Comparison of biological augmentation in rotator cuff repair using inflamed versus non-inflamed bursal tissue in rats.

PURPOSE: To examine how augmentation of a rotator cuff repair with inflamed versus non-inflamed bursal tissue affects tendon-to-bone healing in a rat model of rotator cuff repair. METHODS: 136 Sprague-Dawley rats were randomly assigned to an inflamed or non-inflamed bursal tissue application group. After detachment the supraspinatus tendon was re-attached with bursal tissue sewn onto the tendon-to-bone interface. The specimens were analysed biomechanically 6 and at 7 weeks and immunohistologically at 1 and at 7 weeks after surgery. RESULTS: Immunohistological results showed no significant difference in the percentage of collagen type II in the tendon-to-bone interface at 1 (p = 0.97) and 7 weeks (p = 0.42) when utilising autologous non-inflamed bursal tissue in comparison to inflamed bursal tissue specimens. The inflamed bursa group also showed no significant difference in collagen I to III quotient (p= 0.14) after surgery in comparison to post-surgery non-inflamed bursa groups. Biomechanical assessment showed that tendon stiffness (p = 0.87 resp. p = 0.1) and the tendon viscoelasticity (p = 0.12 resp. p = 0.07) was the same after 6 and 7 weeks comparing inflamed bursa to the non-inflamed bursa group. There was no significant difference (p = 0.8 resp. p = 0.97) in load to failure between in both inflamed and non-inflamed bursa groups after 6 and 7 weeks. CONCLUSION: Autologous inflamed bursal tissue derived from the Achilles bursa and implanted to the tendon-to-bone interface after rotator cuff repair facilitates the same histological and biomechanical healing response as using a non-inflamed bursa interposition in rats. CLINICAL RELEVANCE: During augmentation of a rotator cuff repair, it is irrelevant whether the bursa tissue is inflamed or not.

[Deletion of Aldh4a1 Leads to Impaired Sperm Maturation in Mice].

ALDH4A1, a member of the aldehyde dehydrogenase superfamily, is a key enzyme in the mitochondrial proline metabolism pathway. Recent studies have shown that mutations in aldh4a1 lead to reduced fertility and reproductive premature aging of male nematodes. However, the effect of ALDH4A1 on fertility of male mice has not been studied. In this study, we used CRISPR-Cas9 technology to construct a knockout mouse model of Aldh4a1 for the first time to explore the effect of this gene on the reproduction of male mice. The results showed that compared with WT male mice, Aldh4a1^(-/-) male mice were fertile, had normal spermatogenesis but defect in sperm maturation in the epididymis documented by impaired motility, increased morphological abnormalities and increased spontaneous acrosome reaction. In addition, transmission electron microscopy showed vacuoles in the sperm mitochondria, and fracture in the neck of sperms and vacuoles in these mice. These results revealed that ALDH4A1 plays a vital role in the structure of sperm flagellum and the process of sperm maturation in mice.

HPV16 infection promotes an M2 macrophage phenotype to promote the invasion and metastasis of esophageal squamous cell carcinoma

Objectives High-risk human papillomavirus (HR-HPV) is an important risk factor for esophageal cancer. Macrophages constitute a crucial immune medium for regulating HPV-related tumors; however, the specific regulatory mechanisms remain unknown. Therefore, the purpose of our current study was to investigate the mechanism by which HPV16E6 regulates macrophages to promote the invasion and metastasis of esophageal cancer. Methods HPV16E6 infection was detected by polymerase chain reaction. Immunohistochemistry was used to verify the distribution of tumor-associated macrophages (TAMs) and MMP-9 expression in esophageal squamous cell carcinoma tissues (ESCCs), and cancer adjacent normal tissues (CANs) from Kazakh patients. ESCC cells were transfected with a plasmid over-expressing HPV16E6 and non-contact cocultured with macrophages. Results The infection rate of HPV16E6 in Kazakh ESCCs was clearly higher than that in CANs (P < 0.05). The density of CD163-positive TAMs was significantly positively correlated with HPV16E6 infection in ESCCs (P < 0.05). After coculturing macrophages and EC9706 cells transfected with the HPV16E6 plasmid, the phenotype of macrophages transformed into M2 macrophages. The migration and invasion ability of ESCC cells were higher in the HPV16E6-transfected and coculture group than in the HPV16E6 empty vector-transfected and non-cocultured HPV16E6-transfected groups (all P < 0.05). The density of M2-like TAMs in ESCCs was positively correlated with the level of MMP-9 expression. MMP-9 expression in the HPV16E6-ESCC coculture macrophages group was substantially higher than that in controls (all P < 0.05). Conclusions HPV16 infection mediates tumor-associated macrophages to promote ESCC invasion and migration (AU)

