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Murine models are fundamental in the study of clinical conditions and the development of new drugs and treatments. Transgenic technology has started to offer advantages in oncology, encompassing all research fields related to the study of painful syndromes. Knockout mice or mice overexpressing genes encoding for proteins linked to pain development and maintenance can be produced and pain models can be applied to transgenic mice to model the most disabling neurological conditions. Due to the association of movement disorders with sensitivity and pain processing, our group focused for the first time on the role of the torsinA gene GAG deletion—responsible for DYT1 dystonia—in baseline sensitivity and neuropathic responses. The aim of the present report are to review the complex network that exists between the chaperonine-like protein torsinA and the baseline sensitivity pattern—which are fundamental in neuropathic pain—and to point at its possible role in neurodegenerative diseases.

Background: Alzheimer’s Disease (AD) accounts for approximately 50% of all cases of dementia and, in spite of the great effort for the development of disease-modifying drugs, a definitive treatment of cognitive impairment is not available yet. A perfect adherence to the current therapy of cognitive decline is needed for a better control of the disease and this is proven to reduce, though not completely abolish, the associated Behavioural and Psychological Symptoms of Dementia (BPSDs) from occurring. This cluster of symptoms, remarkably affecting patients’ health-related quality of life (HRQL), is tightly associated with pain states. Antipsychotics are the only treatment for BPSDs. However, these drugs are more effective and safer in the short-term (6-12 weeks), they are able to manage aggression but not agitation and they cannot control pain. Aromatherapy with Melissa officinalis and Lavandula officinalis has been employed to handle BPSDs, but it has not provided strong evidence to offer relief from pain. Objective: Bergamot Essential Oil (BEO) exerts antinociceptive activity through several pharmacological mechanisms: in particular, it is able to enhance autophagy, a process undergoing derangement in chronic pain. Thus, the sound pharmacological basis for clinical translation of aromatherapy with BEO in the treatment of BPSDs has been pointed out. Conclusion: The antinociceptive effects elicited by BEO in experimental pain models make it a possible candidate for the pharmacological management of pain-related BPSDs.

The demand for natural products is steadily increasing, and pharmacotechnological engineering is needed to allow rigorous investigation of their efficacy and safety in clinical conditions representing still unmet needs. Among aged patients affected by dementia, up to 80% of residents in nursing homes suffer from chronic pain and 97% from fluctuant neuropsychiatric symptoms (NPS), of which the most challenging is agitation. It is, at least in part, due to undertreated pain and treated with antipsychotics almost doubling the risk of death. In the frame of a scoping review assessing the existence of essential oils undergoing engineering pharmacotechnological processes using solid lipid nanoparticle delivery systems for clinical translation in pain and/or neuropsychiatric symptoms of dementia following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR), here we identified that the sole essential oil engineered to overcome the criticisms of aromatherapy clinical trials in pain and dementia is the essential oil of bergamot (BEO). Therefore, we present the process leading to the actually ongoing randomized, double-blind, placebo-controlled NCT04321889 clinical trial to assess the efficacy and safety of intervention with bergamot in the management of agitation and pain in severe dementia to be followed also for the proof of concept of efficacy and safety of other essential oils.

Background: DYT1 dystonia is the most common form of early-onset inherited dystonia, which is caused by mutation of torsin A (TA) belonging to the “ATPases associated with a variety of cellular activities” (AAA + ATPase). Dystonia is often accompanied by pain, and neuropathic pain can be associated to peripherally induced movement disorder and dystonia. However, no evidence exists on the effect of gabapentin in mice subjected to neuropathic pain model overexpressing human normal or mutated TA. Methods: Mice subjected to L5 spinal nerve ligation (SNL) develop mechanical allodynia and upregulation of the α2δ-1 L-type calcium channel subunit, forming a validated experimental model of neuropathic pain. Under these experimental conditions, TA is expressed in dorsal horn neurons and astrocytes and colocalizes with α2δ-1. Similar to this subunit, TA is overexpressed in dorsal horn 7 days after SNL. This model has been used to investigate (1) basal mechanical sensitivity; (2) neuropathic pain phases; and (3) the effect of gabapentin, an α2δ-1 ligand used against neuropathic pain, in non-transgenic (NT) C57BL/6 mice and in mice overexpressing human wild-type (hWT) or mutant (hMT) TA. Results: In comparison to non-transgenic mice, the threshold for mechanical sensitivity in hWT or hMT does not differ (Kruskal–Wallis test = 1.478; p = 0.4777, although, in the latter animals, neuropathic pain recovery phase is delayed. Interestingly, gabapentin (100 mg/Kg) reduces allodynia at its peak (occurring between post-operative day 7 and day 10) but not in the phase of recovery. Conclusions: These data lend support to the investigation on the role of TA in the molecular machinery engaged during neuropathic pain.

