CB1 cannabinoid receptor-mediated neurite remodeling in mouse neuroblastoma N1E-115 cells

The morphological remodeling of neuronal cells influences neurogenesis and brain functions. We hypothesize that psychoactive and neurotoxic effects of cannabinoids may be mediated, at least in part, by their morphoregulatory activities. In the present study, mouse neuroblastoma N1E-115 cells were used as an in vitro model to investigate cannabinoid-induced neurite remodeling effects and to identify the involvement of cannabinoid receptors in this neurite remodeling process. Using reverse transcription-polymerase chain reaction and immunofluorescence microscopy, the endogenously expressed CB1, but not CB2, cannabinoid receptors were detected in morphologically differentiated N1E-115 cells. Activation of these natively expressed CB1 cannabinoid receptors by cannabinoid agonist HU-210 led to a concentration-dependent inhibition of adenylate cyclase activity. Importantly, HU-210 treatment induced neurite retraction in a concentration-dependent manner. Pretreatment of N1E-115 cells with a CB1 antisense oligodeoxynucleotide (ODN) suppressed HU-210-induced inhibition of forskolin-stimulated cAMP accumulation, indicating that the knocking down of functional CB1 cannabinoid receptor expression was achieved. Antisense ODN pretreatment also abolished HU-210-induced neurite retraction, demonstrating the involvement of CB1 cannabinoid receptors in mediating the neurite remodeling effects of HU-210. In addition, reversing HU-210-induced intracellular cAMP declination by 8-Br-cAMP partially prevented HU-210-induced neurite retraction, indicating the involvement of cAMP-dependent signaling pathways in mediating the neurite remodeling function of CB1 cannabinoid receptors in N1E-115 cells. These data demonstrate that neurite remodeling is a newly discovered function of CB1 cannabinoid receptors. This morphoregulatory function of CB1 cannabinoid receptors might be a new mechanism that mediates the psychoactive and neurotoxic effects of cannabinoids in developing and adult brain.

Functional roles of the tyrosine within the NP(X)(n)Y motif and the cysteines in the C-terminal juxtamembrane region of the CB2 cannabinoid receptor

In G protein-coupled receptors, a NP(X)(n)Y motif in the seventh transmembrane domain and cysteine residues in the C-terminal juxtamembrane region are conserved. In the current study, the roles of Y299 within the NPVIY motif and C313 and C320 in the C-terminal juxtamembrane region of the human CB2 cannabinoid receptor were investigated by site-directed mutagenesis. Replacing Y299 with alanine resulted in a complete loss of ligand binding and a severe impairment of cannabinoid-induced inhibition of forskolin-stimulated cAMP accumulation. The C313A and C320A mutations markedly reduced functional coupling to adenylate cyclase, but had no effect on ligand binding and agonist-induced receptor desensitization.

[Metabolic regulation of phenylethanoid glycosides from Herba cistanches in dogs' gastrointestine]

AIM

To study the metabolic process of phenylethanoid glycosides (PhGs) in the gastrointestine of beagle dogs that were administered intragastrially process, and develop some new methods of biopharmacology on the effective position of traditional Chinese medicine.

METHODS

High-performance liquid chromatography was used to purify constituents from faeces and analyze relative contents of the three main compounds in the gastrointestinal tract at different times and in the faeces of dogs. Every sample was collected, extracted with methanol and analyzed with integration.

RESULTS

Four compounds, based on reference substances, were identified as echinacoside, acteoside, isoacteoside, and 2'-acetylacteoside from extraction of faces of dogs. Quantitative "with HPLC" analysis reveals that variation of ratios of the three main compounds is not distinct when moving in the gastrointestinal tract 7 h, that is quite different from those in faeces, in which the content of echinacoside fell from 48.0% to 16.0%, and acteoside increased from 11.0% to 34.7%.

CONCLUSION

PhGs are mainly metabolized in large intestine. Among them, a portion of echinacoside is transformed into aceteoside.

