N-(1-arylpropionyl)-4-aryltetrahydropyridines, a new class of high-affinity selective sigma receptor ligands

A series of N-(1-arylpropionyl)-4-aryl-1,2,3,6-tetrahydropyridines, prepared by simple Mannich condensations, have been found by radioligand binding assays to have moderate to high affinity (IC50 0.5-500 nM) for bovine cerebellar sigma receptor/binding sites and no measurable affinity (IC50 > 5000 nM) for bovine striatal D2 receptors. The most active of these compounds rival in potency the most active sigma ligands previously reported. Three of these sigma-active compounds were screened for pharmacological activity under the NIMH-NovaScreen program and showed moderate affinity only for D2 and 5-HT2 receptors among the 40 sites assayed. Since these N-(1-arylpropionyl)-4-aryltetrahydropyridines are structurally related to other potent sigma receptor ligands, in particular haloperidol and 4-phenylpiperidines, these data provide insights into the nature of the essential pharmacophore of the sigma receptor. The selective affinity of these materials for sigma receptors indicates they have potential as prototypes of novel psychotherapeutic medicinal agents, particularly as antipsychotic drugs which would be devoid of debilitating side effects associated with blockade of D2 receptors.

Tumor necrosis factor inhibits stimulated but not basal release of nitric oxide

Tumor necrosis factor alpha (TNF alpha) increases nitric oxide (NO) synthase in vascular endothelium, but it inhibits endothelium-dependent relaxation (EDR) of vascular smooth muscle. We tested whether TNF alpha inhibits the response to, or release of, NO in bovine pulmonary artery (BPA) using the technique of perfusion-superfusion bioassay and ozone chemiluminescence. Effluent from the perfused BPA with endothelium (donor)-relaxed endothelium-rubbed bovine coronary artery (BCA) (detector). Moreover, effluent from the donor stimulated with acetylcholine (ACh) or bradykinin (BK) (0.001 to 100 nmol) relaxed the detector. Direct application of these agonists to the detector failed to produce relaxation. Basal and agonist-stimulated effluent from the donor treated with L-NG-monomethylarginine (LNMMA) (100 microM) suppressed effluent-mediated relaxation of the detector. ACh and BK released LNMMA-inhibitable nitrite and nitrate from the BPA. Thus, the effluent contained NO. Exposure of the donor to TNF alpha (1.25 micrograms/ml) for 60 min did not affect basal release of NO, but it attenuated bioassayable and chemiluminescence-detectable NO release by ACh and BK. The inhibition of NO release was directly related to the magnitude of inhibition of EDR by ACh and BK. Thus, TNF alpha selectively inhibits receptor-mediated release of NO without affecting basal release of NO. This effect differs from that of L-arginine-based inhibitors of NO and represents a unique physiologic mechanism of regulation of NO in the endothelium.

Tumor necrosis factor-alpha inhibits endothelium-dependent relaxation

Tumor necrosis factor-alpha (TNF-alpha) stimulates nitric oxide (NO) in vascular endothelium by induction of the enzyme NO synthase II (NOS II). We examined the effects of TNF-alpha on 1) endothelium-dependent (EDR) and endothelium-independent (EIR) relaxation and 2) contraction of bovine intralobar pulmonary arteries (BPA) and veins (BPV) in vitro. Acetylcholine (ACh), bradykinin (BK), histamine, and A23187 produced EDR of BPA contracted with a 50% effective concentration of U-46619 (15 nM), because relaxation was abolished by endothelium-rubbing and attenuated by L-NG-mono-methylarginine (L-NMMA; 300 microM). TNF-alpha (0.00417, 0.0417, 0.417, and 1.25 micrograms/ml) incubated with BPA for 60 min inhibited EDR of the BPA to ACh, BK, and histamine. The effects of TNF required 30 min for onset. Recovery of EDR occurred 3-4 h after washout of TNF-alpha. Pentoxifylline (1 microM) did not affect ACh-induced EDR but selectively reversed TNF-alpha-mediated inhibition of ACh-induced EDR. TNF-alpha-mediated inhibition of EDR was not reversible by L-NMMA, an inhibitor of NOS I and NOS II, the cyclooxygenase inhibitor ibuprofen, or CV-3908 (1 microM), a platelet-activating factor antagonist. The inhibitory effect of TNF-alpha on EDR was not mediated by nonspecific sensitization of the endothelium to human protein because recombinant human granulocyte colony-stimulating factor (10, 50, and 500 x 10(3) U/ml) did not affect EDR of BPA. The effect of TNF-alpha was specific for release of NO from the endothelium of BPA because TNF-alpha did not affect 1) EDR of BPV to ACh, BK, or ATP; 2) EIR of BPA or BPV to nitroprusside; and 3) contraction of either BPA or BPV to KCl, U-46619, histamine, norepinephrine, or serotonin. Thus TNF-alpha appears to selectively inhibit receptor-mediated EDR and NO release in BPA. TNF-alpha-mediated inhibition of EDR differs from that of L-arginine-based inhibitors and may represent an endogenous physiological mechanism of regulation of NO in the endothelium.

