To explain the problems and countermeasures in the experimental study for postgraduates in the medical school, and to explore proper laboratory management suitable for our medical school postgraduates

With 58 of New Zeeland rabbits, following experiments were carried out: (1) the dose-response relationship of MSG which decreased the body temperat ure; (2) the effects of the propranolol and the anisodamine (654-2) on the action of decreasing body temperature by MSG. The results indicated: following intravenous administration of MSG at a dose of 0.5g/kg. w and 1.0g/kg. w, the body temperature of rabbits were decreased significantly, but at a dose of 0.1g/kg.w, the change of temperature was insignificant.Pretreatment with propranolol did not affect the effect of MSG decreasing body temperature which was blocked significantly by anisodamine, one of blocker of the cholinergic nerve. The authors suggest that the effect of MSG decreasing body temperature may depend on the cholinergic nerve.

AIM: The present study was designed to examine the effect of Bacillus Calmette-Guerin (BCG) vaccination on blood pressure, nitric oxide (NO) production and iNOS expression in hypertensive rats. METHODS: Renal hypertension (RH) were made by renal artery stenosis in SD rats and the sodium induced hypertensive (SH) rats were made by feeding the rats with high sodium chloride diet (5 g NaCl/100 g food). After four weeks, the hypertensive animals were subjected to the experiment. All the rats were vaccinated with BCG (0.1 mL, i.d) and blood pressure were examined every week. Greiss reaction was used to measure the urinary NO excretion and Western blot was applied to probe the iNOS protein expression in aortic tissue. RESULTS: It was shown that one week after BCG vaccination, the blood pressure decreased significantly in hypertensive rats induced by NaCl-overloading and renal artery stenosis, but not in normotensive control rats. Furthermore, the hypotensive effect of BCG vaccination was enhanced by co-administration of L-arginine. A significant increase in NO production was observed in hypertensive rats. Also, Western blot showed BCG vaccination led to an obvious increase in iNOS expression in the aortic tissue of hypertensive, but not of normal control rats. CONCLUSION: BCG vaccination could lower the blood pressure of hypertensive rats through activation of iNOS/NO pathway.

AIM and MEfTHODS: To clarify the role of inducible nitric oxide synthase (iNOS) in the regula- tion of blood pressure, in the present study, we examined the effect of aminoguanidine (AG), a selective inhibitor of iNOS on the hemodinamical response of Dahl salt - sensitive (DS) and Dahl salt - resistant (DR) rats to low (0. 3% ) or high (8%) sodium chloride (Nacl) infusion by chronical in vivo hemodynamic experiment, and the effect of NaCl or NaCl plus AG infusion on urinary nitrate (NO3)/nitrite (NO2), the end product of nitric oxide (NO),ex- cretion by Greiss Reaction. Furthermore, NOS activity assay was the dried out to probe the effect of NaCl and AG on calcium - dependent or independent NOS activity in renal tissue. RESULTS:1. High or low NaCl - infused DR rats and low NaCl - infused DS rats have no hemodinamical response to AG, however, the hpertensive effect of high NaCl (8% ) infusion on DS rats were gnatly amplified by co - infusion of AG. 2. Administration of high NaCl signif- icantly elevated the iNOS activity of renal tissue, and greatly increased urinary NO3/NO2 excretion. CONCLUSION: Ihducthle NOS is an important modulator of arterial pressure, especially in case of higher blood pressure.

AIM: The present study was designed to examine the effect of Bacillus Calmette-Guerin (BCG) vaccination on blood pressure, nitric oxide (NO) production and iNOS expression in hypertensive rats. METHODS: Renal hypertension (RH) were made by renal artery stenosis in SD rats and the sodium induced hypertensive (SH) rats were made by feeding the rats with high sodium chloride diet (5 g NaCl/100 g food). After four weeks, the hypertensive animals were subjected to the experiment. All the rats were vaccinated with BCG (0 1 mL, i.d) and blood pressure were examined every week. Greiss reaction was used to measure the urinary NO excretion and Western blot was applied to probe the iNOS protein expression in aortic tissue. RESULTS: It was shown that one week after BCG vaccination, the blood pressure decreased significantly in hypertensive rats induced by NaCl-overloading and renal artery stenosis, but not in normotensive control rats. Furthermore, the hypotensive effect of BCG vaccination was enhanced by co-administration of L-arginine. A significant increase in NO production was observed in hypertensive rats. Also, Western blot showed BCG vaccination led to an obvious increase in iNOS expression in the aortic tissue of hypertensive, but not of normal control rats. CONCLUSION: BCG vaccination could lower the blood pressure of hypertensive rats through activation of iNOS/NO pathway. [