[A chemiluminescence flow sensor for vitamin B1]

AIM

To determine vitamin B1 in pharmaceutical preparations by chemiluminescence (CL) flow sensor.

METHODS

When 200 microL of Na3PO4 was passed through an anion exchange column, K3Fe(CN)6 was eluted from the resin and then mixed with the vitamin B1 stream containing NaOH to product CL, by the fast oxidation reaction between vitamin B1 and K3Fe(CN)6 in alkaline solution.

RESULTS

The CL emission intensity was correlated with the vitamin B1 concentration in the range 1.0 x 10(-5) to 1.0 x 10(-3) mol.L-1 and the detection limit was 8.0 x 10(-6) mol.L-1 (3 sigma). A complete analysis, including sampling and washing, can be performed within 2 min with a relative standard deviation of less than 4.0%.

CONCLUSION

The vitamin B1 flow sensor was stable for over 200 analyses and has been applied successfully to determination of vitamin B1 in pharmaceutical preparations.

[Separation of echinacoside by reversed-phase preparative high performance liquid chromatography]

Echinacoside, one kind of phenylethanoid glycosides (PhGs), was isolated from the stems of Cistanche tubulosa (Schenk) R. Wight with a series of steps, including solvent extraction, D101 polymer adsorption column separation, Sephadex LH-20 separation, C18 column reversed-phase preparative high performance liquid chromatographic (RP-prep-HPLC) preparation and polyamide thin-layer chromatographic detection. The purity of the product was over 98%. The chemical structure of echinacoside was identified by 1H NMR and 13C NMR. To find out the optimum condition of mobile phase of RP-prep-HPLC, several systems were used in this work. Finally acetonitrile-1% HCOOH water (18:82, V/V) system was found to be the best. On the other hand D101 polymer adsorption column and Sephadex LH-20 were also effective for PhGs separation.

[Studies on chemical constituents of Cistanche tubulosa (Schenk) R. Wight]

OBJECTIVE

To investigate the chemical constituents of Cistanche tubulosa.

METHOD

The chemical constituents were isolated by solvent extraction together with various chromatographic techniques including preparative HPLC. The structures were elucidated on the basis of chemical evidence and spectral data.

RESULTS

Four iridoid glycosides, one lignan glycoside and one monoterpenoid were isolated from the 95% ethanol extract from the stem of C. tubulosa and identified as adoxosidic acid(I), 8-epiloganic acid(II), geniposidic acid (III), mussaenosidic acid(IV), (+)-syringaresinol-O-beta-D-gluco pyranoside(V) and 8-hydroxygeraniol(VI).

CONCLUSION

Compounds I and VI were isolated from the genus of Cistanche for the first time. Compounds III, IV and V were isolated from this plant for the first time.

Long circulating liposomes encapsulating organophosphorus acid anhydrolase in diisopropylfluorophosphate antagonism

These studies are focused on antagonizing organophosphorous (OP) intoxications by a new conceptual approach using recombinant enzymes encapsulated within sterically stabilized liposomes to enhance diisopropylfluorophosphate (DFP) degradation. The OP hydrolyzing enzyme, organophosphorous acid anhydrolase (OPAA), encapsulated within the liposomes, was employed either alone or in combination with pralidoxime (2-PAM) and/or atropine. The recombinant OPAA enzyme, from the ALTEROMONAS: strain JD6, has high substrate specificity toward a wide range of OP compounds, e.g., DFP, soman, and sarin. The rate of DFP hydrolysis by liposomes containing OPAA (SL)* was measured by determining the changes in fluoride-ion concentration using a fluoride ion-selective electrode. This enzyme carrier system serves as a biodegradable protective environment for the OP-metabolizing enzyme (OPAA), resulting in an enhanced antidotal protection against the lethal effects of DFP. Free OPAA alone showed some antidotal protection; however, the protection with 2-PAM and/or atropine was greatly enhanced when combined with (SL)*.

