title: Control of tissue environment during vital microscopy of the microcirculation in the m. tenuissimus in cat.
abstract: The physiological preservation of the tenuissimus muscle preparation in cat during vital microscopy of the microcirculation is assessed, comparing the originally described technique with a modified approach. Differences in the compared techniques include modes of dissection and transillumination, room-air exposure and moisturizing procedures. The original technique involves extensive dissection, inadequate temperature control and irrigation in open air. The modified technique involves less surgery due to a new illumination system, controlled heating and a Mylar foil cover on the preparation to minimize room-air influences. Temperature measurements and analyses of energy metabolism (ATP, CP, glucose, G6-P and lactate) are used as objective criteria of tissue normalcy. The microcirculation and metabolism are evaluated during anesthesia (alpha-chloralose) at rest as well as in hemorrhagic shock. In the resting state, muscle temperature drops to 28 degrees C with the irrigation technique, whereas the Mylar technique keeps the temperature at 34--35 degrees C. Neither technique causes deviations in normal metabolism. In shock, however, the temperature in the irrigated tenuissimus muscle fall 8--9 degrees C below deep muscle temperature and there is a significantly attenuated metabolic response to ischemia, while the Mylar preparation follows the changes of unexposed muscle, both in temperature and metabolism.
mesh_terms: D000818:Animals; D002415:Cats; D005260:Female; D008833:Microcirculation / Q000503:physiopathology; D008853:Microscopy / Q000379:methods*; D009132:Muscles / Q000098:blood supply*; D012771:Shock, Hemorrhagic / Q000503:physiopathology