Biphasic effects of typical antidepressants and mianserin, an atypical antidepressant, on aggressive behavior in socially isolated mice

Effects of several typical antidepressants and of an atypical antidepressant, mianserin, on the aggressive behavior (AGB) in long-term isolated mice were examined. IP administration of maprotiline (2.5 and 5 mg/kg), amitriptyline (5 and 10 mg/kg), clomipramine (2.5 and 5 mg/kg), and mianserin (5 mg/kg) significantly increased the duration of AGB. However, at higher doses (maprotiline, 10 mg/kg; amitriptyline, 20 mg/kg; clomipramine, 10 and 20 mg/kg; mianserin, 10 and 20 mg/kg) these antidepressants either did not affect AGB or inhibited it. Amitriptyline (20 mg/kg) and mianserin (10 mg/kg) but not maprotiline (10 mg/kg) or clomipramine (20 mg/kg) decreased spontaneous motor activity in isolated mice. Yohimbine (0.5 mg/kg, IP), an alpha 2-antagonist, changed the antidepressant-induced enhancement of AGB into inhibition without affecting the basal aggressive responses. Prazosin (0.3 mg/kg, IP), an alpha 1-antagonist, did not affect either maprotiline- or clomipramine-induced enhancement of AGB, but it changed the mianserin-induced enhancement of AGB into inhibition. These results indicate that antidepressants that inhibit noradrenaline uptake and/or stimulate noradrenaline output from nerve terminals have biphasic effects on AGB in isolated mice and that the antidepressant-induced enhancement of AGB is mediated by noradrenergic stimulation of alpha 2-adrenoceptors, whereas the antidepressant-induced inhibition of AGB may be mediated by non-alpha 2-adrenoceptors or by nonadrenergic system(s).

New plasmid vector and host system for genetic engineering in Bacillus sphaericus

A new plasmid, pNQ116, was constructed in Bacillus sphaericus by cloning a promoter fragment from B. sphaericus Ts-1 into pNQ112. The plasmid (CmrKmr, 5.23 kb) contains a restriction endonuclease polylinker used for cloning foreign genes, and its cat-86 gene is expressed at high levels from the Ts-1 promoter. This plasmid vector has been transformed into B. sphaericus AS 1.270, AS 1.465, AS 1.469, and 2362, at frequencies of 10(2)-10(3) transformants per microgram of DNA, and is maintained stably under nonselective conditions in these host strains. The presence of pNQ116 in B. sphaericus 2362 does ot interfere with the mosquito larvicidal activity of the organism.

Corroboration of sexual histories among male homosexual couples

Using data from a study of human immunodeficiency virus transmission among homosexual male partners from Boston, Massachusetts, the authors compared self-reported sexual histories among 155 index-partner pairs during 1985-1988. Overall, high levels of agreement were observed for all reported sexual activities. Agreement on anal sex was very high (Spearman's r = 0.78-0.79, p less than or equal to 0.001; kappa = 0.76-0.88, p less than or equal to 0.001). Level of agreement did vary significantly by a couple's drug and alcohol use; the heavier substance user generally reported fewer sexual encounters than the lighter user. These results have important implications in sexual behavior research and show that among homosexual men, self-reports of sexual behavior may be reasonably valid.

[The effect of lowered pressure on the diastolic ventricular function after antihypertensive treatment]

Thirty hypertensive patients with increased left ventricular (LV) mass and impaired diastolic function received routinely 2 or 3 kinds of captopril, nifedipine and atenolol for a mean period of 98 days. The LV mass index (LVMI) decreased by an average of 21 g/M2, but no significant correlation between blood pressure reduction and decrease in LVMI was found. So there may be some direct effect of these antihypertensive agents on the myocardium in addition to the benefit from blood pressure reduction. Marked reduction in PVA, Ai, A/E and Ai/T-VTi (P less than 0.01) along with elevation in ratio of E/A, Ei/Ai and Ei/T-VTi (P less than 0.01) were also observed by Doppler transmitral filling studies. These results indicated that the impaired LV diastolic function in patients with hypertension can be much improved following reduction of blood pressure and LV mass.