CB1 cannabinoid receptor-mediated cell migration

Recent studies have suggested that cell migratory responses are often mediated by G(i) protein-coupled receptors. Because it is known that CB1 cannabinoid receptors are coupled to pertussis toxin-sensitive G proteins, we proposed that CB1 may mediate cell migration. To test this hypothesis, modified Boyden chamber assays were used to investigate cell migration mediated by CB1 cannabinoid receptors. HU-210, WIN55212-2, and anandamide, three cannabinoid agonists with distinct chemical structures, induced migration of human embryonic kidney 293 cells stably transfected with human CB1 gene, but not 293 cells transfected with an empty expression vector. These migratory responses were concentration-dependent. The EC(50) values for HU-210, WIN55212-2, and anandamide were 0.19 +/- 0.04, 12. 2 +/- 1.4, and 39.9 +/- 3.7 nM, respectively. The maximal migration index for HU-210, WIN55212-2, and anandamide were 8.9 +/- 1.6, 9.5 +/- 1.6, and 8.8 +/- 1.3, respectively. Pretreating cells with 100 ng/ml pertussis toxin eliminated the cannabinoid agonist-induced cell migration. SR141716A, a selective antagonist for CB1, inhibited the cannabinoid agonist-induced migratory responses in a concentration-dependent manner. Checkerboard analysis demonstrated that anandamide-induced cell migrations are due to chemotaxis as well as chemokinesis. Furthermore, anandamide-induced migratory responses were inhibited, in a concentration-dependent manner, by PD098059, an inhibitor of mitogen-activated protein kinase activation, but not by 8-bromoadenosine-3',5'-cyclic monophosphate, a cell-permeable cAMP analog. These data demonstrate that cannabinoid agonists are able to induce chemotaxis and chemokinesis, and that these migratory responses are mediated by G protein-coupled, CB1 cannabinoid receptors. In addition, these data suggest that activation of mitogen-activated protein kinase plays an important role, whereas inhibition of adenylate cyclase is probably not involved in the cell migration mediated by CB1.

Involvement of cannabinoid receptors in the intraocular pressure-lowering effects of WIN55212-2

It is known that marijuana smoking and administration of natural cannabinoids reduce intraocular pressure. However, it has not been established whether the intraocular pressure-lowering effects of cannabinoids are mediated by cannabinoid receptors. Aminoalkylindoles are a new class of cannabimimetics with structures entirely different from those of natural cannabinoids. WIN55212-2, a prototypic aminoalkylindole, has been shown to bind cannabinoid receptors and to exhibit cannabinoid-like activities. The objective of this study was to determine whether aminoalkylindoles lower intraocular pressure and whether the effects of aminoalkylindoles are mediated by ocular cannabinoid receptors. The intraocular pressure of New Zealand White rabbits was measured with the use of applanation pneumatonography. After the measurement of baseline intraocular pressure, drugs were applied topically and the intraocular pressure was monitored. The topical application of WIN55212-2 significantly reduced intraocular pressure in the treated eyes. The intraocular pressure-lowering effects of WIN55212-2 were time and dose dependent, and the maximal reduction was 4.7 +/- 0.5 mm Hg at a dose of 100 microg. In contrast to treated eyes, the intraocular pressure on the contralateral eyes was not significantly affected. The topical application of WIN55212-3, the enantiomer of WIN55212-2, had no effect on intraocular pressure. Furthermore, the intraocular pressure-lowering effects of WIN55212-2 were significantly reduced by topically administered SR141716A, a selective antagonist for the CB1 cannabinoid receptor. The dose-response curve of WIN55212-2 is shifted parallel to the right by SR141716A. These data demonstrate that like natural cannabinoids, WIN55212-2 also reduces intraocular pressure, and the effects of WIN55212-2 are mediated at least in part by the CB1 cannabinoid receptors in the eye.

