Introduction of cremaster muscle chamber technique for long-term intravital microscopy

This study evaluated the microcirculatory hemodynamics of a new chamber imp lantation technique. The cremaster muscle island flap was employed. Sevente en male Sprague-Dawley rats were studied in two groups. In the control grou p, the standard cremaster muscle preparation with no chamber (N = 8) was us ed. After flap isolation, the muscle was preserved in the medial border of the hind limb and removed for observation after 24 hours. For the chamber g roup, the chamber was implanted after muscle isolation, and measurements we re made 30 minutes postoperatively and at 24, 48, and 72 hours. The variabl es measured were microvessel diameter, red blood cell velocity, number of p erfused capillaries, and the number of rolling, sticking, and transmigratin g leukocytes in the postcapillary venules. The chamber group had a signific antly greater number of perfused capillaries at 24 hours compared with cont rols (p < 0.05). The other variables did not differ significantly between g roups at 24 hours. We can conclude that this cremaster muscle chamber model for chronic in vivo studies proved to be equal to the classic cremaster mu scle preparation for chronic microcirculatory measurements for at least 24 hours.