Pre-exposure effects of morphine,diazepam and Δ9-THC on the formation of conditioned taste aversions

Prior to taste aversion conditioning with morphine, diazepam or ⁹-tetrahydrocannabinnol (⁹-THC), rats received pre-exposures to the vehicle or one of the three drugs. Morphine pre-exposures blocked the aversion normally induced by morphine, but not by ⁹-THC or diazepam. Diazepam pre-exposures attenuated both the morphine- and diazepam-induced taste aversions to a significantly greater degree than the taste aversion induced by ⁹-THC. As a result of ⁹-THC pre-exposures, the aversions induced by diazepam and ⁹-THC were attenuated as well as the morphine-induced aversion, which was the most greatly attenuated. These results demonstrate that pre-exposure effects are not necessarily bi-directional and, moreover, they are inconsistent with current hypotheses which attempt to account for the attenuating effect of drug pre-exposures on taste-aversion conditioning.     

Anticonflict and discriminative stimulus effects in the pigeon of a new methoxy-chroman 5-HT1A agonist, (+)S 20244 and its enantiomers (+)S 20499 and (−)S 20500

The present experiments examined the behavioral and receptor binding characteristics of new 5-HT_1A methoxy-chroman derivatives in procedures known to be sensitive to the activity of 5-HT_1A compounds. Key peck responding of pigeons was maintained by a 30-response fixed-ratio schedule of food delivery. In studies involving punished responding, every 30th response during one keylight stimulus also produced shock (conflict procedure). In drug discrimination studies, pigeons were trained to discriminate injections of the 5-HT_1A agonist 8-OH-DPAT (0.3 mg/kg) from saline. Three forms of the methoxy-chroman compounds were tested: the enantiomers (+)S 20499 (0.01–3.0 mg/kg) and (–) S 20500 (0.3–5.6 mg/kg), as well as the racemic mixture (+)S 20244 (0.03–5.6 mg/kg). (+)S 20499 was approximately 10-fold more potent than (–)S 20500 in producing maximal increases in punished responding. (+)S 20244 was comparable in potency to (–)S 20500 in producing maximal increases in punished responding, but increases also occurred at much lower doses with (+)S 20244 and the magnitude of the effect with (–)S 20500 was less than that of the two other compounds. While increases in punished responding were observed with all three drugs at doses that did not affect unpunished responding, the highest doses of all drugs decreased unpunished responding. All compounds substituted for 8-OH-DPAT in the drug discrimination procedure, suggestive of 5-HT_1A agonist activity. (+)S 20499 was approximately 30-fold more potent than (–)S 20500 in substituting for 8-OH-DPAT and 3-fold more potent than the racemate. All three compounds bound with high affinity to pigeon cerebrum receptor sites labelled by [³H]8-OH-DPAT. As in behavioral studies, (+)S 20499 was approximately 10-fold more potent than (–)S 20500 in displacing [³H]8-OH-DPAT (IC₅₀=2.79 versus 20.3 nM). These studies demonstrate that the enantiomers of this compound, as well as the racemic mixture, are effective 5-HT_1A compounds and that (+)S 20499 in particular is likely to be a clinically effective anxiolytic and/or antidepressant.     

Antigenotoxicity properties of Copaifera multijuga oleoresin and its chemical marker,the diterpene (−)-copalic acid

