David E. Green

Effect of sulfhydryl compounds on regeneration in Podarke obscura

SummaryNeither thio-p-cresol, thio-phenol, thio-glycollic acid or cystine accelerates the process of regeneration in thePodarke obscura.

Effect of Sulfhydryl Compounds on Regeneration in Podarke Obscura.

From his studies on the toxicity of Pb ions in cell division in onion root tips, which he explained on the basis of the binding and eliminating of a SH-group, and from his experiments designed to show the effect of SH-groups on rate of growth depending on cell multiplication, as in growing onion root tips, Paramecia cultures, and healing of wounds, Hammett 1 postulates his theory that the SH is the “mitotic hormone” and the wound hormone or essential chemical factor in cell proliferation following trauma. With the thought that a specific mitotic hormone would at least accelerate, if not also actually increase, regeneration since the latter depends on cell division and proliferation in its earlier stages, we performed a series of experiments on regeneration of the polychaete worm, Podarke obscura. This animal was chosen because one of us (S. M.) has had extensive experience with this material and had previously made a long study of its regenerative process. 2 The procedure was simple. Under a magnifying glass we cut away the posterior portion of the worm (which, by the way, never regenerates a head) aiming always to effect the severance at practically the same relative level. The cut must be made clean so that the wound closes up smooth and without any adhering shreds of necrotized tissue. All these details of operation are extremely important, if one is to insure a normal progress of regeneration.