spantide II, concentration dependently inhibited the contraction with pIC50 values of 5.4 and 6.1, respectively. A highly selective NK2 receptor antagonist, actinomycin D, was inactive, while another NK2 receptor antagonist of moderate selectivity, MEN 10,376, produced a slight inhibition of the contraction at high concentrations. Our results suggest that the electrically evoked, tachykinin-mediated contractile response of the rabbit iris sphincter muscle involves NK1 receptors only.
Wang
Z Y
ZY
Department of Pharmacology, Lund University, Sweden.
Håkanson
R
R
D000818:Animals; D004558:Electric Stimulation; D005260:Female; D007498:Iris / Q000187:drug effects* / Q000502:physiology; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D015288:Neurokinin A / Q000378:metabolism*; D011817:Rabbits; D018041:Receptors, Neurokinin-2; D017981:Receptors, Neurotransmitter / Q000187:drug effects* / Q000502:physiology; D015320:Tachykinins / Q000494:pharmacology*
D018041:Receptors, Neurokinin-2; D017981:Receptors, Neurotransmitter; D015320:Tachykinins; D015288:Neurokinin A