Objective To observe the effect of acupuncture on the infracted area and apoptosis of rats with brain contusion.Methods Feeney's method was used to establish brain contusion model.The 40 rats were randomized into sham-operation,model,acupuncture and naloxone (NX) group with 10 in each.Acupuncture was performed for the rats of acupuncture group and NX was injected intraperitoneally for the rats of NX group.The treatment was done once everyday,7 days altogether.Then the brain histotomy was prepared after all the treatment finished.Computer image analysis system was used to detect the infracted area.TUNEL method was adopted to detect the apoptosis.Results The brain contusion in the model group was severe,there were lots of apoptotic cells and the infracted areas were bigger than the injured areas (P0.05).Conclusion Acupuncture can decrease the infracted areas and apoptosis of the rats with brain contusion,being effective in anti-secondary brain injuries.

AIM and METHODS:To investigate the effect of electrical stimulation of VSA on the firing of thermosensitive neurons in preoptic anterior hypothalamus (POAH), the firing rate of thermosensitive neurons in POAH of 20 New Zealand white rabbits was recorded by using extracellular microelectrode techinque. RESULTS:(1)Electrical stimulation of ventral septal area (VSA) caused a significant increase in firing rate of warm-sensitive neurons in the preoptic area of the anterior hypothalamus(POAH).(2) The firing rate of cold-sensitive neurons was decreased remarkably in the POAH by electrical stimulation of VSA. CONCLUSION:VSA may play a controlling role in the thermoregulation through altering the firing rate of thermosensitive neurons in the POAH.

AIM and METHODS: To investigate the effect of electrical stimulation of VSA on the firing of thermosensitive neurons in preoptic anterior hypothalamus (POAH), the firing rate of thermosensitive neurons in POAH of 20 New Zealand white rabbits was recorded by using extracellular microelectrode techinque. RESULTS: (1)Electrical stimulation of ventral septal area (VSA) caused a significant increase in firing rate of warm-sensitive neurons in the preoptic area of the anterior hypothalamus(POAH).(2) The firing rate of cold-sensitive neurons was decreased remarkably in the POAH by electrical stimulation of VSA. CONCLUSION: VSA may play a controlling role in the thermoregulation through altering the firing rate of thermosensitive neurons in the POAH .

AIM: The present study was undertaken to explore the effects of ?-MSH on partial biological activities of LPS. METHODS:Colorimetric method was used for the measurement of hydrogen peroxide(H_2O_2) production in mouse peritoneal macrophages, the apoptosis of polymorphonuclear leukocytes(PMNs) and the binding of LPS to monocytes were studied with flow cytometry. RESULTS: It was found that LPS strongly stimulated macrophages to release H_2O_2. When macrophages were cultured with ?-MSH in the presence of LPS, the H_2O_2 release was markedly suppressed (P0.05). In the presence of LPS, however, ?-MSH significantly promoted the apoptosis of PMNs (P

AIM: To investigate effects of different therapeutic methods and typical recipes on activation of ERK1/2 in Kupffer cells of rats with fatty liver.METHODS: The rat model of fatty liver was established by feeding high fat diet combinated with distillate spirit.Meanwhile Chinese medicines Shugan fang,Jianpi fang,Huoxue fang,Qushi fang,and Zonghe fang were given to treat different groups respectively.12 weeks later,the Kupffer cells were isolated from livers of control group,model group and different treatment groups by sequential in situ perfusion with collagenaseⅣ and pronase E,density gradient centrifugation,selective adherence.The expression of total ERK1/2 and phospho-ERK1/2 in Kupffer cells of control group,model group and different treatment groups were detected by Western blotting.RESULTS: The expressions of total ERK1/2 and phospho-ERK1/2 were higher in Kupffer cells from model group than those in control group(P