[Effect of agonists of opioid receptor on coronary arterial strips in porcine]

Bioassay of spiral strips was used to study the effect of agonists of opioid receptor on coronary artery strips of porcine. It was found that selective agonist of kappa (U-50488H), mu (ohmefentanyl OMF) and delta (morphine and DADLE) receptor and wide spectrum agonist of opioid receptor etorphine all produced the contraction of strips dose-dependently. The order of the effect was U-50488H > morphine > etorphine > OMF, DADLE. Naloxone did not antagonize but increase the effect, or even produce contraction of the strips by itself. Haloperidol inhibited the contraction of the strip produced by U-50488H noncompetitively, also in a dose-dependent manner, probably without involving dopamine mechanism. The results indicated that kappa subtype is chiefly involved in the contraction of porcine coronary artery. The conclusion agrees with our autoradiography study of opioid receptor in porcine coronary artery.

Chlorpromazine attenuated electroacupuncture analgesia in conscious rabbits

By measuring the defense behavior in response to the noxious stimulation induced by potassium iontophoresis on ear-lobe skin of conscious rabbit, chlorpromazine (CPZ) (0.5 mg.kg-1, i.v.) induced hyperalgesia, whereas it significantly attenuated electroacupuncture analgesia (EAA) efficacy. Monoamines and their metabolites in cerebrospinal fluid (CSF) were measured by high pressure liquid chromatography with electrochemical detector (HPLC-ECD) while the attenuation effect of CPZ on EAA was observed. CPZ markedly enhanced 3,4-dihydroxyphenylacetic acid (DOPAC) (P < 0.05) and homovanillic acid (HVA) (P < 0.01) contents in CSF both in the presence and absence of electroacupuncture. CPZ attenuated EAA with elevations of either DOPAC or HVA concentrations in CSF. There was a positive correlation between the increase of DOPAC or HVA content in CSF and the attenuation effect of CPZ on EAA (P < 0.05). These results suggested that the activation of dopamine system was unfavorable for EAA.

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 phencyclidine on contraction of porcine coronary vessel strips

Classic muscular contraction experiment was used to study the effect of phencyclidine (Phe) on spiral strips of porcine coronary vessels. It showed that Phe and its analogs: 1-[1-(2-thienyl)cyclohexyl] piperidine (TCP), (+)-5-methyl-10, 11-dihydro-5H-dibenzo [a,d] cyclohepten-5, 10-imine maleatel (dizocilpine maleate) and sigma receptor ligand N-allyl-N-normetazocine (SKF10047) all exhibited a concentration-dependent contraction of porcine coronary vessel strips. Phe had no effect on the electrically stimulated contraction of the spiral strips. Dextromethorphan (Dex), a Phe receptor antagonist, and haloperidol (Hal), a sigma receptor antagonist, partially antagonized and suppressed the actions of Phe in a non-competitive manner. These results suggested that Phe, TCP, dizocilpine maleate, and (+), (-)-SKF10047 cause contraction through Phe and sigma opioid receptors.

Prolonged disease-free survival after ablative chemoradiotherapy and autologous bone marrow transplantation in adult malignant lymphoma

From June 1983 to December 1991, 21 adult patients with intermediate or high-grade malignant lymphoma (ML) were treated by ablative chemoradiotherapy, including vincristine, cytosine arabinoside, BCNU and cyclophosphamide plus total lymphoid or body irradiation with boost irradiation over bulky and original tumor areas (Hd-VCCA+TL(B) I) together with autologous bone marrow transplantation (ABMT). Five patients were in advanced stage, 2 in drug-resistant relapse, 6 in drug sensitive relapse, 6 in first complete remission (CR1) and 2 in CR2. One with marrow involvement at ABMT. The 8-year disease-free survival after ABMT in patients with Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL) in 89% and 63%, respectively, with a median follow-up up to 34 months. This study demonstrated that our Hd-VCCA+TL(B) I regimen and ABMT performed early in CR or drug-sensitive relapse of adult poor prognosis lymphoma, may potentially cure more than 70% of them. The toxicity of the present treatment is tolerable. The results confirm the value of ABMT in the treatment of adult ML, and suggest that it is necessary to purge the residual tumor cells in the bone marrow at ABMT in patients with marrow infiltration, or lymphoblastic lymphoma.

