Abstract
1. The structure of the wall of the lung from the toad ( Bufo marinus) has been examined using scanning and transmission electron microscopy and the presence of smooth muscle cells in the septal-alveolar walls detected. 2. Responses of toad isolated lung parenchyma strip to agonists causing relaxation and contraction were measured and the potencies of adrenoceptor and 5-hydroxytryptamine receptor antagonists were determined. 3. Results indicated the presence of populations of alpha- and beta-adrenoceptors in toad lung alveoli, both of which mediate relaxation responses. Stimulation of both alpha- and beta-adrenoceptors was required to cause complete relaxation. 5-Hydroxytryptamine also caused complete relaxation. 4. A population of alpha-adrenoceptors mediating contraction may also exist in pulmonary vascular and/or septal edge smooth muscle.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Comparative Biochemistry and Physiology. Part C, Comparative Pharmacology
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
