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Autologous Pump‐Perfused Rat Hind Limb Preparation for Investigating Muscle Function and Metabolism In Vivo
Author(s) -
Peoples Gregory E.,
Hoy Andrew J.,
Henry Renee,
McLennan Peter L.
Publication year - 2013
Publication title -
microcirculation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.793
H-Index - 83
eISSN - 1549-8719
pISSN - 1073-9688
DOI - 10.1111/micc.12048
Subject(s) - hindlimb , isometric exercise , perfusion , anatomy , skeletal muscle , contraction (grammar) , chemistry , vasodilation , muscle contraction , blood flow , medicine , anesthesia , endocrinology
Objective Oxygen delivery, underpinned by vascular tone, is the principle limiting factor in the study of skeletal muscle physiology, particularly during muscle contraction. The aim of this study was to develop an autologous perfused rat hind limb preparation for the study of skeletal muscle contractile function. Methods Adult Wistar rats were surgically prepared using a by‐pass system for pump‐controlled arterial blood flow to, and venous return from the hind limb during periods of quiescence and twitch contraction of the gastrocnemius‐plantaris‐soleus muscle bundle. Results During rest, hind limb perfusion pressure (102 ± 5 mmHg) was not different to systemic arterial pressure (99 ± 4 mmHg). Hind limb pressure was responsive to vasoconstrictors and vasodilators (±50 mmHg). The arterial PO 2 (100 ± 3 mmHg), O 2 saturation, and acid–base balance (pH: 7.42 ± 0.01) contributed to resting hind limb ( a‐v )O 2 difference (4.8 ± 0.5 mL/100 mL) and V O 2 (0.31 ± 0.03 μmol/g/min wet weight). Repetitive isometric twitch tension (1 Hz, 0.05 ms, 10 minutes) was best maintained at a flow rate of 2 mL/min ( V O 2 increased fivefold during muscle contraction) and efficiency of oxygen use increased from 0.27 ± 0.08–0.52 ± 0.07 N/μmol/min. Conclusion The autologous rat hind limb provided resting vascular tone allowing maintenance of perfusion pressure at flows within the physiological range. Oxygen delivery supported repetitive twitch contractions and facilitated measurement of active metabolism.