Intracerebroventricularly administered atrial natriuretric peptide (ANP) antiserum attenuates fear-motivated learning behavior in rats

VOLUME INTAKE AND CRAVING IN ALCOHOL WITHDRAWAL

AIMS

It has been shown that beer consumption is associated with alcohol craving, in contrast to wine or spirits consumption. The present study was undertaken to evaluate whether the daily volume intake of alcoholic beverages is associated with craving in patients undergoing alcohol withdrawal.

METHODS

A total of 158 male patients were assessed using the obsessive compulsive drinking scale (OCDS) at admission. The daily volume intake of alcoholic beverages was calculated by adding the volume of all regularly consumed alcoholic beverages, disregarding their alcohol percentage. Lesch's typology was used to classify patients for subgroup analysis.

RESULTS

The daily volume intake of alcoholic beverages correlated significantly with the extent of the OCDS (r = 0.33; P < 0.001). With general linear models, we found a significant association of the calculated daily volume intake of all alcoholic beverages with craving (F = 6.426; P = 0.012), but not for the daily ethanol intake. Differentiating the patients according to Lesch's typology a significant association was particularly found in Lesch Type 2 (model of anxiety) patients (F = 11.31; P = 0.001).

CONCLUSION

Our results support the hypothesis that volume intake is associated with craving and suggest a role of pathophysiological changes in volume regulating mechanisms (such as vasopressin or ANP) in the neurobiology of alcohol craving, particularly in male patients of Lesch's Type 2 undergoing alcohol withdrawal.

Functional continuum of regulatory peptides (RPs): vector model of RP-effects representation

During the past decades, bioactive (regulatory) peptides have been identified as the major players in the regulation of many important biological processes. Dozens of peptides have found their application as pharmaceutical agents, which further stimulated research in this field making it one of the most rapidly developing areas on the edge of biological science and medicine. However, the fast accumulation of enormous amounts of experimental data has revealed a great difficulty in their analysis and demanded the development of a systematic approach for generalization of the obtained information. We propose a new computer-based algorithm for studying biological activities of regulatory peptides and their groups based on their representation as vectors in n -dimensional functional space. Our method allows the rapid analysis of databases containing thousands of polyfunctional regulatory peptides with overlapping spectra of physiological activity. The described method permits to perform several types of correlations which, when applied to the large databases, could reveal new important information about the system of regulatory peptides. It can select the groups of peptides with similar physiological role (peptide constellations) and search for the optimal peptide combinations with predetermined spectrum of effects and minimal side effects for their further pharmacological application. It can also reveal the role of regulatory peptides in induction of chain physiological reactions.

Effects of peptides on animal and human behavior: a review of studies published in the first twenty years of the journal Peptides

This review catalogs effects of peptides on various aspects of animal and human behavior as published in the journal Peptides in its first twenty years. Topics covered include: activity levels, addiction behavior, ingestive behaviors, learning and memory-based behaviors, nociceptive behaviors, social and sexual behavior, and stereotyped and other behaviors. There are separate tables for these behaviors and a short introduction for each section.

Hyperthermic effect of centrally administered natriuretic peptides in the rat

The effects of atrial natriuretic peptide (ANP-28), brain natriuretic peptide (BNP-32) and C-type natriuretic peptide (CNP-22) on body temperature were investigated in rats. Intracerebroventricular administration of each peptide in doses of 400 or 1000 ng caused a dose-related elevation in colon temperature 30 and 60 min after injection. A 40 ng dose of ANP-28 was also hyperthermic at 60 min. An intramuscular (i.m.) injection of noraminophenazone (a cyclooxygenase inhibitor) abolished the natriuretic peptide-induced hyperthermia. The results show that natriuretic peptides may participate in thermoregulatory processes in the central nervous system, and that their hyperthermic effect may be mediated via a cyclooxygenase-involved pathway.

