[Nirsevimab effectiveness against hospital admission for respiratory syncytial virus bronchiolitis in infants]. / Efectividad de nirsevimab en la prevención de los ingresos por bronquiolitis por virus respiratorio sincitial en lactantes.

OBJECTIVE: Respiratory syncytial virus (RSV) bronchiolitis is the leading cause of hospitalization in infants. This season, a long half-life monoclonal antibody (Nirsevimab) is available to prevent this disease for all infants born from 1 April-30 September to 2023 and all those born during RSV season (October2023- March 2024). The aim of this study was to evaluate the impact of the implementation of this antibody on RSV admissions in a tertiary hospital. METHODS: Observational, retrospective and analytical study. All patients <6 months in October admitted for bronchiolitis at 2 time points were included: T1 or Pre-nirsevimab time: 1 September 2015-30 September 2023 and T2 or Nirsevimab time: 1 October-31 December 2023. Total admissions due to any cause of infants <6 months in the same period were used as the reference population. To assess the impact of the implementation of nirsevimab, we calculated the reduction in the percentage of admissions due to RSV with respect to total admissions in both periods, and also in the 2023-2024 season we calculated the double negative test to calculate the effectiveness of the intervention (1-Odds ratio) x 100. RESULTS: In infants under 6 months of age, we found significant differences in the number of admissions for RSV bronchiolitis between the last season and the previous 7 seasons [574/1195 (48%) vs 6/138 (4.3%); p<0.01, RPI: 91%). In the 2023/2024 season, the effectiveness of nirsevimab in preventing admission for RSV bronchiolitis in children under 6 months of age was 85% (CI 95%: 32-97%). CONCLUSIONS: The implementation of nirsevimab has had an important impact on the number of hospital admissions for RSV bronchiolitis. There were no differences in the severity of bronchiolitis.

Coexisting with dependence and well-being: the results of a pilot study intervention on 75-99-year-old individuals.

BACKGROUND: The objective of this study is to design and implement an intervention program centered on preventing functional dependence. METHODS: A pre/post quasi-experimental (typical case) design study with a control group was conducted on a group of 75-90-year-old individuals with functional dependence (n = 59) at three nursing homes in Madrid (Spain). The intervention program consists of two types of activities developed simultaneously. Some focused on emotional well-being (nine 90-minute sessions, once per week), whereas others focused on improving participants' physical condition (two 30-minute sessions, twice per week). The simple randomized participants included 59 elderly individuals (Intervention Group = 30, Control Group = 29) (mean age 86.80) [SD, 5. 19]. RESULTS: Fifty-nine participants were analyzed. The results indicate that the program is effective in improving mood, lowering anxiety levels (d = 0.81), and increasing both self-esteem (d = 0.65) and the perception of self-efficacy (d = 1.04). There are improvements in systolic pressure and functional dependence levels are maintained. Linear simple regression (independent variable pre-Barthel) shows that the pre-intervention dependence level can predict self-esteem after the intervention. CONCLUSION: We have demonstrated that the program is innovative with regard to bio-psychosocial care in elderly individuals, is based on actual practice, and is effective in increasing both self-esteem and self-efficacy. These variables positively affect functional capabilities and delay functional dependence.

Congenital Harlequin syndrome as an isolated phenomenon: A case report and review of the literature.

UNLABELLED: Harlequin syndrome (HS) is a rare autonomic disorder due to a hemifacial cutaneous sympathetic denervation. It is characterized by unilateral diminished sweating and flushing of the face even though after heat or prolonged exercise. It is typically acquired. Congenital cases only represent a 6% of all individuals with HS. All congenital HS cases reported so far showed a concomitant Horner syndrome, probably due to a stellate ganglion involvement. HS represents an uncommon autonomic disorder due to a hemifacial cutaneous sympathetic denervation. It is clinically characterized by a dramatic alteration in facial appearance: ipsilateral denervated pale and dry half from the other intact red and moist half. CONCLUSION: We present, to the best of our knowledge, the first case of a patient with a congenital HS as an isolated phenomenon.

