Anti-pseudo-allergic components in licorice extract inhibit mast cell degranulation and calcium influx / 中国天然药物

Pseudo-allergic reactions (PARs) widely occur upon application of drugs or functional foods. Anti-pseudo-allergic ingredients from natural products have attracted much attention. This study aimed to investigate anti-pseudo-allergic compounds in licorice. The anti-pseudo-allergic effect of licorice extract was evaluated in rat basophilic leukemia 2H3 (RBL-2H3) cells. Anti-pseudo-allergic compounds were screened by using RBL-2H3 cell extraction and the effects of target components were verified further in RBL-2H3 cells, mouse peritoneal mast cells (MPMCs) and mice. Molecular docking and human MRGPRX2-expressing HEK293T cells (MRGPRX2-HEK293T cells) extraction were performed to determine the potential ligands of MAS-related G protein-coupled receptor-X2 (MRGPRX2), a pivotal target for PARs. Glycyrrhizic acid (GA) and licorice chalcone A (LA) were screened and shown to inhibit Compound48/80-induced degranulation and calcium influx in RBL-2H3 cells. GA and LA also inhibited degranulation in MPMCs and increase of histamine and TNF-α in mice. LA could bind to MRGPRX2, as determined by molecular docking and MRGPRX2-HEK293T cell extraction. Our study provides a strong rationale for using GA and LA as novel treatment options for PARs. LA is a potential ligand of MRGPRX2.

Growth hormone deficiency with advanced bone age: phenotypic interaction between GHRH receptor and CYP21A2 mutations diagnosed by sanger and whole exome sequencing

SUMMARY Isolated growth hormone deficiency (IGHD) is the most common pituitary hormone deficiency and, clinically, patients have delayed bone age. High sequence similarity between CYP21A2 gene and CYP21A1P pseudogene poses difficulties for exome sequencing interpretation. A 7.5 year-old boy born to second-degree cousins presented with severe short stature (height SDS −3.7) and bone age of 6 years. Clonidine and combined pituitary stimulation tests revealed GH deficiency. Pituitary MRI was normal. The patient was successfully treated with rGH. Surprisingly, at 10.8 years, his bone age had advanced to 13 years, but physical exam, LH and testosterone levels remained prepubertal. An ACTH stimulation test disclosed a non-classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency explaining the bone age advancement and, therefore, treatment with cortisone acetate was added. The genetic diagnosis of a homozygous mutation in GHRHR (p.Leu144His), a homozygous CYP21A2 mutation (p.Val282Leu) and CYP21A1P pseudogene duplication was established by Sanger sequencing, MLPA and whole-exome sequencing. We report the unusual clinical presentation of a patient born to consanguineous parents with two recessive endocrine diseases: non-classic congenital adrenal hyperplasia modifying the classical GH deficiency phenotype. We used a method of paired read mapping aided by neighbouring mis-matches to overcome the challenges of exome-sequencing in the presence of a pseudogene.

Changes in neuromedin S and its receptor after traumatic brain injury in cycling rats

Animal studies indicate that gonadal steroids have prominent neuroprotective effects in several models of experimental traumatic brain injury (TBI). Neuromedin U (NMU) and neuromedin S (NMS) are regulatory peptides involved in inflammatory and stress responses, and modulation of the gonadotropic axis. Since steroid hormone levels change during the estrous cycle, we sought to determine whether variations in ovarian hormones would affect blood-brain barrier (BBB) permeability and brain levels of NMS, NMU, and neuromedin S receptor 2 in experimental TBI. Two groups (proestrus and nonproestrus) of female rats underwent diffuse TBI. At 24 hrs after TBI, results showed a significantly decrease in BBB permeability in traumatic-proestrus animals (TBI-P) in comparison to traumatic nonproestrus (TBI-NP) rats. Western blot analyzes demonstrated an enhanced expression of prepro-NMS in TBI-P compared with that in the TBI-NP group. Likewise, TBI-P rats exhibited significantly higher NMUR2 gene expression compared with those of TBI-NP, whereas no significant difference in brain NMU content was seen between sham and traumatic animals. Our findings indicate that diffuse TBI induces an increase in prepro-NMS and neuromedin S receptor 2 expression in traumatic-proestrus rats which may mediate the anti-edematous effects of gonadal hormones in proestrus rats following trauma.