The difference between the CB(1) and CB(2) cannabinoid receptors at position 5.46 is crucial for the selectivity of WIN55212-2 for CB(2)

It has been reported that WIN55212-2, a prototypic aminoalkylindole, has higher affinity for CB(2) than for CB(1). To explain the selectivity of WIN55212-2 for CB(2), molecular modeling studies were performed to probe the interacting sites between WIN55212-2 and cannabinoid receptors. In TMH5 the position 5.46 is a Phe in CB(2) versus a Val in CB(1). Docking of WIN55212-2 into the models of CB(1) and CB(2) predicts that F5.46 will result in a greater aromatic stacking of CB(2) with WIN55212-2. Using site-directed mutagenesis, this hypothesis was tested by exchanging the amino acids at position 5.46 between CB(1) and CB(2). Two mutations, including a Phe to Val mutation at the position 5.46 in CB(2) (CB2F5. 46V), and a corresponding Val to Phe mutation at the position 5.46 in CB(1) (CB(1)V5.46F), were made. The mutant receptors were transfected into 293 cells, and stable cell lines expressing similar numbers of receptors as wild-type receptors were chosen for additional ligand binding and cAMP accumulation studies. In ligand- binding assays, the CB(2)F5.46V mutation decreased the affinity of WIN55212-2 for CB(2) by 14-fold. In contrast, the CB(1)V5.46F mutation increased the affinity of WIN55212-2 for CB(1) by 12-fold. However, these mutations did not change the affinity of HU-210, CP-55940, and anandamide for CB(1) and CB(2). In cAMP accumulation assays, the changes in EC(50) values of WIN55212-2 were consistent with the changes in its binding affinity caused by the mutations. These results strongly support the hypothesis that the selectivity of WIN55212-2 for CB(2) over CB(1) is attributable to the change from Val in CB(1) at position 5.46 to Phe in CB(2).

Determination of the thermogenesis curves and studies of the thermodynamics and thermokinetics of seed germination

The thermogenesis curves of the germination of different rice and tree seeds were determined and studied by using a newly constructed microcalorimeter. The thermogenesis curves of the germination of the seeds demonstrate the existence of physiological triphasic patterns, which include imbibition, activation and growth stages in the germination process. The thermodynamics and thermokinetics of the main growth phase of the growth stage in the germination process have been studied. The growth heat effect (deltaH), the growth rate constant (k), the growth inhibitory factor (s) and deceleration rate constant (beta) have been determined and calculated, In addition, the experimental thermokinetic equations of the growth stage in the seed germination process have been established.

A lysine residue of the cannabinoid receptor is critical for receptor recognition by several agonists but not WIN55212-2

Lys192 in the third transmembrane domain of the human CB1 cannabinoid receptor was converted to an alanine to study its role in receptor recognition and activation by agonists. HU-210, CP-55940, WIN55212-2, and anandamide, four cannabinoid agonists with distinct chemical structures, were used to characterize the wild-type and the mutant receptors. In human embryonal kidney 293 cells stably expressing the wild-type receptor, specific binding to [3H]WIN55212-2 and inhibition of cAMP accumulation by cannabinoid agonists were demonstrated, with different ligands exhibiting the expected rank orders of potency and stereoselectivity in competition binding and functional assays. In cells expressing the mutant receptor, the binding affinity of the receptor for [3H]WIN55212-2 was only slightly affected (the Kd for the mutant receptor was twice that of the wild-type), and the ability of WIN55212-2 to inhibit cAMP accumulation was unchanged. However, HU-210, CP-55940, and anandamide were unable to compete for [3H]WIN55212-2 binding to the mutant receptor. In addition, the potencies of HU-210, CP-55940, and anandamide in inhibiting cAMP accumulation were reduced by > 100-fold. These results demonstrate that Lys192 is critical for receptor binding by HU-210, CP-55940, and anandamide. Because Lys192 is not important for receptor binding and activation by WIN55212-2, WIN55212-2 must interact with the cannabinoid receptor through at least one point of interaction that is distinct from those of the three other agonists.