In view of the biological activities and growing therapeutic interest in oleoresin obtained from Copaifera multijuga, this study aimed to determine the genotoxic and antigenotoxic potential of this oleoresin (CMO) and its chemical marker, diterpene (?)-copalic acid (CA). The micronucleus (MN) assay in V79 cell cultures and the Ames test were used for in vitro analyses, as well as MN and comet assays in Swiss mice for in vivo analyses. The in vitro genotoxicity/mutagenicity results showed that either CMO (30, 60, or 120 µg/ml-MN assay; 0.39–3.12 mg/plate-Ames test) or CA (2.42; 4.84, or 9.7 µg/ml-MN assay; 0.39–3.12 mg/plate-Ames test) did not induce a significant effect on the frequency of MN and number of revertants, demonstrating an absence of genotoxic and mutagenic activities, respectively, in vitro. In contrast, these natural products significantly reduced the frequency of MN induced by methyl methanesulfonate (MMS), and exerted a marked inhibitory effect against indirect-acting mutagens in the Ames test. In the in vivo test system, animals treated with CMO (6.25 mg/kg b.w.) exhibited a significant decrease in rate of MN occurrence compared to those treated only with MMS. An antigenotoxic effect of CA was noted in the MN test (1 and 2 mg/kg b.w.) and the comet assay (0.5 mg/kg b.w.). Data suggest that the chemical marker of the genus Copaifera, CA, may partially be responsible for the observed chemopreventive effect attributed to CMO exposure.

Abbreviations: 2-AA, 2-anthramine; 2-AF, 2-aminofluorene; AFB₁, aflatoxin B₁; B[a]P, benzo[a]pyrene; BOD, biological oxygen demand; BPDE, benzo[a]pyrene-7,8-diol-9,10-epoxide; CA, (?)-copalic acid; CMO, oleoresin of Copaifera multijuga, DMEM, Dulbecco`s Modified Eagles`s Medium; DMSO, dimethylsulfoxide; EMBRAPA, Brazilian agricultural research corporation; GC–MS, gas chromatography–mass spectrometry; HAM-F10, nutrient mixture F-10 Ham; HPLC, high performance liquid chromatography; LC–MS, liquid chromatography–mass spectrometry; MI, mutagenic index; MMC, mitomycin C; MMS, methyl methanesulfonate; MN, micronucleus; MNPCE, micronucleated polychromatic erythrocyte; NCE, normochromatic erythrocyte; NDI, nuclear division index; NMR, nuclear magnetic resonance; NPD, 4-nitro-o-phenylenediamine; PBS, phosphate-buffered saline; PCE, polychromatic erythrocyte; SA, sodium azide; V79, Chinese hamster lung fibroblast.     

Transfer of the discriminative stimulus effects of Δ9-THC and nicotine from one operant response to another in rats

Objective  

Transfer of the discriminative stimulus effects of two drugs from one operant (original-response) to a topographically different response (transfer-response) that was spared drug discrimination training was investigated.     

Altered regulation of glutamate release and decreased functional activity and expression of GLT1 and GLAST glutamate transporters in the hippocampus of adolescent rats perinatally exposed to Δ9-THC

The long-term effects of perinatal Δ⁹-tetrahydrocannabinol (Δ⁹-THC) exposure – from gestational day (GD) 15 to postnatal day (PND) 9 – on hippocampal glutamatergic neurotransmission were studied in slices from the 40-day-old offspring of Δ⁹-THC exposed (Δ⁹-THC-rats) and vehicle-exposed (control) dams. Basal and in K+-evoked endogenous hippocampal glutamate outflow were both significantly decreased in Δ⁹-THC-rats. The effect of short Δ⁹-THC exposure (0.1 μM) on K⁺-evoked glutamate release disclosed a loss of the stimulatory effect of Δ⁹-THC on hippocampal glutamate release in Δ⁹-THC-rats, but not in controls. In addition, l-[³H]-glutamate uptake was significantly lower in hippocampal slices from Δ⁹-THC-rats, where a significant decrease in glutamate transporter 1 (GLT1) and glutamate/aspartate transporter (GLAST) protein was also detected. Collectively, these data demonstrate that perinatal exposure to cannabinoids induces long-term impairment in hippocampal glutamatergic neurotransmission that persist into adolescence.     

