| Dorsal root ganglion (DRG) cells are the primary afferent neurons of algaesthesis of trunk and extremities. DRG connects the spinal cord with internal and external environment of the organism. It not only transmits and accommodates sensations but also accepts and conveys nociception of the organism, so it plays an important role in occurance and maintenance of neuropathologic pain. Adriamycin, a broad-spectrum anthracycline antibiotic and anticancer therapeutic agent, has obvious neurotoxic effect.Objective: 1. Observing distribution of the drug and it's effect on DRG cells after paravertebral injection with 0.1-1% adriamycin in rabbits. Investigating whether adriamycin entered selectively into DRG and damages DRG cells. 2. Observing localization of the drug and morphologic change in DRG cells and motor neurons in spinal cord anterior hom after 1% adriamycin intraneural injection into the sciatic nerve of rabbits. Moreover, evaluating sensory and motor function 1-8 weeks following injection. Exploring whether the agent, injected into sciatic nerve, has the effect of chemo-ganglionectomy on the corresponding DRG.Methods: 90 adult rabbits (weight:2.0~2.5kg) were distributed into two parts.The first part include 42 rabbits which were randomly divided into 7 groups (6 in each). After general anesthesia, the margin of right L5 intervertebral foramina of the rabbits was exposed. Group 1, 2 and 3 were injected 0.2ml adriamycin into the intervertebral foramina at the concentration of 0.1%, 0.33% and 1%, respectively. After 24 hours, the specimens of L4~Si segments of spinal cord and bilateral anterior root and DRG were removed to made frozen sections. Observing the distribution of autofluorescence by fluorescence microscope. Group 4,5and 6 were injected 0.33%, 0.2ml adriamycin into the L5 intervertebral foramina.4Following 1, 4 and 8 weeks respectively, the specimens of bilateral L5 DRG were removed to made paraffin sections, which stained with HE and toluidine blue solutions to observe morphologic change of DRG cells by light microscope. Group 7 were injected 0.9% saline into the right L intervertebral foramina as control. The second part involves 48 rabbits which were randomly divided into 6 groups (4 in each group of 1-3, 12 in each group of 3-6). After general anesthesia, the bilateral ischiofemoral ligament and sciatic nerve of the rabbits were exposed. 1%, 0.2ml adriamycin was injected into the site of the right sciatic nerve which intersecting ischiofemoral ligament, while isodose 0.9% saline was injected into the same site of the left sciatic nerve as auto-control. Drawing the specimens from bilateral Lj-Si DRG and 1,5-82 segments of spinal cord to made frozen section to observe autofluorescence localization of adriamycin by fluorescence microscope following 4 and 24 hours respectively in group 1 and 2. The specimens of bilateral LS~SI DRG were removed to made ultrathin sections to observe ultrastructural change in the DRG cells 2 weeks after injection in group 3. Motor conduction function of sciatic nerve was measured before and 1, 4 and 8 weeks after injection, respectively in group 4,5and 6. Furthermore, observing weekly the sensory and motor function of hindlimb of the rabbits. 1, 4 and 8 weeks after injection respectively in group 4,5and 6, the specimens from bilateral LSi DRG and 1,5-82 segments of spinal cord were drew to made paraffin section , which stained with HE and toluidine blue to observe morphologic change of DRG cells and the motor neurons in spinal cord anterior horn.Result: 1. The zonale distribution of orange-red autofluorescence of the drug in the capsule of LS DRG and the spot distribution in LS DRG were observed after paravertebral injection with 0.1-1% adriamycin. Moreover, the intensity of autofluorescence was the strongest in group 3 with 1% adriamycin, stronger ingroup 2 with 0.33% adriamycin and the weakest in group 1 with 0.1% adriamycin. However, autofluorescence of adriamycin was observed only in the capsule of LS anterior root and spinal cord except for scatter spots auto...
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