The effects of brain and C-type natriuretic peptides on corticotropin-releasing factor in brain of rats

The central corticotropin-releasing factor (CRF)-ergic system plays a critical role in anxiety and other behavioral stress responses. It has been shown that atrial (ANP), brain (BNP) and C-type (CNP) natriuretic peptides exert anxiolytic-like effects in behavioral studies. Our previous findings demonstrated that various doses of centrally administered ANP selectively altered the CRF content in different brain areas. In the present study, CRF immunoreactivity was determined in hypothalamic and extrahypothalamic brain regions after central injection of BNP or CNP in rats. A high dose (400 ng) of BNP significantly increased the CRF-like immunoreactivity (CRF-LI) in the hypothalamus and amygdala, while only a tendency towards an increase was found in the hippocampus. In the hypothalamus, the CRF-LI decreased after a high dose (400 ng) of CNP. The CRF-LI increased in the basal forebrain after a low dose (100 ng) of CNP. These results suggest that CRF may be involved in the mediation of some neuroendocrine and behavioral responses to BNP and CNP.

Localization of natriuretic peptide-activated guanylate cyclase mRNAs in the rat brain

Physiological actions of atrial natriuretic peptide (ANP) and C-type natriuretic peptide (CNP) are elaborated by membrane-bound natriuretic peptide receptors (NPRs). These receptors possess intracellular guanylate cyclase domains that mobilize cyclic guanosine monophosphate upon binding of peptide. Two distinct NPR subtypes have been described in brain: the NPR-A selectively binds ANP, whereas NPR-B exhibits high affinity for CNP. To define further the potential domains of ANP and CNP action in brain, the present study used in situ hybridization histochemistry to map NPR-A and NPR-B mRNA-expressing cell populations. Significant levels of neuronal NPR-A mRNA expression were observed only in the mitral cell layer of the olfactory bulb, medial habenula, subfornical organ, and area postrema. Expression of NPR-A mRNA was observed in forebrain white matter tracts, suggesting synthesis in glial cells. In contrast, NPR-B mRNA was widely expressed throughout the neuraxis. In the telencephalon, signal was abundant throughout limbic cortex and neocortex, olfactory bulb, hippocampus, and amygdala. Intense NPR-B mRNA hybridization was observed in preoptic-hypothalamic neuroendocrine circuits and in motor nuclei of cranial nerves. Intermediate expression of NPR-B mRNA was observed in brainstem nuclei controlling autonomic function. Labeling for NPR-B but not NPR-A mRNA was observed in pituicytes in the neural lobe of the pituitary and in scattered cells of the anterior pituitary. These results suggest that CNP is the primary biologically active natriuretic peptide in brain. In contrast with NPR-B, NPR-A appears to be expressed largely in restricted cell populations containing high levels of ANP and in circumventricular organs. These data implicate the NPR-A in autoregulation of ANP neurons and central registration of cardiac ANP release.

Anatomical localisation of preproatrial natriuretic peptide mRNA in the rat brain by in situ hybridisation histochemistry: novel identification in olfactory regions

Atrial natriuretic peptide (ANP) is one of three structurally homologous natriuretic peptides present in heart and brain, which is thought to be involved in the regulation of water and salt intake, blood pressure, and hormone secretion. In the present study, the distribution of preproatrial natriuretic peptide (ppANP) mRNA in the central nervous system of the rat was examined by in situ hybridisation histochemistry by using [35S]-labelled oligonucleotides. Cells expressing ppANP mRNA were apparent in several major neuronal systems, being present in hypothalamic, limbic, pontine and forebrain olfactory regions. Relatively high densities of ppANP mRNA-positive neurones were found in the anterior medial preoptic hypothalamic nucleus, medial habenular nucleus, and in Barrington's nucleus in the pons. Moderate numbers of ppANP mRNA-positive cells were present in a number of amygdaloid nuclei, including the posterolateral and anterior cortical nuclei, in the zona incerta, and the pedunculopontine tegmental nucleus. Other areas, including the ventromedial hypothalamic nucleus and the laterodorsal tegmental nucleus, displayed only low densities of ppANP mRNA-positive neurones. A number of structures in which ppANP mRNA (or ANP-like immunoreactivity) has not previously been reported were found to contain moderate to high numbers of ppANP mRNA-positive neurones including several nuclei associated with the olfactory system, such as the anterior olfactory nucleus and neurones of the tenia tecta and ventrolateral orbital cortex. Although ppANP mRNA in CA1 pyramidal cells of the hippocampus has been described, we also detected labelling in CA2 and ventral CA3 regions of the hippocampus. Conversely, nuclei such as the bed nucleus of the stria terminalis and the nucleus of the solitary tract, which are reported to possess ANP-like immunoreactivity, were found not to contain ppANP mRNA. Overall, these results demonstrate the presence of ANP gene expression in discrete neuronal populations of the rat central nervous system and provide additional evidence to support a putative role for this peptide in regulating and integrating hypothalamic, olfactory, limbic, and neuroendocrine systems.