Comparison of interactions of R(+)- and S(−)-isomers of β-adrenergic partial agonists,befunolol and carteolol,with high affinity site of β-adrenoceptors in the microsomal fractions from guinea-pig ciliary body,right atria and trachea

• 1.1. The stereoselectivities of β-adrenergic partial agonists for the high affinity binding site of β-adrenoceptors in the guinea-pig ciliary body, right atria and trachea were studied.
• 2.2. The inhibition curves by the S(−)-isomers of befunolol and carteolol were not significantly different from that by the R(+)-isomers in the guinea-pig ciliary body.
• 3.3. The inhibition curves by the S(−)-isomers of befunolol and carteolol were about 10 times as potent as the R(+)-isomers in the guinea-pig atria and trachea.
• 4.4. The pK_i values of the S(−)-isomers of befunolol and carteolol were significantly larger than those of R(+)-isomers in the guinea-pig atria and trachea but not larger than those of the R(+)-isomers in the guinea-pig ciliary body.
• 5.5. These results suggest that the high affinity binding site of β-adrenoceptors in ciliary body cannot discriminate stereoselectively between the R(+)- and S(−)-isomers, while in other tissues there is stereoselectivity between the two enantiomers.

     

The sea urchin, Paracentrotus lividus, as a model to investigate the onset of molecules immunologically related to the α-7 subunit of nicotinic receptors during embryonic and larval development

Nicotinic acetylcholine receptors play a major role in the regulation of electrochemical synapses at neuromuscular junctions. During the early stages of Paracentrotus lividus development, the nicotinic receptor-like molecules are found and localized by use of the specific blocker, -bungarotoxin, and by α-7 subunit immunoreactivity. Both the methods identify and localize the nicotinic receptor-like molecules at the sites where active changes in ionic intracellular concentration take place. These are well known to lead either fertilization, sperm propulsion or co-ordinated ciliary movement. After neural differentiation, immunoreactivity for the α-7 subunit is localized mainly in ganglia, ectoderm ciliary bands and in the motile cells forming the gut wall. Both α-bungarotoxin binding sites and α-7 subunits are also localized at the cells linked to the skeletal rods, performing the small movements which drive the swimming direction in the water column. The localization of these molecules paves the way to a speculation on their function and possible role in neurogenesis as well as neurodegeneration.     

Tolerance to the effects of Δ 9-tetrahydrocannabinol in mice on intestinal motility,temperature and locomotor activity

The onset and duration of tolerance to three effects of ⁹-tetrahydrocannabinol ( ⁹-THC) given orally to mice were compared. The effects of ⁹-THC studied were: hypothermia, the depression of intestinal motility and the effect on spontaneous locomotor activity. When mice were dosed and tested at 24 hrs intervals it was apparent that tolerance was complete to its hypothermic and locomotor depressant effects after the first doses and to depression of intestinal motility after the fourth dose. Duration of tolerance also differed so that the normal hypothermic response had returned after 12 dose-free days, but not after 5 drug-free days; the effect on locomotor activity had returned within 4 days; and, apparent partial tolerance to the depressant effect of an acute challenging dose of ⁹-THC on intestinal motility still existed after 19 dose-free days.It is apparent that the time of onset and the duration of tolerance to ⁹-THC in mice showed a different pattern in the three parameters studied. It seems unlikely therefore that any one mechanism, such as metabolic tolerance, explains all the results observed and that several mechanisms should be explored to explain the phenomenon of tolerance to ⁹-THC.     

A multidisciplinary approach combining molecular biology,bio-analytical chemistry,and immunochemistry to probe the role of bioactivation of naphthalene in cytotoxicity

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A comparison of the effects of TMB-8 and nifedipine on pressor responses to α1- and α2-adrenoceptor agonists in pithed rats

