Tags

Type your tag names separated by a space and hit enter

Thromboxane A2 mimetic (U-46619) induces hyperresponsiveness of smooth muscle in the canine bronchiole, but not in the trachea.
Prostaglandins Leukot Essent Fatty Acids. 1996 Feb; 54(2):129-34.PL

Abstract

It has been reported that cholinergic agonists induce bronchoconstriction by directly stimulating M3 muscarinic receptors on the surfaces of smooth muscle cells. Although thromboxane A2 (TXA2) has been demonstrated to induce airway hyperresponsiveness to cholinergic agonists in vivo, it does not affect the contractile response of smooth muscle to cholinergic agonists in vitro. To investigate the causes for the discrepancy between the in vivo and in vitro data, we compared the effects exerted by a TXA2 mimetic, U-46619, on the smooth muscle of canine trachea and bronchiole. We measured the contractile response to exogenously applied acetylcholine (ACh) before and after the application of a subthreshold dose of U-46619. The subthreshold dose was determined as that dose which did not induce smooth muscle contraction, this being 10(-9) M in the present study. The contractile responses of tracheal strips to ACh were not affected by the subthreshold dose of U-46619. By contrast, the responses of bronchiolar rings were significantly enhanced by this subthreshold dose. The excitatory effect of U-46619 on the ACh-induced contraction was completely prevented by treatment with a TXA2 antagonist, BAY u3405. These results indicate that TXA2 directly increases the responsiveness of smooth muscle in the bronchiole, and suggest that increases in the responsiveness of small airways may play an important role in the development of the airway hyperresponsiveness induced by TXA2.

Authors+Show Affiliations

Research Institute for Diseases of the Chest, Faculty of Medicine, Kyushu University, Fukuoka, Japan.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

8848432

Citation

Takata, S, et al. "Thromboxane A2 Mimetic (U-46619) Induces Hyperresponsiveness of Smooth Muscle in the Canine Bronchiole, but Not in the Trachea." Prostaglandins, Leukotrienes, and Essential Fatty Acids, vol. 54, no. 2, 1996, pp. 129-34.
Takata S, Aizawa H, Shigyo M, et al. Thromboxane A2 mimetic (U-46619) induces hyperresponsiveness of smooth muscle in the canine bronchiole, but not in the trachea. Prostaglandins Leukot Essent Fatty Acids. 1996;54(2):129-34.
Takata, S., Aizawa, H., Shigyo, M., Matsumoto, K., Inoue, H., Koto, H., & Hara, N. (1996). Thromboxane A2 mimetic (U-46619) induces hyperresponsiveness of smooth muscle in the canine bronchiole, but not in the trachea. Prostaglandins, Leukotrienes, and Essential Fatty Acids, 54(2), 129-34.
Takata S, et al. Thromboxane A2 Mimetic (U-46619) Induces Hyperresponsiveness of Smooth Muscle in the Canine Bronchiole, but Not in the Trachea. Prostaglandins Leukot Essent Fatty Acids. 1996;54(2):129-34. PubMed PMID: 8848432.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Thromboxane A2 mimetic (U-46619) induces hyperresponsiveness of smooth muscle in the canine bronchiole, but not in the trachea. AU - Takata,S, AU - Aizawa,H, AU - Shigyo,M, AU - Matsumoto,K, AU - Inoue,H, AU - Koto,H, AU - Hara,N, PY - 1996/2/1/pubmed PY - 1996/2/1/medline PY - 1996/2/1/entrez SP - 129 EP - 34 JF - Prostaglandins, leukotrienes, and essential fatty acids JO - Prostaglandins Leukot. Essent. Fatty Acids VL - 54 IS - 2 N2 - It has been reported that cholinergic agonists induce bronchoconstriction by directly stimulating M3 muscarinic receptors on the surfaces of smooth muscle cells. Although thromboxane A2 (TXA2) has been demonstrated to induce airway hyperresponsiveness to cholinergic agonists in vivo, it does not affect the contractile response of smooth muscle to cholinergic agonists in vitro. To investigate the causes for the discrepancy between the in vivo and in vitro data, we compared the effects exerted by a TXA2 mimetic, U-46619, on the smooth muscle of canine trachea and bronchiole. We measured the contractile response to exogenously applied acetylcholine (ACh) before and after the application of a subthreshold dose of U-46619. The subthreshold dose was determined as that dose which did not induce smooth muscle contraction, this being 10(-9) M in the present study. The contractile responses of tracheal strips to ACh were not affected by the subthreshold dose of U-46619. By contrast, the responses of bronchiolar rings were significantly enhanced by this subthreshold dose. The excitatory effect of U-46619 on the ACh-induced contraction was completely prevented by treatment with a TXA2 antagonist, BAY u3405. These results indicate that TXA2 directly increases the responsiveness of smooth muscle in the bronchiole, and suggest that increases in the responsiveness of small airways may play an important role in the development of the airway hyperresponsiveness induced by TXA2. SN - 0952-3278 UR - https://www.unboundmedicine.com/medline/citation/8848432/Thromboxane_A2_mimetic__U_46619__induces_hyperresponsiveness_of_smooth_muscle_in_the_canine_bronchiole_but_not_in_the_trachea_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0952-3278(96)90070-8 DB - PRIME DP - Unbound Medicine ER -