HPV16 infection promotes an M2 macrophage phenotype to promote the invasion and metastasis of esophageal squamous cell carcinoma.

OBJECTIVES: High-risk human papillomavirus (HR-HPV) is an important risk factor for esophageal cancer. Macrophages constitute a crucial immune medium for regulating HPV-related tumors; however, the specific regulatory mechanisms remain unknown. Therefore, the purpose of our current study was to investigate the mechanism by which HPV16E6 regulates macrophages to promote the invasion and metastasis of esophageal cancer. METHODS: HPV16E6 infection was detected by polymerase chain reaction. Immunohistochemistry was used to verify the distribution of tumor-associated macrophages (TAMs) and MMP-9 expression in esophageal squamous cell carcinoma tissues (ESCCs), and cancer adjacent normal tissues (CANs) from Kazakh patients. ESCC cells were transfected with a plasmid over-expressing HPV16E6 and non-contact cocultured with macrophages. RESULTS: The infection rate of HPV16E6 in Kazakh ESCCs was clearly higher than that in CANs (P < 0.05). The density of CD163-positive TAMs was significantly positively correlated with HPV16E6 infection in ESCCs (P < 0.05). After coculturing macrophages and EC9706 cells transfected with the HPV16E6 plasmid, the phenotype of macrophages transformed into M2 macrophages. The migration and invasion ability of ESCC cells were higher in the HPV16E6-transfected and coculture group than in the HPV16E6 empty vector-transfected and non-cocultured HPV16E6-transfected groups (all P < 0.05). The density of M2-like TAMs in ESCCs was positively correlated with the level of MMP-9 expression. MMP-9 expression in the HPV16E6-ESCC coculture macrophages group was substantially higher than that in controls (all P < 0.05). CONCLUSIONS: HPV16 infection mediates tumor-associated macrophages to promote ESCC invasion and migration.

[Effect of cigarette smoke exposure on the expression of CCR7 and levels of Th1/Th2 cytokines in asthmatic rats].

Objective: To investigate the effect of cigarette smoke exposure on the expression of CC Chemokine receptor 7 (CCR7) and levels of Th1/Th2 cytokines in asthmatic rats. Methods: Forty Wistar rats were randomly divided into four groups: control group, asthma group, smoke exposure group, asthma-smoke exposure group. The asthma group were sensitized with ovalbumin (OVA) and Aluminum hydroxide at day 1, 8 and challenged with OVA at day 15 by atomization for 8 weeks.While control group was sensitized and challenged with normal saline instead of OVA.The smoke exposure group was sensitized and challenged with normal saline instead of OVA followed passive smoking for 8 weeks. The asthma-smoke exposure group was challenged with OVA followed passive smoking. The pathological changes of different groups were observed by HE-staining. CCR7 was semiquantitatively analyzed in lungs by immunohistochemistry.The concentration of CC chemokine ligand (CCL)19, CCL21, interferon (IFN)-γ and interleukin (IL)-4 in peripheral blood and CCL19 and CCL21 in bronchoalveolar lavage fluid (BALF) were measured by enzyme-linked immunosorbent (ELESA) assay. Results: In asthma group, smoke exposure group and asthma-smoke exposure group, the various degrees of inflammatory reaction appeared in lung tissue and the asthma-smoke exposure group was with the most significant reaction. In the lung tissues of the rats from asthma group, smoke exposure group and asthma-smoke exposure group, the average optical density (AOD) of CCR7 were significantly higher than those in control group (0.350±0.023, 0.252±0.022, 0.400±0.029 vs 0.180±0.020, all P<0.01). The AOD of CCR7 of asthma-smoke exposure group was much higher than both that in asthma group and in smoke exposure group (both P<0.01). In asthma group, smoke exposure group and asthma-smoke exposure group, the concentrations of both CCL19 and CCL21 in peripheral blood and BALF were significantly higher than that in control group (all P<0.01). The concentrations of both CCL19 and CCL21 in peripheral blood and BALF of asthma-smoke exposure group were significantly higher than the results in asthma group and in smoke exposure group (all P<0.01). The concentrations of IFN-γ in peripheral blood of asthma group and asthma-smoke exposure group were lower than those in control group [(33±3), (17±3) vs (70±4) pg/ml], but asthma-smoke exposure group was much lower than the results in asthma group (all P<0.01). The concentration of IFN-γ in peripheral blood of smoke exposure group[(100±5)pg/ml]was higher than that in control group and asthma-smoke exposure group (both P<0.01). In asthma group, smoke exposure group, asthma-smoke exposure group, the concentrations of IL-4 in peripheral blood were significantly higher than those in control group [(54±4), (42±4), (76±4) vs (30±4) pg/ml, all P<0.01]. The concentrations of IL-4 in peripheral blood of asthma-smoke exposure group was significantly higher than those in asthma group and in smoke exposure group (both P<0.01). Conclusion: Cigarette smoke could enhance the expression of CCR7 and its ligand, and it can also result in exacerbations of asthma by reducing the expression level of IFN-γ (the representative of Th1 cytokine) and increasing the expression level of IL-4 (the representative of Th2 cytokine).

