Abstract: The aim of this study was to show the presence, distribution and function of the pituitary adenylate cyclase activating polypeptide (PACAP) and its receptors in the CNS and peripheral nervous system of the mollusk, Helix pomatia. PACAP-like and pituitary adenylate cyclase activating polypeptide receptor (PAC1-R)-like immunoreactivity was abundant both in the CNS and the peripheral nervous system of the snail. In addition several non-neuronal cells also revealed PACAP-like immunoreactivity. In inactive animals labeled cell bodies were mainly found and in the neuropile of active animals dense immunostained fiber system was additionally detected suggesting that expression of PACAP-like peptide was affected by the behavioral state of the animal. RIA measurements revealed the existence of both forms of PACAP in the CNS where the 27 amino acid form was found to be dominant. The concentration of PACAP27 was significantly higher in samples from active animals supporting the data obtained by immunohistochemistry. In Western blot experiments PACAP27 and PACAP38 antibodies specifically labeled protein band at 4.5 kDa both in rat and snail brain homogenates, and additionally an approximately 14 kDa band in snail. The 4.5 kDa protein corresponds to PACAP38 and the 14 kDa protein corresponds to the preproPACAP or to a PACAP-like peptide having larger molecular weight than mammalian PACAP38. In matrix-assisted laser desorption ionization time of flight (MALDI TOF) measurements fragments of PACAP38 were identified in brain samples suggesting the presence of a large molecular weight peptide in the snail. Applying antibodies developed against the PACAP receptor PAC1-R, immunopositive stained neurons and a dense network of fibers were identified in each of the ganglia. In electrophysiological experiments, extracellular application of PACAP27 and PACAP38 transiently depolarized or increased postsynaptic activity of neurons expressing PAC1-R. In several neurons PACAP elicited a long lasting hyperpolarization which was eliminated after 1.5 h continuous washing. Taken together, these results indicate that PACAP may have significant role in a wide range of basic physiological functions in snail.
Abstract: The liver is one of the major target organs affected in sepsis that are usually accompanied with free radical formation. The use of minus charge for the prevention and cure of various radical related diseases is gaining wide importance in the medicinal field. Here, we investigate whether minus charge stimulation (MCS) inhibits nitric oxide (NO) production induced by lipopolysaccharide (LPS) in the mice liver. The survival rate was compared in LPS-treated group with MCS group. The liver NO radical was measured using electron spin resonance technique. Serum alanine transaminase (ALT) was estimated for liver injury. MCS significantly improved the survival rate of LPS-treated mice and inhibited increase of ALT in serum levels. MCS also reduced NO radical production significantly in the LPS-treated mice liver tissue. In conclusion, our results indicate that MCS prevents LPS-induced liver injury, which may be through the inhibition of liver NO radical production.
Abstract: Pituitary adenylate cyclase-activating polypeptide (PACAP) is expressed at very early stages in the vertebrate nervous system, and its functions in the embryonic development have been shown by various studies. PACAP is an extremely conserved molecule in phylogeny; however, little is known about its presence and functions in invertebrates. Our previous studies have shown the occurrence of PACAP-like immunoreactivity in the invertebrate nervous system. The aim of this study was to investigate the presence and localization of PACAP-like compounds during the embryonic development of earthworms from cocoon deposition to hatching using immunological methods (radioimmunoassay, dot blot, immunohistochemistry). PACAP-like immunoreactive compounds were detected at very early stages of the embryonic development of the earthworm Eisenia fetida. No significant changes were observed during the early stages in the developing embryo, but a marked increase occurred before hatching. In contrast, during the embryonic development, the level of PACAP-like compounds gradually decreased in cocoon fluids. Immunohistochemistry revealed the presence of PACAP-like immunoreactive cell bodies and processes in the developing body wall, prostomium, pharyngeal wall, and central nervous system. Cells located in the body wall correspond to putative progenitor cells of primary sensory cells. In the present study, we also showed that the clitellum (reproductive organ) of sexually mature worms contained significantly higher levels of PACAP-like immunoreactivity than other regions of the same animals or the clitellar region of a non-reproducing animal. In summary, these observations provide a morphological basis and suggest a role of PACAP(-like peptides) in the reproductive and developmental functions of invertebrates.
Abstract: Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide that was first isolated from the ovine hypothalamus. PACAP has previously been shown in in vitro experiments to have neuroprotective effects, but its possible application in clinical situations must first be tested in vivo. We examined the protective effect of PACAP against retinal ganglion cell (RGC) death following optic nerve transection in the rat. Fourteen days after sectioning of the optic nerve, the number of RGCs in the vehicle control (untreated: vehicle 0.9% saline, volume 3 mul, injected into the vitreous body) group with axotomized optic nerve was decreased compared with that of intact animals. The number of RGCs in PACAP-treated animals (10 or 100 pM dose added to the vehicle) was significantly increased compared with the vehicle control group. These results indicate that PACAP suppresses ganglion cell death induced by optic nerve transection.