Effect of salinity on enzymatic activities in a submerged fixed bed biofilm reactor for municipal sewage treatment.

The effect of salinity on the hydrolytic enzymatic activities (acid phosphatase, alkaline phosphatase, glucosidase, protease and esterase) released by the microorganisms in a submerged fixed bed bioreactor for real urban wastewater treatment was investigated. The influence of salt (NaCl) on the enzymatic activities was evaluated in four different experiments with concentrations of NaCl of 0, 3.7, 24.1 and 44.1g/L, remaining constant all other operating parameters of the bioreactor. The results show that enzymatic activities were reduced when the salinity was increased in the influent and consequently the biotransformation of organic matter in the submerged fixed bed bioreactor significantly decreased. A redundancy analysis was performed to evaluate the relationships between enzymatic activities and physic-chemical parameters analyzed in the influent. According to the results obtained with the Monte Carlo permutation test, salinity and sampling day significantly contributed to explain the variation of enzymatic activities, showing a negative correlation.

Comparative analysis of Met-enkephalin, galanin and GABA immunoreactivity in the developing trout preoptic-hypophyseal system.

We studied the organization of Met-enkephalin-containing cells and fibers in the developing preoptic-hypophyseal system of the brown trout (Salmo trutta fario) by immunohistochemistry and determined the relationship of these cells and fibers to the galaninergic and GABAergic systems. Met-enkephalin immunoreactivity was observed in cells in the preoptic area, the hypothalamus and the pituitary of late larvae. In the hypophysis, a few Met-enkephalin-containing cells were present in all divisions of the adenohypophysis, and some immunoreactive fibers were present in the interdigitations of the neural lobe with the proximal pars distalis. Concurrently, GABAergic fibers innervated the anterior and posterior neural lobe. Galanin cells coexisted with Met-enkephalin cells in neuronal groups of the preoptic-hypophyseal system. Galaninergic and GABAergic fibers innervated the preoptic and hypothalamic areas, but GABAergic fibers containing galanin were not observed. These results indicate that Met-enkephalin, galanin and GABA may modulate neuroendocrine activities in the preoptic area, hypothalamus and pituitary during the transition from larval to juvenile period. To better know how the development of the trout preoptic-hypophyseal system takes place, we studied the patterns of cell proliferation and expression of Pax6, a conserved transcription factor involved in the hypophysis development. Pax6 expressing cells and proliferating cells were present in the Rathke's pouch, the hypothalamus and the hypophysis of early larvae. In late larvae, Pax6 expression was no longer observed in these areas, and the density of proliferating cells largely decreased throughout development, although they remained in the hypophysis of late larvae and juveniles, suggesting that Pax6 might play an important role in the early regionalization of the pituitary in the trout.

[Non invasive gene therapy in neurological diseases]. / Terapia genica no invasiva en enfermedades neurologicas.

INTRODUCTION: Brain gene therapy consists of introducing nucleic acids into nerve tissue whose expression may prove to be therapeutically useful. This genetic material is indirectly introduced by means of non invasive gene therapy into the blood thereby avoiding its direct injection into the brain and the damage to the blood brain barrier. AIM: The different non invasive vectors and means of gene transfer to the central nervous system will be discussed. DEVELOPMENT: There has been a remarkable breakthrough in recent years in non invasive gene transfer strategies into the central nervous system. The development of new serotypes of adenoassociated vectors, such as AAV9, and of functionalized nanoparticles, such as pegylated immunoliposomes, polymeric nanoparticles, pegylated nanoparticles, dendrimers, fullerens, as well as specific transporters specific to the low density lipoprotein receptor family, means that it is now possible to introduce and express gene material in nerve tissue following peripherical administration of the above mentioned vectors. CONCLUSIONS: Non invasive gene therapy entails exciting new perspectives for the treatment of the numerous neurological diseases for which there are no effective pharmacological treatments. Studies already performed on animals have proved to be highly promising and it is likely that, in the next few years, they will give rise to non invasive gene therapy procedures which will be useful and safe for treating patients.

