Russian scientists from the Institute of Theoretical and Experimental Physics (Russian academy of sciences) and Pushchino State University performed a research, aimed at finding out conditions, which promoted intensive growth of tumor cells. The study was conducted on laboratory animals: rats, suffering from malignant tumors.

Rats received intraperitoneal injections of malignant tumor cells – Zaidel ascitic hepatoma. Cells of ascetic tumor usually float in liquid, filling abdominal cavity. After cell transplantation, rats remained alive for 12-14 days, during which scientists performed a detailed study of cell composition and concentration of active forms of oxygen in blood plasma and ascitic liquid (tumor growth area).

When an organism detects tumor cells, his immune system does its best to fight with them. It rapidly generates special cells: macrophages and monocytes (phagocytes) and neutrophils (neutrophil granulocytes). These cells, which are all white blood cells, produce enzymes and chemically active substances, aimed at destroying the tumor. Among other means of fighting cancer cells, cells of immune system release active from of oxygen, able to destroy tumor cells, into blood plasma, ascitic liquid of abdominal cavity, and intertissue space. However, this defense tends to fail very often.

 

 

Russian biologists and physicists discovered that as soon as tumor cells have been introduced into rats, animal blood has showed increased amount of monocytes and neutrophils – common reaction of an immune system. These cells produced active forms of oxygen. Measurements showed that during sixth day of the experiment concentration of these cells in plasma has 2.5 times exceeded normal values and kept growing. As a result, blood plasma developed extremely strong oxidative stress, which led to damage of healthy cells, including phagocytes themselves.

The situation is dramatically different in a tumor growth area. Â çîíå ðîñòà îïóõîëè ñèòóàöèÿ èíàÿ. At first, macrophages from blood plasma and neighboring tissues have showed a tendency to migrate and accumulate in the tumor growth area. At the same time amount of cancer cells, also kept growing. During tumor gradual development, the amount of macrophages in ascitic liquid has been dropping, and the liquid’s volume has been increasing. Concentration of active forms of oxygen in the tumor growth area has followed general tendency – first, it has grown, and then dropped. Researchers indicate that decrease of macrophage concentration, oxygen and active forms of oxygen content may lead to growth of tumor cells.

After reading this article you may think that scientists are demons, who dream of torturing laboratory animals 24/7. This is a very complicated problem, but I think that without laboratory animals, on which many life-saving treating agents were tested, mankind would have been much less healthier, than it is now. Rats, rabbits, guinea pigs, mice – thank you all so much for letting human beings prosper on Earth.

Source: Science News

Kizilova Anna