Electroacupuncture reversed the inhibition of intestinal peristalsis induced by intrathecal injection of morphine in rabbits

Morphine elicits a series of adverse effects including the inhibition of intestinal motility in addition to the therapeutic benefit of alleviating postoperative pain. To ascertain the role of electroacupuncture (EA) in diminishing those detrimental effects on recovery, we imitated the clinical procedures in rabbits. Morphine was given via a preimplanted cannula within spinal subarachnoid space, while the duodenal motility, respiration rate and arterial pressure were simultaneously recorded. It was found that morphine (6 mg/rabbit, IT) markedly suppressed duodenal peristalsis, decreased respiration rate throughout 90 min observation. When EA was administered together with morphine, peristalsis of the duodenum was much less inhibited (P < 0.05, vs morphine alone group), but no significant improvement of respiratory depression was noticed (P > 0.05), nor obvious change of arterial pressure in both groups. The results strongly recommend extensive application of EA in postoperative care, so as to decrease both the required dosage of morphine and the subsequent occurrence of postoperative ileus, while attaining sufficient analgesia.

[Effect of D1 and D2 dopamine receptor antagonists on acupuncture analgesia]

Some highly selective D1 or D2 receptor antagonists were tested on rabbit skin pain model to investigate the effect of the subtypes of dopamine receptor on acupuncture analgesia. It was found that iv. of D2 receptor antagonists haloperidol and clozapine, had a potentiating effect on acupuncture analgesia. Icv. of D2 receptor antagonists domperidone and sulpiride and D1 receptor antagonist SCH23390 also enhanced acupuncture analgesia markedly. The effect of D1 and D2 receptor on acupuncture analgesia was discussed.

[Phencyclidine receptors in porcine coronary artery]

By using radioligand assay, there was a phencyclidine (Phe) binding site in porcine coronary artery. This binding was specific, reversible, saturable, and stereoselective. The Scatchard analysis showed that the binding site was a single class, with dissociation constant (Kd) and maximum binding (Bmax) of 27.7 +/- 6.9 nmol.L-1 and 0.82 +/- 0.15 pmol/mg protein, respectively. The displacement experiments revealed that the [3H]Phe binding was displaced by nonradioactive Phe, TCP (Phe receptor agonists), and dextrophan (its antagonist). d-INN, a ligand of sigma receptor, had a weaker activity of displacement. These showed a dose-dependent manner. Both etorphine, an agonist of opioid receptor, and N-methyl-D-aspartic acid (NMDA), an excitatory amino acid, failed to displace the binding. These results suggest that the Phe receptors exist in the porcine coronary artery.

[Determination of interleukin 2 activity in patients with pulmonary tuberculosis]

The activity of Interleukin-2 (IL-2) in 34 patients with pulmonary TB and 25 normal adults were determined by means of the bioassay. The results showed that the activity of IL-2 determined by immediate stimulating method (Ohs IL-2) and delayed stimulating method (24hs IL-2) are markedly increased in the mild cases than that of controls; In the advanced cases and the controls, no significant difference was found between the activities of ohs IL-2, but the activity of 24hs IL-2 is markedly reduced in the former group. All these showed that the activity of IL-2 is depended on the serious degree of illness and the clinical type, it can also reflect the condition of immune function in the patients with pulmonary TB.

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.