Displasia evolutiva de cadera: controversia sobre el cribado ecográfico universal / Developmental hip dysplasia: controversy on universal echographic screening

Pese a la elevada incidencia de displasia de cadera clínicamente importante (3-5 casos por cada 1000 recién nacidos vivos) y a los ampliamente estudiados factores de riesgo principales (parto de presentación podálica, sexo femenino y antecedentes familiares de displasia evolutiva de cadera), no se ha conseguido encontrar una estrategia efectiva que reduzca la incidencia de casos tardíos. Reabrimos, a propósito de un caso, la controversia existente acerca del cribado ecográfico universal en la patología osteomuscular más frecuente de la infancia (AU)

Despite the elevated incidence of clinically relevant hip dysplasia (3-5 per 1000 live births) and the broadly studied main risk factors (breech position, female sex and family cases), we have not achieved an effective prevention strategy, and so the detection of late cases has not decreased. We reopen, following a case, the existent controversy upon universal ultrasound screening on the most frequent musculo-skeletal disorder in the infancy (AU)

What can man do without basal ganglia motor output? The effect of combined unilateral subthalamotomy and pallidotomy in a patient with Parkinson's disease.

We have studied motor performance in a man with Parkinson's disease (PD) in whom thermolytic lesions of the left subthalamic and left globus pallidus nuclei interrupted the basal ganglia (BG)-thalamo-cortical motor circuit in the left hemisphere. This allowed us to study remaining motor capabilities in the absence of aberrant BG activity typical of PD. Movements of the left arm were slow and parkinsonian whereas movement speed and simple reaction times (RT) of the right (operated) arm were within the normal range with no obvious deficits in a range of daily life activities. Two main abnormalities were found with the right hand. (a) Implicit sequence learning in a probabilistic serial reaction time task was absent. (b) In a go/no-go task when the percent of no-go trials increased, the RT superiority with the right hand was lost. These deficits are best explained by a failure of the cortex, deprived of BG input, to facilitate responses in a probabilistic context. Our findings confirm the idea that it is better to stop BG activity than allowing faulty activity to disrupt the motor system but dispute earlier claims that interrupting BG output in PD goes without an apparent deficit. From a practical viewpoint, our observations indicate that the risk of persistent dyskinesias need not be viewed as a contraindication to subthalamotomy in PD patients since they can be eliminated if necessary by a subsequent pallidotomy without producing deficits that impair activities of daily life.

La integración laboral de las personas con trastorno mental grave. Una cuestion pendiente / Work integration of people with severe mental disorder: a pending question

El empleo en la mayoría de las personas genera amplios beneficios psicológicos. Los avances científicos en el descubrimiento de la regeneración y estimulación del cerebro, la nueva visión integradora de la discapacidad y una sociedad que camina hacia el pleno empleo, hacen que se presente en el siglo CCI un escenario de nuevas oportunidades para todos, entre ellas, para las personas con trastorno mental grave. La eliminación de las barreras culturales, muy vinculadas a la discriminación y al estigma, será determinante para hacer realidad el deseo de un amplio número de estas personas. Sabemos que un 30-40 por ciento de estas personas con apoyo se mantienen en el empleo. A la luz de la revisión realizada los profesionales y las familias no deberíamos fijarnos tanto en las características de la persona, sino en la forma en que intentamos apoyarla para conseguir y mantener un empleo. Existe legislación referida a la integración laboral de este colectivo que plantea medidasa promover la misma; sin embargo, el altísimo incumplimiento que se da por nuestra parte hacen que se tornen en ineficaces. Debemos emplear técnicas que hayan demostrado su eficacia de forma científica. Múltiples expertos de distintos países, reconocen la validez de los contextos normalizados como el terreno propio de la integración social en su más amplio sentido (AU)

The origin of motor fluctuations in Parkinson's disease: importance of dopaminergic innervation and basal ganglia circuits.