Molecular characterization of Saccharomyces cerevisiae URA6 gene. DNA sequence, mutagenesis analysis, and cell cycle regulation relevant to its suppression mechanism to cdc8 mutation

Yeast SOC8 DNA fragment was isolated as a wild type dominant suppressor of cdc8 mutation. We have used Bal31 deletion analysis to define the minimal 1 kilobase HpaI-NcoI DNA element required for complementing the cdc8 mutation. The complementing sequence harbored a multicopy plasmid also enhanced by uridine monophosphate kinase in crude extracts. DNA sequence analysis revealed an open reading frame encoding a protein with a molecular weight of 24,949. Since our SOC8 sequence was identical to that of URA6 gene, which encodes uridine monophosphate kinase, we conclude that SOC8 is allelic with URA6, and we use the term URA6 hereafter. Northern blotting experiments showed that the size of mRNA is about 0.9 kibobases. Primer extension experiments showed multiple transcriptional starting sites primarily located at -160 The size and the deduced amino acid composition are consistent with information obtained from purified uridine monophosphate kinase. Thus, both molecular genetic and biochemical evidence supports a notion that the URA6 is SOC8 encoding a yeast uridine monophosphate kinase. Mutagenesis analysis of its putative nucleotide-binding site, altering essential lysine to glutamic acid, resulted in loss of its uridine monophosphate kinase activity. Complementation analysis studies indicated that the mutated ura6 gene abolished its ability to complement ura6 mutant cells; nor could it suppress cdc8 mutation. Unlike CDC8, the mRNA level of the URA6 gene did not fluctuate throughout the cell cycle; presumably, the temporal order of these two enzymatic activities might be different during cell cycle progression. These data may explain an incomplete suppression of cdc8 by URA6, as previously observed. Taken together, the results support our previous speculation that the suppression of the cdc8 mutation mechanisms by URA6 is due to the provision of the trans-acting dTMP kinase activity to complement the cdc8 defect.

Apparent enhancement by SCH 23390 of apomorphine-induced locomotor activity in mice

Effects of the dopamine (DA) D1 antagonist SCH 23390 and the DA D2 antagonist (-)-sulpiride on apomorphine-induced characteristic changes in spontaneous motor activity were investigated in mice using the system we have devised for automatically analyzing animal behaviors in mice. Apomorphine (3 mg/kg, SC) markedly increased parameters of spontaneous motor activity such as locomotor activity and rearing time. Apomorphine-induced increase in locomotor activity had peaks at 5-20 and 30-50 min after administration, and its trough was closely related to the marked increase in rearing time induced by this agonist. Apomorphine-induced locomotor activity accumulated over a 40-min period from 5 to 45 min after apomorphine injection, during which apomorphine-induced increase in rearing time peaked, was significantly increased by intraperitoneal administration of 0.03 and 0.1 but not 0.01 mg/kg SCH 23390. Apomorphine-induced increase in rearing time was dose-dependently depressed by this antagonist. In contrast, (-)-sulpiride (10-40 mg/kg, IP) decreased apomorphine-induced increases in rearing time and locomotor activity rather than enhancing the latter parameter. These data suggest that the apparent enhancement by SCH 23390 of apomorphine-induced locomotor activity is mediated through DA D1 receptors and does not always correlate with depression of apomorphine-induced rearing behavior in mice.

Desipramine enhances isolation-induced aggressive behavior in mice

Effects of desipramine on aggressive behavior induced by long-term (6-7 weeks) isolation of mice were examined. Aggressive behavior was measured as duration of biting attack and/or wrestling during a 20-min observation period. Desipramine (5, 10 and 20 mg/kg, IP) and imipramine (10 and 20 mg/kg, IP) dose-dependently increased the duration of aggressive behavior in isolated mice, without inducing aggressive behavior in group-housed animals. Desipramine-induced increase in aggressive behavior was blocked by phentolamine (3 mg/kg, IP) and yohimbine (0.3 mg/kg, IP), but not prazosin (0.5 mg/kg, IP). Clonidine (0.001 mg/kg, IP), an alpha 2 agonist, significantly blocked desipramine-induced enhancement of aggressive behavior in isolated mice without affecting the basal aggression. These data suggest that long-term isolation may induce functional changes in the sensitivity of alpha 2 receptor in the noradrenergic system and that desipramine enhancement of aggressive behavior in isolated mice is modulated by drugs acting onto alpha 2 noradrenergic receptors.