Background We previously reported that the combination of the dopamine (DA) receptor agonist apomorphine and the 5-hydroxytryptamine (5-HT2) receptor agonist m-chlorophenylpiperazine (m-CPP) in rats potently and selectively facilitates the ejaculatory response through activation of D2-like and 5-HT2C receptors, respectively. Aim The aim of this study was to clarify the target level of the proejaculatory effects induced by combination of these agonists. Methods For in vivo behavioral studies, apomorphine and m-CPP were given intracerebroventricularly and intrathecally alone or in combination with either drug administered systemically. Male rats were acclimated to observational cages bedded in paper towels, and the occurrence of ex copula ejaculation was assessed by evaluating the presence and weight of ejaculatory plugs dropped from the tip of the penis to the paper towels or adhered to the tip of the penis at 30 min after drug administration. For in vitro contraction studies, seminal vesicles isolated from rats were suspended in an organ bath to test contractile responses to drug combinations, and the effects of the combined drugs on the contractile response of noradrenaline were also tested. Main Outcome Measures The presence and weight of ejaculatory plugs produced by drug-induced ejaculation and the contractile responses of the seminal vesicle were evaluated. Results Intrathecal m-CPP (10 μg), but not intracerebroventricular m-CPP, evoked the synergistic effects on ejaculation when used in combination with systemically administered apomorphine (0.1 mg/kg, subcutaneous). Moreover, the synergy between m-CPP and apomorphine was completely abolished by the intrathecal 5-HT2C receptor antagonist SB242084 (10 μg). Intrathecal or intracerebroventricular apomorphine (1–10 μg) evoked proejaculatory effects in combination with systemically administered m-CPP (0.3 mg/kg, intraperitoneal). The selective peripherally acting D2-like receptor agonist carmoxirole did not evoke ejaculation when used in combination with m-CPP. Furthermore, isolated rat seminal vesicles were completely insensitive to the combination of apomorphine and m-CPP. Conclusion These results indicated that the synergistic effects of the drugs on ejaculation were induced at the central level but not at peripheral sites. Our findings also suggested that the 5-HT2C receptor mediated the stimulation of the spinal ejaculatory pattern generator and was synergistically potentiated by the spinal DA receptor and that activation of the supraspinal DA receptor was also involved in mediating these synergistic effects. Yoshizumi M, Yonezawa A, Kimura Y, et al. Central Mechanisms of Apomorphine and m-Chlorophenylpiperazine on Synergistic Action for Ejaculation in Rats. J Sex Med 2021;18:231–239.

The essential oil obtained by the fresh fruit of Citrus bergamia Risso et Poiteau is used worldwide in aromatherapy to reduce pain, facilitate sleep induction, and/or minimize the effects of stress-induced anxiety. Preclinical pharmacological data demonstrate that bergamot essential oil (BEO) modulates specific neurotransmissions and shows an anxiolytic-relaxant effect not superimposable to that of the benzodiazepine diazepam, suggesting that neurotransmissions, other than GABAergic, could be involved. Several studies on essential oils indicate a role for serotonergic (5-HT) neurotransmission in anxiety. Interestingly, among serotonergic receptors, the 5-HT1A subtype seems to play a key role in the control of anxiety. Here, we report that modulation of the 5-HT1A receptor by selective agonist ((&plusmn, )8-OH-DPAT) or antagonist (WAY-100635) may influence some of the anxiolytic-relaxant effects of BEO in Open Field and Elevated Plus Maze tests.

Bergamot essential oil (BEO) has proven wide evidence of pharmacological antinociceptive effectiveness both in nociceptive and in neuropathic pain models. The antinociceptive properties of BEO for inhalation have not been investigated. The purpose of this study is to evaluate the effects of the inhalation of BEO on formalin-induced nociceptive response in mice. Male ddY-strain mice (Japan SLC, Hamamatsu, Japan) of 23–25 g of weight at the time the experiments underwent the formalin test. Twenty μl of formalin (2% in saline) were administered into the plantar surface of the mice hindpaw and the time of licking/biting was observed and recorded at intervals of 5 min. The device for BEO inhalatory delivery consisted in a filter paper disc soaked with known volume of BEO placed on the edge of the cage. Inhalation of BEO exerted antinociceptive activity. In particular, it reduced the formalin-induced licking/biting behaviour in a manner that was dependent on the volume of BEO used in the device for its release and on the time of exposure to the phytocomplex. The results support the use of BEO in aromatherapy for complementary management of chronic pain relief in a stepwise therapeutic programme.

The involvement of spinal release of histamine on nociceptive behaviors induced by spermine was examined in mice. Intrathecal spermine produced dose-dependent nociceptive behaviors, consisting of scratching, biting and licking. The nociceptive behaviors induced by spermine at 0.02 amol and 10 pmol were markedly suppressed by i.t. pretreatment with antiserum against histamine and were abolished in histidine decarboxylase-deficient mice. In histamine H1 receptor-deficient mice, the nociceptive behaviors induced by spermine were completely abolished after treatment with 0.02 amol of spermine and significantly suppressed after treatment with 10 pmol of spermine. The i.t. pretreatment with takykinin NK1 receptor antagonists eliminated the nociceptive behaviors induced by 0.02 amol of spermine, but did not affect the nociceptive behaviors induced by 10 pmol of spermine. On the other hand, the nociceptive behaviors induced by spermine at both 0.02 amol and 10 pmol were suppressed by i.t. pretreatment with antagonists for the NMDA receptor polyamine-binding site. The present results suggest that the nociceptive behaviors induced by i.t. administration of spermine are mediated through the spinal release of histamine and are elicited via activation of NMDA receptors.