The severity of dopamine depletion and the consequent pathophysiologic changes that occur in basal ganglia circuits determine the severity of parkinsonian signs. Restoring the dopamine deficit or the downstream physiologic abnormalities improves Parkinson's Disease (PD) main motor features and as a result, attenuates the short-duration response (SDR). Therefore, both the magnitude and duration of the motor response are a function of the degree of motor severity, which is primarily governed by the loss of tonic dopaminergic activity and disruption of basal ganglia homeostatic mechanisms among which the STN-GPe/GPi circuits play a fundamental role. As neurodegeneration advances, standard levodopa administration give rises to wider oscillations in striatal dopamine availability and "pulsatile" stimulation of striatal dopamine receptors becomes predominant. This induces molecular and physiologic changes that further accentuate and aggravate the SDR that sustains motor fluctuations. Treatments capable of providing and restoring more tonic and physiologic dopaminergic stimulation may avoid many of these abnormalities and lead to better clinical outcomes.

Glycosylated phosducin-like protein long regulates opioid receptor function in mouse brain.

Phosducin (Phd), a protein that in retina regulates rhodopsin desensitization by controlling the activity of Gt beta gamma-dependent G-protein-coupled receptor kinases (GRKs), is present in very low levels in the CNS of mammals. However, this tissue contains proteins of related sequence and function. This paper reports the presence of N-glycosylated phosducin-like protein long (PhLP(L)) in all structures of mouse CNS, mainly in synaptic plasma membranes and associated with G beta subunits and 14-3-3 proteins. To analyze the role PhLP(L) in opioid receptor desensitization, its expression was reduced by the use of antisense oligodeoxynucleotides (ODNs). The antinociception induced by morphine, [D-Ala(2), N-MePhe(4),Gly-ol(5)]-enkephalin (DAMGO), beta-endorphin, [D-Ala(2)]deltorphin II, [D-Pen(2,5)]-enkephalin (DPDPE) or clonidine in the tail-flick test was reduced in PhLP(L)-knock-down mice. A single intracerebroventricular (icv)-ED(80) analgesic dose of morphine gave rise to acute tolerance that lasted for 4 days, but which was prevented or reversed by icv-injection of myristoylated (myr(+)) G(i2)alpha subunits. PhLP(L) knock-down brought about a myr(+)-G(i2)alpha subunit-insensitive acute tolerance to morphine that was still present after 8 days. It also diminished the specific binding of (125)I-Tyr(27)-beta-endorphin-(1-31) (human) to mouse periaqueductal gray matter membranes. After being exposed to chronic morphine treatment, post-dependent mice required about 10 days for complete recovery of morphine antinociception. The impairment of PhLP(L) extended this period beyond 17 days. It is concluded that PhLP(L) knock-down facilitates desensitization and uncoupling of opioid receptors.

Motor behavioural changes after intracerebroventricular injection of 6-hydroxydopamine in the rat: an animal model of Parkinson's disease.

At the beginning of the 1970s, different studies reported behavioural disturbances after the intracerebroventricular (icv) administration of 6-hydroxydopamine (6-OHDA) in the rat. Despite the fact that this neurotoxic agent degenerates brain dopaminergic (DA-) cells, its potential utility to produce a rat model of Parkinson's disease (PD) was never systematically studied because the aphagia and adipsia were often observed. In the present study, a procedure that induces a marked DA-cell degeneration that bypasses these and other undesirable complications of icv injection of 6-OHDA is reported. Lesioned animals (50-500 microg of 6-OHDA) showed a persistent motor syndrome composed of hypokinesia, purposeless chewing and catalepsy. The intensity of motor signs was dose-dependent, and recovered partially after administration of DA-receptor agonists, exposure to sensorial stimuli and stress, three procedures that reduce motor dysfunctions in Parkinson's disease (PD). Lesioned animals showed bilateral and symmetrical midbrain DA-cell degeneration with the highest cell-loss in A9 group (substantia nigra), followed by A8 (retrorubral field) and A10 (ventral tegmental area) groups. The similarity between the behavioural syndrome and the topographical profile of cell-loss after icv injection of 6-OHDA in rats and the clinical and neuropathological features of PD indicates that this may be a convenient animal model of PD particularly useful for checking in rats the possible efficacy of new anti-parkinsonian drugs on specific parameters of motor dysfunctions.

