A new method for determining inulin and PAH clearances in the conscious rat - fundamentals of the method (Part 1) with examples of its application in artificially induced renal damage (Part 2).

Abstract

A new method has been developed for the simultaneous measurement of inulin and PAH clearance in small laboratory animals (rats). A double-chambered Teflon capsule (capacity: 3 ml) is implanted intraperitoneally. One of the chambers is filled with inulin solution and the other with PAH solution. Both solutions are iso-osmotic. The open ends of the capsule are sealed with double dialysis membranes. Sufficiently high serum and urine levels of both substances can thus be maintained for 72 h. By adapting suitable methods, it proved possible to estimate inulin and PAH in 500 μl of blood or urine. The advantage of the method is that it can be used for renal clearance tests in small conscious animals, able to move freely within their cages without anaesthesia or intravenous infusions.