DEVELOPMENT OF INTRAVITAL LASER MICROSCOPE FOR THE OBSERVATION OF OXYGEN DISTRIBUTION

虽然它已经被遗忘了100年，其中一个主要的功能microcirculation is deliver oxygen to tissue，our understanding of the processes in the transport of oxygen from blood to cells is一个主要的问题是，我们不知道如何处置oxygen tissue varies，particularly in the vicinity of blood vessels and around individual cells. in the present study wenewly designed phosphorescence intravital microscopy，which enable to measure oxygen tension (pO2) in small regions of tissue，to examine the gradient of pO2 in the tissue around the arteriole. Experiments performed inanesthetized rat cremaster muscle. Pd-porphyrin complexes, the oxygen-dependent：phosphorescence dye used to measure the quenching decay curve in the tissue. the pO2 wascalculated from the time constant of the decay curve, following the Stern-Volmer equation：to/t=1+Kq = pO2 where to and are the phosphorescence lifetimes in the absence of O2 and in thetissue being measured and Kq是the quenching constant. Obtained arteriolar pO2 values decreasedaccording to increase the number of branching (1st-order: 70mmHg, 2nd: 55mmHg, 3rd：45 mmhg),however venular pO2 values at the different position showed almost same level(30mmHg). Tissue pO2values showed large gradient between the area closed to arterioles （mmHg -20mmHg）100mum apart（收缩压5-8mmHg） .这是包括当前方法提供的连续，non-invasive determina-tion of oxygen distribution in the skeletal muscle on a microscopic lengthscale。

Although it has been recognized for over 100 years that one of the principal functions of the microcirculation is to deliver oxygen to tissue, our understanding of the processes involved in the transport of oxygen from blood to cells is incomplete. A major problem is that we do not know how the concentration of oxygen in tissue varies, particularly in the vicinity of blood vessels and around individual cells. In the present study we used newly designed phosphorescence intravital microscopy, which enable to measure oxygen tension (pO2) in small regions of tissue, to examine the gradient of pO2 in the tissue around the arteriole. Experiments were performed in anesthetized rat cremaster muscle. Pd-porphyrin complexes, the oxygen-dependent : phosphorescence dye were used to measure the quenching decay curve in the tissue. The pO2 was calculated from the time constant of the decay curve, following the Stern-Volmer equation : to/t=1+Kq・to・pO2 where to and are the phosphorescence lifetimes in the absence of O2 and in the tissue being measured and Kq is the quenching constant. Obtained arteriolar pO2 values decreased according to increase the number of branching (1st-order : 70mmHg, 2nd : 55mmHg, 3rd : 45mmHg), however venular pO2 values at the different position showed almost same level(30mmHg). Tissue pO2 values showed large gradient between the area closed to arterioles (arteriolar pO2 minus 15-20mmHg) and 100mum apart (5-8mmHg) . It was concluded that present method offers the continuous, non-invasive determina-tion of oxygen distribution in the skeletal muscle on a microscopic length scale.