Restoration of limb regeneration ability in frog tadpoles by electrical stimulation.

Electrical stimulation of advanced tadpoles of Rana breviceps for 24 hr with 3 microA current after hindlimb amputation through shank and ankle slightly increased the number of perfect regenerates as compared to controls. When amputation was made through thigh in tadpoles of the same stage regeneration failed in all cases of the controls but 24 hr stimulation of these tadpoles after similar operation with 3 and 10 microA currents induced fair degree of regeneration in 9 and 40% cases, respectively.

Regeneration induced in the forelimbs by treatment with vitamin A in the froglets of Rana breviceps.

Young froglets Rana breviceps do not possess the power to regenerate forelimbs after amputation through metacarpals. However, 5 min immersion of limb stumps in an oily solution of 150,000 IU vitamin A palmitate immediately after amputation, and once on each of the 3 subsequent days, induced definite though hypomorphic regeneration in 100% cases.