RGS9 proteins facilitate acute tolerance to mu-opioid effects.

This paper reports that regulators of G-protein signalling (RGS) proteins modulate the timing and amplitude of opioid signals by a push-pull mechanism. This is achieved without noticeable changes in the binding properties of opioids, e.g. beta-endorphin to mu-opioid receptors. The expression of RGS proteins was reduced by blocking their mRNA with antisense oligodeoxynucleotides (ODN). Knock down of RGS2 or RGS3 diminished morphine and beta-endorphin analgesia, whereas that of RGS9 or RGS12 enhanced this activity. In mice with impaired RGS9, but not impaired RGS2, the potency and, in particular, the duration of opioid antinociception increased. Further, the animals did not exhibit acute tolerance generated by a single and efficacious dose of morphine, nor did they develop tolerance after a daily i.c.v. injection of the opioid for 4 days. In a model of sustained morphine treatment, the impairment of RGS9 proteins facilitated increases in the response to the delivered opioid. This was only effective for 2--3 h after the subcutaneous implantation of an oily morphine pellet; later, tolerance developed. To reduce the impact of the chronic morphine acting on opioid receptors, other RGS proteins presumably substitute the GTPase-activating function of RGS9 on morphine-activated G-alpha-GTP subunits. The desensitization of mu-opioid receptors appears to be a cell membrane-limited process facilitated by RGS9's sequestering of agonist-segregated G alpha subunits.

Lack of dependence and rewarding effects of deltorphin II in mu-opioid receptor-deficient mice.

We have previously shown that the antinociceptive effects produced by the delta opioid-selective agonist deltorphin II are preserved in mu-opioid receptor (MOR)-deficient mice. We have now investigated rewarding effects and physical dependence produced by deltorphin II in these animals. Wild-type and MOR-deficient mice were implanted with a cannula into the third ventricle and deltorphin II was administered centrally. The rewarding effects induced by deltorphin II were then investigated using the place preference paradigm. Wild-type mice showed place preference for the compartment previously associated with deltorphin II and this effect was not observed in MOR-deficient mice. In a second experiment, mice received a chronic perfusion of deltorphin II over 6 days, via an Alzet minipump connected to the intraventricular cannula, and withdrawal was precipitated by naloxone administration. Wild-type animals showed a moderate but significant incidence of several somatic signs of withdrawal. This withdrawal response was suppressed in MOR-deficient mice. Analysis of the immunoreactivity levels of PKC-alpha, PKC-beta (I and II) and PKC-gamma isozymes in the cerebral cortex of mice infused chronically with deltorphin II showed a significant up-regulation of all these isozymes in the soluble fraction in wild-type but not in MOR-deficient mice. In conclusion, mu-opioid receptors, which are not involved in deltorphin II antinociception, appear to mediate the effects of chronic deltorphin II on rewarding responses, physical dependence and adaptive changes to PKC.

Myr+-Gi2 alpha and Go alpha subunits restore the efficacy of opioids, clonidine and neurotensin giving rise to antinociception in G-protein knock-down mice.

In mice whose Gi/o-protein function had been impaired by antisense 'knock-down' or pertussis toxin treatment, i.c.v. injection of myr+-Gi/o alpha subunits restored the effectiveness of beta-endorphin, morphine, DPDPE, clonidine and neurotensin to produce antinociception. Myr+-G alpha subunits of the class of G-proteins actually impaired were more effective than unlike but related myr+-G alpha subunits. Selectivity was noted in that only exogenous myr+-G alpha subunits affected (enhanced) the activity of agonists in G alpha-deficient signalling systems. This treatment had little effect on agonist potency when the impairment resided at the receptor level. The potential of the opioids, clonidine and R-PIA to increase G alpha-related in vitro hydrolysis of GTP was also re-established after injecting myr+-Gi2 alpha subunits into Gi2-knocked-down mice. Myr+-Gi2 alpha subunits pre-incubated with GTPgammaS or GDPbetaS before i.c.v. injection did not improve the activity of agonists in vivo (antinociception) or in vitro (regulation of low Km GTPase). After impairing the function of PKCbeta1 by antisense treatment or with the inhibitor H7, the effect of myr+-G alpha subunits on agonist potency was prevented. Electron microscope analysis showed the entry of gold-conjugated myr+-G alpha subunits into neural cells. These particles were found in the cytoplasm, associated with the plasma membranes of different neuronal processes and also in synaptic junctions. In cultured neurons and astrocytes myr+-Gi2 alpha-associated fluorescence was internalised in a dose-dependent manner and distributed in the plasma membrane and cytosol, as well as in nuclei of dividing astrocytes. Thus, G alpha subunits in CSF enter into neurons and functionally couple to the receptor-triggered signalling cascade. As G-proteins have been implicated in the pathophysiology of several neural disorders, this finding may be valuable in the therapy of such dysfunctions.