Background: glaucoma is a remarkable social issue being the leading cause of irreversible blindness worldwide. It is a progressive neuropathy characterized by the death of the retinal ganglion cells, of which the most important risk factor is represented by the increase of intraocular pressure (IOP). The role of nutraceutical supplementations with anti-oxidant activity has been extensively tested in preclinical models of glaucoma. The clinical efficacy of nutraceuticals in glaucoma is still controversial. Objectives: the aim of this systematic review is to assess the efficacy of nutraceuticals with anti-oxidant activity in glaucoma through the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) rigorous criteria. Data sources: the literature search has been performed on the electronic databases currently recognized of most relevance for medical scientific literature, i.e. PubMed, MEDLINE, The Cochrane Central Register of Controlled Trials (CENTRAL) with access to EMBASE, ClinicalTrials.gov and Scopus. The date of last search is April 8th, 2020. Study eligibility criteria, participants, and interventions: prospective randomized clinical trials assessing the effects of nutraceuticals and anti-oxidants on IOP and/or visual field in patients with glaucoma. The eligible papers must be published in English and available in full text. Study appraisal and synthesis methods: the evaluation of the eligibility of the studies has been carried out independently by two authors. The selection process has followed the PRISMA flow diagram, assessing the quality of the body of evidence and the risk of bias. Results: the search of literature has retrieved 1615 papers and 2 clinical trials with results, among which only 6 are eligible for inclusion in the present systematic review to address the preset participants, interventions, comparisons, outcomes and study design (PICOS) “are the nutraceuticals effective in glaucoma?”. In 5 out of 6 studies the nutraceutical supplementation is effective in providing additional decrease of IOP to current usual therapy, without the occurrence of side effects. However, all the studies present high heterogeneity and some concerns in terms of risk of bias, apart from one trial for which the risk of bias is low. Conclusions: the evidence of effectiveness of nutraceutical formulations is still uncertain and inconclusive. Therefore, large double-blind randomized clinical trials with adequate design, methodology and statistical power are needed to support the use of nutraceuticals in glaucoma.

The most recently identified tachykinin, hemokinin-1, was cloned from mouse bone marrow. While several studies indicated that hemokinin-1 is involved in pain and inflammation, the physiological functions of hemokinin-1 are not fully understood. Our previous research demonstrated that the intrathecal (i.t.) administration of hemokinin-1 (0.00625-1.6 nmol) dose-dependently induced nociceptive behaviors, consisting of scratching, biting and licking in mice, which are very similar with the nociceptive behaviors induced by the i.t. administration of substance P. Low-dose (0.0125 nmol) hemokinin-1-induced nociceptive behavior was inhibited by a specific NK1 receptor antagonist; however, high-dose (0.1 nmol) hemokinin-1-induced nociceptive behavior was not affected. In the present study, we found that the nociceptive behaviors induced by hemokinin-1 (0.1 nmol) were inhibited by the i.t. co-administration of MK-801 or D-APV, which are NMDA receptor antagonists. Moreover, we measured glutamate in the extracellular fluid of the mouse spinal cord using microdialysis. The i.t. administration of hemokinin-1 produced a significant increase in glutamate in the spinal cord, which was significantly reduced by co-administration with NMDA receptor antagonists. These results suggest that hemokinin-1-induced nociceptive behaviors may be mediated by the NMDA receptor in the spinal cord.

Morphine has been widely used for the treatment of acute, chronic, and cancer pain and is considered the strongest analgesic in clinical care. Conversely, morphine-induced analgesia may be accompanied by several side effects. Animal studies have demonstrated that low doses of morphine administered intrathecally can produce reliable analgesia for thermal, mechanical, and chemical nociceptive stimulation. On the other hand, high doses of morphine administered intrathecally may induce spontaneous nociceptive responses such as scratching, biting, and licking in mice as well as agitation and vocalization in rats. In addition, similar nociceptive responses including hyperalgesia, allodynia, and myoclonus have been observed in humans following intrathecal or systemic administration of high-dose morphine. It has been suggested that the spontaneous nociceptive behaviors evoked by high-dose morphine may be mediated by a non-opioid mechanism that is not yet fully understood. This review describes the mechanisms of spontaneous nociceptive behaviors evoked by high-dose morphine focusing on the neurotransmitters/neuromodulators released from primary afferent fibers.

