Change of the guanine nucleotide-binding protein in lamina Ⅰ-Ⅲ of spinal cord posterior horn and lateral spinal nucleus of rats after transection of dorsal roots / 中国组织工程研究

BACKGROUND: In China, this laboratory is the first one to report such researches, confirming that strong αo-immunoreactive (IR) appears in the substantia gelatinosa (SG) of spinal cord and lateral spinal nucleus which is similar to the distribution of certain neuropeptides that participate in sensory regulation, which suggests that guanine nucleotide binding protein (G protein) may be related to primary afferent informational transfer. OBJECTIVE: To observe the change of αo-IR in gelatinous substance by the method of transection of unilateral spinal dorsal roots.DESIGN: A randomized controlled experiment on animals.SETTING: Staff Room of Neurobiology, Tongji Medical College, Huazhong University of Science and Technology.MATERIALS: The experiment was conducted at the Staff Room of Neurobiology, Tongji Medical College, Huazhong University of Science and Technology from December 1995 to December 1996. Fifteen healthy adult SD rats were selected and divided into 3 groups: ①normal group with five rats (not dealt with any disposal), ②transected dorsal root group with 10 rats (right side) and ③control group (non-transected left sidedness as control).METHODS: Right lumbar 1-3 spinal neural dorsal roots were cut off under the anesthesia of 100 g/L chloral hydrate (300 mg/kg)through intraperitoneal injection in rats, living for 48-60 hours after operation. The subunit αo of guanine nucleotide-binding protein (rabbit polyclonal antiserum) was demonstrated in the αo-IR of rat spinal cord by immunohisto chemical methods. G protein was oriented, and its change was observed after transection ofneural dorsal roots MAIN OUTCOME MEASURES: ①The αo-IR of Ⅰ to Ⅲ of the dorsal horn and lateral spinal nucleus of the normal rats and control rats. ②The αo-IR of Ⅰ to Ⅲ of the dorsal horn and lateral spinal nucleus of rats in the transected dorsal root group. RESULTS: Data of a total of 15 rats were involved in the result analysis. ①In the normal group and control group, intense αo-IR was presented in rexed lamina ( Ⅰ to Ⅲ ) of the dorsal horn of rats, and the highest αo-IR in second lamina (SG). Lateral spinal nucleus of rat revealed higher density of αo-IR containing fiber networks. Following unilateral transection of dorsal roots in SG, αo-IR was markedly decreased. ②Quantitative analysis of absorbance (A) of αo-IR, it was (0.847±0.081) in the inside of the control group, (0.633±0.073)(t=5.71 ,P ＜ 0.001 ) in the inside of transected dorsal root group. It was (0.823±0.089) in the middle area of the control group,(0.660 4±0.074)(t=6.90,P ＜ 0.001 ) in the middle area of the transected dorsal root group. It was (0.915±0.090) in the lumbar region of the control group, and (0.656±0.077)(t=10.31 ,P ＜ 0.001 ) in the lumbar region of the transected dorsal root group. Average value of the control group was (0.852±0.084), and average value of the transected dorsal root group was (0.639±0.078)(t=10.23 ,P ＜ 0.001 ).CONCLUSION: Part of G protein of end-brush neurons related with the primary afferent noxious stimulation in SG derives from primary sensory neurons, which maybe join the adjustment of primary sensory transfer.

Magnetic stimulation accelerating rehabilitation of peripheral nerve injury / 华中科技大学学报（医学）（英德文版）

The effect of magnetic stimulation (MS) on sciatic nerve injury was observed. After sciatic nerve was crushed in 40 Sprague Dawley (SD) rats, one randomly selected group (group D) was subjected, from the 4th day post-operatively to 3 min of continuous 70% of maximum output of MS daily for 8 weeks. The other group (group E) served as a control group. The nerve regeneration and motor function recovery were evaluated by walking track analysis (sciatic function index, SFI; toe spreading reflex, TSR), electrophysiological, histological and acetylcholineesterase histochemistry. The SFI in the group D was greater than in the group E with the difference being statistically significant (P < 0.01). TSR reached its peak on the 4th day in the group D and on the 10th day in the group E respectively. The amplitude and velocity of MCAP and NCAP in the group D was greater than in the group E with the difference being statistically significant (P < 0.01), while the latency and duration of MCAP and NCAP in the group D were less than in the group E with the difference being also statistically significant (P < 0.01). Histological examination showed the mean axon count above the lesion for thick myelinated fibers (> 6.5 microns) in the group D was greater than in the control group with the difference being statistically significant (P < 0.01), while the mean axon count below the lesion for thick myelinated fibers was less than that in the group E with the difference being statistically significant (P < 0.01). The mean axon count above the lesion for thin myelinated fibers (2-6.5 microns) in the group D was greater than that in the group E with the difference being statistically significant (P < 0.05), while the mean axon count below the lesion for thin myelinated in the group D was greater than that in the group E with the difference being statistically significant (P < 0.01). Acetylcholine esterase examination showed that the MS could significantly increase the number of the motor neurons. There was no significant difference in the number of the motor neurons between the treatment side and the normal side (P > 0.05). It can be concluded that MS can enhance functional recovery and has a considerable effect in the treatment of the peripheral nerve injury.

Magnetic stimulation accelerating rehabilitation of peripheral nerve injury / 华中科技大学学报（医学）（英德文版）

The effect of magnetic stimulation (MS) on sciatic nerve injury was observed. After sciatic nerve was crushed in 40 Sprague Dawley (SD) rats, one randomly selected group (group D) was subjected, from the 4th day post-operatively to 3 min of continuous 70% of maximum output of MS daily for 8 weeks. The other group (group E) served as a control group. The nerve regeneration and motor function recovery were evaluated by walking track analysis (sciatic function index, SFI; toe spreading reflex, TSR), electrophysiological, histological and acetylcholineesterase histochemistry. The SFI in the group D was greater than in the group E with the difference being statistically significant (P 6.5 microns) in the group D was greater than in the control group with the difference being statistically significant (P 0.05). It can be concluded that MS can enhance functional recovery and has a considerable effect in the treatment of the peripheral nerve injury.

EFFECTS OF FORMALDEHYDE FIXATION ON THE BINDING CAPACITY OF OPIATE RECEPTORS / 解剖学报

The effects of formaldehyde fixation on the binding capacity of opiate receptors were studied with radioreceptorassay and in vitro receptor autoradiography. Incubation with 1% paraformaldehyde for 30 minutes or 12 hours has no significant influence on the binding capacity of opiate receptors of rat brain P_2 membranes, and incubation with 2% or 4% paraformaldehyde for 30 minutes also did not alter the binding capacity of opiate receptors significantly, but 12 hour incubation with 2% or 4% paraformaldehyde would change the binding capacity significantly. The saturation curve of [~3H]-etorphine binding with opiate receptors in formaldehyde fixed brain tissue sections coincided with that of unfixed brain tissue sections. The opiate receptors were successfully demonstrated with in vitro receptor autoradiography in 1% paraformaldehyde fixed spinal cord sections. These results indicate that formaldehyde fixed tissue are applicable to in vitro receptor autoradiography.