Partial regeneration of the above‐elbow amputated rat forelimb. II. Electrical and mechanical facilitation

Abstract

This investigation was undertaken to examine the observations of Becker ('72) pertaining to the electrical facilitation of partial limb regenerative responses by means of Ag-Pt wire couples applied to the limb stumps of young, forelimb-amputated white rats. Additionally, in order to examine the possible role of mechanical effects of such device implantations, we have employed uncoupled devices delivering no current or potential difference. In the present experiments, in response to coupled device implantation, cartilage and bone were actively formed in the vicinity of the Pt electrode tip. These tissues contributed to the lengthwise extension of the limb and to the partial restoration of the distal humeral extremity. In limbs bearing the uncoupled electrical devices, qualitatively similar responses were noted, but osteogenesis was diminished in extent compared to that seen in limbs bearing the active or coupled devices. It is therefore necessary to consider the role of mechanical factors in the elicitation of the observed regenerative responses. Myogenesis was enhanced in electrically stimulated limbs, but not in those rats bearing uncoupled devices.

Bone healing after amputation of mouse digits and newt limbs: Implications for induced regeneration in mammals

“…The reasons for failure of mammalian regeneration remain obscure. However, prolongation of wound epithelium with subjacent mitotically active cells (Neufeld, 1980a), alteration of tissue appearances following nerve deviation (Neufeld, 1980b), and formation of cartilage distal to the amputation plane (Libbin et al, 1979;Sisken et al, 1979;Smith, 1981;Neufeld, 1983) are features which are consistent with an enhanced regenerative effort. It remains to be determined whether cartilagenous templates within a blastema can be generated.…”

“…Recently, several authors have reported growth of cartilage distal to the amputation plane of experimentally treated rodents (Libbin et al, 1979;Sisken et al, 1979;Smith, 1981). The interpretation of these results is unclear, in part because the pattern of bone repair following amputation has not been methodically documented.…”

Response of amputated rat limbs to fetal nerve tissue implants and direct current

“…Many attempts have been made to induce limb regeneration in higher vertebrates (adult frogs, chick embryos, newborn opossums, young rats). Experimental procedures that have been used in this pursuit include diversion of nerve fibers to the amputated limb (1,17), transplantation of adrenals (16), skin removal with application of salt solution (14), electrical stimulation (2,4,11,19,20), electrical stimulation with nerve growth factor injection (19), and implantation of fetal nervous tissue into the amputated stump (8,12). The only studies that demonstrated significant numbers of successful limb regenerates (including digits) were those of Mizell (12), who implanted fetal brain tissue prior to am-putating the hindlimbs of newborn opossums, and our own studies of implantation of embryonic neural tube into amputated stumps of chick embryos (8).…”

“…Previous studies in rats by Becker (2), Sisken et al (19), and Libbin et al (11) demonstrated the extraordinary growth of the amputated humerus and tissue regeneration with formation of new skeletal elements after treatment with applied direct current (DC). The appearance of such new skeletal elements was also noted after the addition of embryonic nerve tissue in our chick embryo studies in those animals demonstrating partial, as well as complete, regeneration.…”

Effects of vasoactive intestinal peptide and nerve growth factor on rat osteosarcoma cells

“…Regeneration of an amputated limb, has been reported in the newt (Singer, 1952), rats (Becket, 1972;Libbin et al, 1979), mice (Neufeld, 1980) and children (Douglas, 1972;Illingworth, 1974;Rosenthal et al, 1979). Singer (1952) postulated that the role of nerves in regeneration is mediated by a chemical trophic factor.…”