The involvement of the μ-opioid receptor subtypes on the presynaptic or postsynaptic inhibition of spinal pain transmission was characterized in ddY mice using endomorphins. Intrathecal treatment with capsaicin, N-methyl-d-aspartate (NMDA) or substance P elicited characteristic nociceptive behaviors that consisted primarily of vigorous biting and/or licking with some scratching. Intrathecal co-administration of endogenous μ-opioid peptide endomorphin-1 or endomorphin-2 resulted in a potent antinociceptive effect against the nociceptive behaviors induced by capsaicin, NMDA or substance P, which was eliminated by i.t. co-administration of the μ-opioid receptor antagonist D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP). The antinociceptive effect of endomorphin-1 was significantly suppressed by i.t.-co-administration of the μ2-opioid receptor antagonist Tyr-D-Pro-Trp-Phe-NH2 (D-Pro2-endomorphin-1) but not the μ1-opioid receptor antagonist Tyr-D-Pro-Phe-Phe-NH2 (D-Pro2-endomorphin-2) on capsaicin- or NMDA-elicited nociceptive behaviors. In contrast, the antinociceptive effect of endomorphin-2 was significantly suppressed by i.t.-co-administration of D-Pro2-endomorphin-2 but not D-Pro2-endomorphin-1 on capsaicin-, NMDA- or substance P-elicited nociceptive behaviors. Interestingly, regarding substance P-elicited nociceptive behaviors, the antinociceptive effect of endomorphin-1 was significantly suppressed by i.t.-co-administration of another μ2-opioid receptor antagonist, Tyr-D-Pro-Trp-Gly-NH2 (D-Pro2-Tyr-W-MIF-1), but not D-Pro2-endomorphin-1 or D-Pro2-endomorphin-2. The present results suggest that the multiple μ-opioid receptor subtypes are involved in the presynaptic or postsynaptic inhibition of spinal pain transmission.

The antinociceptive effect of morphine in the inflammatory pain state was described in the von Frey filament test using the complete Freund’s adjuvant (CFA)-induced mouse inflammatory pain model. After an i.pl. injection of CFA, mechanical allodynia was observed in the ipsilateral paw. The antinociceptive effect of morphine injected s.c. and i.t. against mechanical allodynia was reduced bilaterally at 1 day and 4 days after the CFA pretreatment. The expression level of mRNA for μ-opioid receptors at 1 day after the CFA pretreatment was reduced bilaterally in the lumbar spinal cord and dorsal root ganglion (DRG). In contrast, the protein level of μ-opioid receptors at 1 day after CFA pretreatment was decreased in the ipsilateral side in the DRG but not the lumbar spinal cord. Single or repeated i.t. pretreatment with the protein kinase Cα (PKCα) inhibitor Ro-32-0432 completely restored the reduced morphine antinociception in the contralateral paw but only partially restored it in the ipsilateral paw in the inflammatory pain state. In conclusion, reduced morphine antinociception against mechanical allodynia in the inflammatory pain state is mainly mediated via a decrease in μ-opioid receptors in the ipsilateral side and via the desensitization of μ-opioid receptors in the contralateral side by PKCα-induced phosphorylation. Keywords:: antinociception, morphine, inflammatory pain, μ-opioid receptor, protein kinase C

The physiological role of the distinct splice variants for cloned mouse μ-opioid receptor (mMOR-1), mMOR-1J, mMOR-1K and mMOR-1L, which are sensitive to N(α)-amidino-Tyr-D-Arg-Phe-β-Ala (amidino-TAPA) and insensitive to [D-Ala(2),N-MePhe(4),Gly-ol(5)]enkephalin (DAMGO), was described in the mouse spinal cord. The antinociception induced by intrathecally (i.t.) injected amidino-TAPA was attenuated by i.t. pretreatment with antisera against the endogenous opioid peptides dynorphin A, dynorphin B, α-neo-endorphin, or [Leu(5)]enkephalin in naïve mice. However, in mice whose spinal mMOR-1J had been knocked-down using the antisense oligodeoxynucleotide (ODN) for exon-12 of mMOR-1 gene, the inhibiting effect of antiserum against dynorphin A on amidino-TAPA-induced antinociception was eliminated. In contrast, the inhibiting effect of antisera against dynorphin B or α-neo-endorphin on amidino-TAPA-induced antinociception was eliminated in mice whose spinal mMOR-1K had been knocked-down using the antisense ODN for exon-13 of mMOR-1 gene. Moreover, the inhibiting effect of antisera against dynorphin A or [Leu(5)]enkephalin on amidino-TAPA-induced antinociception was eliminated in mice whose spinal mMOR-1L had been knocked-down using the antisense ODN for exon-14 of mMOR-1 gene. The present results suggest that the distinct antinociceptive profile of amidino-TAPA, that is the release of endogenous κ- and δ-opioid peptides in spinal cord, is mediated through the activation of mMOR-1J, mMOR-1K or mMOR-1L, which contain the sequence encoded by exon-12, exon-13 or exon-14 of mMOR-1 gene, respectively.