Nucleotide sequence of the Rhodobacter capsulatus fruK gene, which encodes fructose-1-phosphate kinase: evidence for a kinase superfamily including both phosphofructokinases of Escherichia coli

The fruK gene encoding fructose-1-phosphate kinase (FruK), located within the fructose (fru)-catabolic operon of Rhodobacter capsulatus, was sequenced. FruK of R. capsulatus (316 amino acids; molecular weight = 31,232) is the same size as and is homologous to FruK of Escherichia coli, phosphofructokinase B (PfkB) of E. coli, phosphotagatokinase of Staphylococcus aureus, and ribokinase of E. coli. These proteins therefore make up a family of homologous proteins, termed the PfkB family. A phylogenetic tree for this new family was constructed. Sequence comparisons plus chemical inactivation studies suggested the lack of involvement of specific residues in catalysis. Although the Rhodobacter FruK differed markedly from the other enzymes within the PfkB family with respect to amino acid composition, these enzymes exhibited similar predicted secondary structural features. A large internal segment of the Rhodobacter FruK was found to be similar in sequence to the domain bearing the sugar bisphosphate-binding region of the large subunit of ribulose 1,5-bisphosphate carboxylase/oxygenase of plants and bacteria. Proteins of the PfkB family did not exhibit statistically significant sequence identity with PfkA of E. coli. PfkA, however, is homologous to other prokaryotic and eukaryotic ATP- and PPi-dependent Pfks (the PfkA family). These eukaryotic, ATP-dependent enzymes each consist of a homotetramer (mammalian) or a heterooctamer (yeasts), with each subunit containing an internal duplication of the size of the entire PfkA protein of E. coli. In some of these enzymes, additional domains are present. A phylogenetic tree was constructed for the PfkA family and revealed that the bacterial enzymes closely resemble the N-terminal domains of the eukaryotic enzyme subunits whereas the C-terminal domains have diverged more extensively. The PPi-dependent Pfk of potato is only distantly related to the ATP-dependent enzymes. On the basis of their similar functions, sizes, predicted secondary structures, and sequences, we suggest that the PfkA and PfkB families share a common evolutionary origin.

[A study on components and compound prescription of huangqin decoction]

The results obtained from the pharmacological experiments have preliminarily demonstrated that the compound prescription is better than its individual component drug in the range and potency of pharmacological activities. In the prescription Radix Scutellariae plays a principal role in pharmacological effects. Radix Scutellariae and Radix Paeoniae Alba can potentiate each other. Radix Glycyrrhizae and Fructus Jujubae in the compound prescription also exhibit biological activities to some extent. The relieving effect of the prescription for spasm and pain may result from the synergistic interaction between Radix Paeoniae Alba and Radix Glycyrrhiza, and the heat clearing and diarrhea stopping action is due to the biological activity of Radix Scutellariae.

[A new system for the measurement and analysis of motor activity in mice: effect of several central stimulants]

To estimate the spontaneous motor activity in mice, a new system with highly stable sensitivity and good reproducibility was made, and the effects of five central stimulants were investigated. The apparatus consists of a doughnut-shaped cage with detectors for measuring spontaneous motor activity; i.e., the number of movements, vertical activity, total distance, etc., for every five min. Methamphetamine (0.5, 1 and 2 mg/kg, s.c.) produced an increase in the number of movement and markedly increased total distance. Cocaine (20, 50 and 75 mg/kg, s.c.) caused a marked increase in movement and total distance. Mice injected with 50 mg/kg of cocaine showed long-lasting locomotion with few stops throughout the observation period. Caffeine (10, 30 and 100 mg/kg, s.c.) produced a long-lasting and moderate excitation. Morphine (5, 10 and 20 mg/kg, s.c.) caused a marked increase in continuous locomotion dose-dependently. Apomorphine produced a transient increase in rearing and locomotion at a dose of 1 mg/kg, s.c.; and it produced long-lasting rearing and moderate locomotor activity at 3 mg/kg. These results suggest that this apparatus is able to detect characteristic changes in spontaneous motor activity produced by central stimulants and may be useful for analyzing drug-induced motor activity in mice in more detail.

[A preliminary study on the pharmacology of the compound prescription huangqin tang and its component drugs]

Results obtained from the pharmacological experiments demonstrated that the compound prescription Huangqin Tang and its component drugs, roots of Paeonia lactiflora, Scutellaria baicalensis and Glycyrrhiza uralensis, and the fruit of Ziziphus jujuba showed marked anti-inflammatory effect. The compound prescription and its component drugs, except the peony root, possessed significant antispastic effect. Antipyretic effect of Radix Scutellariae, Radix Glycyrrhizae and Huangqin Tang was suggested. Huangqin Tang, Radix Paeoniae alba, and Radix Glycyrrhizae showed marked analgesic effect. In addition, the experiments confirmed that both Huangqin Tang and single Radix Scutellariae have sedative effect.