METHOD OF SCREENING SUBSTANCES FOR USE IN THE TREATMENT OF CIRCULATORY SYSTEM DISEASES

• US 3,722,504 A
• Filed: 12/23/1969
• Issued: 03/27/1973
• Est. Priority Date: 12/23/1969
• Status: Expired due to Term

• Current Assignee: HV Corporation
• Original Assignee: Philip Nicholas Sawyer
• Inventors: Sawyer, Philip Nicholas
• Primary Examiner(s): Howell, Kyle L.
• Application Number:
  US04/887,649
• Time in Patent Office: 1,190 Days
• Field of Search: 128/2,2.1 23/23B 424/2,3,7,9
• US Class Current: 424/9.2
• CPC Class Codes: G01N 33/4905 Determining clotting time of blood by chemical methods G01N33/86, C12Q1/56

Abstract

A method as set forth for screening chemical agents and compounds to determine their usefulness in the treatment of circulatory system diseases and to enable distinguishing the anticoagulant and antithrombotic characteristics of the same. The method consists of a plurality of interrelated steps including the evaluation of the agent or compound on an exposed laboratory animal mesentery. Also included are tests on streaming potential in blood vessels, both in vivo and in vitro. In addition, the method includes checking the effect of the tested substances on electro-osmosis and evaluating the effect of the substance undergoing test on the charge of blood cells. Still further, the test includes checking the effect of the substance on the transport of ions across blood vessel walls and on the sorption and desorption of ions with respect to the circulatory system. In addition, the effect of the substance on destruction of various cells and proteins in blood is determined. The above characteristics are evaluated to determine the antithrombotic, antiatherogenic usefulness of the substance undergoing test.

Claims

1. A method of screening a substance for use in the treatment of circulatory system diseases, said method comprising determining the effect of the substance on streaming potential in circulatory systems by measuring the change in potential between an electrode pair inserted into the systems;

determining the effect of the substance on electro-osmosis in the circulatory systems by measuring the rate at which a fluid containing the substance can be pumped by a constant current of known polarity through blood vessel walls from said systems;

determining the effect of the substance on the charge of blood cells by measuring the catephoretic mobility of cell samples containing the substance;

determining the effect of the substance on the transport of ions through walls of the circulatory systems by measuring the change in rate of ion isotope diffusion across the walls in the presence of said substance;

determining the effect of the substance on the sorption and desorption of ions in the circulatory systems by measuring the change in rate of ion desorption from walls of the systems produced by said substance;

determining the effect of the substance on blood destruction; and

determining the effect of the substance on test animal mesentery thrombosis by measuring the change in rate of the mesentery vessel occlusion after administration of said substance.

2. A method as claimed in claim 1, wherein the effect of streaming potential is determined in vivo.

3. A method as claimed in claim 1, wherein the effect on streaming potential is determined in vitro.

4. A method as claimed in claim 1 comprising measuring the change of rate of the deposition of blood cells and thrombus on an electrode immersed in a fluid containing the substance.

5. A method as claimed in claim 1 comprising evaluating said effects to distinguish an anticoagulant from an antithrombitic agent based on said change in rate of occlusion.

6. A method as claimed in claim 1, wherein the test animal mesentery is examined in vivo by extracting the mesentery from the animal, passing a light through the mesentery, passing an electrical current through the mesentery, and observing the occlusion of blood vessels in the mesentery.

7. A method as claimed in claim 6, wherein the current is in the order of 10-20 microamperes.

8. A method as claimed in claim 7, wherein the mesentery is bathed in a gelatin Ringer'"'"''"'"'s solution.

9. A method as claImed in claim 1, wherein the streaming potential is examined with a segment of the circulatory system in vitro by placing the segment in a bathing solution having the same ionic composition as blood and establishing flow rates through the segment with an inert gas.

10. A method as claimed in claim 9 comprising measuring the streaming potential across the ends of the segment by placing the electrodes at said ends and connecting the electrodes to an electrometer.

11. A method as claimed in claim 10, wherein the downstream electrode is connected to the positive terminal of the electrometer.

12. A method as claimed in claim 1, wherein the streaming potential is examined with a segment of the circulatory system in vivo, comprising inserting tubes into spaced positions in said system and connecting the said positions to electrodes which are, in turn, connected to an electrometer.

13. A method as claimed in claim 1, wherein the transport of ions is examined by separating two chambers having bathing solutions therein with a segment of said system, and adding a radioactive substance to one of said chambers.

14. A method as claimed in claim 13, wherein the transport is examined under aerobic conditions.

15. A method as claimed in claim 13, wherein the transport is examined under anaerobic conditions.

16. A method as claimed in claim 1, wherein ion elution is determined by placing a segment of said system into a solution containing an isotope and then removing the segment and placing the same for periodic intervals in isotope-free aliquots of solution, the rate at which the isotope escapes from the segment being a measure of ion turnover rate.