The involvement of spinal glial cells in the nociceptive behaviors induced by 1600 pmol of histamine was determined in mice. Histamine injected intrathecally (i.t.) produced nociceptive behaviors, consisting of scratching, biting and licking. The nociceptive behaviors induced by histamine were significantly suppressed by i.t. pretreatment with the glial cell inhibitor DL-fluorocitric acid or minocycline. In Western blot analysis using lumber spinal cords, i.t. treatment with histamine increased the phosphorylation of the NR1 subunit of N-methyl-D-aspartate (NMDA) receptors. The increased phosphorylation of the NR1 subunit of NMDA receptors by histamine was abolished by i.t. pretreatment with DL-fluorocitric acid or minocycline. We have previously reported that the nociceptive behaviors induced by 1600 pmol of histamine were significantly suppressed by the i.t. co-administration of (5R,10 S)-(+)-5-methyl-10,11-dihydro-5 H-dibenzo[a,d]cycloheptene-5,10-imine (MK-801), an ion channel blocker of NMDA receptors, or agmatine, an antagonist for the polyamine recognition site on the NR1 subunit of NMDA receptors. In the present study, the increased phosphorylation of the NR1 subunit of NMDA receptors by histamine was also abolished by i.t. co-administration of agmatine or MK-801. The present results suggest that histamine at 1600 pmol elicits nociceptive behaviors by stimulating the polyamine recognition site on the NR1 subunit of NMDA receptors on spinal glial cells.

It has been suggested that dopamine (DA) and serotonin (5-HT) and their receptors, particularly D(2)-like and 5-HT(2C) receptors, may play a significant role in the control of male sexual function. The purpose of this study was to investigate whether the combination of a dopamine receptor agonist apomorphine and a 5-HT(2) receptor agonist m-CPP would potentiate penile erection and ejaculation in male rats. Systemic administration of either apomorphine (0.01-0.1 mg/kg, s.c.) or m-CPP (0.01-0.3 mg/kg, i.p.) dose-dependently elicited penile erections, but did not induce ejaculation. When combined, there was a drastic increase in both the incidence of ejaculation and the amount of ejaculated seminal materials, while the proerectile effect induced by each drug was not potentiated. The proejaculatory effect induced by the combination of apomorphine (0.1 mg/kg, s.c.) and m-CPP (0.3 mg/kg, i.p.) was completely blocked by pretreatment with the D(2)-like receptor antagonists haloperidol and sulpiride, but not by the D(1)-like receptor antagonist SCH-23390. The synergistic action for ejaculation was also blocked by domperidone, the D(2)-like receptor antagonist that dose not cross the blood-brain barrier. The rats pretreated with the 5-HT(2C) receptor antagonist SB242084 did not show the synergistic action by the combination of apomorphine and m-CPP, whereas the rats pretreated with the 5-HT(2A) receptor antagonist ketanserin and the 5-HT(2B) receptor antagonist SB204741 showed the combination-induced synergistic action. These results suggest that the combination of a small dose of apomorphine and m-CPP potently and selectively facilitates the ejaculatory response through the activation of D(2)-like and 5-HT(2C) receptors, respectively. The D(2)-like receptors involved in the synergistic action may be, at least in part, located in the peripheral sites.

Objectives: To investigate the effects of insulin replacement on ejaculatory dysfunction in streptozotocin (STZ)-induced diabetic rats. Methods: Rats were divided into three groups: (i) STZ-treated group; (ii) STZ-treated + insulin replacement (5 and 2 international units [IU]) group; and (iii) control group. The ejaculatory function in rats was evaluated using the spontaneous seminal emission (SSE) test. The amount of seminal vesicle fluid (SVF) stored in seminal vesicle was measured after the SSE test. Blood glucose was measured using a simplified blood glucose meter. Results: In the SSE test, the ejaculatory capacity in STZ-induced diabetic rats deteriorated with time after the onset of diabetes, and the incidence of SSE and the amount of ejaculated seminal material (SM) were significantly decreased from 5 weeks after STZ administration. Likewise, the amount of SVF was also significantly decreased in a time-dependent manner. One week after STZ administration when ejaculatory capacity had not yet diminished, insulin replacement (for 4 weeks) completely prevented the decrease in frequency of SSE, the amount of SM and SVF. However, insulin replacement after the dysfunction had occurred (5 or 15 weeks after STZ administration) did not allow all parameters for ejaculatory function to be restored to the levels of the control group. Conclusion: This study demonstrates that at an early stage following the onset of diabetes, insulin replacement can prevent ejaculatory dysfunction in STZ-induced diabetic rats, but once the dysfunction occurs, treatment with insulin alone does not restore the ejaculatory capacity to normal levels. In addition, this study suggests that the loss of seminal emission that results from a decrease in SVF may be involved in the mechanism of ejaculatory dysfunction in diabetic rats.