Nitric oxide is involved in phosphorus deficiency-induced cluster-root development and citrate exudation in white lupin.

*White lupin (Lupinus albus) forms specialized cluster roots characterized by exudation of organic anions under phosphorus (P) deficiency. Here, the role of nitric oxide (NO) in P deficiency-induced cluster-root formation and citrate exudation was evaluated. *White lupin plants were treated with the NO donor sodium nitroprusside (SNP) and scavenger or inhibitor of NO synthase under conditions of P deficiency (0 muM) or P sufficiency (50 muM). *Phosphorus deficiency enhanced NO production in primary and lateral root tips, with a greater increase in cluster roots than in noncluster roots. NO concentrations decreased with cluster root development from the pre-emergent stage, through the juvenile stage, to the mature stage. The P deficiency-induced increase in NO production was inhibited by antagonists of NO synthase and xanthine oxidoreductase, suggesting the involvement of these enzymes in NO production. SNP markedly increased the number of cluster roots. Citrate exudation from different root segments in P-deficient roots was positively correlated with endogenous root NO concentrations. *These findings demonstrate differential patterns of NO production in white lupin, depending on root zone, developmental stage and P nutritional status. NO appears to play a regulatory role in the formation of cluster roots and citrate exudation in white lupin under conditions of P deficiency.

Biphasic manner of melittin on isolated guinea pig atria.

AIM: To investigate the effect of melittin (Mel) on isolated guinea pig atria. METHODS: The effect of Mel on the contraction and heart rate of isolated guinea pig atria at different concentrations was determined. RESULTS: Mel at a lower concentration (0.1-0.8 mumol.L-1) enhanced the contraction of left atria in a concentration-dependent manner; but at a higher concentration (1.6-12.8 mumol.L-1) it exerted an inhibitory effect. At 0.1-30 mumol.L-1 it was found to increase heart rate of right atria. In addition, verapamil (Ver) 0.3 mumol.L-1 was found to depress the effect of Mel. CONCLUSION: Mel possesses a biphasic effect on left atria and a positive chronotropic effect on right atria. Its mechanism might be related with Ca2+ channel.

Melatonin decreases production of hydroxyl radical during cerebral ischemia-reperfusion.

AIM: To study the effect of melatonin on hydroxyl radical (.OH) contents during cerebral ischemia-reperfusion in rats. METHODS: Ischemia was induced by occluding left lateral middle cerebral artery for 30 min following reperfusion. The salicylate trapping method coupled with ipsilateral striatal microdialysis for measurement of hydroxyl radicals generated during ischemia and reperfusion. RESULTS: The contents of dihydroxybenzoic acid (DHBA) were increased at 15 min after ischemia and remained high for 30 min after reperfusion. Melatonin (4 mg.kg-1, sc, 30 min before ischemia) decreased the production of DHBA during ischemia for 16-30 min and reperfusion for 1-30 min. CONCLUSION: Melatonin inhibits the production of hydroxyl radicals in rat brain during ischemia and reperfusion.