Efectos del Hipo-E Hipertiroidismo sobre la regulación de nei en áreas encefálicas relacionadas con la reproducción / Effects of Hypo-and hyperthyroidism on the regulation of nei in brain areas related to reproduction

El hipo- y el hipertiroidismo afectan el correcto funcionamiento del eje hipotálamohipófiso-gonadal (eje HHG) y del sistema nervioso central (SNC), el estudio de estas disfunciones en animales de experimentación ha permitido demostrar que las hormonas tiroideas (THs) pueden ser responsables de dichas alteraciones actuando en forma directa, o indirecta mediante la regulación a nivel central de moléculas neurotransmisoras y neuromoduladoras. El neuropéptido ácido-glutámico-isoleucina-amida (NEI) actúa como neuromodulador en la iberación de la hormona luteinizante (LH) y como neurotransmisor en ciertos comportamientos como la actividad motora (MA) y el comportamiento de aseo excesivo (CAE). El presente trabajo de tesis fue realizado con la finalidad de estudiar la posible regulación de las THs sobre la expresión de NEI en distintas áreas hipotalámicas y de correlacionar las modificaciones de la misma con las manifestaciones clínicas que se producen en estas patologías. Para esto se desarrolló un modelo de hipo- en hipertiroidismo en ratas macho adultas y en hembras durante el ciclo estral en las que se estudiaron distintas regiones hipotalámicas involucradas en el controlde la reproducción y del comportamiento. El análisis de lasmismas fue realizado midiendo la concentración del péptido por radioinmunoanálisis y su expresión por estudios de inmunohistoquímica e inmunofluorescencia. La relación de NEI con la expresión de enzimas como tirosina hidroxilasa (TH) y descarboxilasa del ácido- glutámico (GAD) y su posible modificación secundaria a la disfunción tiroidea también fue estudiada. Para determinarsi la hormona liberadora de tirotropina (TRH) podría ejercer algún efecto regulatorio sobre la neurona de NEI, sedeterminó la presencia de su receptor 1 (TRH-R1) en los somas que expresan el péptido.

Hypo- and hyperthyroidism affect the proper functioning of the hypothalamic-pituitarygonadal axis (HPG axis) and the central nervous system (CNS), studies done in experimental animals have demonstrated that in the CNSthyroid hormones (THs) are responsible of these changes acting directly or indirectly trhough the modulation of neurotransmitters and neuromodulators. The neuropeptide glutamic-acid-isoleucineamide (NEI) acts as a euromodulator in the release of luteinizing hormone (LH) and as a neurotransmitter in certain motivated behaviors as motor activity (MA) and excessive grooming behavior (EGB).This thesis work was performed in order to study the possible regulation of TSH on NEI expression in varioushypothalamic areas and to correlate that changes with the clinical manifestations that occur in these pathologies at the reproductive and central levels. For this aim a rat model ofhypo- and hyperthyroidism was developed in adult male and females during the estrous cycle. A series of hypothalamic regions involved in the control of reproduction and motivated behaviors were studied. NEI was determined by radioimmunoassay, immunohistochemistry and immunofluorescence methods. The relation of NEI with other molecules such as tyrosine hydroxylase (TH) and glutamic-acid-decarboxylase (GAD) and its possible modification secondary to the changes on thyroid hormones levels was studied.