Distribution of natriuretic peptide precursor mRNAs in the rat brain

Atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP) represent members of a recently discovered neuropeptide family involved in central regulation of endocrine and autonomic functions. The present study employed an in situ hybridization approach to provide the first detailed comparative mapping of ANP, BNP, and CNP mRNAs in brain. Results indicate that ANP mRNA is highly expressed in anterior olfactory nuclei, limbic cortices, dorsal endopiriform nucleus, hippocampal subfield CA1, cortical amygdaloid nuclei, medial habenula, anteroventral periventricular and arcuate nuclei, periventricular stratum, zona incerta, mammillary nuclei, inferior olive, nucleus ambiguus, and pontine paragigantocellular nuclei. CNP mRNA is expressed at highest levels in olfactory nuclei, limbic cortices, dorsal endopiriform nucleus, hippocampal subfields CA1-3, anteroventral periventricular and arcuate nuclei, and numerous brainstem regions (including the pontine, lateral reticular, solitary tract, prepositus hypoglossal, and spinal trigeminal nuclei). Positive labeling for BNP mRNA was not observed in brain. The presence of both ANP and CNP mRNA in the same regions of distinct nuclei (e.g., the anteroventral periventricular and arcuate nuclei) suggests the potential for coexpression. Overall, the present data are consistent with a prominent role for both ANP and CNP in neuroendocrine regulation and central cardiovascular integration. The extensive localization of ANP and/or CNP mRNA in olfactory nuclei, limbic cortex, hippocampus, amygdala and diencephalic limbic relays further indicate a putative role for ANP and CNP as neuromodulators of olfactory/limbic information processing.

The action of ANP, BNP and related peptides on motivated behavior in rats

This review summarizes the action of atrial natriuretic (ANP) and some related compounds such as BNP, CNP and fragments on the central nervous system, based mainly on the results obtained in the author's laboratory. The aim of the investigations was to assess the physiological significance of the natriuretic peptide family in the brain by administering the peptides into the lateral brain ventricle. Effects were studied on motivated behavior, including active and passive avoidance learning, food-reinforced conditioning, open-field activity, electroshock-induced amnesia, development of morphine tolerance and dependence, and picrotoxin-kindled seizure syndrome. Antisera against ANP were used in order to follow the specificity of the resulting action. The role of neurotransmitters in the mediation of peptide action was elucidated by treating the animals with receptor blockers before peptide administration.

CNS effects of peptides: a cross-listing of peptides and their central actions published in the journal Peptides, 1986-1993

The centrally mediated effects of peptides as published in the journal Peptides from 1986 to 1993 are tabulated in two ways. In one table, the peptides are listed alphabetically. In another table, the effects are arranged alphabetically. Most of the effects observed after administration of peptides are grouped, wherever possible, into categories such as cardiovascular and gastrointestinal. The species used in most cases has been rats; where other animals were used, the species is noted. The route of administration of peptides and source of information also are included in the tables, with a complete listing provided at the end. Many peptides have been shown to exert a large number of centrally mediated effects.