ABSTRACT
Objective To investigate the inhibition of rutaecarpine (Rut) on left ventricular hypertrophy rat induced by abdominal aorta coarctation (AAC) and further explore the potential mechanisms. Methods Left ventricular hypertrophy was induced by AAC in male Sprague-Dawley rats.Fifty rats were randomly divided into five groups:model control group,sham operation group,low-,middle- and high-dose (10,20,40 mg?kg-1?d-1 ) Rut group,with 10 rats of each group.Rut was administrated by gavage once daily from the first day after operation for consecutive 4 weeks.The sham operation and model groups were administrated with equal volume of 0.9％ sodium chloride solution.The hemodynamics parameters were detected by BL-420 E biology function laboratory system,and the left ventricular hypertrophy index (LVHI,left ventricular weight/ body weight) was measured at 8 h after administration of the last dose.The pathological changes of left ventricular hypertrophy were evaluated by HE staining.To elucidate the mechanism of protection,the mRNA expressions of atrial natriuretic factor ( ANF),extracellular signal-regulated kinase 2 (ERK2) and MAPK phosphatase-1 (MKP-1) were analyzed by real time RT-PCR,and the protein expressions of MKP-1 and phosphorylated ERK2 (p-ERK2) were examined by Western blotting. Results Left ventricular hypertrophy induced by AAC was evidenced by the increased left ventricular weight (LVW) and LVHI (P<0.01),the decreased± dp/ dt max (P<0.01),and the elevated expression of ANF (P<0.01).Compared with model control,Rut (20,40 mg?kg-1?d-1 ) treatment significantly attenuated AAC-induced rat left ventricular hypertrophy,decreased the LVHI (P<0.05),left ventricular systole pressure (LVSP),and left ventricular end diastolic pressure ( LVEDP ) ( P < 0. 05), and increased ± dp/ dtmax ( P < 0. 01). In addition, Rut ( 20, 40 mg?kg-1?d-1 ) downregulated the expression of ANF,ERK2 mRNA,and ERK2 protein,but upregulated the MKP-1 mRNA and protein expression.However,Rut low-dose (10 mg?kg-1 ?d-1 ) was ineffective (P> 0.05). Conclusion Rut alleviates left ventricular hypertrophy induced by abdominal aorta coarctation,and the protection appears to be due,at least in part,to its inhibitory effects on the MAPK/ ERK signal pathway.
ABSTRACT
Introduction of clinical cases to experiment teaching of pharmacology is an effective method,which combines basic theory with clinical medicine.It can stimulate students' interest in pharmacology,enhance their go-aheadism in study and also improve teaching effects.Moreover,it plays an important role in improving the students qualities such as the reasoning ability,the verbal capacity and the ability to analve and resolve problems,etc..In this article,we explored the teaching method in experiment teaching of pharmacology,and evaluated the effect by questionnaire.
ABSTRACT
OBJECTIVE: To observe the protective effects of Corydalis ambailis migo total alkaloids (COAMTA) on cerebral ischemia/reperfusion injury in rats and to investigate its mechanism. METHODS: The effects of COAMTA on decapitated gasping mouse model and rat model of middle cerebral artery ischemia (2 h)/reperfusion (22 h) were observed. The neurological scale, cerebral infarcted volume and cerebral water content subjected to cerebral middle artery ischemia/reperfusion in rats were recorded. The activities of nitric oxide synthase (NOS) and superoxide dismutase (SOD) and the content of malondialdehyde (MDA) in the ratso brain were measured. Cell apoptosis in ischemic penumbral area was observed with light microscope in the method of terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labeling (TUNEL). RESULTS: The average gasping time of the mice (6.0 mg/kg or 9.0 mg/kg COAMTA) was significantly prolonged, the cerebral infarcted volume and cerebral water content of the rats (5.0 mg/kg or 7.5 mg/kg COAMTA) were significantly decreased, as compared with the control groups. The average activity of SOD in cerebral tissue of the rats (5.0 mg/kg or 7.5 mg/kg COAMTA) was significantly higher than that of the control groups, meanwhile, the average activity of NOS and the content of MDA declined significantly. The cell apoptosis in ischemic penumbral area of the rats (5.0 mg/kg COAMTA) was significantly inhibited as compared with the control groups. CONCLUSION: COAMTA can facilitate the protection against cerebral ischemia/reperfusion damage. The mechanism is related to inhibiting the activity of NOS and lipoperoxidation, increasing the activity of SOD and decreasing the neuronal apoptosis.
ABSTRACT
Aim To study the effect of naftopidil(Naf) on noradrenalin(NA)-induced proliferation of rats vascular smooth muscle cells (VSMCs),and explore its mechanisms. Methods The cultured VSMCs was induced to proliferate by NA,and effects of Naf on the VSMCs proliferation was tested by MTT assay and cell counting method respectively. The intra-cellular calcium concentration is investigated by fluorimetry,and the expressions of c-myc,c-fos and hypertension related gene-1(HRG-1) mRNA were tested by Real-Time RT-PCR. Results The proliferation of VSMCs induced by NA was inhibited by Naf(10-7~10-6mol?L-1),which diminished clearly VSMCs [Ca2+]i and decreased mRNA expressions of c-myc,c-fos and increased the expression of HRG-1 mRNA. Conclusions Proliferation of VSMCs induced by NA can be inhibited clearly by Naf. The mechanisms may be related to diminishing [Ca2+]i,antagonizing the up-regulation of c-myc and c-fos mRNA expressions by NA and antagonizing the down-regulation of HRG-1 mRNA expression.
