Conference on Biophotons 1999 - ON THE CELL'S CAPACITY TO SELF-REGULATE THEIR ABSOLUTE QUANTITY

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Conference on Biophotons 1999
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ON THE CELL'S CAPACITY TO SELF-REGULATE THEIR ABSOLUTE QUANTITY
A.A. Kozlov
University of Tbilisi, Tbilisi Georgia

Ciliates Colpoda have been cultivated in hay-water without adding fresh nutritive medium in the cylindrical vessels of the identical geometry having volumes either V(1) = 30 ml or V(2) = 3 ml. The initial cell concentration (ICC) was the same in all the vessels. ICC time dependence has been determined. After passing the exponential phase and reaching its maximum a rapid (about 30% per day) ICC decline has been registered, reducing later on up to 8% per day. At that time ICC in V(2) vessels exceeded that in V(1) vessels in 3,80 ( 0.004 times (average from 4 experiments). Thereafter a content of some of V(1) vessels have been poured, after a careful mixing, into V(2) vessels while the content from another set of V(1) vessels was poured into another set of the similar V(1) vessels. As soon as during the next day ICC of the samples poured into V(2) vessels started to increase, reaching its maximum to the 4th day and coming into a stationary phase to the 8th day. ICC measured at that time appeared to be roughly equal to that established into V(2) vessels in the stationary phase of the first part of experiment. Meanwhile ICC detected in V(1) vessels after a slight increase (owed, most probably, to a mixing) have been stabilized at the level typical for this kind of vessels in the first part of the experiment.
Later on the content of V(2) vessels has been poured in the similar way into the third set of vessels V(3) having 0,8 ml volumes. After a rapid ICC increase the poured cultures entered the stationary phase characterized by ICC roughly twice as high as detected during the stationary phase in V(2) vessels.
In another experiment we used two sets of quasi-spherical glass vessels with the volumes V(4) = 45 ml and V(5) = 0,8 ml. After reaching a stationary phase, the ratio of the total cell numbers in V(5) to those in V(4) was 0,8.
One may conclude, that the populations of Ciliates possess some kind of information about the total number of cells within the whole volume. This information is used somehow for limiting the total number of cells. Whereas such an information cannot be transmitted by any chemical mediators, one should assume the existence of a physical channel of an information exchange between the cells. Most probably, this information is transmitted by some kind of electromagnetic or sound (ultrasound) radiation. If suggesting that each cell acts as a source of such a radiation, the radiation density within a spherical volume will be proportional to its radius R, since the number of emitters is proportional to R3 while the loss of radiation through a spherical surface are proportional to R2. One can speculate that it is a certain critical radiation density which regulates the total amount of cells within a given population.

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