Neuropilin-1 contributes to esophageal squamous cancer progression via promoting P65-dependent cell proliferation.

Neuropilin-1 (NRP1) is a non-kinase receptor recently implicated in tumor progression. Here we revealed that over-expression of NRP1 correlates with poor prognosis in esophageal squamous cell carcinoma (ESCC). NRP1-knockdown suppressed ESCC cell proliferation and xenograft tumor growth. Reduced NRP1 expression downregulated P65 mRNA and protein expression, and ectopic expression of P65-restored cell proliferation in NRP1-silenced cells. NRP1 regulates P65 transcription by activating cAMP responsive element binding protein (CREB). NRP1 interacted with and activated epidermal growth factor receptor (EGFR), and b1/b2 domain of NRP1 is responsible for the activation of EGFR. We also found that EGFR regulated CREB transcriptional activity via AKT. These data suggest that NRP1 is an upstream regulator in the P65-dependent proliferation signaling pathway and a candidate therapeutic target for ESCC.

[Changes of central glucose metabolism following caudate stimulation produced analgesia in the rat--an autoradiographic deoxyglucose A study].

Sokoloff's 2-deoxyglucose (2-DG) autoradiographic technique was used to identify changes of glucose metabolic rate in the rat brain following unilateral stimulation of the head of the caudate nucleus. The results were as follows. The local glucose metabolic rate after noxious stimulation was increased in the somatosensory cortex, cingulate cortex, ventroposterior and parafascicular nucleus of the thalamus, septal area, habenular nucleus, head of caudate nucleus, periaqueductal gray (PAG) and dorsal raphe nucleus (P < 0.05). After stimulating the head of the caudate nucleus, the local glucose metabolic rate of nucleus raphe magnus (rm) and nucleus paragigantocellularis (pgcl) was increased significantly and that of the PAG and dorsal raphe nucleus had a tendency to increase, while stimulation of the head of caudate nucleus could partially abolish the increased glucose metabolic rate in the somatosensory cortex, cingulate cortex, ventroposterior and parafascicular nucleus of the thalamus, septal area and habenular nucleus as induced by noxious stimulation. These results suggest that caudate stimulation is able to depress the activation of some brain structures related to nociception and to activate those related to antinociception. The pgcl, rm, PAG and dorsal raphe nucleus might be the key structures participating in the caudate stimulation produced analgesia.

[Change of preoptic opiate receptors after injection of 6-OHDA into sublocus coeruleus in the rabbit].

The formaldehyde histofluorescence method and receptor autoradiography were respectively used to investigate the distribution and densities of the catecholamine (CA) terminals and [3H]-etorphine binding sites, after 20 days of injection of 6-hydroxydopamine (6-OHDA) into N. subcoerulens of the rabbit. The results showed that both CA terminals and [3H]-etophine binding sites in the preoptic area, especially in the medial preoptic area, were reduced in 6-OHDA pretreated animals, thus suggesting the possible location of opioid receptors on the CA terminals.

[Effect of electroacupuncture on electroconvulsive shock--an autoradiographic study for opioid receptors].

Radioreceptor-binding assay combined with autoradiography technique in the brain slices of rats was used to investigate cerebral areas related to electroconvulsive shock (ECS) and to analyze changes of opioid receptors of these areas in electroacupuncture (EA) anticonvulsion. The results from image processing and detection of optic density (O.D.) showed that repeated ECS resulted in an increase of opioid receptor densities in the caudate nucleus, hippocampus, habenulae nucleus and amygdala. In the group of EA plus ECS, however, the opioid receptor densities in the hippocampus, habenula nucleus and amygdala decreased as compared with that in ECS group. In addition, the receptor density in the caudate nucleus showed a decrease tendency. The results provided morphological evidence of the involvement of opioid receptors in these cerebral areas in the process of ECS and EA anticonvulsion.

[Effects of astragalus (ASI, SK) on experimental liver injury].

