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1.
Auris Nasus Larynx ; 51(1): 99-105, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37120318

ABSTRACT

OBJECTIVE: To determine if tokishakuyakusan (TSS) is effective for treating post-infectious olfactory dysfunction (PIOD) compared with vitamin B12 (mecobalamin). METHODS: We conducted a randomized, nonblinded clinical trial. Patients with PIOD enrolled in 17 hospitals and clinics from 2016 to 2020 were randomly divided into two groups, and we administered TSS or mecobalamin for 24 weeks. Their olfactory function was examined using interviews and T&T olfactometry. The improvement of olfactory dysfunction was assessed following the criteria of the Japanese Rhinologic Society. RESULTS: Overall, 82 patients with PIOD were enrolled in this study. In the TSS and mecobalamin groups, 39 patients completed the medication regimen. In the TSS and mecobalamin groups, olfactory dysfunction was significantly improved based on self-reports and olfactory test results. The improvement rate of olfactory dysfunction was 56% in the TSS group and 59% in the mecobalamin group. Early intervention within 3 months produced a better prognosis than the treatment initiated after 4 months. Furthermore, age and sex differences were not observed. Both medications produced no severe adverse events. CONCLUSION: The present study showed that TSS and mecobalamin might be useful for treating PIOD.


Subject(s)
Drugs, Chinese Herbal , Olfaction Disorders , Smell , Vitamin B 12/analogs & derivatives , Humans , Male , Female , Prospective Studies , Olfaction Disorders/drug therapy , Olfaction Disorders/etiology
2.
Geriatr Gerontol Int ; 21(3): 291-298, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33465821

ABSTRACT

AIM: Olfactory impairment as a prodromal symptom, as well as sarcopenia, frailty and dependence as geriatric syndromes, is often associated with cognitive decline in older adults with progression of Alzheimer's disease. The present study aimed to evaluate the associations of olfactory and cognitive decline with these geriatric syndromes, and with structural changes of the brain in older adults. METHODS: The participants were 135 older adults (47 men and 88 women, mean age 79.5 years), consisting of 64 with normal cognition, 23 with mild cognitive impairment and 48 with Alzheimer's disease. Olfactory function was evaluated by the Open Essence odor identification test. Shrinkage of the regional brain was determined by magnetic resonance imaging. RESULTS: Logistic regression analysis with Open Essence, Mini-Mental State Examination, age and sex as covariates showed higher olfactory-cognitive index (|coefficient for Open Essence (a) / coefficient for Mini-Mental State Examination (b)|) in participants with sarcopenia (Asia Working Group for Sarcopenia), and lower values of (|a/b|) in participants with Barthel Index dependence, Kihon Checklist frailty, Lawton Index dependence and support/care-need certification as objective variables. Logistic regression analysis adjusted by age and sex also showed significant shrinkage of the frontal lobe in participants with AWGS sarcopenia, especially in women, and shrinkage of the medial temporal areas and global brain in participants with Kihon Checklist frailty/dependence. CONCLUSIONS: Olfactory-cognitive index (|a/b|) might be a useful tool to distinguish involvement of frontal lobe shrinkage, as in sarcopenia from shrinkage of the medial temporal areas, and global brain, as in frailty/dependence, in older adults with progression of normal cognition to Alzheimer's disease. Geriatr Gerontol Int 2021; ••: ••-••.


Subject(s)
Brain/diagnostic imaging , Checklist , Frailty , Frontal Lobe/diagnostic imaging , Geriatric Assessment/methods , Activities of Daily Living , Aged , Aged, 80 and over , Cognition , Cross-Sectional Studies , Female , Frailty/diagnosis , Frailty/epidemiology , Humans , Japan/epidemiology , Magnetic Resonance Imaging , Male , Sarcopenia/diagnosis , Sarcopenia/epidemiology
3.
Article in English | MEDLINE | ID: mdl-22327010

ABSTRACT

PURPOSE: To investigate the expression of erbBs in the nasal mucosa of patients with chronic hypertrophic rhinitis. PROCEDURES: Inferior turbinates were collected from 12 turbinectomized patients with allergic and nonallergic chronic hypertrophic rhinitis. Differential cell counts in the peripheral blood and allergy tests were conducted before surgery. The expressions of erbB1, 2, 3 and 4 were examined by fluorescence immunohistochemistry and by quantitative real-time transcription polymerase chain reaction (qRT-PCR). Immunohistochemical fluorescence was quantitatively measured using image-analyzing software. Eosinophils infiltrated into the mucosa were counted in sections stained with Hansel solution. RESULTS: Each of the erbB types 1-4 was expressed in both epithelial cells and nasal gland cells. Immunoreactivity for erbB1 was strong and that for erbB2 and 3 was moderate, while that for erbB4 was faint. These findings were consistent with the results of qRT-PCR. The percentage of peripheral blood eosinophils was significantly correlated with the eosinophil count in the nasal mucosa and with immunoreactivity for erbB1 in the nasal gland. CONCLUSIONS: These results suggest a possible role of eosinophils in regulating erbB1 and thus in regulating mucosal hypertrophy in chronic hypertrophic rhinitis.