Growth hormone response to growth hormone-releasing peptide-2 in growth hormone-deficient Little mice

OBJECTIVE: To investigate a possible direct, growth hormone-releasing, hormone-independent action of a growth hormone secretagogue, GHRP-2, in pituitary somatotroph cells in the presence of inactive growth hormonereleasing hormone receptors. MATERIALS AND METHODS: The responses of serum growth hormone to acutely injected growth hormone-releasing P-2 in lit/litmice, which represent a model of GH deficiency arising frommutated growth hormone-releasing hormonereceptors, were compared to those observed in the heterozygous (lit/+) littermates and wild-type (+/+) C57BL/6J mice. RESULTS: After the administration of 10 mcg of growth hormone-releasing P-2 to lit/lit mice, a growth hormone release of 9.3±1.5 ng/ml was observed compared with 1.04±1.15 ng/ml in controls (p<0.001). In comparison, an intermediate growth hormone release of 34.5±9.7 ng/ml and a higher growth hormone release of 163±46 ng/ml were induced in the lit/+ mice and wild-type mice, respectively. Thus, GHRP-2 stimulated growth hormone in the lit/lit mice, and the release of growth hormone in vivo may be only partially dependent on growth hormone-releasing hormone. Additionally, the plasma leptin and ghrelin levels were evaluated in the lit/lit mice under basal and stimulated conditions. CONCLUSIONS: Here, we have demonstrated that lit/lit mice, which harbor a germline mutation in the Growth hormone-releasing hormone gene, maintain a limited but statistically significant growth hormone elevation after exogenous stimulation with GHRP-2. The present data probably reflect a direct, growth hormone-independent effect on Growth hormone S (ghrelin) stimulation in the remaining pituitary somatotrophs of little mice that is mediated by growth hormone S-R 1a.

Motilin receptor expression in the interstitial cells of Cajal / 中华儿科杂志

<p><b>OBJECTIVE</b>To look for the evidences of motilin receptor expression on interstitial cells of Cajal (ICC) of the rabbit.</p><p><b>METHOD</b>Smooth muscle segments with ICC were isolated from the small intestine of 10-day old rabbits. The tissue segments equilibrated in Ca(2+)-free Hanks' solution were dispersed with an enzyme solution containing collagenase type II and then Ficoll density centrifugation was used to dissociate ICC. The cells were suspended and cultured in the M199 medium. The c-kit antibody was applied to distinguish the cultured ICC. The motilin receptor was identified by immunocytochemical assay with GPR38 antibody, c-kit antibody and hoechst 33342 combined to label ICC. Cells cultured for a few days were sorted for ICC with c-kit stained green fluorescent through flow cytometry. The total RNA and proteins extracted from the sorted ICC were respectively used to verify motilin receptor on the ICC by reverse-transcriptase polymerase chain reaction (RT-PCR) and Western blotting.</p><p><b>RESULT</b>We had successfully dissociated and cultured ICC of rabbit small intestine in vitro. Fluorescent staining with c-kit antibody confirmed that the culture ICC was successful. Triple-labeled immunofluorescent staining had detected the motilin receptor on membrane of ICC. Flow cytometry analysis showed that the ratio of c-kit positive cell in the cultured cells was 64.3%. The number of sorted ICC was 6.7 × 10(5) and 5.6 × 10(6). The results of RT-PCR and Western blot confirmed that the ICC had motilin receptor expression.</p><p><b>CONCLUSION</b>Our study demonstrated presence of motilin receptor on ICC of the rabbit. The present results may suggest that ICC play an important role in gastrointestinal movement induced by motilin.</p>

Cardiovascular effect of intracerebroventricular injection of orexin-1 receptor antagonist in rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To study the cardiovascular effect of selective orexin-1 receptor (OX1R) antagonist SB408124 in anesthetized rats and explore the underlying mechanism by using intracerebroventricular (ICV) microinjection combined with immunohistochemical assay.</p><p><b>METHODS</b>The changes of mean arterial blood pressure (MAP) and heart rate (HR) of male Sprague-Dawley rats were recorded during ICV microinjection of SB408124 with or without pretreatment of atropine methyl nitrate or hexamethonium bromide. Furthermore, tyrosine hydroxylase (TH) immunopositive neurons in the rostral ventrolateral medulla (RVLM) of the rat were detected with immunohistochemical assay after ICV microinjection of SB408124.</p><p><b>RESULTS</b>ICV administration of SB408124 resulted in a significant decrease in MAP in anesthetized rats, which was accompanied with a mild decrease in HR. The cardiovascular responses elicited by SB408124 were not abolished by pretreatment of atropine methyl nitrate whereas fully abolished by pretreatment of hexamethonium bromide. The number of TH-immunopositive neurons in rat RVLM were significantly decreased following ICV administration of SB408124.</p><p><b>CONCLUSION</b>ICV microinjection of selective OX1R antagonist SB408124 can cause decreases of MAP and HR mediated by inhibiting sympathetic activity in anesthetized rats.</p>