Use of selective antagonists and antisense oligonucleotides to evaluate the mechanisms of BUBU antinociception.

Evidence suggests that the antinociceptive effects of selective delta-opioid receptor agonists may involve an activation of the mu-receptor in some experimental conditions. The aim of this study was to clarify the receptors involved in the antinociceptive responses of the selective and systemically active delta-opioid receptor agonist Tyr-D-Ser-(O-tert-butyl)-Gly-Phe-Leu-Thr-(O-tert-butyl) (BUBU). The antinociception induced by systemic (i.v.) or central (i.c.v.) administration of BUBU was measured in the hot plate (jumping and paw lick latencies) and tail immersion tests in mice. In both tests, the responses were more intense when BUBU was administered by central route. The pre-treatment with the mu-opioid receptor antagonist cyprodime blocked the effects induced by central BUBU in the hot plate and tail immersion tests. The delta-opioid receptor antagonist naltrindole had no effect on BUBU-induced antinociception in the hot plate but decreased BUBU responses in the tail immersion test. Further evidence for this dual receptor action of BUBU was demonstrated by using antisense oligodeoxynucleotides. Thus, a reduction in central BUBU-induced antinociception was observed in the tail immersion test after the administration of antisense probes that selectively blocked the expression of mu- or delta-opioid receptors. These findings clearly indicate using a dual pharmacological and molecular approach that BUBU mediates its antinociceptive effects via activation of both mu- and delta-opioid receptors.

Endomorphin-1 and endomorphin-2 show differences in their activation of mu opioid receptor-regulated G proteins in supraspinal antinociception in mice.

Endomorphin-1 and endomorphin-2 are tetrapeptides of the brain whose binding profiles and analgesic activities indicate that they are endogenous ligands at micro opioid receptors. To analyze the classes of G transducer proteins activated by these opioids in the production of supraspinal antinociception, the expression of alpha subunits of the G(i) protein class, G(i1), G(i2), G(i3), G(o1), G(o2), and G(z), and those of the G(q) protein family, G(q) and G(11), was reduced by administration of antisense oligodeoxynucleotides (ODNs) complementary to sequences in their respective mRNAs. The ODN treatments promoted differences in the analgesic effects displayed by morphine, [D-Ala(2),N-MePhe(4), Gly-ol(5)]enkephalin (DAMGO), and the novel opioids endomorphin-1 and endomorphin-2. The impairment of G(i1)alpha and G(i3)alpha function led to a weaker analgesic response to the endomorphins and to the alpha(2)-adrenoceptor agonist clonidine, whereas the effects of morphine and DAMGO were not affected. An antisense probe targeting G(i2)alpha blocked the antinociceptive effects of endomorphin-2, morphine, DAMGO, and clonidine but was without effect on the activity of endomorphin-1. Mice receiving the ODN to G(z)alpha subunits showed impaired response to all agonists. The knockdown of either G(o1)alpha, G(o2)alpha, G(q)alpha, or G(11)alpha had little or no influence on the antinociception induced by any of the opioids in the study. Thus, agonists exhibit differences in activating the variety of GTP-binding proteins regulated by mu opioid receptors.

Tryptophan ingestion by pregnant rats induces pituitary and mammary tumours in the adult female offspring.