Spatioangular-multiplexing scheme for dense holographic storage

A novel multiplexing scheme for dense holographic storage in photorefractive crystals, spatioangular multiplexing, is described in detail. Compared with spatial multiplexing, spatioangular multiplexing increases the storage capacity by fully utilizing the volume of the storage medium. On the other hand, spatioangular multiplexing reduces the number of holograms overlapping any one hologram in a given volume and so increases the diffraction efficiency achievable as compared with angular multiplexing. Using this scheme, we succeeded in storing 756 high-resolution patterns in an Fe:LiNbO(3) crystal of volume 1 cm(3), with an average diffraction efficiency of 0.5%. This large database is designed for practical use in a novel associative-memory system, called a high-order feedback neural network.

Molecular cloning and chromosomal localization of human genes encoding three closely related G protein-coupled receptors

Cosmids containing human genes for three orphan G protein-coupled receptors, GPR12, GPR6, and GPR3, were isolated using their rat homologs as probes. Previous studies of the mouse and rat cDNAs have shown the receptors to be expressed primarily in brain but have failed to identify their ligands. The three receptor proteins of 334, 363, and 330 amino acids, respectively, are encoded by a single exon in each gene. Excluding the divergent sequences preceding the first transmembrane domain, they have approximately 60% amino acid identity with each other. Fluorescence in situ hybridization of GPR12, GPR6, and GPR3 localized these three genes to human chromosomal regions 13q12, 6q21, and 1p34.3-p36.1, respectively.

[Study of treatment on acquired infantile mental retardation with traditional Chinese and Western medicine]

80 cases with acquired infantile mental retardation caused by perinatal brain injury was treated with large doses of hyoscyamus, self made Retarded Recovery Pill and acupuncture. At the same time, 50 cases were taken as control group treated with Nao An Tai, Nao Fu Kang, etc. After 3 month treatment, the Intelligence Quotient (IQ) increased by 15 points in 29 cases of treatment group, while 3 cases in control group, chi 2 = 15.2, P < 0.01. After treatment for 6 month the IQ increased in 41 and 5 cases respectively, t = 5.53, P < 0.01. In 58.75% of the faculty of speech and motion greatly improved. It revealed that to treat the acquired infantile mental retardation, the combined therapy of traditional Chinese and Western medicine is effective.

Molecular cloning of a novel candidate G protein-coupled receptor from rat brain

A PCR cloning strategy using primers designed from sequences selectively conserved among a cannabinoid receptor and two orphan receptors, was used to isolate novel G protein-coupled receptors. rCNL3, a 1.75 kb cDNA encoding a 363 amino acid protein, was isolated from a rat cerebral cortex library. Sequence analysis showed that rCNL3 possesses a number of structural characteristics of G protein-coupled receptors and has 61% amino acid identity (from transmembrane region one through the carboxyl-terminus) with two other candidate G protein-coupled receptors. Therefore, these three receptors may comprise a receptor subfamily with identical or closely related endogenous ligands. Northern and in situ hybridization experiments demonstrated that rCNL3 mRNA is expressed in the rat brain, with a prominent distribution in striatum.

Stimulation by corticotropin-releasing factor of the release of immunoreactive dynorphin A from mouse spinal cords in vitro

Corticotropin-releasing factor (CRF) has been shown to release endogenous opioid peptides from several rat brain regions. Since we have demonstrated previously that the actions produced by intrathecally administered CRF in mice involve spinal kappa opioid receptors, experiments were conducted in this study to test the possibility that CRF may release dynorphin A, a putative endogenous kappa opioid agonist, from the mouse spinal cord. Using a superfusion system in vitro, mouse spinal cords were superfused with aerated (95% O2, 5% CO2) Krebs-Ringer buffer. Fractions of superfusion were collected and dynorphin A levels in each fraction were monitored by radioimmunoassay. The presence of CRF in the perfusion buffer stimulated significantly the release of immunoreactive dynorphin A. The releasing rate of immunoreactive dynorphin A returned to the basal level after withdrawing CRF from the superfusion buffer. The stimulatory effect of CRF on the release of immunoreactive dynorphin A was abolished by alpha-helical CRF-(9-41), a CRF receptor antagonist, indicating that the dynorphin-releasing effect of CRF was mediated by CRF receptors in the spinal cord. Also the dynorphin-releasing effect of CRF was a concentration-related phenomenon, with an estimated EC50 value of 5.3 nM. The results from this study support the hypothesis that intrathecally administered CRF may produce its effects by releasing endogenous dynorphin from the terminals of dynorphin-containing neurons in the spinal cord. This study also provides evidence to support the notion that there is a close communication between CRF- and opioid peptide-containing neuronal pathways in the central nervous system.