Effect of interstitial cells of Cajal on gastrointestinal motility induced by motilin receptor agonist ABT-229 / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate the effect of interstitial cells of Cajal (ICC) on contraction of intestinal tract smooth muscle induced by motilin receptor agonist.</p><p><b>METHODS</b>Two kinds of smooth muscle segments were isolated from the duodenum and colon of rabbit. Both kinds of smooth muscle were divided into two groups: group a (normal ICC group of duodenum); group c (impaired ICC group of duodenum); group b (normal ICC group of colon); group d (impaired ICC group of colon), each group contained 20 segments. The impairment of ICC was induced by selectively destroying ICC in the smooth muscle via treatment with methylene blue plus light. Then the frequency and amplitude of contraction of group a and c, group b and d was compared. Then motilin receptor agonist (ABT-229) was added into the Krebs solution, the frequency and amplitude of smooth muscle contraction before and after adding ABT-229 were recorded and compared.</p><p><b>RESULTS</b>The electron microscopy demonstrated that ICC in methylene blue plus light group were destroyed; the smooth muscle cells and neuron scattered close to ICC were normal. In group a, the contraction frequency, (17.89 +/- 1.88) times/min, was significantly lower as compared with that measured after ABT-229 was added [(18.76 +/- 1.18) times/min (P > 0.05)]; the amplitude of group a was (343 +/- 28) mg, which was lower as compared with that after adding ABT-229 [(597 +/- 68) mg (P < 0.001)]; in group b, the frequency was (5.89 +/- 1.03) times/min, the amplitude was (724 +/- 85) mg, after ABT-229 was added, the construction frequency increased to (8.45 +/- 0.69) times/min (P < 0.001), and the amplitude was (897 +/- 89) mg (P < 0.05), which was not affected by pretreatment with TTX, however it could be weakened by nifedipine significantly. In group c and d, the rhythmic contraction almost disappeared: in group c the contraction frequency was (1.06 +/- 0.24) times/min, and the amplitude were (50 +/- 10) mg. In group d, the amplitude and frequency significantly decreased as compared with the normal group (P < 0.001), in group c, and d, no significant difference in amplitude and frequency was found between the values measured before and after adding ABT-229 (P > 0.05). After Ach (100 micromol/L) was added, both group c and d could generate contraction.</p><p><b>CONCLUSION</b>ICC may play an important role in the rhythmic contraction of intestinal tract. The promoting effect of motilin receptor agonist on intestinal tract may be mediated by ICC. ICC deficiency may cause functional impairment of gastrointestinal tract motivation. The medication may become ineffective when the number of ICC is reduced to a certain extent or the network of ICC is incomplete.</p>

