Internal factors in the response of amoebocytes to stimulation.

Abstract

In the preceding paper we have shown that the character of the amoeboid response of amoebocytes to various stimuli varies within a certain range in accordance with the character of the solutions with which we surround these cells. However, we found in certain cases that the same kind of solution did not in all experiments produce the same effect, and by varying the conditions of our experiments sufficiently, we could demonstrate that one of the principal causes of such lack of constancy in results consists in the difference in the age of the cells which we use.

By age of the cells we understand the time which elapsed between the beginning of the migration of the cells out of the piece and the testing of the amoebocytes. Young cells are 6 to 12 hours old, cells of medium age are 24 to 36 hours old, and old cells are two or more days old. In general, young cells have a greater tendency to the formation of thread and tongue pseudopodia, while in older cells the tendency to produce balloon and drop pseudopodia is greater. Furthermore, in older cells the tendency to produce under unfavorable conditions pathological formations like courts and pseudofertilization membranes is likewise greater than in young cells. These two factors, favorable or unfavorable character of the medium, and age of the cells, may therefore either mutually intensify, or, on the other hand, neutralize their effects.

To cite some examples : Young cells may in addition to balloons form some tongue and thread pseudopodia in a N/2, NaC1 solution, while older cells tend to form exclusively balloons. As we stated in a previous paper, if we add N/1000 HC1 in N/2 NaCl to amoebocytes, balloon formation occurs, and if this solution is replaced by a solution of Nil000 NaOH in Nj2 NaCl tongue and thread pseudopodia are usually sent out after some time.