Subject(s)
ErbB Receptors/genetics , Nasal Mucosa/physiology , Receptor, ErbB-2/genetics , Receptor, ErbB-3/genetics , Rhinitis, Allergic, Perennial/physiopathology , Adolescent , Adult , Eosinophils/pathology , Eosinophils/physiology , Epidermal Growth Factor/metabolism , ErbB Receptors/metabolism , Female , Gene Expression/physiology , Humans , Hypertrophy , Male , Middle Aged , Nasal Mucosa/pathology , Receptor, ErbB-2/metabolism , Receptor, ErbB-3/metabolism , Receptor, ErbB-4 , Rhinitis, Allergic, Perennial/genetics , Rhinitis, Allergic, Perennial/pathology , Turbinates/pathology , Turbinates/physiology , Young Adult
4.
J Trauma Acute Care Surg ; 72(1): 130-5, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21768895

ABSTRACT

OBJECTIVE: To examine the hypothesis that resuscitative hypothermia would (1) reduce fluid requirements and reactive oxygen species production during a period of resuscitation and (2) improve survival after hemorrhagic shock (HS) in rats. METHODS: Sixteen rats underwent an HS phase (phase I: 0-75 minutes), with pressure-controlled HS at a mean arterial pressure of 30 mm Hg ± 5 mm Hg; a resuscitation phase (phase II: 75-150 minutes), with fluid resuscitation to maintain mean arterial pressure ≥75 mm Hg; and an observation phase (phase III: from 150 minutes to 72 hours). During phase II, eight rats were randomized into a normothermia group (group 1: 38°C) or a hypothermia group (group 2: 34°C). Fluid requirements during phase II and survival at 72 hours were compared between groups. Plasma levels of Vitamin E and %coenzyme Q9 (%CoQ9) were also assessed. RESULTS: The fluid requirement during resuscitation in phase II was 8.2 ± 1.4 mL/100 g in group 1 versus 2.1 mL/100 g ± 0.7 mL/100 g in group 2 (p < 0.01). Vitamin E level decreased to 10.8 µmol/L ± 1.8 µmol/L during HS in all rats. After resuscitation, it was restored to a baseline level of 15.9 µmol/L ± 3.1 µmol/L in group 2 but remained at 10.2 µmol/L ± 0.8 µmol/L in group 1 (p < 0.05). %CoQ9 did not differ significantly between the groups. At 72 hours, six of eight rats in group 1, and all rats in group 2 survived (NS). CONCLUSION: In a rat HS model, hypothermia during resuscitation from HS reduces resuscitation fluid volume required to maintain blood pressure and restores Vitamin E to the baseline level, and appears to have no adverse impact on long survival after HS.


Subject(s)
Blood Pressure , Fluid Therapy , Hypothermia, Induced , Shock, Hemorrhagic/therapy , Animals , Blood Pressure/physiology , Disease Models, Animal , Fluid Therapy/methods , Hemodynamics/physiology , Hypothermia, Induced/methods , Male , Rats , Rats, Sprague-Dawley , Reactive Oxygen Species/blood , Respiratory Rate/physiology , Resuscitation/methods , Shock, Hemorrhagic/physiopathology , Ubiquinone/blood , Vitamin E/blood
5.
Resuscitation ; 82(1): 110-4, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21056525