Neuroendocrine Regulation of Growth Hormone Secretion / 대한소아내분비학회지

The regulation of growth hormone (GH) secretion is, to a larger extent, controlled by three hypothalamic hormones: GH-releasing hormone (GHRH), somatostatin, and ghrelin. Each binds to G protein-linked membrane receptors through which signaling occurs. We used a series of genetic and transgenic animal models with perturbations of individual compounds of the GH regulatory system to study somatotrope signaling. Impaired GH signaling is present in the lit mouse, which has a GHRH receptor (GHRH-R) mutation, and the dw rat, which has a post-receptor signaling defect. Both models also have impaired response to GH secretagogues (GHS), implying an interaction between the two signaling systems. The spontaneous dwarf rat (SDR), in which a mutation of the GH gene results in total absence of the hormone, shows characteristic changes in the hypothalamic regulatory hormones due to an absence of GH feedback and alterations in the expression of each of their pituitary receptors. Treatment of SDRs with GHRH and a GHS has allowed demonstration of a stimulatory effect GHRH on GHRH-R and GHS-R, and somatostatin receptor type 2 (sst2) expression and an inhibitory effect on sst5 expression. GH also modifies the expression of these receptors, though its effects are seen at later time periods and appear to be indirect. In the absence of GH negative feedback, both hypothalamic and pituitary expression is altered to favor stimulation of GH synthesis and release. However, in the presence of GH negative feedback, both hypothalamic and pituitary expression is altered to favor suppression of GH synthesis and release. Loss of liver insulin-like growth factor I (IGF-I) feedback on the hypothalamic-pituitary system increases GH secretion, which, in turn, stimulates liver growth. Depletion of liver-derived IGF-I increases the expression and sensitivity of pituitary GHRH-R and GHS-R. The major site of action of liver-derived IGF-I in the regulation of GH secretion is at the pituitary level. Neuropeptide Y (NPY) is not required for basal regulation of the GH axis. NPY is required for fasting-induced suppression of GHRH and SRIH expression. NPY is also required for fasting-induced augmentation of pituitary GHS-R mRNA. Overall, the results indicate a complex regulation of GH secretion in which somatotrope receptor, as well as ligand expression, exerts an important physiological role.

Role of Glucocorticoids in Fasting-induced Changes in Hypothalamic and Pituitary Components of the Growth Hormone (GH)-axis

To directly test if elevated glucocorticoids are required for fasting-induced regulation of growth hormone (GH)-releasing hormone (GHRH), GHRH receptors (GHRH-R) and ghrelin receptors (GHS-R) expression, male rats were bilaterally adrenalectomized or sham operated. After 7 days, animals were fed ad libitum or fasted for 48 h. Bilateral adrenalectomy increased hypothalamic GHRH to 146% and decreased neuropeptide Y (NPY) mRNA to 54% of SHAM controls. Pituitary GHRH-R and GHS-R mRNA levels were decreased by adrenalectomy to 30% and 80% of sham-operated controls. In sham- operated rats, fasting suppressed hypothalamic GHRH (49%) and stimulated NPY (166%) mRNA levels, while fasting increased pituitary GHRH-R (391%) and GHS-R (218%) mRNA levels. However, in adrenalectomized rats, fasting failed to alter pituitary GHRH-R mRNA levels, while the fasting-induced suppression of GHRH and elevation of NPY and GHS-R mRNA levels remained intact. In fasted adrenalectomized rats, corticosterone replacement increased GHRH-R mRNA levels and intensified the fasting-induced decrease in GHRH, but did not alter NPY or GHS-R response. These data suggest that elevated glucocorticoids mediate the effects of fasting on hypothalamic GHRH and pituitary GHRH-R expression, while glucocorticoids are likely not the major determinant in fasting-induced increases in hypothalamic NPY and pituitary GHS-R expression.

Expression of motilin in the hypothalamus and the effect of central erythromycin on gastric motility in diabetic rats / 神经科学通报·英文版

<p><b>OBJECTIVE</b>To investigate the expression of motilin-immunoreactive neurons in the hypothalamus and the effect of central administration of erythromycin (EM) on the regulation of gastric motility in diabetic rats.</p><p><b>METHODS</b>The motilin immunoreactive neurons in the hypothalamus and the hippocampus were detected by immunohistochemistry with rabbit anti-motilin polyclonal antibody. To measure the gastric motility, force transducers were surgically affixed to the gastric serosa. A microinjection syringe was connected via a plastic tube to an injection cannula, which was connected with a stainless steel guide cannula. The syringe was inserted into the right lateral cerebral ventricle for microinjecting the chemicals.</p><p><b>RESULTS</b>Diabetic mellitus was successfully induced in cohorts of rats. Motilin-immunoreactive neurons significantly increased in the paraventricular (PVN) and supraoptic nuclei (SON) of the hypothalamus in the diabetic rats. Intracerebroventricular (i.c.v.) administration of EM, a motilin receptor agonist, stimulated the gastric motility of diabetic rats. EM (91.56 nmol, i.c.v.) dose-dependently increased the amplitude by (174.82 +/- 48.62)% (P<0.05), and increased the frequency by (70.43 +/- 27.11)% (P < 0.05) in 5 min. The stimulatory effect lasted more than 15 min to the end of the measurement, and can be blocked partially by the prior treatment of motilin receptor antagonist GM-109.</p><p><b>CONCLUSION</b>Motilin-immunoreactive neurons are increased in the PVN and SON of the hypothalamus in diabetic rats. Centrally administered EM may regulate gastric motility by binding to the central motilin receptors, and central motilin might be involved in regulation of gastric motility in diabetic rats.</p>