The present study was designed to evaluate the long-term consequences of tryptophan treatment on the central serotonergic activity in the female offspring of rats, and particularly on serotonin-controlled hormone release. During the second half of gestation, tryptophan (200 mg/kg/day) was given daily by stomach intubation to pregnant rats and the brain concentrations of serotonin and 5-hydroxyindole acetic acid and the plasma concentrations of prolactin, progesterone, oestradiol and luteinizing hormone were quantified in the adult female offspring. The offspring showed an increase in hypothalamic serotonin and serum progesterone and prolactin. In addition, maternal ingestion of tryptophan induced a marked rise in 665-day-old offspring in the incidence of both pituitary prolactinomas (62%) and mammary adenomas (49%). Present data suggest that tryptophan regulates serotonergic differentiation during early development. A transitory modification of the tryptophan concentration in the fetal brain induces a permanent increase in hypothalamic serotonin level and, in addition to modifying the release of prolactin, increases the incidence of tumours in the hypophysis and mammary gland.

Antisense oligodeoxynucleotide targeting distinct exons of the cloned mu-opioid receptor distinguish between endomorphin-1 and morphine supraspinal antinociception in mice.

Antisense oligodeoxynucleotides (ODN) were used to investigate the supraspinal antinociceptive effects of endomorphin-1, an endogenous peptide whose analgesic profile suggests that it is a ligand at the mu-opioid receptor. To selectively restrict the expression of this receptor, five ODN targeting distinct exons of the gene sequence were injected subchronically by the intracerebroventricular route (i.c.v.) into mice. The antinociception induced by endomorphin-1 was greatly reduced in animals receiving the ODN directed to nucleotides 677-697, which code for a sequence located on the second extracellular loop of the mu receptor. ODN-mu(un), one of the two antisense ODN directed to exon 1, also impaired endomorphin-1 antinociception. ODN targeting exons 2 and 4 were totally inactive. In contrast, all five ODN blocked the antinociception induced by morphine and beta-casomorphin. The analgesic potency of endomorphin-1, morphine, and beta-casomorphin remained unaltered by administration of an ODN to nucleotides 29-46 of the murine delta-opioid receptor gene sequence of a random-sequence ODN. This suggest the existence of diverse molecular forms for the mu-opioid receptor that mediate the antinociceptive effects of endomorphin-1 and morphine/beta-casomorphin.

Stimulation of mu- and delta-opioid receptors enhances phosphoinositide metabolism in mouse spinal cord: evidence for subtypes of delta-receptors.

The accumulation of inositol phosphates (IPs) induced by agonist-activated opioid receptors was analysed in mouse spinal cord slices pre-labelled with myo-[3H]inositol. Agonists showing selectivity to mu-opioid receptors, morphine and [D-Ala2,MePhe4, Gly(ol)5]enkephalin (DAMGO), promoted concentration-dependent increases in the formation of IPs. The activation of delta-opioid receptors by the selective agonists [D-Pen2,5]enkephalin (DPDPE) and [D-Ala2]deltorphin II produced similar increases in phosphoinositide (PI) metabolism. Pre-treatment of the slices with pertussis toxin (PTX) blocked the effect of opioid agonists on IP production. The involvement of Gi/Go-protein (guanine nucleotide-binding protein) classes in this opioid effect is therefore suggested. The activity of the opioid agonists was reduced by the opioid antagonists naltrexone and naloxone. The antagonist at delta1-receptors, 7-benzylidenenaltrexone (BNTX), exhibited greater potency than the antagonists at delta2-receptors, naltriben methanesulphonate (NTB) or naltrindrole 5'-isothiocyanate (NT II), in reducing the activating effect of DPDPE on phosphoinositide metabolism. Conversely, NTB and NT II were more potent antagonists of the activity of [D-Ala2]deltorphin II than BNTX. This work demonstrates the coupling of spinal mu- and delta-opioid receptors to phospholipase C and the generation of IPs. It also provides biochemical evidence for pharmacological subtypes of delta-opioid receptors in the activation of this signalling pathway.