TMB-8 has been characterized as an inhibitor of the release of Ca⁺ from intracellular pools. We have studied the modification of the pressor responses to selective _l-adrenoceptor agonists (methoxamine and phenylephrine), and to selective ₂-adrenoceptor agonists (B-HT 920 and B-HT 933) in pithed rats, produced by TMB-8. We have compared this modification with that produced by the calcium antagonist nifedipine. Nifedipine (100 g/kg, 300 g/kg, and 1000 g/kg) inhibited in a dose-dependent manner the pressor responses to the ₁- and ₂-adrenoceptor agonists, the dose-response curves to the ₂-adrenoceptor agonists being shifted further to the right. TMB-8 at a dose of 3000 g/kg did not modify the pressor effects of the _l-adrenoceptor agonists, and neither did it reinforce the inhibition of such responses produced by nifedipine. By contrast, TMB-8 pretreatment (0.03 g/kg, 0.3 g/kg, 3 g/kg, 30 g/kg, 300 g/kg and 3000 g/kg) inhibited the responses to both ₂-adrenoceptor agonists, the inhibition being more pronounced with B-HT 920. A similar effect was obtained with 0.03 g/kg TMB-8 and 0.3 g/kg TMB-8, particularly in the case of B-HT 920. It was stronger with higher doses, but similar for all doses over 3 g/kg. The inhibition of the pressor responses mediated by the stimulation of ₂-adrenoceptors by TMB-8 was less in rats treated with the Ca²⁺ entry promoter BAY K 8644 (300 g/kg), and could also be reduced by the continuous infusion of CaCl₂ (0.25 g/min). These results suggest that in pithed rats TMB-8 may also behave as an inhibitor of the Ca⁺ influx into vascular smooth muscle.     

Pharmaceuticals in the environment – A short review on options to minimize the exposure of humans,animals and ecosystems

Pharmaceuticals are indispensable for human and animal health. After use, the active agents and their metabolites are excreted and enter the environment via different pathways. For decades, pharmaceuticals and metabolites have been found in the environment, e.g. surface water, groundwater, drinking water, sediment, sewage sludge and manure. About half of the 2300 active ingredients used in Germany are considered to be potentially of environmental relevance. Monitoring in the environment is still under way, but an impact on living organisms has already been detected. There is still a lack of knowledge concerning: quantities of pharmaceuticals entering the environment, origin of the pharmaceutical active agents, metabolism and transformation pathways, the effects of the active substances, metabolites and transformation products on aquatic organisms, as well as their persistence or degradability in the environment. Sporadically, traces of drugs are detected in drinking water. The concentrations are usually far below the µg per liter range and below concentration levels, which might have an effect on humans. Long-term effects cannot be excluded, though, and should be investigated. Moreover, antibacterial agents and antibiotic-resistant bacteria enter the environment in different ways. They are widely distributed. There is an urgent need for concepts and priorities in order to eliminate the exposure by pharmaceuticals in the environment. The authors suggest short-, medium- and long-term measures for the reduction of pharmaceuticals in the environment, with a clear prioritization of preventive measures.     

A Review of: “Interpreting and Reporting Clinical Trials: A Guide to the CONSORT Statement and the Principles of Randomised Controlled Trials,by A. Keech,V. Gebski,and R. Pike (eds.)”

Traditionally, Phase II trials have been conducted as single-arm trials to compare the response probabilities between an experimental therapy and a historical control. Historical control data, however, often have a small sample size, are collected from a different patient population, or use a different response assessment method, so that a direct comparison between a historical control and an experimental therapy may be severely biased. Randomized Phase II trials entering patients prospectively to both experimental and control arms have been proposed to avoid any bias in such cases. The small sample sizes for typical Phase II clinical trials imply that the use of exact statistical methods for their design and analysis is appropriate. In this article, we propose two-stage randomized Phase II trials based on Fisher’s exact test, which does not require specification of the response probability of the control arm for testing. Through numerical studies, we observe that the proposed method controls the type I error accurately and maintains a high power. If we specify the response probabilities of the two arms under the alternative hypothesis, we can identify good randomized Phase II trial designs by adopting the Simon’s minimax and optimal design concepts that were developed for single-arm Phase II trials.     

A combined,bioidentical, oral, 17β-estradiol and progesterone capsule for the treatment of moderate to severe vasomotor symptoms due to menopause

ABSTRACT

Introduction: Many women seek treatment to alleviate menopausal vasomotor symptoms (VMS). Numerous women use combination compounded hormone therapy (CHT) to achieve the benefits of estrogen/progesterone for endometrial protection. TX-001HR is a combination of bioidentical 17β-estradiol (E2) and progesterone (P4) in a single capsule designed for continuous daily use to treat moderate to severe VMS.