Effects of motilin agonists on intracellular calcium mobilization in cultured rat myenteric neurons / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of motilin agonists on intracellular Ca(2+) mobilization in primary cultured rat myenteric neurons.</p><p><b>METHODS</b>Motilin-induced and erythromycin-induced intracellular Ca(2+) signaling was studied in primary cultures of rat myenteric neurons using the radiometric Ca(2+) indicator Furo3/AM with a laser confocal microscope.</p><p><b>RESULTS</b>In Hank's solution, 10(-8), 10(-7), and 10(-6) mol/L motilin could elevate intracellular Ca(2+) concentration ([Ca(2+)]i) to the peak levels of 10.6-/+2.1, 15.9-/+1.2, and 30.6-/+3.7 respectively with their relative percentage change in fluorescent intensity of (40.1-/+6.3)%, (63.0-/+11.2)%, and (100.8-/+18.4)% respectively, indicating the dose-dependent effect of motilin on [Ca(2+)]i. In Hank's solution, 10 microg/ml erythromycin could induce the elevation of [Ca(2+)]i to the average peak of 23.2-/+5.6 with the relative percentage change in fluorescent intensity of (82.8-/+13.0)%. When pretreated with the antibody against motilin receptor in Hank's solution, the effect of 10 microg/ml erythromycin was almost inhibited completely.</p><p><b>CONCLUSION</b>Motilin can increase [Ca(2+)]i, and erythromycin also has this effect by binding to motilin receptor.</p>

Expression of Neuropeptides and Their Receptors in Psoriatic Lesions / 대한피부과학회지

BACKGROUND: Neuroimmunocutaneous system alteration can be responsible for the induction and maintenance of the inflammatory process of psoriasis. OBJECTIVE: This study was carried out to examine the expression of Substance P (SP), calcitonin gene-related peptide (CGRP), somatostatin (SOM), neutral endopeptidase (NEP), SP receptor, and CGRP receptor in psoriatic lesions. METHODS: A skin biopsy was obtained from 10 psoriatic patients and 10 normal control subjects. Confocal laser scanning microscopy was performed. RESULTS: The SP and CGRP receptors consistently increased in psoriatic lesions, compared to the normal controls. CONCLUSION: The increased expression of neuropeptides and their receptors may be involved in the pathogenesis of psoriasis.

Effect of motilin receptor agonist-erythromycin on the glucose responsive neurons in hypothalamus of rats / 中国应用生理学杂志

<p><b>AIM</b>In order to explore the mechanism of central motilin-induced feeding behavior, the effects of erythromycin, a motilin receptor agonist, on glucose responsive neurons in hypothalamus were observed.</p><p><b>METHODS</b>Extracellular recordings were made from single neurons in region of lateral hypothalamic area (LHA) and ventromedial hypothalamic nucleus (VMH) in anesthetized rats. On the basis of their responsiveness to intracarotid injection of 0.58 mol/L glucose solution 0.2 ml, glucose-sensitive neurons (GSNs) in LHA and glucoreceptor neurons (GRNs) in VMH were recognized. Effects of intracerebroventricularly (i. c. v.) administration of 4 microg erythromycin on neural activities of glucose responsive neurons and non-glucose responsive neurons were examined. The mixture of EM and GM-109 1 microl were used to GSNs and GRNs which were sensitive to i. c. v. administration of EM.</p><p><b>RESULTS</b>In LHA, EM increased activity of GSNs significantly (P < 0.05 vs non-glucose-sensitive neurons group). Whereas in VMH, EM significantly decreased the activities of GRNs (P < 0.01 vs non-glucoreceptor neurons group). The mixture of EM and GM-109 had no effect on GSNs and GRNs.</p><p><b>CONCLUSION</b>EM, a motilin receptor agonist, can stimulate GSNs in LHA and suppress GRNs in VMH and this may contribute to central motilin's effect on feeding behavior.</p>