Abstract: Novel neuropeptides acting as G-protein-coupled receptor (GPCR) ligands are known to be localized in the brain and play a range of physiologic functions, one of which is feeding regulation. We describe the distribution and localization of these recently identified GPCR ligands and review their involvement in neuronal networks, particularly in feeding regulation. This review addresses aspects of some novel GPCR ligands, including feeding-regulating neuropeptides such as orexin, ghrelin, and galanin-like peptide and other known neuropeptides such as neuropeptide Y and pro-opiomelanocortin. These neuropeptides have been studied by our research group and others, particularly with regard to interactions in the hypothalamus of neurons containing these neuropeptides. In the hypothalamus, cross-talk among such neurons plays a key role in determining feeding states and feeding behavior. We describe some structural and functional characteristics of these neuropeptides and summarize the known interactions between the different kinds of feeding-regulating neurons and leptin-targeting neurons in the hypothalamus. Moreover, we present a new strategy for analyzing neural circuits involving these feeding-regulating GPCR ligands in the brain, with research in this field aided by the use of transgenic mouse models. We also present our recent results that involve aspects of feeding regulation, energy homeostasis, and body temperature regulation. Research in this field will serve the important role of clarifying neurologically based causes for appetite dysfunctions and diseases and may help in establishing new therapies for patients with such conditions.
Abstract: alpha-Melanocyte-stimulating hormone (alpha-MSH) and corticotropin-releasing hormone (CRH) both suppress food intake, and the alpha-MSH- or CRH-signaling pathway has possible potency to mediate anorexigenic actions induced by most other neuropeptides in goldfish. Therefore, using specific receptor antagonists, we examined whether the anorexigenic actions of alpha-MSH and CRH mutually interact. The inhibitory effect of ICV injection of the alpha-MSH agonist, melanotan II (MT II), on food intake was abolished by treatment with a CRH 1/2 receptor antagonist, alpha-helical CRH((9-41)), whereas the anorexigenic action of ICV-injected CRH was not affected by treatment with a melanocortin 4 receptor antagonist, HS024. This led us to investigate whether alpha-MSH-containing neurons in the goldfish brain have direct inputs to CRH-containing neurons, using confocal laser scanning microscopy. alpha-MSH- and CRH-like immunoreactivities were distributed throughout the brain, especially in the diencephalon. alpha-MSH-containing nerve fibers or endings lay in close apposition to CRH-containing neurons in a region of the hypothalamus, the nucleus posterioris periventricularis (NPPv). These results indicate that, in goldfish, alpha-MSH-induced anorexigenic action is mediated by the CRH-signaling pathway, and that CRH plays a crucial role in the regulation of feeding behavior as an integrated anorexigenic neuropeptide in this species.
Abstract: Since we have been exposed to excessive amounts of stressors, aromatherapy for the relaxation has recently become very popular recently. However, there is a problem which responds to light with the essential oil used by aromatherapy. It is generally believed that singlet oxygen is implicated in the pathogenesis of various diseases such as light-induced skin disorders and inflammatory responses. Here we studied whether essential oils can effectively scavenge singlet oxygen upon irradiation, using the electron spin resonance (ESR) method. Green light was used to irradiate twelve essential oils from rutaceae. Among these twelve essential oils, eight were prepared by the expression (or the compression) method (referred to as E oil), and four samples were prepared by the steam distillation method (referred to as SD oil). Five E oils enhanced singlet oxygen production. As these essential oils may be phototoxic, it should be used for their use whit light. Two E oils and three SD oils showed singlet oxygen scavenging activity. These results may suggest that the antioxidant activity of essential oils are judged from their radical scavenging activity. Essential oils, which enhance the singlet oxygen production and show higher cytotoxicity, may contain much of limonene. These results suggest that limonene is involved not only in the enhancement of singlet oxygen production but also in the expression of cytotoxic activity, and that attention has to be necessary for use of blended essential oils.
Abstract: We examined brain region-specific changes in monoamines and metabolites, and their ratios, after short-term administration of antidepressants to rats. Serotonin noradrenaline reuptake inhibitors (SNRIs; duloxetine, venlafaxine, milnacipran) and a serotonin-selective reuptake inhibitor (SSRI; sertraline) elevated serotonin (5-HT) levels in the midbrain (MB). Duloxetine and venlafaxine increased 5-HT levels in the brainstem and 5-HT terminal areas, whereas milnacipran and sertraline increased levels in the brainstem only. Significant reductions in 5-HT turnover were observed in various forebrain regions, including the hippocampus and hypothalamus, after treatment with all of the tested drugs except for milnacipran. In addition, there was reduced 5-HT turnover in the dorsolateral frontal cortex (dlFC), the medial prefrontal cortex (mPFC), and both the dlFC and the mPFC after treatment with duloxetine, sertraline, and venlafaxine, respectively. Venlafaxine significantly increased dopamine (DA) levels in the nucleus accumbens (NAc) and the substantia nigra and decreased DA turnover in the NAc. Similar changes were observed after treatment with duloxetine and sertraline in the NAc, whereas milnacipran increased DA levels in the mPFC. Limited increases in noradrenaline levels were detected after treatment with duloxetine, venlafaxine, or sertraline, but not after treatment with milnacipran. These results show that SNRIs and SSRIs induced region-specific monoaminergic changes after short-term treatment.
