Sardine procalcitonin amino-terminal cleavage peptide has a different action from calcitonin and promotes osteoblastic activity in the scales of goldfish.

The nucleotide sequence of a sardine preprocalcitonin precursor has been determined from their ultimobranchial glands in the present study. From our analysis of this sequence, we found that sardine procalcitonin was composed of procalcitonin amino-terminal cleavage peptide (N-proCT) (53 amino acids), CT (32 amino acids), and procalcitonin carboxyl-terminal cleavage peptide (C-proCT) (18 amino acids). As compared with C-proCT, N-proCT has been highly conserved among teleosts, reptiles, and birds, which suggests that N-proCT has some bioactivities.

Static and dynamic hypergravity responses of osteoblasts and osteoclasts in medaka scales.

Fish scales are a form of calcified tissue similar to that found in human bone. In medaka scales, we detected both osteoblasts and osteoclasts and subsequently developed a new scale assay system. Using this system, we analyzed the osteoblastic and osteoclastic responses under 2-, 3-, and 4-gravity (G) loading by both centrifugation and vibration.

Prostaglandin E₂ increases both osteoblastic and osteoclastic activity in the scales and participates in calcium metabolism in goldfish.

Using our original in vitro assay system with goldfish scales, we examined the direct effect of prostaglandin E₂ (PGE₂) on osteoclasts and osteoblasts in teleosts. In this assay system, we measured the activity of alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP) as respective indicators of each activity in osteoblasts and osteoclasts. ALP activity in scales significantly increased following treatment at high concentration of PGE₂(10⁻⁷ and 10⁻⁶ M) over 6 hrs of incubation.

Shared features of S100B immunohistochemistry and cytochrome oxidase histochemistry in the ventroposterior thalamus and lateral habenula in neonatal rats.

The ventroposterior thalamus and the habenular nuclei of the epithalamus are relevant to the monoaminergic system functionally and anatomically. The glia-derived S100B protein plays a critical role in the development of the nervous system including the monoaminergic systems. In this study, we performed an immunohistochemical study of glia-related proteins including S100B, serotonin transporter, and microtubule-associated protein 2, as well as cytochrome oxidase histochemistry in neonatal rats.

Neuroanatomy of melanocortin-4 receptor pathway in the lateral hypothalamic area.

The central melanocortin system regulates body energy homeostasis including the melanocortin-4 receptor (MC4R). The lateral hypothalamic area (LHA) receives dense melanocortinergic inputs from the arcuate nucleus of the hypothalamus and regulates multiple processes including food intake, reward behaviors, and autonomic function. By using a mouse line in which green fluorescent protein (GFP) is expressed under control of the MC4R gene promoter, we systemically investigated MC4R signaling in the LHA by combining double immunohistochemistry, electrophysiology, and retrograde tracing techniques.

Cloning of two members of the calcitonin-family receptors from stingray, Dasyatis akajei: possible physiological roles of the calcitonin family in osmoregulation.

In cartilaginous fish, two cDNAs encoding calcitonin-family receptors were isolated for the first time from the stingray brain. The open reading frame of one receptor cDNA coded a 525-amino acid protein. The amino acid identity of this receptor to human calcitonin-receptor-like receptor (CRLR) is 64.

Melanocortin-4 receptor expression in a vago-vagal circuitry involved in postprandial functions.

Vagal afferents regulate energy balance by providing a link between the brain and postprandial signals originating from the gut. In the current study, we investigated melanocortin-4 receptor (MC4R) expression in the nodose ganglion, where the cell bodies of vagal sensory afferents reside. By using a line of mice expressing green fluorescent protein (GFP) under the control of the MC4R promoter, we found GFP expression in approximately one-third of nodose ganglion neurons.

Divergence of melanocortin pathways in the control of food intake and energy expenditure.

Activation of melanocortin-4-receptors (MC4Rs) reduces body fat stores by decreasing food intake and increasing energy expenditure. MC4Rs are expressed in multiple CNS sites, any number of which could mediate these effects. To identify the functionally relevant sites of MC4R expression, we generated a loxP-modified, null Mc4r allele (loxTB Mc4r) that can be reactivated by Cre-recombinase.