Effects of acute hypoglycemia on the orexin system in rat / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To evaluate the effects of acute glucose level changes on expression of prepro-orexin, orexin 1 receptor (OX1R) and orexin 2 receptor (OX2R) mRNA in rat hypothalamus tissue and pancreatic islets cells.</p><p><b>METHODS</b>Thirty adult male Wistar rats were randomly divided into three equal groups (n = 10). The acute hypoglycemia rat model was induced by a single subcutaneous injection of insulin. Twenty acute hypoglycemia rats were divided into group B and group C. Group B was allowed to eat freely, while group C was food-deprived. Control rats were injected the same volume of saline. The effect of glucose levels (2.8 mmol/L and 8.3 mmol/L) on pancreatic islet cell orexin system was detected in pancreas islet cell cultured in vitro. The expression of prepro-orexin and OXR mRNA was examined in rat hypothalamus tissue and pancreatic islets cell cultured in vitro using reverse transcription-polymerase chain reaction (RT-PCR).</p><p><b>RESULTS</b>Expression of orexin mRNA increased about 150% for the food-deprived hypoglycemia rats in comparison with control group (P < 0.01), whereas expression of OX1R mRNA decreased up to 30% (P < 0.01). However, expression of OX2R mRNA was unchanged in comparison with control group. In vitro, after incubation with 2.8 mmol/L glucose for 6 hours, the expression of prepro-orexin mRNA increased 2 times in rat pancreas islet cells in comparison with 8.3 mmol/L glucose group (P < 0.01). But the expression of OX1R mRNA was not sensitive to acute glucose fluctuation.</p><p><b>CONCLUSIONS</b>Orexin in rat hypothalamus is stimulated by decline in blood glucose and inhibited by signals related to feeding. Moreover, glucose plays a role in modulating the gene expression of prepro-orexin in rat pancreatic islet cells.</p>

Hormônio do crescimento ou somatotrófico: novas perspectivas na deficiência isolada de GH a partir da descrição da mutação no gene do receptor do GHRH nos indivíduos da cidade de Itabaianinha, Brasil / Growth or somatotrophic hormone: new perspectives in isolated GH deficiency after description of the mutation in the GHRH receptor gene in individuals of Itabaianinha county, Brazil

Além de influenciar o crescimento corpóreo, o hormônio do crescimento, ou somatotrófico, desempenha importante papel no metabolismo, composição corporal, perfil lipídico, estado cardiovascular e longevidade. Seu controle é multi-regulado por hormônios, metabólitos e peptídeos hipotalâmicos. Dados sobre a Deficiência Isolada de GH (DIGH) obtidos a partir da descrição da mutação IVS1+1G®A no gene do receptor do hormônio liberador do GH (GHRH-R) em indivíduos da cidade de Itabaianinha, SE, são revisados. São abordadas novas perspectivas sobre o modelo de resistência ao GHRH, a importância do GHRH no controle da secreção de GH, a freqüência das mutações do gene do GHRH-R, a relevância diagnóstica do IGF-I e os achados metabólicos, cardiovasculares e de qualidade de vida nestes indivíduos.

Expression of orexin A, orexin receptor-1, and Ob-R of hypothalamus in rats with chronic renal failure / 中国医学科学院学报