Inhibitory effects of dextromethorphan on c-fos protein expression during focal cerebral ischemia in rats.

AIM: To study the effect of dextromethorphan (DM) in focal cerebral ischemia. METHODS: The c-fos protein was detected immunohistochemically in the brain of rats after focal cerebral ischemia (induced by placing a nylon thread in the lumen of the internal carotid artery) with and without treatment with DM. RESULTS: Focal cerebral ischemia induced c-fos protein expression outside the core territory of the middle cerebral artery (MCA) and neuronal damage in the core territory of the MCA. There was an evident expression of c-fos protein in the ipsilateral regions outside the MCA territory (e.g. cingulate cortices, piriform cortices and entorhinal cortices), and in the contralateral regions of hippocampus after 4-h reperfusion following 1-h MCA occlusion. But morphological results showed severe edema and neuronal damage in the core territory and the ipsilateral hippocampus. DM blocked both the c-fos protein induction and neuronal damage in all regions. CONCLUSION: DM reduced c-fos protein expression and blocked the neuronal damage after focal cerebral ischemia.

Effects of sigma and phencyclidine receptor ligands on electric field-stimulated rabbit ear artery constriction in vitro.

Several ligands of phencyclidine (Phe) receptors: Phe, dizocilpine maleate (Diz, MK-801), 1-[1-(2-thionyl)cyclohexyl] piperidine (TCP), and ligands of sigma (sigma) receptors: dl-N-allylnormetazocine (dl-SK&F-10047), 1, 3-di-ortho-tylyl-guanidine (DTG), dl-pentazocine, were tested on rabbit ear arteries in vitro. It was found that the ligands of Phe receptors enhanced the electric field stimulated vasoconstriction (ESV). Their concentration-effect curves of these compounds were parallel in the order of potencies: Phe > Diz > TCP. The ligands of sigma receptors had no effect on ESV of the arteries, but 5 mumol.L-1 reduced or increased the effect of Phe (5 mumol.L-1) on ESV. d-SK&F-10047, d-pentazocine, and DTG inhibited the effect of Phe on ESV from 364 +/- 22 mg to 142 +/- 49 mg (n = 5, P < 0.01), 262 +/- 95 mg (n = 5, P < 0.05), and 291 +/- 80 mg (n = 5, P > 0.05), respectively. The levoisomers: l-SK&F-10047 and l-pentazocine enhanced the effect of Phe on ESV from 364 +/- 22 mg to 484 +/- 78 mg (n = 5, P < 0.05), and 466 +/- 95 mg (n = 5, P < 0.05), respectively. These results revealed that there were mainly Phe receptors but hardly any sigma receptors in the arteries.

Effects of kappa, sigma, and phencyclidine receptors agonists in rat tail arteries of spontaneously hypertensive rats.

The effects of the kappa receptor agonist trans-4-dichloro-N-methyl-N-(2-(1-pyrrolidin)cyclohexyl)-benzen eacefamide methane sulfonate (U-50 488H), etorphine, the sigma (sigma) receptor agonists (+)-3-(3-hydroxychenyl)-N-(1-propyl) piperidine ((+)-3-PPP), 1, 3-di-o-tolyl-guanidine (DTG), and the phencyclidine (Phe) receptor agonists Phe, N-(1-(2-thienyl)cyclohexyl) piperidine (TCP), and dizocilipine maleate (MK-801) on electrically stimulated constriction (ESC) were investigated in the rat tail arteries (RTA) of spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats. Etorphine and U-50 488H inhibited the response to ESC in SHR more than that in WKY. The effects of U-50 488H were greater than those of etorphine. The IC50 and Kact of U-50 488H in SHR were 2.5 +/- 2.0 and 0.43 +/- 0.22 mumol.L-1, respectively, while the corresponding figures in WKY were 23 +/- 15 and 2.3 +/- 1.0 mumol.L-1, respectively (P < 0.05). The inhibitory effects of (+)-3-PPP on ESC in RTA of SHR were weaker than those in WKY. Its IC50 and Kact in SHR were 11.6 +/- 5.4 and 0.87 +/- 0.30 mumol.L-1, respectively, while the corresponding figures in WKY were 0.63 +/- 0.16 and 0.35 +/- 0.18 mumol.L-1, respectively (P < 0.05). But the inhibitory effect of DTG was very slight and the difference of Kact between WKY and SHR was not significant. The enhancing effects of Phe, TCP, and MK-801 in SHR were not at all different from those in WKY at each concentration tested.(ABSTRACT TRUNCATED AT 250 WORDS)