Phorbol esters induce oscillatory contractions of intestinal smooth muscles

The actions of tumor-promoting phorbol esters in smooth muscle excitation-contraction coupling were studied in isolated guinea pig ileum in the presence of various contractile agents. Muscarinic agonists, histamine and bradykinin elicited an initial transient phasic contraction and a subsequent sustained tonic contraction in guinea pig ileum. The Ca2+ channel antagonist nifedipine selectively inhibited the tonic contraction. Phorbol esters, protein kinase C activators, induced immediate muscle relaxation followed by oscillatory contractions when added during the tonic phase of contraction. Phorbol esters, when added in advance, slightly altered the ligand-induced phasic contraction but converted tonic contractions into oscillatory spikes. The amplitude, frequency and shape of the oscillation induced by phorbol esters were dependent upon the dose of phorbol ester: amplitude was increased and frequency was decreased by increasing the doses of phorbol ester. In contrast, the phorbol ester potentiated the tonic contraction induced by high potassium chloride with little effect on the phasic component. It also sensitized the muscles to Bay K 8644. Bay K 8644, which was ineffective in stimulating muscle contraction at 1 nM, became a very effective stimulator in the presence of the phorbol ester. All of these phorbol ester-induced potentiations and oscillations were sensitive to inhibition by staurosporine or nifedipine. These data suggest that in guinea pig ileum, protein kinase C plays a positive regulatory role in Ca2+ channel activation and promotes a complex regulatory effect on Ca(2+)-mobilizing ligand-stimulated Ca2+ channel activity, which results in oscillatory contractile responses to carbachol, methacholine, histamine and bradykinin.

Effect of tiapride on electroacupuncture analgesia

Tiapride icv 400 micrograms/rabbit exhibited analgesic and synergistic effects on electroacupuncture analgesia (EAA) in rabbits. Both electroacupuncture (EA) and tiapride (icv 400 micrograms/rabbit) enhanced the beta-endorphin-like immunoreactive substance (beta-EPIS) level in cerebrospinal fluid (CSF) measured by radioimmunoassay (RIA). When EA and tiapride were used in combination, a further increase of beta-EPIS content was found. The results suggested that promotion of beta-EPIS release by tiapride may be one of the mechanisms of synergistic effect of tiapride on EAA.

Effects of phencyclidine on contractile forces of isolated rabbit papillary muscles

Phencyclidine (PCP) (0.01-50 mumol.L-1) and its analogue, TCP (0.01-50 mumol.L-1) exhibited positive inotropic effects on electrically stimulated rabbit papillary muscle preparations. Dextrorphan (5 or 10 mumol.L-1) antagonized the actions of PCP in non-competitive manner (pD'2 = 5.25). This demonstrated the involvement of PCP receptors in the positive inotropic effects of PCP. By using high performance liquid chromatography with electrochemical detector (HPLC-ECD), an increase of DOPAC content was found in bath medium after PCP addition. Each of the dopamine receptor antagonists SCH23390, haloperidol and sulpiride (1 mumol.L-1) attenuated the maximal inotropic effects of PCP. These results suggest that PCP induces positive inotropic effects by increasing the release and/or blocking the uptake of dopamine.

The attenuation effect of chlorpromazine on electro-acupuncture analgesia: involvement of dopamine system

The effect of chlorpromazine (CPZ) (0.1 or 0.5 mg/kg, iv) on electroacupuncture analgesia (EAA) was examined by using potassium dolorimetry in rabbits. CPZ itself induced hyperanalgesia, whereas it attenuated EAA in terms of maximal increase of pain threshold as well as EAA after effect. Therefore, CPZ is not a good candidate for enhancing EAA in clinics. Monoamines and their metabolites in cerebrospinal fluid (CSF) of the rabbits were detected by high pressure liquid chromatography coupled to electrochemical detector (HPLC-ECD) method. It was revealed that CPZ enhanced DOPAC and HVA contents in CSF in both the presence and absence of electroacupuncture. CPZ attenuated EAA with elevations of DOPAC and HVA concentration in CSF. There was a positive correlation between the increases of DOPAC and HVA contents in CSF and attenuation effect of CPZ on EAA. These results suggested that activation of dopamine system be unfavorable for EAA.

[Relationship between spinal PCP receptor on cardiovascular effect and noradrenergic system]

By using receptor blockade, HPLC, destroying catecholaminergic nerve terminals by 6-OHDA, autoradiography, and other techniques, the relationship between effects of the spinal PCP receptor on cardiovascular function and noradrenergic system was studied. The main results were as following. Hypotension and bradycardia induced by ith PCP were significantly antagonized by prazosin and yohimbine; the MHPG levels in spinal CSF were significantly increased during the ith PCP induced hypotension and bradycardia; pretreatment with 6-OHDA to destroy NA terminals in the spinal cord significantly decreased the ith PCP induced hypotension and bradycardia, and the density of PCP receptors in the spinal cord. The results suggest that there are PCP receptors on the NA terminals in the spinal cord, which promoted the release of NA and/or inhibited the reuptake of NA. This may be a possible mechanism underlying the influence of spinal PCP receptors on cardiovascular function.

