- Title
- Dynamic range of evoked cholinergic and non-cholinergic non-adrenergic vasodilatation in bronchoesphageal circulation in the awake dog
- Creator
- White, Saxon William; van der Touw, T. J.; Hennessy, E. J.; Porges, W. L.; Moore, P.G.; Glenfield, P. J.
- Relation
- The European Respiratory Journal. Supplement Vol. 3, Issue 12
- Publisher
- Maney Publishing
- Resource Type
- journal article
- Date
- 1990
- Description
- The functional characteristics and control factors of the bronchoesophageal circulation under natural conditions are unknown. In 8 awake dogs 2-3 weeks after mounting a 3mm i.d. Doppler flow probe on the right bronchoesophageal artery under halothane-oxygen anaesthesia, the bronchial circulation is a low-flow, high resistance bed under resting thermoneutral conditions (mean bronchovascular flow (Qbr) = 0.27ml·s⁻¹, range 0.03-0.75, n=8; mean bronchovascular conductance (Cbr) = 8.5x10⁻⁴ml·s⁻¹·mmHg⁻¹, range 2x10⁻⁴21x10⁻⁴, n=5). Sequential autonomic blockade (i.v. methscopolamine 270 μg·kg⁻¹; propranolol 1 mg·kg⁻¹; phentolamine 4mg followed by 0.15−0·4 mg·min⁻¹ infusion) reveals significant resting α-adrenoceptor vasoconstrictor tone and suggest the presence of resting cholinoceptor vasoconstrictor tone. Notwithstanding acetylcholine (0.063-2·0 μg·kg⁻¹, i.v. bolus) evokes transient increased in Qbr (2-7 times; ED₅₀ 0.68 μg·kg⁻¹) and in Cbr (2-8 times; ED₅₀ 0.46 μg·kg⁻¹). Rapid (
- Subject
- vasodilatation; bronchoesophageal; bronchial circulation
- Identifier
- http://hdl.handle.net/1959.13/939335
- Identifier
- uon:12782
- Identifier
- ISSN:0903-1936
- Language
- eng
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