The saponins (ASI, SK) used in this study was extracted from the root of Astragalus membranaceous Bge and Astragalus sieversianus Pull. ASI and SK were found to protect liver from chemical injury induced by CCl4, D-galactosamine and acetaminophen in mice. The two saponins were shown to impede the elevation of SGPT level, decrease the MDA content and increase the GSH concentration in mouse liver. Obvious improvement of histological changes were also observed. The protective action of ASI and SK against the hepatotoxicity was also shown in experiments using primary cultured rat hepatocytes. The average value of GPT in the medium treated with different concentration of ASI and SK (0.00075-0.18 mmol/L) was lower than that in control. Analyzing through multiple linear correlation, we showed that the lowering of SGPT was negatively related to the increase of GSH, positively related to the decrease of MDA in mice given CCl4 or acetaminophen in combination with ASI or SK. These results indicate that the hepato-protective effects of ASI and SK may be due to their anti-oxidation activities, since the content of liver protein in mice given ASI or SK was more than that in the controls. Moreover, the level of hepatic microsomal cytochrome P-450 in all mice given the two saponins were significantly increased, the liver metabolism and immunoregulating action produced by ASI and SK may be also involved in their hepato-protective effects.

[Rejection of physico-chemical indices for pathological matrix in a quantitative drug design].

In a quantitative drug design, correlation of coefficient matrix of physico-chemical indices Xi is often pathological when these indices are highly correlated. The regression equation of biological activity Y about these indices Xi obtained in this case is not stable. In this paper, a method is given to obtain a stable regression equation: giving a critical valne alpha and finding out the indices among which correlation coefficient is not less than alpha. The following are the rules to reject some of them. If Xi and Xj is highly correlated (magnitude of rij greater than or equal to alpha, rij is the correlation coefficient of Xi and Xj), and magnitude of rin greater than magnitude of rjn (rin and rjn are correlation coefficients of Xi and Xj about Y, respectively), than the index Xj is rejected, otherwise, Xi is rejected. Stable equation can be obtained by stepwise regression with the remaining indices.

The central effect of electro-acupuncture analgesia on visceral pain of rats: a study using the [3H] 2-deoxyglucose method.

This study had the objective to understand the central effect of electro-acupuncture analgesia (EAA) on visceral pain of rats. We used the method of Sokoloff's 2-deoxyglucose (2-DG) auto-radiographic quantitative analysis to observe the changes of local cerebral metabolic rate of glucose (LCMRG) in rats given electrical stimulation of greater splanchnic nerve (GSN) followed by electro-acupuncture. From the results of this study, we found that the LCMRG had a significant difference between EAA group and pain group at some structures, such as the spinal thoracic and lumbar dorsal horns (segments T6-T8, L1-L3), locus coeruleus (lc), nucleus raphe magnus (rm), nucleus reticular gigantocellularis (rgi), periaqueductal gray (PAG) and habenulae lateralis (hl) of thalanum. The results combining reports by other investigators, suggest that these local cerebral structures might be the key nuclei in EAA on visceral pain.

C-fos expression during electroacupuncture analgesia in rats--an immunohistochemical study.

Although the central mechanisms of electroacupuncture analgesia (EAA) have been investigated, a systematic study for the involvement of neuronal populations of central nervous system (CNS) in EAA has not been well undertaken, largely due to the difficulty in tracing the neuronal pathways by traditional techniques. Recently developed c-fos expression examination by immunohistochemical method with Ab-1 antisera might be used for this purpose as a useful marker for neuronal activity in CNS. In this study, tail flick latency (TFL) was tested as an index of pain threshold in conscious rats. After unilateral electroacupuncture was applied at 'Zuan-san-li' and 'Huan-tiao', the TFL was significantly prolonged. To explore the possible involvement of certain neuronal groups of central nervous system in EAA, we examined the EAA accompanied c-fos expression throughout the neuraxis, and a lot of specific c-fos protein labelled neurons were found in lumbar spinal cord (laminae I and II), nucleus raphe magnus, nucleus raphe dorsalis, substantia grisea centralis, nucleus habenulae lateralis, nucleus habenulae medialis, nucleus medialis thalami, nucleus lateralis hypothalami, nucleus supramamillaris, nucleus supraopticus, nucleus arcuatus, nucleus preopticus medialis, nucleus amygdala, nucleus tractus diagonalis, etc. No obvious c-fos expression was shown in these areas on control rats. These results strongly suggested that the functional activation of above-mentioned nuclei by electroacupuncture was underlied in EAA action.