Coexistence of salusin and vasopressin in the rat hypothalamo-hypophyseal system.

Salusins are two newly discovered TOR-related peptides consisting of 28 and 20 amino acids and designated salusin-alpha and salusin-beta, respectively. Using immunohistochemistry techniques, salusin-like immunoreactivity was detected in the rat hypothalamo-neurohypophyseal tract and immunopositive cells were distributed in the suprachiasmatic, supraoptic and paraventricular nucleus. In the paraventricular nucleus, salusin-like immunoreactivity was observed both in parvocellular and magnocellular neurons.

Gamma aminobutyric acid regulates glucosensitive neuropeptide Y neurons in arcuate nucleus via A/B receptors.

Gamma aminobutyric acid (GABA) is localized in neuropeptide Y (NPY) neurons of the hypothalamic arcuate nucleus (ARC). We examined regulation of ARC NPY neurons by GABA. Light and electron microscopic immunohistochemistry confirmed that GABA-containing nerve terminals contacted NPY-containing neurons in the ARC.

Immunohistochemical analysis of cholecystokinin A receptor distribution in the rat pancreas.

Cholecystokinin (CCK) plays a major role in the regulation of pancreatic enzyme secretion based on its binding to the CCK-A receptor (CCK-AR). While CCK-AR is known to be expressed in rat islet B cells, the localization of CCK-AR in rat pancreatic A and D cells remains poorly understood. The aim of this study was to identify the localization of CCK-AR in rat pancreatic islets by means of double immunofluorescence straining with antibodies against CCK-AR, glucagon, insulin and somatostatin and with in situ hybridization to detect its transcript.

Neuronal interactions between galanin-like-peptide- and orexin- or melanin-concentrating hormone-containing neurons.

Galanin-like peptide (GALP) is a novel orexigenic neuropeptide that is recently isolated from the porcine hypothalamus. GALP-containing neurons predominantly locate in the hypothalamic arcuate nucleus (ARC). The expression of GALP mRNA within the ARC is increased after the administration of leptin.

Morphological analysis of ghrelin and its receptor distribution in the rat pancreas.

Ghrelin, a novel peptide isolated from stomach tissue of rats and humans, has been identified as the endogenous ligand for the growth hormone secretagogue receptor (GHS-R). In addition to its secretion from the stomach, ghrelin is also expressed in the hypothalamic arcuate nucleus, intestine, kidney, placenta, and pancreas. GHS-R mRNA, on the other hand, is expressed in the hypothalamus, pituitary, heart, lung, liver, pancreas, stomach, intestine, and adipose tissue.

Orexin-1 receptor expression after global ischemia in mice.

Orexins are neuropeptides that have a range of physiological effects including the regulation of feeding behavior and the sleep-wakefulness cycle. Recently, we reported that level of orexin A in spinal fluid was decreased in the patients of some neurodegenerative diseases and it is considered that orexin A and the receptors might be related to central nervous system disorders. However, the expression and localization of orexin receptors is not elicited well.

Expression of PAC1 receptor in rat thymus after irradiation.

In the present work, PAC1-R (G-protein-coupled receptor specific for PACAP) was detected on cells in the normal thymus. Immunohistochemically PAC1-R was expressed strongly in stromal cells of the thymic medulla. Positive cells were also observed in the thymus of fetal and old adult rats.

Synaptic interactions between ghrelin- and neuropeptide Y-containing neurons in the rat arcuate nucleus.

Morphological relationships between neuropeptide Y- (NPY) like and ghrelin-like immunoreactive neurons in the arcuate nucleus (ARC) were examined using light and electron microscopy techniques. At the light microscope level, both neuron types were found distributed in the ARC and could be observed making contact with each other. Using a preembedding double immunostaining technique, some NPY-immunoreactive axon terminals were observed at the electron microscope level to make synapses on ghrelin-immunoreactive cell bodies and dendrites.

Orexins (hypocretins) directly interact with neuropeptide Y, POMC and glucose-responsive neurons to regulate Ca 2+ signaling in a reciprocal manner to leptin: orexigenic neuronal pathways in the mediobasal hypothalamus.