Neuroprotective effects of phencyclidine on acute cerebral ischemia and reperfusion injury of rabbits.

Acute cerebral ischemia and reperfusion injury of rabbits was produced by permanently occluding the vertebral arteries and temporarily clamping the common carotid arteries for 30 min. Phencyclidine [1-(phenylcyclohexyl)piperidine, PCP] 40-80 micrograms.kg-1 icv 30 min before ischemia significantly attenuated the decrease of the total power of electroencephalogram (EEG) within 30 min of ischemia and improved the recovery of brain electric activity following reperfusion. PCP 20-80 micrograms.kg-1 dose-dependently suppressed the creatine kinase (CK) release during cerebral ischemia and reperfusion, and PCP 40-80 micrograms.kg-1 reduced brain ischemic damage. These improvements indicated that PCP has protective effects on acute cerebral ischemia and reperfusion injury.

[Effects of phencyclidine on rabbit basilar artery in vitro and rabbit cerebral blood flow in vivo].

The effect of phencyclidine [1-(1-phenylcyclohexyl)piperidine, PCP] on rabbit basilar arteries was studied with an in vitro model of ring segment arteries. PCP 0.05-500 mumol.L-1 caused vasoconstriction of basilar arteries in a concentration-dependent manner. Its maximal effect (Emax) was 94 +/- 21 mg and the concentration causing half maximal effect (EC50) was 25 +/- 18 mumol.L-1. PCP 0.01-10 mumol.L-1 also concentration-dependently augmented the vasoconstriction induced by electric stimulation in rabbit basilar arteries. Its Emax was 91 +/- 18 mg and EC50 was 0.27 +/- 0.17 mumol.L-1. The effects of PCP on mean arterial blood pressure (MABP) and heart rate (HR) of rabbits were observed. PCP iv 4 mg.kg-1 reduced MABP from 14.3 +/- 0.8 to 12.2 +/- 1.0 kPa and HR from 300 +/- 0 to 278 +/- 5 bpm in 5 min. Using the technique of radionuclide imaging in rabbit brain in vivo, we studied the effect of PCP on cerebral blood flow. After iv PCP 4 mg.kg-1, the tp of radiocerebrogram was increased from 4.5 +/- 1.1 to 6.1 +/- 1.0 s, the tg of radiocerebrogram was increased from 11.7 +/- 0.6 to 18.2 +/- 3.3 s and the rate of clearance was decreased. After iv PCP 2 mg.kg-1, only tg increased from 12.6 +/- 2.1 to 15.9 +/- 0.6 s. Hence PCP increased the transit time of nondiffusible indicators (99mTc) through the cerebral circulation. These results suggest that PCP causes constriction of basilar artery and slows down the cerebral blood flow.

[Antagonistic effect of phencyclidine on cerebral ischemic damage of rats].

