Quantitation of Fibrin Deposition and Elimination in Organs of Rats Injected with Labelled Fibrinogen and Albumin

Abstract

SummaryA method for quantitation of fiprin deposits in organs of rats, using labelled fibrinogen and albumin, is described. In rats previously injected with 125I-fibrinogen, thrombin was used to induce intravascular deposition of fibrin in various organs. 131I-albumin was injected shortly before sacrifice for determination of the organ plasma volume. The fibrin content of the organ was calculated by subtraction of the plasma and extravascular 125I-radioactivities from the total 125I-content of the organ. The organ plasma radioactivity was obtained as the product of 12 5I in plasma and the organ plasma volume and the extravascular radioactivity as the difference between total and plasma radioactivity in organs of rats before the thrombin infusion. It was found that the method is especially suited for quantitation of fibrin deposition and elimination in the lungs, but it should be also applicable to other organs. In the liver and kidneys certain problems occur which interfere especially with fibrin elimination studies in these organs.

Protective Effect of Angiotensin II Inhibition on Acute Renal Failure after Intravascular Coagulation in the Rat

“…During the intravascular coagulation a decrease in intravascular fibrinogen and an increase in fibrin degrada tion products occur. These changes, however, have been shown to influence measurements to only a moderate degree [12],…”

Influence of Brinase on Fibrinogen: Fibrin Transition in in vitro and in vivo Studies

“…As it was shown in earlier studies that identical results are ob tained with rat and human fibrinogen, and the latter is more stable, human l2sI-fibrinogen was used in the investigation. For labelling a modification of the io dine monochloride method was used [5]. The prepara tion used had a coagulability of 90%, the iodination was < 1 atom/molecule fibrinogen, and the specific activity was 5-6 pCi/mg protein.…”

“…30 min [21], using thrombin or Rcptilase, as polymerizing agents; and by a method with a longer (2 h) reaction time [2], For determination of fibrinogen in plasma from heparinized animals, the thrombin dose was doubled. Quantitation o f fibrin in lungs and kidneys was carried out according to a method described pre viously [4,5,25]. l25I-fibrinogen was injected into the Table I [4,15].…”

“…Blood samples were obtained, lungs and kid neys were rapidly removed, dissected free from con nective tissue, cleaned with filter paper and weighed. The left lung and kidney were placed in weighed plas tic Ellermann tubes for radioactivity measurement in a gamma-spectrometer and for calculation of the fi brin content according to a formula described pre viously [5]. The amount of fibrin was, moreover, determined after homogenization of the right lung and kidney, respectively, in an Ultra-Turrax homogenizer, in a solution containing 10,000 IU heparin and 3g AMCA/I distilled water.…”

Effect of Beta-Adrenergic Blockade by Propranolol upon Intravascular Coagulation in the Rat Kidney

“…The radioactivity of blood, dissolved fibrinogen and organ samples was measured in a gammaspectrometer (LKB 1280, Ultrogamma). The fibrin content of tissues was calculated by the formula [10]:…”