[Cardiovascular effect mediated by phencyclidine receptor in central nervous system]

In recent years, more and more attention has been paid to the studies about the cardiovascular function of phencyclidine (PCP) receptor, but very little about the cardiovascular function of central PCP receptor. In this study, we observed the effects of PCP on the blood pressure (BP) and heart rate (HR) by injecting the agonist or antagonist of PCP receptor into cerebral ventricle (icv) or spinal subarachnoid space (ith), to find out the cardiovascular function of central PCP receptor. It was found that icv PCP (250 nmol) elicited a slow and long lasting hypotension or fast and long lasting bradycardia. ith PCP elicited sharp hypotension and bradycardia immediately, with dose-dependent response. The hypotension and bradycardia of ith PCP (150 nmol) were significantly antagonized by ith 15 nmol dextrorphan. TCP, an agonist of PCP receptor, also elicited sharp hypotension and bradycardia immediately. However, subcutaneous injection (sc) of PCP (10 mg/kg) elicited hypertension and had no effect on HR. The results mentioned above indicate that central PCP receptors have the inhibitory effect on cardiovascular system. The cardiovascular effect of sc PCP may be the effect of combination of central and peripheral PCP receptors.

[Existence of phencyclidine receptor in guinea pig atria]

[3H]-PCP was used in receptor binding studies on membrane preparation from guinea pig atria. It was found that this binding was specific, saturable, reversible and stereoselective. Scatchard plots revealed that guinea pig atria had two different affinity binding sites. The high affinity constant (Kd1) and low affinity constant (Kd2) were 12.15 +/- 0.414 nmol/l and 561.23 +/- 121.36 nmol/l, respectively; the maximum bindings (Bmax) were 0.71 +/- 0.029 pmol/mg protein (Bmax1) and 1.047 +/- 0.099 pmol/mg protein (Bmax2), respectively. The displacement analysis revealed that the [3H]-PCP binding was inhibited by the ligands of both PCP and sigma receptors, while the inhibition of PCP ligands was larger than of sigma ligands. Etorphine, an agonist of opioid receptors, failed to inhibit the binding of [3H]-PCP. The results mentioned above show the existence of a specific PCP receptor in guinea pig atria. The autoradiographic analysis of guinea pig right atria was shown that there was autoradiographic localization of [3H]-PCP on atria of guinea pig with homogeneous distribution, suggesting that the distribution of PCP receptor in atria was homogeneous relatively.

Effect of combination of drugs with acupuncture on analgesic efficacy

In rabbit experiments, some drugs used in clinics were selected and combined with electroacupuncture to observe the effect of drugs on acupuncture analgesia (AA). According to the effect of drugs on AA, the drugs were divided into three kinds: (1) Drugs with potentiating effect: fentanyl, pethidine, droperidol, perphenazine, metoclopramide, fenfluramine, tetrahydrocannabinol, fentanyl plus droperidol, fentanyl plus fenfluramine. (2) Drugs with reducing effect: ketamine and diazepam, (3) Drugs with no effect: sulpiride.

The analgesic and respiratory depressant actions of metorphamide in mice and rabbits

Metorphamide (MET) elicited a potent, dose-dependent analgesia and respiratory depression in mice and rabbits. MET induced-analgesia was naloxone reversible and potentiated by bestatin. Naloxonazine, a relatively selective mu 1 blocker, at certain dosage (50 micrograms per rabbit, icv), could abolish the analgesia but not the respiratory inhibition produced by MET. Our result indicates that mu 1 receptors mediate the MET induced-analgesia but not its respiratory effect. Since MET is a mu- and kappa-ligand with very low delta activity, the MET induced respiratory depression may be mediated by mu 2 or kappa binding sites.