Dynorphin and catecholamine were measured in ischemic rat produced by four-vessel (2 vertebral arteries and 2 common carotid arteries) occlusion for 10 min. The results showed that: (1) The contents of dynorphine (pg/mg tissue) in cerebral cortex were 5.5 +/- 0.6 (n = 7) in normal rats and decreased to 4.9 +/- 0.5 (n = 9, P less than 0.05) in cerebral ischemic rats; with immediate ip phencyclidine (1-(1-phenylcyclophexyl)piperidine, PCP, 1 mg.kg-1), the contents of dynorphin were increased to 5.3 +/- 0.4 (n = 5, P less than 0.05 vs the ischemic rats). (2) The contents of DOPAC (pg/mg tissue) in cerebral cortex were 38 +/- 6 (n = 7) and increased to 120 +/- 60 (n = 5, P less than 0.05) in 10 min cerebral ischemic rats; with immediately ip PCP (1 mg.kg-1), the contents of DOPAC were decreased to 26 +/- 13 (n = 7, P less than 0.05 vs the ischemic rats). (3) The release of DA (pg/mg tissue) in cortical slices in vitro, in high K+ solution were 24 +/- 3 (n = 5) and significantly increased to 57 +/- 15 (n = 5, P less than 0.05) in ischemic rat brain slices; with immediate ip PCP (1 mg.kg-1), the contents of DA were decreased to 38 +/- 10 (n = 5, P less than 0.05 vs the ischemic rats). These results suggest PCP play an antagonistic role in cerebral ischemic damage of rats.

[Antagonistic effects of dextromethorphan on vasoconstriction of phencyclidine in vitro].

Bioassay and spectrophotofluorometry were used to study the antagonistic effect of dextromethorphan (DM) on phencyclidine (PCP) vasoconstriction in rabbit ear artery. DM (5 mumols.L-1) antagonized enhancement of PCP, N-[1-(2-thienyl) cyclohexyl] piperidine (TCP) and dizocilpine maleate (MK-801) (5 mumols.L-1) on electrical stimulation-induced vasoconstriction by 86 +/- 18%, 84 +/- 17%, and 86 +/- 18%, respectively (n = 6, P less than 0.01), but had no obvious bioactivity itself at the same concentration. DM (1, 2.5, and 5 mumols.L-1) inhibited the PCP effect and reduced the maximal effect of PCP with pD2' = 5.3 +/- 0.3 (n = 4). The contents of norepinephrine (NE) in control, PCP, and DM + PCP groups were 5 +/- 6, 12 +/- 8, and 5 +/- 6 ng.ml-1, respectively (n = 9). PCP (10 mumols.L-1) increased the NE release (P less than 0.05) but DM (10 mumols.L-1) inhibited it (P less than 0.01). The results suggest DM may be a noncompetitive blockader for PCP receptors.

[Effects of l-stepholidine on isolated rabbit basilar artery, mesenteric artery, and thoracic aorta].

l-Stepholidine (SPD) has been shown to be effective in treating migraine, but its mechanism is not clear. So the effects of SPD on isolated rabbit basilar artery (BA), mesenteric artery (MA) and thoracic aorta (TA) were studied. The contractions of BA and MA were induced by KCl (10-160 mmol.L-1) and the contraction of TA was caused by 5-HT (0.1-100 mumol.L-1). Ketanserin was used as reference. SPD (0.1-0.2 mmol.L-1) relaxed the contractions of BA and MA induced by KCl in a noncompetitive manner with pD'2 3.4 +/- 0.3 and 4.0 +/- 0.3, respectively. SPD had no selectivity in BA and MA. SPD also inhibited the contraction of TA induced by 5-HT with pA2 9.7 +/- 2.0 and pD'2 5.4 +/- 0.6, which showed a dual of both competitive and noncompetitive antagonisms. These results suggested that SPD had a blockade effect on the calcium channel and 5-HT2 receptors.

[Effects of phencyclidine analogs and phencyclidine/sigma ligands on vasoconstrictor response of rat mesenteric arteries induced by electrical field stimulation].

Using the model of perfused mesenteric arteries of rat, we studied the effect of phencyclidine (PCP), N-[1-(2-thienyl)cyclohexyl] piperidine (TCP), N,N-dimethylphenylcyclohexylamine (PCDA), N-(iso-propyl)-1-phenylcyclohexylamine (PCIPA), (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate (MK-801), (+),(-)-N-allylnormetazocine (SKF 10 047), dextrorphan, and levorphanol on vasoconstrictor response induced by electrical field stimulation. PCP, TCP, PCDA, PCIPA, MK-801, levorphanol, and (-)-SKF 10 047 were found to increase the vasoconstrictor response in dose-dependent manner. The dose-effect curves of these compounds were similar to the curve of PCP. Although dextrorphan, an antagonist for PCP receptors, did not affect the vasoconstrictor response, it could non-competitively antagonize PCP's action. These studies suggest that some PCP analogs and PCP/sigma ligands may enhance the vasoconstrictor response induced by electrical field stimulation via action on PCP receptors.

