Inhibitory Neurotransmission in the Bovine Retractor Penis and the Rat Anococcygeus Muscle

Liu, Xiaorong (1989) Inhibitory Neurotransmission in the Bovine Retractor Penis and the Rat Anococcygeus Muscle. MSc(R) thesis, University of Glasgow.

Abstract

1. The aims of this study were twofold. First to try to detect the non-adrenergic non-cholinergic (NANC) neurotransmitter in the bovine retractor penis by bioassay and secondly to study the effects of various drugs which might reveal its relationship with nitric oxide and endothelium-derived relaxing factor (EDRF). This second objective was pursued in both the bovine retractor penis and rat anococcygeus muscles. 2. The attempt to detect the NANC inhibitory neurotransmitter released by field stimulation from the donor bovine retractor penis muscle and detected by a variety of test tissues (bovine retractor penis, rat anococcygeus and rabbit aortic strip) arranged in several different test systems failed. 3. Superoxide dismutase (10 u./ml. up to 400 u./ml.) had no effect on NANC inhibitory relaxation and had no measurable effect in protecting the NANC neurotransmitter. 4. L-Arginine, a precursor of EDRF, did not potentiate NANC inhibitory relaxation in the BRP either fresh or cold stored up to ten days. 5. L-Monomethyl-N-arginine (L-NMMA, a competitive inhibitor of L-arginine in endothelial cells) and D-monomethyl-N-arginine (D-NMMA) up to 3x10-4M. were without effect on NANC inhibitory relaxation of the bovine retractor penis muscle. But at higher concentration of 10 -3M. L-NMMA inhibited the NANC relaxation and further raised guanethidine-induced tone, an effect partially reversed by L-arginine 10 -3M. 6. L-NMMA (10 -5M. up to 3x10 -4M.), but not D-NMMA (10-5M. up to 3x10-4M.), raised tone and inhibited the NANC inhibitory relaxation on the rat anococcygeus muscle in a dose-dependent manner, an effect competitively reversed by L-arginine (3x10-5M. up to 10-3M.) or by washing out the L-NMMA. 7. L-NMMA up to 6x10 -4M. was without effect on the relaxation induced by nitric oxide on the rat anococcygeus or the rabbit aortic preparations suggesting the inhibition of the response to nerve stimulation was not post-synaptic. 8. L-NMMA, but not D-NMMA, dose-dependently (10-5M. up to 3x10-4M.) inhibited the EDRF relaxation induced by acetylcholine in the rabbit aortic preparations, an effect reversed by L-arginine or washing out L-NMMA. 9. L-Canavanine, an inhibitor of nitric oxide production in macrophages, at concentration up to 3x10 -4M. had no effect on NANC relaxation of the BRP preparation. But at higher concentration of 10 -3M. it inhibited the NANC relaxation, an effect partially reversed by L-arginine 10-3M. 10. L-Canavanine up to 2x10 -3M. exhibited no effect on NANC inhibitory relaxation on the rat anococcygeus preparation.

• Item Type: Thesis (MSc(R))
• Qualification Level: Masters
• Keywords: Neurosciences
• Date of Award: 1989
• Depositing User: Enlighten Team
• Unique ID: glathesis:1989-77909
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 30 Jan 2020 15:48
• Last Modified: 30 Jan 2020 15:48
• URI: https://theses.gla.ac.uk/id/eprint/77909