Orexin-A and -B (hypocretin-1 and -2) have been implicated in the stimulation of feeding. Here we show the effector neurons and signaling mechanisms for the orexigenic action of orexins in rats. Immunohistochemical methods showed that orexin axon terminals contact with neuropeptide Y (NPY)- and proopiomelanocortin (POMC)-positive neurons in the arcuate nucleus (ARC) of the rats.

Pituitary adenylate cyclase activating polypeptide-mediated intracrine signaling in the testicular germ cells.

Pituitary adenylate cyclase activating polypeptide (PACAP) is found not only in the brain, but is also abundantly expressed in the testicular germ cells. However, the physiological role of testicular PACAP remains unknown. Autoradiographic studies showed a considerable number of PACAP-specific binding sites in the seminiferous tubules.

Suppression of proliferation and neurite extension of human neuroblastoma SH-SY5Y cells on immobilized Psathyrella velutina lectin.

Glycoproteins from mammalian brain tissues contain unique N-linked oligosaccharides terminating with beta-N-acetylglucosamine residues. Lectin blot analysis of membrane glycoprotein samples from human neuroblastoma SH-SY5Y cells showed that several protein bands bind to Psathylera velutina lectin (PVL), which interacts with beta-N-acetylglucosamine-terminating oligosaccharides. No lectin positive bands were detected by digestion with jack bean beta-N-acetyl-hexosaminidase or N-glycanase before incubation with the lectin, indicating that the cells contain beta-N-acetylglucosamine-terminating N-linked oligosaccharides.

A transgenic mouse model for the detailed morphological study of astrocytes.

We have generated a transgenic mouse model in which astrocytes express an enhanced green fluorescent protein (EGFP) under the control of the mouse glial fibrillary acidic protein (GFAP) promoter. EGFP, which is characteristically found throughout the cell, was expressed in these animals even in astrocytic fine processes, and EGFP expressing cells demonstrated morphological characters of protoplasmic, fibrous, or reactive astrocytes. In contrast, GFAP immunoreactivity was found only in the perinuclear region and in the main processes.

Hypothalamic neuronal networks and feeding-related peptides involved in the regulation of feeding.

The hypothalamus is a region of the brain that plays a critical role in feeding regulation. It has been revealed by various physiological experiments that the feeding-regulating center is confined to the ventromedial hypothalamus, lateral hypothalamus (LH) and arcuate nucleus (ARC). Many kinds of neurons in these areas of the hypothalamus express factors such as melanin-concentrating hormone (MCH), neuropeptide Y (NPY), proopiomelanocortin (POMC), orexin (OX) and ghrelin, which have been implicated in feeding regulation.

Co-existence of leptin- and orexin-receptors in feeding-regulating neurons in the hypothalamic arcuate nucleus-a triple labeling study.

The arcuate nucleus (ARC) of the hypothalamus has been identified as a prime feeding regulating center in the brain. Several feeding regulating peptides, such as neuropeptide Y (NPY) and proopiomelanocortin (POMC), are present in neurons of the ARC, which also serves as a primary targeting site for leptin, a feeding inhibiting hormone secreted predominantly by adipose tissues, and for orexin (OX)-containing neurons. OX is expressed exclusively around the lateral hypothalamus, an area also established as a feeding regulating center.

Distribution, function, and properties of leptin receptors in the brain.

Leptin, a peptide hormone, is implicated in the modulation of food intake and maintenance of energy balance in many vertebrates including humans. It is considered to act via its receptor mainly through several hypothalamic nuclei that play critical roles in the regulation of appetite. This article looks mainly at the functional significance of leptin in rat brain by drawing on published reports of morphological and physiological analyses.

Direct evidence for the activation of phospholipase C gamma 1 by in vivo treatment with morphine in the mouse periaqueductal gray matter.

The aim of the present study was to investigate whether in vivo morphine treatment could participate in the activation of phospholipase Cgamma1 (PLCgamma1) isoform in the mouse periaqueductal gray matter (PAG) which can be accompanied by antinociceptive responses induced by morphine. As well as mu-opioid receptor-like immunoreactivity (MOR-IR), moderate PLCgamma1-like immunoreactivity (PLCgamma1-IR) was noted in the mouse PAG section. After s.