[A simple method for estimating half-life of drugs obeying Michaelis-Menten elimination kinetics].

AIM: To establish a simple method for estimating half-life of drugs obeying Michaelis-Menten elimination kinetics. METHODS: A linear relationship is sketched between elimination half-life and drug concentration in blood that obey Michaelis-Menten elimination kinetics. A simple method is proposed to draw a regression line of blood drug concentration vs time after a single bolus intravenous injection. RESULTS & CONCLUSION: The elimination half-life can be read from the regression line. The method can also be used to estimate the time required for the plasma concentration of a drug to decrease any fraction.

[Evaluation of the tissue-to-blood partition coefficient R for physiological pharmacokinetic models].

The tissue-to-blood partition coefficient R, fraction of drug unbound in blood fB and intrinsic clearance of elimination organ/tissue Cl'L are important parameters used in physiological pharmacokinetic models. Simple equations to evaluate R by AUC were derived in this paper for single bolus iv, the tissue-to-blood partition coefficient of nonelimination organ/tissue was exactly the ratio of AUC between tissue and blood, those equations were examined by the experimental data of rats following iv ethoxybenzamide 20 mg.kg-1, and compared with other methods. Equations to evaluate fBCl'L and other parameters were also given for linear elimination model.

Different distributions of opioid receptors in spontaneously hypertensive rats and Wistar-Kyoto rats.

AIM: To compare the densities of opioid receptors in spontaneously hypertensive rats (SHR) with those of normotensive Wistar-Kyoto (WKY) rats in central nervous system which are related to the regulation of BP. METHODS: [3H] Etorphine, a nonspecific opioid ligand, was used to determine the distributions of opioid receptors in 16-wk-old SHR and WKY rats by quantitative autoradiography. RESULTS: The densities of [3H]etorphine in hippocampus (P < 0.01), periaqueductal gray, nucleus of the solitary tract, and thoracic (T4-6) spinal cord (P < 0.05) of SHR were lower than those of WKY rats. But in basolateral amygdaloid nucleus (P < 0.01), habenular nuclei (P < 0.05), and hypothalamic nuclei including arcuate nucleus (P < 0.01), higher densities of opioid receptors were found in SHR. No difference existed in interpeduncular nuclei between the 2 groups. CONCLUSION: The difference in distributions of opioid receptors is related to the hypertension in SHR.

Central expression of c-fos protein after peripheral noxious thermal stimulation in awake rats.

This study applied immunohistochemistry method to examine the pattern of c-fos expression in the neuraxis following peripheral noxious thermal stimulation accomplished by immersion of tail of awake rat into hot water (50 degrees C). In unstimulated control rats, no obvious baseline expression of c-fos protein was found except in nucleus paraventricularis hypothalami and colliculus inferior, probably associated with restraint-induced stress and auditory stimulus, respectively. Noxious thermal stimulation resulted in the activation of c-fos expression, and bilateral increased nuclear immunostaining was counted in dorsal horn of lumbar and sacral segments of spinal cord (laminae I, II), nucleus raphe dorsalis, substantia grisea centralis (ventralis), nucleus paraventricularis thalami, nucleus anterior thalami, nucleus ventralis thalami, nucleus medialis thalami, nucleus reuniens, nucleus rhomboideus, nucleus habenulae lateralis, nucleus paraventricularis hypothalami, nucleus arcuatus, nucleus lateralis hypothalami, nucleus preopticus lateralis, nucleus septi lateralis, nucleus amygdala, nucleus striae terminalis, nucleus tractus diagonalis, and cortex cerebri. The results demonstrated that peripheral noxious stimulation induced central c-fos protein expression in a pattern of labeling nociresponsive cells.

