Effect of hypoxic hypoxia and ritanserin on capillary flow and oxygenation in rabbit skeletal muscle

• Published in: Acta physiologica Scandinavica 1994-01, Vol.150 (1), p.39-45
• Main Authors: GUSTAFSSON, U., SJOBERG, F., LEWIS, D. H., THORBORG, P.
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Blood Gas Analysis; Blood Pressure - drug effects; Capillaries - drug effects; Capillaries - physiology; Fundamental and applied biological sciences. Psychology; hydrogen clearance; Hydrogen-Ion Concentration; Hypoxia - physiopathology; Laser-Doppler Flowmetry; laser-Doppler flowmetry (LDF); micro-electrode; microcirculation; Microelectrodes; Muscles - blood supply; Muscles - drug effects; Muscles - metabolism; Oxygen Consumption - drug effects; Oxygen Consumption - physiology; oxygen pressure; Rabbits; Regional Blood Flow - drug effects; Regional Blood Flow - physiology; Ritanserin - pharmacology; serotonin; Space life sciences; Striated muscle. Tendons; Vertebrates: osteoarticular system, musculoskeletal system
• ISSN: 0001-6772; 1365-201X
• DOI: 10.1111/j.1748-1716.1994.tb09657.x

Gustafsson, U., Sjöberg, F., Lewis, D. H. & Thorborg, P. 1994. Effect of hypoxic hypoxia and ritanserin on capillary flow and oxygenation in rabbit skeletal muscle. Acta Physiol Stand 150, 39–45. Received 2 April 1993, accepted 21 July 1993. ISSN 0001–6772. Clinical Research Centre and the Burns Unit, Department of Hand and Plastic Surgery, and Department of Anaesthesiology, University Hospital, Linkoping, Sweden, and Dept of Anesthesiology, University of Rochester Medical Center, NY, USA. This study examined capillary flow and oxygenation in rabbit skeletal muscle during hypoxic hypoxia (inspired oxygen fraction = 0.10) and after administration of ritanserin (highly selective 5‐Hydroxytryptamine‐2‐receptor antagonist). Capillary flow (hydrogen clearance) or oxygen pressure was measured with a multiwire micro‐electrode which was placed on the surface of the left vastus medialis muscle. For measurement of regional microcirculatory blood flow a laser‐Doppler flowmeter probe was placed on the contralateral muscle. An experimental sequence with normoxaemia (arterial Po2 12.5 kPa), followed by hypoxaemia (arterial Po2 3.9 kPa) and thereafter sustained hypoxaemia (arterial Po2 4.0 kPa) during which ritanserin (0.035 mg kg‐1 i.v.) was administered, was used. During hypoxaemia a decrease was seen in mean arterial pressure (MAP) by 27%, capillary flow by 25%, muscle oxygen pressure by 32% and laser‐Doppler flowmetry (LDF) flow by 24%. After the administration of ritanserin the mean arterial pressure was further reduced by 7%, whereas the capillary flow increased by 59% and the muscle oxygen pressure by 31 %. The LDF flow remained unchanged. These results demonstrate that, in this animal model, a decrease in skeletal muscle capillary flow and oxygenation during hypoxaemia can be reversed by the administration of ritanserin, despite a further reduction in blood pressure.