[Phencyclidine receptors in porcine cerebral arteries].

A specific, saturable, reversible, and selective binding site with Kd = 87 +/- 33 nmol/L, Bmax = 0.78 +/- 0.11 pmol/mg protein was detected in the binding of [3H] phencyclidine (PCP) to porcine cerebral blood vessels. Only ligands of PCP/sigma series were able to bind to the PCP receptors. [3H]PCP bound to its receptors was not displaced by etorphine or norepinephrine 0.1 mmol/L. A specific [3H]PCP binding site was found in porcine brain with Kd = 75 +/- 34 nmol/L, Bmax = 0.61 +/- 0.23 pmol/mg protein. Bioassay in vitro showed PCP enhanced the perfusion pressure of porcine cerebral blood vessels in a dose-dependent manner. This study provides direct evidence for PCP receptors on cerebral blood vessels, and suggests that PCP may produce cerebral vasospasm via PCP receptor interaction.

[Mechanism of dynorphin inhibition on vasoconstriction in vitro].

Bioassay and HPLC detection were used to analyze the mechanism of inhibition of stimulation-induced vasoconstriction by dynorphin 1-13 (D1-13). Bioassay showed that D1-13 inhibited the contraction of rabbit ear artery and mesenteric artery induced by electrical field stimulation with IC50s of 8.5 +/- 1.2 x 10(-8) mol/L (n = 4) and 5.02 +/- 1.3 x 10(-7) mol/L (n = 5), respectively. D1-13 was ineffective in rabbit femoral artery at a concentration even larger than 10(-6) mol/L. D1-13 did not alter the basal tension of the blood vessel, nor the vasoconstriction induced by adding norepinephrine (NE) into the bath medium, and both constriction were markedly inhibited by phentolamine, an alpha-adrenoceptor blocker. With HPLC detection, the contents of NE in the bath medium were significantly reduced by D1-13 (5 x 10(-7) mol/L) from 340.56 +/- 73.13 pg/ml to 76.91 +/- 10.26 pg/ml as compared with control group (P less than 0.05). The effect could be completely reversed by naloxone at a concentration of 10(-6) mol/L (P less than 0.05). The results suggest that D1-13 reduces stimulation-induced vasoconstriction probably through a presynaptic inhibition of NE release from the nerve terminals.

[Autoradiographic study on etorphine and phencyclidine specific binding sites in rabbit mesenteric artery].

Autoradiography was used to study the localization of kappa and PCP/sigma receptors in the blood vessels. Slices of rabbit mesenteric arteries were incubated with 0.4 nmol/L [3H]etorphine or/and 10 mumol/L etorphine for 45 min at 25 degrees C, or incubated with 5.2 nmol/L [3H]PCP or/and 20 mumol/L PCP for 60 min at 4 degrees C. Then, slices were covered with emulsion coated coverslip and kept for 8-10 wk at 4 degrees C. The results were as follows: Microscopy Autoradiographic analysis indicated that etorphine and PCP specific binding sites were both located in the outer-layer and the smooth muscle of the artery. However, most of these binding sites were lost in the 6-OHDA pretreated arteries in which the adrenergic nerve endings were destroyed. Microspectrophotometry The absorbance (A) of [3H]etorphine autoradiographic density for total binding (TB) and nonspecific binding (NSB) in control group were 0.416 +/- 0.056 and 0.044 +/- 0.011, respectively (P less than 0.01), and for TB after incubation with 6-OHDA was 0.068 +/- 0.013 which was different from the A value of TB in the control (P less than 0.01). The A value of [3H]PCP autoradiographic density for TB and NSB in the control were 0.546 +/- 0.087 and 0.023 +/- 0.060, respectively (P less than 0.01), and for TB after incubation with 6-OHDA was 0.065 +/- 0.015 which was significantly less than that of TB in the control group (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)