FAP患者の看護について、筆者はこれまでに人口肛門造設術や遺伝子診断について報告してきた。田口らは異常感覚の強い患者の苦痛緩和に向けた援助を事例報告し、海外では、Jonsenらが肝臓移植後のQOLについて報告している。しかし、FAP患者の看護について体系的に整理したものは、国内外をみても報告されていない。そこで、FAP患者の看護を体系化するための基礎的研究として、本研究では肝臓移植を受けておらず、症状が進行している4名の患者の看護記録を分析し、行われた看護内容を明らかにした。, The purpose of this study is to identify some points to take into consideration when nursing patients with advanced Familial Amyloidotic Ployneuropathy (ATTR Val30Met) who have not had a liver transplantation. We analyzed the nursing records of four cooperating patients during their stay in the hospital. In regard to their clinical symptoms, all 4 patients showed clear symptoms of a dysautonomia and a peripheral neuropathy and other general bodily symptoms. Three of them were admitted to the hospital in order to have a pacemaker inserted. One of those three patients had a marked kidney disorder as well and was having dialysis. The other patient was staying in the hospital in order to receive treatment for malnutrition, orthostatic hypotension and diarrhea. Examination of the records identified the necessity for the nursing staff to provide assistance in all aspects of everyday activities including exercises, rest, food intake, excretion and hygiene as well as assistance in their medical treatment. However, it is also important for the staff to anticipate, and cope with, such symptoms as peripheral neuropathy and dysautonomia and other general bodily symptoms that may appear as the patients' conditions progress.

Previous research has demonstrated that a high dose of histamine (1600 pmol) injected i.t. in mice can evoke nociceptive behaviors consisting of biting/licking along with occasional scratching. The present study was undertaken to examine the involvement of spinal N-methyl-d-aspartate (NMDA) and histamine H(1) and H(2) receptors in the nociceptive behaviors evoked by high-dose histamine. Co-administration of the histamine H(1) receptor antagonists, d-chlorpheniramine and pyrilamine, or the histamine H(2) receptor antagonists, ranitidine and zolantidine, failed to suppress the histamine-evoked nociceptive behaviors. Moreover, following histamine administration, nociceptive behaviors in histamine H(1) receptor-knockout and histamine H(2) receptor-knockout mice were indistinguishable from those in wild-type mice, suggesting that histamine-induced nociceptive behaviors are not mediated through histamine H(1) and H(2) receptors in the spinal cord. The histamine-induced nociceptive behaviors were inhibited by co-administration of the competitive NMDA receptor antagonists, d-(-)-2-amino-5-phosphonovaleric acid (D-APV) and 3-((+)-2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPPA), and the ion channel blocker, (5R,10S)-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cycloheptene-5,10-imine maleate (MK-801). Co-administration of ifenprodil, an antagonist for both the polyamine site and the NR2B subunit of NMDA receptors, also inhibited the histamine-induced nociceptive behaviors. (R-[R, S])-alpha-(4-hydroxyphenyl)-beta-methyl-4-(phenylmethyl)-1-piperidinepropanol hydrochloride (Ro25-6981), an antagonist of the NMDA receptor subtype containing the NR2B subunit, did not inhibit histamine-induced nociceptive behaviors, whereas these behaviors were attenuated by pretreatment with an antisense oligodeoxynucleotide against the mRNA for the NR1 subunit of the NMDA receptor. Moreover, agmatine and arcaine, antagonists for a polyamine site on the NMDA receptor, inhibited nociceptive behaviors induced by histamine. These results suggest that a polyamine site on spinal NMDA receptors is involved in eliciting the nociceptive behavioral episode following intrathecal injection of histamine.

Previous research has shown that injection of high-dose of morphine into the spinal lumbar intrathecal (i.t.) space of rats elicits an excitatory behavioral syndrome indicative of severe vocalization and agitation. Substance P N-terminal fragments are known to inhibit nociceptive responses when injected i.t. into animals. In this study, we investigated the effect of i.t. substance P (1-7) on both the nociceptive response and the extracellular concentrations of glutamate and nitric oxide (NO) metabolites (nitrite/nitrate) evoked by high-dose i.t. morphine (500 nmol). The induced behavioral responses were attenuated dose-dependently by i.t. pretreatment with the substance P N-terminal fragment substance P (1-7) (100-400 pmol). The inhibitory effect of substance P (1-7) was reversed significantly by pretreatment with [d-Pro2, d-Phe7]substance P (1-7) (20 and 40 nmol), a d-isomer and antagonist of substance P (1-7). In vivo microdialysis analysis showed a significant elevation of extracellular glutamate and NO metabolites in the spinal cord after i.t. injection of high-dose morphine (500 nmol). Pretreatment with substance P (1-7) (400 pmol) produced a significant reduction on the elevated concentrations of glutamate and NO metabolites evoked by i.t. morphine. The reduced levels of glutamate and NO metabolites were significantly reversed by the substance P (1-7) antagonist (40 nmol). The present results suggest that i.t. substance P (1-7) may attenuate the excitatory behavior (vocalization and agitation) of high-dose i.t. morphine by inhibiting the presynaptic release of glutamate, and reducing NO production in the dorsal spinal cord.