Antagonism of morphine antinociception by intrathecally administered corticotropin-releasing factor in mice

Intrathecally (i.t.) administered corticotropin-releasing factor (CRF) has been shown to produce antinociception in the mouse abdominal stretching (writhing) assay. It also has been demonstrated that spinal kappa opioid receptors as well as CRF receptors are involved in the antinociception induced by CRF. In the present study, the role of CRF i.t. in modulating nociception was assessed further using the mouse tail-flick test. In addition, the modulatory effect of i.t. administered CRF on the antinociceptive activity of morphine was studied. Despite its potent and long-lasting antinociceptive effect in the writhing assay, CRF injected i.t. produced no consistent antinociception in the tail-flick test at doses up to 20 times the antinociceptive ED50 of CRF in the writhing test. In contrast, i.t. injection of CRF significantly attenuated the antinociceptive action of s.c. administered morphine. CRF at doses of 0.1 and 0.2 nmol/mouse i.t. increased the antinociceptive ED50 of s.c. morphine by 2- and 4-fold, respectively. The antagonistic action of CRF peaked between 15 min and 1 hr after i.t. injection and was still observable 4 hr after injection, demonstrating a time course similar to that of the antinociceptive effect of CRF in the writhing test. Intrathecal injection of alpha-helical CRF(9-41), a competitive CRF receptor antagonist, was able to inhibit, in a dose-dependent manner, the antagonistic activity of CRF. The antagonistic action of CRF also was attenuated dose-dependently by i.t. injection of nor-binaltorphimine (nor-BNI), a highly selective kappa opioid receptor antagonist. However, intrathecal injection of (+)-1-nor-BNI, an inactive enantiomer of nor-BNI, did not affect the antagonistic action of CRF. These data suggest that spinal kappa opioid receptors as well as CRF receptors are involved in the antagonistic effect of CRF against morphine antinociception.

Involvement of spinal kappa opioid receptors in the antagonistic effect of dynorphins on morphine antinociception

The modulatory effects of intrathecally (i.t.) administered dynorphin A(1-17) and dynorphin A(1-13) on morphine antinociception have been studied previously in rats by other investigators. However, both potentiating and attenuating effects have been reported. In this study, the modulatory effects of i.t. administered dynorphin A(1-17) as well as the smaller fragment, dynorphin A(1-8), were studied in mice. In addition, nor-binaltorphimine (nor-BNI), a highly selective kappa opioid receptor antagonist, and naltrindole (NTI), a highly selective delta opioid receptor antagonist, were used to characterize the possible involvement of spinal kappa and delta opioid receptors in the modulatory effects of the dynorphins. Dynorphin A(1-17) and dynorphin A(1-8) administered i.t. at doses that did not alter tail-flick latencies, were both able to antagonize in a dose-dependent manner, the antinociceptive action of s.c. administered morphine sulfate. The antinociceptive ED50 of morphine sulfate was increased 3.9- and 5.3-fold by 0.4 nmol/mouse of dynorphin A(1-17) and dynorphin A(1-8), respectively. Injections of 0.4 and 0.8 nmol/mouse of nor-BNI i.t., but not its inactive enantiomer (+)-1-nor-BNI, inhibited dose-dependently the antagonistic effects of the dynorphins. These doses of nor-BNI alone did not affect the antinociceptive action of morphine sulfate. Intrathecal administration of 5 nmol/mouse of NTI also did not affect the modulatory effects of dynorphins. These observations that dynorphins exert their antagonistic effects on morphine-induced antinociception stereoselectively through spinal kappa opioid receptors may suggest a coupling between spinal kappa and mu opioid receptors.

