Nihon yakurigaku zasshi. Folia pharmacologica Japonica
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Nippon Yakurigaku Zasshi · Aug 2000
[The effect of anti-NGF and NGF on the responses to noxious heat in mice treated with capsaicin in the neonatal period].
Unexpectedly, despite the profound loss of C-fibers in the dorsal roots of mice injected capsaicin on day 2 of life, they showed normal responses to nociceptive heat. To examine the cause of this conflicting phenomenon, we studied the effect of anti-NGF and NGF on the response to noxious heat in mice pretreated with capsaicin. Capsaicin (50 mg/kg) was injected on the 2nd day of life, and 5 days later, anti-NGF (3 microliters/g) was daily injected for 30 days. ⋯ On the other hand, the latencies of the mice treated with both capsaicin and NGF were short compared with those of the animals treated with only capsaicin. The results may be attributed to the reinforcement of the sprouting from remaining neurons. However, we must not neglect the effect of individual treatment with NGF or anti-NGF.