Effects Of Capsaicin Applied Locally To Infraorbital Nerve On Primary Afferent Nerve In Adult Rats

Object: To study the effect of capsaicin applied locally to infraorbital nerve on primary afferent nerve in adult rats Methods: Twenty-eight male adult SD rats were divided into seven time groups ( 3 days, 7 days, 14 days, 21 days, 28 days, 35 days or 42 days after local administration) 2% capsaicin solution was directly applied onto one lateral infraorbital nerve, and another lateral nerve was acted as self-control Experimental and control infraorbital nerves were examined by electron microscopy and substance P (SP) in both lateral regions of nucleus caudalis spinalis nervi trigemini (CNV) were examined by iniinunohistochemical method Results: SP-like immunoreactive positive granules in the capsaicin-treated sides of CNV were markedly less than that in the control sides (p