Effect of dose of metoprolol on its elimination by isolated perfused rat liver in vitro.

The effects of dose of metoprolol (Met) on hepatic elimination was studied in isolated rat liver perfused at a flow of 25 ml.min-1. The results showed that Met was eliminated by rat liver in accordance with one-compartment model. Linear kinetic eliminating processes (apparent first-order kinetics) were found in doses of Met 0.2, 0.5, 1.0, and 2.0 mg, T1/2 were 8.3, 8.8, 9.6, and 10.6 min and the clearance rate were 11.7, 11.8, 9.6, and 8.6 ml.min-1, respectively. Nonlinear eliminating processes were found in doses of Met 4, 8, and 12 mg. Vm and Km were 0.98, 1.05, and 0.94 microgram/min-1.ml-1 and 15.6, 16.9, and 14.6 micrograms.ml-1, respectively. It is concluded that hepatic Met elimination is independent on lower doses, but rested upon high doses.

Pharmacokinetic-pharmacodynamic modeling of metoprolol stereoisomers in spontaneously hypertensive rat.

AIM: To study the combined pharmacokinetic-pharmacodynamic (PK-PD) model of metoprolol stereoisomers, and compare their inhibitory effects on cardiovascular system in the spontaneously hypertensive rats (SHR). METHODS: The drug concentration in plasma was measured by the reversed phase HPLC and the drug effects were recorded by polygraph. The pharmacokinetic parameters and the PK-PD model parameters were calculated. RESULTS: The plasma concentration-time profiles were adequately described by two-compartment model. Differences of Vd between (+)-Met and (-)-Met were found. The relationships between effects and concentration of effect compartment were represented by the sigmoid-Emax model. The Css50 of Vmax, dp/dtmax, and HR inhibitory effects of (+)-Met were larger than those of (-)-Met. CONCLUSION: Stereo-selective drug distribution and different potencies of the inhibitory effects of (+)-Met and (-)-Met existed in SHR.

Pharmacokinetics of sustained-release capsule of 5-isosorbide mononitrate in 20 healthy Chinese young men.

AIM: To compare the pharmacokinetics of domestic and imported sustained-release capsule of 5-isosorbide mononitrate (5-IM). METHODS: A single and 5-d-repeated oral doses of 5-IM 50 mg were performed on 2 groups of 20 Chinese healthy subjects (10 subjects for each group) in a randomized crossover protocol. The 5-IM in plasma were measured by gas chromatography with electron-captured detector method. Data were analyzed automatically by using a CAPP program on a PC computer. RESULTS: Fitting the 5-IM concentration-time curves to one-compartment model or following trapezoidal rule, the parameters such as Tmax, Cmax, Ke, MRT, and AUC were calculated and there were no significant differences between the two kinds of capsule. The major pharmacokinetic parameters of domestic and imported 5-IM sustained-release capsule with a 5-d multiple dose were respectively: Cmax (677 +/- 103) and (702 +/- 76) micrograms.L-1; Tmax (5.1 +/- 2.0) and (5.6 +/- 1.3) h; MRT (11.5 +/- 0.5) and (11.4 +/- 0.7) h; AUC0-infinity (12,121 +/- 1346) and (12,352 +/- 988) micrograms.h.L-1. The fraction of drug absorbed in vivo was correlated well with the percentage amount of drug released in vitro at corresponding time (P < 0.05), and the fluctuation indices on d 5 in multiple dose study were not significantly different between the two formulations (P > 0.05). The relative bioavailability of the domestic capsule for single and multiple dose were 96% +/- 11% and 98% +/- 10%, respectively. CONCLUSION: Domestic 5-IM sustained-release capsule showed bioequivalence compared with the imported capsule and provided the same nitrate-low interval in the latter part of the 24-h dosing interval.