ABSTRACT
Objective To study the effect of protopine (Pro) on the intracellular free calcium ions of the smooth muscular cells of the thoracic aorta in rats. Methods The procedure of calcium absence-calcium addition was designed to observe the changes of the level of calcium ions in the strips of the smooth muscle of the thoracic aorta indirectly. The concentration of calcium ions in the smooth muscle of the thoracic aorta was determined with Fura-2/AM loaded SMCs. The elevation of calcium ions was induced with norepinephrine (NE). The concentration of potassium ions was observed in the presence of Pro. Results Pro significantly inhibited the NE-induced transient contract of the smooth muscle of the thoracic aorta in calcium-free medium and long-lasting contraction after the addition of calcium ions in a concentration-dependent manner. In Fura-2/AM loaded SMCs, Pro (50 ?mol/L or 100 ?mol/L) exerted no effect on the resting calcium ions but obvious effect on the NE-induced and high potassium level-induced elevation of calcium ions. In the presence of extracellular calcium ions, Pro (50 ?mol/L) decreased the NE-induced elevation of calcium ions but showed no effect on potassium-induced elevation of calcium. Pro (100 ?mol/L) significantly decreased NE-induced and high potassium level-induced elevation of calcium ions. Conclusion Pro reduces NE-induced or high potassium level-induced elevation of calcium ions in the smooth muscle of the thoracic aorta through its effect on calcium release and/or calcium influx.
ABSTRACT
Aim To study the protective effects of Rhynchophyll a of total alkaloids ( RTA ) on cerebral ischemia/reperfusion injury and the possi ble mechanism of action. Methods The effects of RTA on decapit ated gasping model and model of middle cerebral artery ischemia 2 h/reperfusion 22 h were observed. The neurological scores, cerebral infarct volume and cerebr al water content after ischemia/reperfusion were observed in rats respectively. The activities of NOS and SOD and the content of MDA in rat's brain tissue were measured. Neuron apoptosis in ischemia penumbral area were detected by terminal depoxynucleotidyl transferase mediated dUTP-biotin nick end labeling ( TUNEL ) . Results The average gasping times in mice treated with RTA 50 , 75 mg?kg -1 was significantly prolonged. The cerebral infarct volume and cerebral water content in rats treated with RTA 40, 60 mg?kg -1 were sign ificantly decreased in ischemic rats. RTA 40, 60 mg?kg -1 increased the ac tivity of SOD ,and decreased the activity of NOS and the content of MDA in the i schemic brains of rats. The number of apoptotic neurons in ischemia penumbral ar ea of cerebral tissue of rats treated with RTA 40, 60 mg?kg -1 was signif icantly lower than that in control rats. Conclusions RTA has pr otective effect on cerebral ischemia/reperfusion injury; this may be related to inhibit the activity of NOS and lipoperoxidation, and increasing the activity of SOD and decreasing neuron apoptosis.
ABSTRACT
AIM To study the distrubution and excretion of protopine in rats. METHODS Reversed phase high performance liquid chromatographic method (RP HPLC) was developed for determining the level of protopine in rats. The analytical column were packed with 5 ?m C 18 . The mobile phase was a mixture of methanol, water and 10% acetic acid (80∶20∶2), in which the pH was modulated to 5 6 with 15% ammonia. Protopine biological samples were isolated well, in which two extraction with ether under basical condition and an extraction with 0 02 mol?L -1 sulfuric acid were performed, respectively. The content of protopine in the biological sample was measured by an UV detector at 285 nm. The distrubution and excetion of protopine have been investigated in rats after intravenous administration 10 mg?kg -1 . RESULTS Protopine distrubuted in many tissues after iv a dose of 10 mg?kg -1 . The higher level of protopine was found in lung, kidney, spleen and brain, and the highest was observed in lung at 5, 15 minutes after administration. However the top level tissue was testicle at 3 h, which may be due to small blood circulation. The excretion of the parent compound in urine was 36 87% of dose, but the excretion of the parent compound in feces and bile was less than 1% of dose. Plasma protein binding was less than 5%. CONCLUSION The distrubution of protopine is extensive and the parent compoud was mainly excreted by urine and plasma protein binding was low.
ABSTRACT
The contractions induced by acetylcholine or Ca2 + after high-K+ depolarization in isolated guinea-pig taenia coli were markedly inhibited by rhynchophylline (Rhy). It caused rightward displacement of the dose-response curve for CaCl2 & significantly depressed the maximal response, showing a non-competitive antigonism. The pD'2 value of Rhy was 4.95?0.05. In Ca2+-free solution,Rhy similar to verapamil (Ver), inhibited acetylcholine-induced contraction of guinea-pig taenia coli, which is dependent on Ca2+ released from an intracellular store. After Ca2+ concentration in bath solution was restored, Ver did not influence the contraction of taenia coli depending on extracellular Ca2 + , However 40 ?mol/L Rhy could exhibit marked inhibitory action.