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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Adult, Blood Flow Velocity, Blood Pressure, Catheters, Indwelling, Epinephrine, Heart Rate, Humans, Infusions, Intravenous, Male, Microdialysis, Muscle, Skeletal, Regional Blood Flow, Sweden, Time Factors, Vasoconstriction, Vasoconstrictor Agents, Xenon Radioisotopes, Young Adult.
user
Does intravenous adrenaline infusion cause vasoconstriction close to an intramuscular microdialysis catheter in humans? Context: To test if a small muscle injury influences the vascular reactivity to adrenaline in human skeletal muscle. Blood flow was measured by ¹³³Xenon clearance in the gastrocnemius muscle of eight male subjects at basal and during i.v. infusion of adrenaline (0.1 nmol kg⁻¹ min⁻¹) or placebo. Measurements were done with (expts 2 and 3) or without (expt 1) the influence of a small muscle injury induced by inserting a microdialysis catheter. ¹³³Xenon was administered either (expt 1) conventionally into the muscle via a fine needle, or (expts 2 and 3) through a fine tube close to the inserted microdialysis catheter. Expt 3 (control expt) was identical to expt 2 except that placebo was infused instead of adrenaline. Mean ± SEM, n= 8.   The blood flow tended to increase during the adrenaline infusion in expt 1 (1.17 ± 0.10 to 1.39 ± 0.15, N.S.), whereas it decreased during the adrenaline infusion in expt 2, from 1.39 ± 0.14 to 1.03 ± 0.14 ml min⁻¹ 100 g tissue⁻¹ (P<0.001). The blood flow change in response to adrenaline infusion was significantly different in expt 1 and expt 2 (P<0.05). Blood flow also decreased during the placebo infusion in expt 3 (1.15 ± 0.10 to 1.00 ± 0.09, P<0.01), but this decrease was significantly smaller than in response to the adrenaline infusion in expt 2, P<0.01.
assistant
The present results are consistent with the hypothesis that the small muscle injury caused by the inserted microdialysis catheter influences the vascular reactivity to adrenaline in a vasoconstrictive direction. Final Decision: yes