Intra-brachial artery drug infusion Sample Clauses

Intra-brachial artery drug infusion. Vasoactive drugs were infused directly into the right brachial artery to probe the regulatory mechanisms of vascular tone in muscular conduit and resistance arteries in the human forearm. When infused locally, physiological or pharmacological concentrations can be achieved in the forearm circulation with negligible systemic drug delivery. This route of drug administration, therefore, avoids a systemic haemodynamic response and consequent activation of baroreceptors and other autonomic responses, which would make interpretation of the local vasodilatory responses difficult. A 27 gauge unmounted steel needle (Xxxxxx’x Needle Works, UK) sealed with dental wax to an epidural catheter (Smiths Medical Portex ®, UK) was inserted into the right brachial artery using ≤1ml of 1% lidocaine hydrochloride (Xxxxx Pharmaceuticals) to provide local anaesthesia. Following successful cannulation, either 0.9% saline or drugs dissolved in 0.9% saline vehicle were infused at 1ml/min using a syringe driver (Injectomat, Agilia®, Fresenius Kabi, Germany). Cumulative doses of comparator drugs were infused at each dose until steady state was achieved (typically between 6-12 minutes). Infusion of each drug was preceded by a baseline period, a washout period or studies were performed on different occasions. Brachial cuff blood pressure measurements and FBF were obtained from the non-cannulated arm to ensure there were no significant systemic responses that would influence the interpretation of the results of the FBF response to local infusion of the drugs.