Inhibition effect of Guizhi decoction on cardiac sympathetic sprouting / 中国药理学通报

Aim To investigate the preventive effect of Guizhi decoction on cardiac sympathetic sprouting induced by 4-Methylcatechol (4-MC) . Methods The rat models of cardiac sympathetic sprouting were in-duced by 10 mg · L-1 4-MC ( 10μg · kg-1 body weight, i. p. ) . Guizhi decoctions ( with different pro-portion between Ramulus Cinnamomi and Radix Paeon-iae Alba, 1 : 1, 1 : 2 and 2 : 1) and metoprolol were administered to the rats. Heart rate and electrocardio-gram ( ECG ) were observed, the content of norepi-nephrine (NE), growth associated protein (GAP-43), tyrosine hydroxylase ( TH ) and acetylcholine transfer-ase enzyme ( CHAT) in myocardial homogenate of left ventricular and right atrial were determined by ELISA method, and immunofluorescence assay was used to observe cardiac nerve sprouting and sympathetic distri-bution. Results 4-MC caused cardiac sympathetic sprouting and parasympathetic was not influenced. Heart rate of the model group was improved significant-ly and higher than that of the other groups . Compared with the model group, the content of NE, GAP-43 and TH in left ventricle and right atrium of the metoprolol group and Guizhi decoction group were decreased( P<0.05 ) , and the immunofluorescence result showed that the distribution of TH positive nerve was reduced sig-nificantly(P<0.05). It was demonstrated that Guizhi decoction of the proportion between Ramulus Cinnamo-mi and Radix Paeoniae Alba 1 : 1 and 1 : 2 had the best efficacy, which was similar to the efficacy of meto-prolol. Conclusion Guizhi decoction ( with the pro-portion between Ramulus Cinnamomi and Radix Paeon-iae Alba 1 : 1 and 1 : 2 ) effectively inhibits the cardi-ac sympathetic sprouting induced by 4-MC.

Spinal alpha2 Adrenoceptor and Antiallodynic Effect by Clonidine after Chronic Administration of 4-Methylcatechol in Neuropathic Rat Pain Model / 대한통증학회지

BACKGROUND: The adrenergic nervous system in the spinal cord contributes to the development of neuropathic pain after nerve injury. Brain derived neurotrophic factor may facilitate the sympathetic change in the spinal cord and influence the state of neuropathic pain. We probed the effect of chronic repetitive administration of systemic 4-methylcatechol, which is known to be a neurotrophic factor inducer, in a spinal nerve ligation model. METHODS: We made the rat neuropathic pain model by the ligation of the L5 spinal nerve. Intraperitoneal 4-methylcatechol (10microgram/kg) or the same volume of saline wasadministrated twice daily just after the operation for 7 days. The tactile allodynia was measured by using von Frey filaments and its change was followed up from 3 days after SNL. The lumbosacral enlargement of the spinal cord was taken out and the mRNA contents of the alpha(2)-adrenoceptor subtypes were measured by real time polymerase chain reaction and this was then compared with the control groups. The antiallodynic effect of intrathecal clonidine (3, 10, 30 microgram) was evaluated and compared in the 4-methylcatechol treated rats and the control rats. RESULTS: The expression of the alpha(2A) and alpha(2C) adrenoceptor subtypes did not change after 4-methylcatechol treatment. Intrathecal clonidine showed an earlier and better effect at the highest dose (30 microgram intrathecal), but not with any other doses. CONCLUSIONS: Chronic intraperitoneal administration of 4-methylcatechol may improve the effect of intrathecal clonidine, but we could not prove the increase of alpha(2A) and alpha(2C) adrenoceptors in the spinal cord of 4-methylcatechol treated rats.

The effect of 4-Methylcatechol treatment in chronic constrictive injury of the rat sciatic nerve on the allodynia and spinal neurotrophic factors / 대한마취과학회지

BACKGROUND: The effect of chronic administration of 4-methylcatechol known as a neurotrophic factor inducer on the allodynia and spinal neurotrophic factors was investigated in chronic constrictive injury of sciatic nerve in rats. METHODS: With the Sprague Dawly rat, sciatic nerve was loosely ligated with 4-0 chromic catgut and neuropathic pain model was made. The threshold for tactile allodynia was measured with von Frey hair by up-down method and cold allodynia was measured by dropping 20microliter of 100% acetone on the dorsum of the injured foot. 4-Methylcatechol (100microgram/kg, intraperitoneal) was injected once a day for 14 days and the effect on allodynia was compared with saline injected group. At 3, 7 and 14 days after injection, lumbar spinal cord was harvested and the mRNA content of nerve growth factor (NGF) and brain derived neurotrophic factor (BDNF) was measure by real time PCR. RESULTS: Mechanical and cold allodynia improved from 7 days after 4-methylcatechol administration. NGF and BDNF in spinal cord decreased compared to sham operated group. BDNF in lumbar spinal cord has increased tendency after treatment without statistical significance. CONCLUSIONS: Chronic intraperitoneal administration of 4-methylcatechol may improve tactile and cold allodynia in chronic constrictive injury rat model of neuropathic pain. The BDNF mRNA in spinal cord might increase after 4-methylcatechol treatment.