Areas covered: This drug profile describes the efficacy and safety of 4 doses of this E2/P4 (mg/mg: 1/100, 0.5/100, 0.5/50, 0.25/50) for treating moderate to severe VMS in menopausal woman with a uterus.

Expert opinion: In REPLENISH (NCT01942668), the two highest doses of TX-001HR significantly reduced VMS frequency and severity at 4 and 12 weeks versus placebo (co-primary endpoints); all doses met the primary endpoint of endometrial safety. Rates of amenorrhea were high and improved over time; the Menopause Quality of Life and Medical Outcomes Study-Sleep instruments improved with E2/P4. TX-001HR was well tolerated and had no clinically significant impact on vital signs, metabolic or coagulation parameters, or breast safety. The combination bioidentical E2/P4 capsule (1 mg/100 mg dose was FDA-approved as Bijuva in October 2018) may provide a safe, effective, rigorously studied alternative for women with a uterus who prefer CHT for relief of VMS.     

Ready,willing, and able to provide MTM services?: A survey of community pharmacists in the USA

BackgroundChanges in US Medicare legislation could benefit pharmacy's attempt to make medication therapy management (MTM) practice more commonplace; however, little is known about pharmacists' capabilities and preferences to do so.ObjectivesThe purpose of this study was to explore US pharmacists' perceived preparedness, willingness, and challenges toward providing MTM services.MethodsA brief purpose of the survey and its website link were included in the electronic weekly newsletter of the National Community Pharmacists Association (NCPA) in January 2007. The web-based survey consisted of 8 demographic questions, 8 questions examining preparedness and willingness of the respondents regarding MTM, 2 questions regarding reimbursement to pharmacists, and 2 checklists for challenges in establishing MTM services.ResultsMost of the 143 respondents indicated that they were aware of MTM, and 92 (65%) reported that they were currently practicing MTM. A majority of the sample agreed that pharmacists should provide MTM and have the ability to do so. Major challenges reported by the sample include the different specification of MTM by each health plan, time, staffing, and reimbursement issues. Respondents selected valid measures of program effectiveness but revealed that they needed help with documentation and billing. Expected reimbursement range was $1-10/minute.ConclusionCommunity independent pharmacists reported being ready, willing, and able to provide MTM services, but need assistance in the process, that is, standardized MTM protocols, documentation and billing.     

A method to estimate the potency of the μ-component of an opioid having mixedμ-, andκ- and/orδ-agonist activities

The SC administration of either typical-agonists such as morphine, pethidine, fentanyl and levorphanol or a mixed- and-agonist like [d-Ala²,d-Leu⁵]-enkephalin to 10-day-old rats produced loss of righting reflex. Additionally, the loss of righting reflex induced by these opioid agonists was antagonized by naloxone, an opioid antagonist having a preference for-receptors, but by neither nor-binaltorphimine nor naltrindole, a specific- or-antagonist, respectively, indicating that the loss of righting reflex was produced by the interaction of an opioid with-receptors. Moreover, the potency of each opioid agonist relative to that of morphine estimated by the present in vivo method was similar to that determined by the traditional in vitro isolated preparation. In contrast to-agonists, neither typical-agonists such as U-50, 488H, ketocyclazocine, pentazocine and butorphanol, nor a selective-agonist like [d-Pen²,d-Pen⁵]-enkephalin affected the righting reflex of 10-day-old rats, indicating that-agonists, but neither- nor-agonists, produced the naloxone-reversible loss of righting reflex in infant rats. By employing the present in vivo method to estimate the-agonist activity of an opioid with mixed agonist activities, it was indicated that the-agonist activity of ethylketocyclazocine, which had been employed as a representative-agonist, was essentially the same as that of morphine, a representative-agonist.