The antagonism by Tyr-D-Pro-Trp-Gly-NH2 (D-Pro2-Tyr-W-MIF-1), a Tyr-Pro-Trp-Gly-NH2 (Tyr-W-MIF-1) analog, of the antinociception induced by the mu-opioid receptor agonists Tyr-W-MIF-1, [D-Ala2,NMePhe4,Gly(ol)5]-enkephalin (DAMGO), Tyr-Pro-Trp-Phe-NH2 (endomorphin-1), and Tyr-Pro-Phe-Phe-NH2 (endomorphin-2) was studied with the mouse tail-flick test. D-Pro2-Tyr-W-MIF-1 (0.5-3 nmol) given intracerebroventricularly (i.c.v.) had no effect on the thermal nociceptive threshold. High doses of D-Pro2-Tyr-W-MIF-1 (4-16 nmol) administered i.c.v. produced antinociception with a low intrinsic activity of about 30% of the maximal possible effect. D-Pro2-Tyr-W-MIF-1 (0.25-2 nmol) co-administered i.c.v. showed a dose-dependent attenuation of the antinociception induced by Tyr-W-MIF-1 or DAMGO without affecting endomorphin-2-induced antinociception. A 0.5 nmol dose of D-Pro2-Tyr-W-MIF-1 significantly attenuated Tyr-W-MIF-1-induced antinociception but not DAMGO- or endomorphin-1-induced antinociception. The highest dose (2 nmol) of D-Pro2-Tyr-W-MIF-1 almost completely attenuated Tyr-W-MIF-1-induced antinociception. However, that dose of D-Pro2-Tyr-W-MIF-1 significantly but not completely attenuated endomorphin-1 or DAMGO-induced antinociception, whereas the antinociception induced by endomorphin-2 was still not affected by D-Pro2-Tyr-W-MIF-1. Pretreatment i.c.v. with various doses of naloxonazine, a mu1-opioid receptor antagonist, attenuated the antinociception induced by Tyr-W-MIF-1, endomorphin-1, endomorphin-2, or DAMGO. Judging from the ID50 values for naloxonazine against the antinociception induced by the mu-opioid receptor agonists, the antinociceptive effect of Tyr-W-MIF-1 is extremely less sensitive to naloxonazine than that of endomorphin-1 or DAMGO. In contrast, endomorphin-2-induced antinociception is extremely sensitive to naloxonazine. The present results clearly suggest that D-Pro2-Tyr-W-MIF-1 is a selective antagonist for the mu2-opioid receptor in the mouse brain. D-Pro2-Tyr-W-MIF-1 may also discriminate between Tyr-W-MIF-1-induced antinociception and the antinociception induced by endomorphin-1 or DAMGO, which both show a preference for the mu2-opioid receptor in the brain.

We investigated the dynamics of cardiovascular system in order to search for the characteristic of vascular pain model using power spectrum analysis. The animals were anesthetized with urethane (1.3g/kg, i.p.) and arterial cannula was inserted into a bifurcation of femoral artery. The recording of heartbeats was carried out by chest bipolar lead. Systolic blood pressure went through a transducer from femoral artery and measured it invasively. In the power spectrum density (PSD) of R-R intervals, it was almost the same as that of un-stimulating state at very low frequency (VLF

The antinociceptive mechanisms of the selective mu-opioid receptor agonists [D-Ala2,NMePhe4,Gly(ol)5]enkephalin (DAMGO), H-Tyr-D-Arg-Phe-beta-Ala-OH (TAPA) or H-Tyr-D-Arg-Phe-beta-Ala-NH2 (TAPA-NH2) against substance P (SP)- or capsaicin-elicited nociceptive behaviors was investigated in mice. DAMGO, TAPA or TAPA-NH2 given intrathecally inhibited the nociceptive behaviors elicited by intrathecally administered SP or capsaicin, and these antinociceptive effects were completely eliminated by intrathecal co-administration with D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP), a selective mu-opioid receptor antagonist. Pretreatment subcutaneously with naloxonazine, a selective mu1-opioid receptor antagonist, partially attenuated the antinociceptive effect of TAPA-NH2, but not DAMGO and TAPA, against SP. However, the antinociception induced by TAPA, but not DAMGO and TAPA-NH2, against capsaicin was significantly inhibited by naloxonazine. On the other hand, co-administration intrathecally with Tyr-D-Pro-Trp-Gly-NH2 (D-Pro2-Tyr-W-MIF-1), a selective mu2-opioid receptor antagonist, significantly attenuated the antinociceptive effects of DAMGO, but not TAPA and TAPA-NH2, against capsaicin, while the antinociceptions induced by three opioid peptides against SP were significantly inhibited by D-Pro2-Tyr-W-MIF-1. These results suggest that differential inhibitory mechanisms on pre- and postsynaptic sites in the spinal cord contribute to the antinociceptive effects of the three mu-opioid peptides.

