EVIDENCE OF 2 DIFFERENT GLOMERULAR POPULATION THROUGH SIEVING TECHNIQUES IN PIG RENAL CORTEX

Abstract

Amelioration of a sieving technique for the isolation of glomeruli was aimed at obtaining purer and more homogeneous preparations with a high degree of preservation of glomerular function. Sieves should be adapted to different glomerular size. Kidneys should have exactly the same weight in order to obtain very homogeneous glomerular suspensions. The homogeneity of the glomerular was improved through a preliminary dissection of the renal cortex in order to isolate glomeruli situated in the same cortical zone. Pig renal cortex, because of its size, worked well with this technique. Glomeruli were isolated with 160/120 .mu. mesh sieves. Diameter mean value was 218.8 .+-. 30.1 .mu. in superficial glomeruli and 270.4 .+-. 30.1 .mu. in juxta-medullary ones, showing a highly significant difference, (P < 0.001). Repartition frequency histograms of the juxta-medullary glomerular populations diameter showed a large shift to higher values. This renal dissection preceding the glomeruli isolation sieving technique countributes to the homogeneity of the isolated glomeruli suspensions. This allows comparison of in vitro vasoreactivity of these 2 different glomerular populations after incubation with physiological or pharmacological reagents.