Splenic hemodynamics was measured and analysed in detail for better understanding of its role in red cell destruction.
In the first step of this study, hemodynamics character through the spleen was determined by perfusion experiments of isolated dog spleens with radiotracers of red cell and the plasma. Analysis of radiograms of the spleen and its out-put revealed the dynamics character which was composed of the fast and slow phase and was represented by sum of corresponding exponential components.
Clinical study was designed to measure the dynamics in vivo under physiological condition in 10 controls, 15 hereditary sperocytosis with autogeneous cell and normal cell, 16 studies in autoimmune hemolytic anemias and 44 studies in portal congestive splenomegalies. The dynamics study was carried out separately in the fast phase and in the slow phase applying appropriate method and analysis technique to each dynamic phase. With these results, a over-all hemodynamics chracter was constructed for each blood tracer in each spleen. Three compartments with different dynamic character, i.e., the fast, intermediate and slow ones, were allotted to red cell flow, while two were allotted to the plasma as the fast and intermediate ones.
Average value in hereditary spherocytosis exhibited that 77.5% of red cells of splenic arterial inflow passed the fast compartment with mean transit time of 11 seconds, only 2% of them entered the slow one with the transit time of 19 minutes and the residual participated in the intermediate one. There was no significant differnce in partition ratio of red cell into the fast compartment among control and disease groups and the dynamics in this compartment was supposed to be under a control to maintain a certain flow rate.
With the parameters which represent red cell and plasma dynamics, multiple regression analysis was performed agaist red cell destruction rate to elucidate the relationship between the spleen hemodynamics character and red cell destruction. A close relationship was manifested in hereditary sherocytosis by a multiple correlation coefficient of 0.956 with cotributors of plasma flow, red cell dynamics in the slow compartment and the spleen size. In autoimmunehemolytic anemias, a poor relationship was yielded as a whole but a closely resembled pattern was displayed in some cases to that observed in hereditary spherocytosis and splenectomy yielded a excellent effect in these cases.
In some cases of portal congestive splenomegaly, accelerated red cell destruction developed following the shunt operation in spite of reduction in the spleen size. This hemolysis was closely related to postoperative alteration in the splenic hemodynamics, i.e., acceleration of plasma flow, stagnation of red cell in the slow compartment and change in the dynamics in intermediate one accompanying the spleen size reduction. The multiple correlation coefficient was 0.880.
Red cells obtained in delayed phase of perfusion of surgecally removed human spleen demostrated increased fragility by coil planet centrifuge as well as stomato-echinocyte alteration by scanning electron microscopy. Splenic dynamics and extraction of artificially denaturated red cells was determined. These cells had been treated with NEM or heating and demonstrated increased fragility and morphological changes and displayed the shift to slower dynamics, which was accompanied by a proportional increase in their extraction rate.
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