The involvement of endogenous opioid peptides and opioid receptors in supraspinal site on the antinociception induced by cold water swimming was determined using the mouse tail-flick test. The mice forced to swim in cold water for 3 min, showed the marked antinociception. The antinociception induced by cold water swimming was significantly attenuated by intracerebroventricularly (i.c.v.) pretreatment with antiserum against β-endorphin, but not against dynorphin A or [Leu^5] enkephalin. On the other hand, the antinociception was not affected by i.c.v. pretreatment with μ-opioid receptor antagonists β-funaltrexamine and D-Phe-cyclo-(Cys-Tyr-D-Trp-Orn-Thr-Pen)-Thr-NH_2, δ-opioid receptor antagonists naltrindole, 7-benzylidene naltrexone and naltriben, or κ-opioid receptor antagonist nor-binaltorphimine. The present results suggest that the antinociception induced by cold water swimming may be mainly mediated through the release of β-endorphin in the supraspinal site, which act on β-endorphin-sensitive non-μ-, non-δ-, and non-κ-opioid receptor, so called putative ε-opioid receptor.

The antagonistic properties of Tyr-d-Pro-Trp-Gly-NH(2) (d-Pro(2)-Tyr-W-MIF-1), a Tyr-Pro-Trp-Gly-NH(2)(Tyr-W-MIF-1) analog, on the antinociception induced by the mu-opioid receptor agonists Tyr-W-MIF-1, [d-Ala(2),N-Me-Phe(4),Gly(5)-ol]-enkephalin (DAMGO), Tyr-Pro-Trp-Phe-NH(2) (endomorphin-1), and Tyr-Pro-Phe-Phe-NH(2) (endomorphin-2) were studied in the mouse paw-withdrawal test. d-Pro(2)-Tyr-W-MIF-1 injected intrathecally (i.t.) had no apparent effect on the thermal nociceptive threshold. d-Pro(2)-Tyr-W-MIF-1 (0.1-0.4 nmol) coadministered i.t. showed a dose-dependent attenuation of the antinociception induced by Tyr-W-MIF-1 without affecting endomorphin- or DAMGO-induced antinociception. However, higher doses of d-Pro(2)-Tyr-W-MIF-1 (0.8-1.2 nmol) significantly attenuated endomorphin-1- or DAMGO-induced antinociception, whereas the antinociception induced by endomorphin-2 was still not affected by d-Pro(2)-Tyr-W-MIF-1. Pretreatment i.t. with various doses of naloxonazine, a mu(1)-opioid receptor antagonist, attenuated the antinociception induced by Tyr-W-MIF-1, endomorphin-1, endomorphin-2, or DAMGO. Judging from the ID(50) values for naloxonazine against the antinociception induced by the mu-opioid receptor agonists, the antinociceptive effect of Tyr-W-MIF-1 is extremely less sensitive to naloxonazine than those of endomorphin-1 or DAMGO. In contrast, endomorphin-2-induced antinociception is extremely sensitive to naloxonazine. The present results clearly suggest that d-Pro(2)-Tyr-W-MIF-1 is the selective antagonist to be identified for the mu(2)-opioid receptor in the mouse spinal cord. d-Pro(2)-Tyr-W-MIF-1 may also discriminate between Tyr-W-MIF-1-induced antinociception and the antinociception induced by endomorphin-1 or DAMGO, all of which show a preference for the mu(2)-opioid receptor in the spinal cord.

We previously reported that systemic administration of yohimbine, an alpha2-adrenoceptor antagonist, exerts a biphasic effect (stimulating and suppressing) on ejaculation in dogs, when this function is analyzed using the amount of ejaculated semen in response to genital stimulation. To clarify the effect of alpha2-adrenoceptor blockade on male sexual function, we investigated the effects of four selective alpha2-adrenoceptor antagonists, rauwolscine, idazoxan, RX821002 and mydaglizole, on sexual responses (ejaculation, penile erection and pelvic thrusting behavior) elicited by manual penile stimulation in dogs. Rauwolscine (intraperitoneal, 30 min before the testing) caused a biphasic effect on ejaculation; the amount of ejaculated semen produced by the stimulation was significantly increased by the lower doses (0.1 and 0.3 mg/kg), whereas it was decreased by the higher doses (1.0 and 2.0 mg/kg). The higher doses of rauwolscine also markedly inhibited both penile erection and pelvic thrusting behavior. Idazoxan and RX821002, at doses of 0.1 and 0.3 mg/kg, caused a significant increase in the amount of ejaculated semen without affecting other sexual functions. RX821002 (2.0 mg/kg), but not idazoxan (2.0 mg/kg), moderately inhibited both penile erection and pelvic thrusting behavior. Mydaglizole, a peripherally acting alpha2-adrenoceptor antagonist, did not affect the sexual responses at any doses (0.1-4.0 mg/kg). In the ejaculatory declining test, all alpha2-adrenoceptor antagonists (0.1 mg/kg), except for mydaglizole, completely prevented the decrease in ejaculatory capacity produced by antecedent ejaculation. These results indicate that, though the range of the effective dose is narrow, the alpha2-adrenoceptor antagonists that can block the central alpha2-adrenoceptors have the stimulatory effects on ejaculatory function. The difference of the sexual effects may be based on the action except for the alpha2-adrenoceptor blockade.