Effects of sumatriptan nasal spray (Imigran) on isolated rat's tracheal smooth muscle.
Sumatriptan (Imigran) is a potent and highly selective 5-HT1 receptor agonist often used in treating acute migraine. Intranasal sumatriptan is well absorbed and is generally effective in relieving headache. However, the effects of Imigran given intratracheally have rarely been well explored. We aimed to verify the effect of Imigran, which acts on the tracheal smooth muscle directly in vitro. We examined the effectiveness of Imigran on isolated rat tracheal smooth muscle by testing: (1) effect on tracheal smooth muscle resting tension; (2) effect on contraction caused by 10(-6) M methacholine as a parasympathetic mimetic; (3) effect of the drugs on electrically induced tracheal smooth muscle contractions. The results indicated that the addition of methacholine to the incubation medium caused the trachea to contract in a dose-dependent manner. The addition of Imigran at doses of 10(-5) M or above elicited a significant relaxation response to 10(-6) M methacholine-induced contraction. Imigran could inhibit electrical field stimulation-induced spike contraction. It also had a minimal effect on the basal tension of trachea as the concentration increased. The study indicated high concentrations of Imigran could cause bronchodilation to reduce asthma attacks not only by blocking parasympathetic tone, but also by directly antagonizing the effect of cholinergic receptors.
Department of Otolaryngology-Head and Neck Surgery, National Defense Medical Center, Tri-Service General Hospital, Taipei, Taiwan, Republic of China.
Li-Hsiang
LH
Cheng
Pei-Chuan
PC
Wu
Shao-Cheng
SC
Liu
Feng-Shiang
FS
Chiu
Yueng-Hsiang
YH
Chu
Ying-Nan
YN
Chang
Hsing-Won
HW
Wang
D000818:Animals; D001249:Asthma / Q000188:drug therapy* / Q000503:physiopathology; D004195:Disease Models, Animal; D004558:Electric Stimulation; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects* / Q000503:physiopathology; D059085:Nasal Sprays; D051381:Rats; D058825:Serotonin 5-HT1 Receptor Agonists / Q000008:administration & dosage; D018170:Sumatriptan / Q000008:administration & dosage*; D014132:Trachea / Q000187:drug effects*
D059085:Nasal Sprays; D058825:Serotonin 5-HT1 Receptor Agonists; D018170:Sumatriptan