Involvement of spinal kappa opioid receptors in the antinociception produced by intrathecally administered corticotropin-releasing factor in mice

Corticotropin-releasing factor (CRF), a putative stress transmitter, in previous studies failed to show any antinociceptive effect after central intracerebroventricular administration. In this study, a possible role of intrathecally (i.t.) administered CRF in modulating nociception and the involvement of opioid receptors were examined. CRF (i.t.) produced a dose-dependent antinociceptive effect in the mouse abdominal stretching (writhing) assay, with an ED50 of 22.1 (18.9-25.8) pmol/mouse. This antinociceptive effect of CRF peaked from 10 min to 1 hr after i.t. administration, although a significant antinociceptive effect was still observable 4 hr after injection. The dose-response curve of CRF antinociception was shifted to the right by i.t. administered alpha-helical CRF (9-41), a CRF antagonist, and the ED50 was raised by 3.7-fold. Naloxone, an opioid antagonist, also dose-dependently shifted the antinociceptive dose-response curve of CRF to the right. Naloxone at 1 and 10 mg/kg s.c. increased the ED50 value of CRF by 2- and 4-fold, respectively. In contrast, s.c. injection of 10 mg/kg of (+)-naltrexone, an inactive enantiomer of naltrexone, did not affect significantly the antinociception of i.t. administered CRF. Intrathecal injection of nor-binaltorphimine, a highly selective kappa opioid antagonist, increased the antinociceptive ED50 of CRF by 5.6-fold. However, the antinociceptive activity of CRF (i.t.) was not significantly affected by either beta-funaltrexamine, an irreversible mu selective opioid antagonist, or naltrindole, a highly selective delta opioid antagonist. Furthermore, the antinociceptive ED50 of CRF was not altered by (+)-1-nor-binaltorphimine, an inactive enantiomer of nor-binaltorphimine.(ABSTRACT TRUNCATED AT 250 WORDS)

Supersensitivity to electrical stimulation for assessing physical dependence on opioids in isolated tissues

The use of the guinea pig ileum (GPI) and mouse vas deferens (MVD) to quantify opiate tolerance and physical dependence in the same preparation was examined. In the GPI, tolerance to and physical dependence on various opiates were induced by direct incubation with an agonist and tolerance and abstinence were assessed after its rapid removal by extensive washing. Dependence, as evidenced by an increase in twitch height and after removal of the agonist as compared to that before incubation, provided an index of the degree of physical dependence. The extent of the supersensitive response after agonist removal was noted to be related directly to the agonist concentration and the degree of tolerance development. Furthermore, the supersensitive response was found to be stereospecific, naloxone reversible and preferentially mu receptor-mediated. Likewise, tolerance to opiates could be demonstrated in the MVD by direct incubation with an agonist. Unlike the GPI, rapid removal of the agonist by washing did not produce a supersensitive response to electrical stimulation. However, a supersensitive response was demonstrable in the presence of naloxone. Thus, after a tolerant/dependent state was induced by incubation of the vas with a predetermined dose of [D-Ala2, D-Leu5]enkephalin that completely abolished the twitch response, the subsequent addition of naloxone resulted in a supersensitive response to electrical stimulation that was concentration-dependent. The maximum twitch response in the presence of naloxone, compared to that obtained before incubation with the agonist, provided an index of the extent of dependence.(ABSTRACT TRUNCATED AT 250 WORDS)

[Determination of thermograms of bacterial growth]

The fundamental growth thermograms of bacteria have been determined by using the microcalorimetric method. These perfect thermogram curves reflect the changes of bacterial growth patterns (including the lag phase of growth, log growth, stationary phase and the decline phase of growth). In our experiments, highly characteristic and reproducible growth patterns are observed under the same condition, therefore one can use these thermograms as "finger print" to discriminate bacteria. On the other hand, there thermogram curves contain ample information, which are very significant for the studies on microorganism metabolism, bio-thermokinetic and clinical fields.