American gerontologists have found that the dilution of blood plasma, saline solution itself has a firming effect on the tissues of liver, muscle and brain of mice. A similar effect on the cells provided by the blood serum of people who have gone plasmapheresis — therapeutic blood filtration. This means that a risky and ethically questionable blood transfusions from young donors may give way to filtering their own blood, although its rejuvenating effects have yet to prove. Work published in the journal Aging.
The idea that the blood of young organisms can facilitate health old, many scientists still considered controversial. In the second half of the twentieth century there had been many experiments with mice of different age at which animals were stitched, side in pairs (this design is called parabiosis). In a few cases, when one of the animals was old or sick, and the second — young and healthy (heterochroneity the parabiosis), the health of old individuals better. The parabiosis helped the irradiation of muscular dystrophy, and in some experiments even extended to old individuals life.
However, to find out what exactly is provided by this effect was difficult. Maybe it’s just that the bodies of young individuals together. To check this simply: you need to stop to sew the individuals and to begin to transfuse blood between them. In such experiments sometimes do succeed to achieve positive results — to the extent that a transfusion is now trying to use as a remedy for Alzheimer’s disease.
Another possible explanation is that young blood contains some substances that act on the tissues and organs of the old animal. But since the blood is composed of hundreds of substances, the search for a one particular — a difficult task, which is still not solved.
Finally, the third answer is that the effect of parabiosis is not associated with young and with old blood. It contains their substance that “old” body, and it can be assumed that the infusion of young blood dilutes the solution, reducing their concentration and, hence, inhibits their action.
A group of researchers led by Irina Conboy (Irina Conboy) from Berkeley long been engaged in research heterochronies of parabiosis. This time they decided to test whether it is sufficient to dilute the blood to achieve similar effects. For their work they took two groups of mice: young (2-3 months) and old (22-24 months). Each animal was subjected to a complex procedure: it has small portions were taken and blood was changed to physiological saline with the red blood cells and platelets from the donor isochronous (i.e. of the same age as the recipient). In the end, each mouse had lost about half the blood plasma, while retaining all blood cells. As a control, the researchers used a classic a blood transfusion from isochronous donor.
Six days after the procedure, the authors evaluated the intensity of muscle regeneration after injury. It turned out that the index of regeneration, as well as the diameter of new muscle fibers (the thicker, the better) in older animals after a single dilution of the blood was compared with that of the young. Then the researchers tested whether these properties from human blood. They took blood samples of patients before and after plasmapheresis, a common clean — up procedure of the blood, which is used, for example, in autoimmune diseases. The authors treated cultures of muscle cells mouse these serum samples and found that to plasmapheresis, the serum inhibits cell division, and after him the number of dividing myocytes increases by almost four times.