<p><b>OBJECTIVE</b>To examine the changes of expressions of orexin A, orexin receptor-1 (OX1R), prepro-orexin (Prepro-OX) mRNA, OX1R mRNA and ob-R of hypothalamus in rats with chronic renal failure (CRF).</p><p><b>METHODS</b>Sixty-two male Wister rats weighing 200-250 g were divided into three groups, including group 1 (normal, n = 5), group 2 (sham-operated, n = 25) and group 3 (CRF, n = 32). Hypothalamus orexin A was assayed by radioimmunoassay. Serum leptin was assayed by enzyme linked immunosorbent assay. The expression of Prepro-OX mRNA and OX1R mRNA of hypothalamus were measured by reverse transcription polymerase chain reaction, and expression of orexin A, OX1R and ob-R by immunohistochemistry. Automatic biochemical analyzer was used to measure the serum creatinine.</p><p><b>RESULTS</b>Hypothalamus orexin A levels were negatively correlated (r = -0.63, P < 0.001) with serum leptin levels in the rats. The expression of hypothalamus Prepro-OX mRNA in CRF rats was significantly lower than that of sham-operation at week 12 (P < 0.01). Hypothalamus Prepro-OX mRNA levels were negatively correlated (r = -0.81, P < 0.001) with the levels of serum leptin and serum creatinine (r = -0.68, P < 0.05) in the rats at week 12. The expression of hypothalamus OX1R mRNA in CRF rats was lower than that of sham-operation at week 12 (P > 0.05). Specific immunoreactivity for orexin A was present in perikeryon of the hypothalamus neuron. Specific OX1R-like immunoreactivity was observed in some nerve fibres. Specific immunoreactivity for ob-R was present in membranes of the hypothalamus neuron. Hypothalamus neurons of orexin A-like specific immunoreactivity in CRF rats were significantly fewer than those in shamoperated rats at week 8. Hypothalamus neurons of OX1R-like specific immunoreactivity in CRF rats were similar to those in sham-operated rat at week 8. Hypothalamus neurons of ob-R-like specific immunoreactivity in CRF rats were significantly more than those in sham-operated rats at week 8.</p><p><b>CONCLUSIONS</b>The lower hypothalamus orexin A levels may be induced by high serum leptin level in CRF rats. The lower expression of hypothalamus Prepro-OX mRNA in CRF rats may be one of the main causes inducing lower hypothalamus orexin A. The expression of OX1R in hypothalamus neurons is somewhat reduced and the expression of ob-R in hypothalamus neurons is somewhat raised in CRF rats. These remain to be studied further.</p>

Neuropeptídios e dermatologia / Neuropeptides and dermatology

Os autores apresentam novos conceitos científicos dosneuropeptídeos, que atuam como neurotransmissores, neuro moduladores e neuro hormônios. Sua participaçäo na imunidade cutânea, nos processos de cicatrizaçäo e doenças crônicas da pele, säo evidentes. Os neuropeptídeos agem como mensageiros químicos, interligando o cérebro com os receptores da pele. Existem mais de cinqüenta neuropeptídeos envolvidos na transmissäo de sinais entre as células nervosas e o sistema auto-imune. Säo produzidos na pele neuropeptídeos opióides, que atuariam nas dores e emoçöes, promovendo a integraçäo do sistema neuroimunocutâneo. Uma das propostas do trabalho é uma visäo integrativa da Dermatologia na medicina geral.

Regulación neuropeptídica de la secreción ácido-gástrica / Neuropeptidic regulation of acid-gastric secretion

La secreción ácida gástrica es el resultado de la actividad habitual de las células oxínticas, activadas por un interjuego estimulador e inhibidor de factores que actúan por vía neurocrina, paracrina y endocrina. Hoy se sabe que los centros nerviosos superiores a través del vago, mantienen una influencia permanente sobre estas células y su secreción. El vago fúndico estimula colinérgicamente la célula parietal, y por otro lado, inhibe colinérgicamente la liberación antral de gastrina. El vago antral estimula a través de bombesina y/o péptido liberador de gastrina (PLG) la liberación de gastrina. Además, participa de un mecanismo inhibidor neuroendocrino de la secreción ácida o acción vagogastrona. La alimentación, aminoácidos en especial, provoca el mayor estímulo de la secreción de gastrina, que por vía endocrina sistémica o por vía endocrina portal, constituye el estímulo mas eficiente de la secreción ácida. La regulación o feed-back de la secreción ácida se efectiviza por agonistas y antagonistas neurocrinos, paracrinos o endocrinos, a través de un verdadero tandem integrado por somatostatina, VIP, secretina y GIP, entre otros.