ABSTRACT

OBJECTIVE: To examine whether reactive oxygen species (ROS) production is affected by arterial oxygen content (CaO(2)) in attempted resuscitation to restore blood pressure from hemorrhagic shock (HS) or not. METHODS: Under light anesthesia and spontaneous beating, 16 rats underwent HS for 80min, during which 3.0mL/100g of blood was withdrawn, followed by resuscitation attempt for 70min. At 80min, rats were randomized into a high-CaO(2) group (Group 1, transfusion under fractional inspired oxygen (F(I)O(2)) of 1.0, n=8) or a low-CaO(2) group (Group 2, fluid administration under F(I)O(2) of 0.21, n=8). In each group, either blood or lactate Ringer's (LR) solution was infused to maintain mean arterial pressure ≥75mmHg under each F(I)O(2) concentration. CaO(2), O(2) utilization coefficient (UC) and plasma %CoQ9 were compared between groups. RESULTS: Mean infused volume for attempted resuscitation was 7.6±1.0mL of blood in Group 1, and 31.4±5.5mL of LR solution in Group 2. At the end of resuscitation, CaO(2) was 18.5±1.2 vol% in Group 1, almost double the 9.1±0.8 vol% in Group 2 (P<0.01). O(2) UC and %CoQ9 in all rats increased from baselines of 0.25±0.12 and 7.6±1.8% to 0.44±0.13 and 9.7±1.8% after resuscitation, respectively (P<0.05 vs. baseline for each), but did not differ significantly between the groups. CONCLUSION: In a rat HS model, attempted resuscitation to restore blood pressure increased O(2) UC as well as %CoQ9. However, the magnitude of %CoQ9 increase that represents ROS production is not affected by CaO(2) during resuscitation from HS.


Subject(s)
Cardiopulmonary Resuscitation/methods , Oxidative Stress/physiology , Oxygen/blood , Resuscitation/methods , Shock, Hemorrhagic/blood , Animals , Blood Pressure , Disease Models, Animal , Male , Rats , Rats, Sprague-Dawley , Reactive Oxygen Species/blood , Shock, Hemorrhagic/physiopathology , Shock, Hemorrhagic/therapy
6.
Eur Arch Otorhinolaryngol ; 268(4): 497-500, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21042804

ABSTRACT

The aim of this study is to develop a regression model for predicting hearing outcome in patients with idiopathic sudden sensorineural hearing loss (ISSNHL). A total of 174 consecutive patients with ISSNHL (average of the hearing levels at 250, 500, 1,000, 2,000, and 4,000 Hz was ≥40 dB; time from onset to treatment was ≤30 days) were retrospectively analyzed. They received steroid administration (400 mg/day of hydrocortisone sodium succinate followed by tapered doses) in combination with hyperbaric oxygen therapy. The hearing improvement rate compared to the unaffected contralateral ear was calculated. Correlations between the hearing improvement rate and four prognostic factors (patient's age, days from onset to treatment, initial hearing level, and the presence of vertigo) were examined by simple and multiple regression analyses. In the simple regression analysis, significant correlations were observed between the hearing improvement rate and all four prognostic factors. In the multiple regression analysis, the correlation was significant for patient's age, days from onset to treatment, and the presence of vertigo with partial correlation coefficients of -0.221, -0.324, and -0.329, respectively, but was not significant for the initial hearing level. We subsequently formulated a multiple regression equation for predicting the hearing improvement rate. The multiple correlation coefficient was 0.495 with a p value of 1.42 × 10(-9). Using this regression model, the hearing improvement rate is still difficult to predict with 95% probability, but is predictable with 70% probability.


Subject(s)
Glucocorticoids/therapeutic use , Hearing Loss, Sensorineural/physiopathology , Hearing Loss, Sudden/physiopathology , Hearing/physiology , Hyperbaric Oxygenation/methods , Recovery of Function , Adolescent , Adult , Aged , Aged, 80 and over , Audiometry , Female , Follow-Up Studies , Hearing Loss, Sensorineural/therapy , Humans , Male , Middle Aged , Prognosis , Retrospective Studies , Young Adult
7.
Neurol Med Chir (Tokyo) ; 50(8): 693-7, 2010.
Article in English | MEDLINE | ID: mdl-20805658

ABSTRACT

A 56-year-old woman with Langerhans cell histiocytosis of the petrous bone presented with sudden onset of sensorineural hearing loss and vertigo without other neurological impairment, mimicking idiopathic sudden sensorineural hearing loss. Differential diagnosis was difficult until neuroimaging demonstrated a lesion of the petrous bone. The patient eventually underwent removal of the lesion via the transpetrosal approach, and received postoperative chemotherapy consisting of vinblastine, methotrexate, 6-mercaptopurine, and prednisolone. Although her hearing did not recover, complete remission was achieved, and the patient is currently free from disease. Physicians need to be aware that patients with sudden onset of hearing loss may have an unexpected and hidden disease which requires neuroimaging and histological examinations for definitive diagnosis and appropriate treatment.


Subject(s)
Bone Diseases/complications , Hearing Loss, Sensorineural/etiology , Histiocytosis, Langerhans-Cell/complications , Petrous Bone/pathology , Vertigo/etiology , Acute Disease , Bone Diseases/pathology , Bone Diseases/therapy , Drug Therapy, Combination , Female , Hearing Loss, Sensorineural/pathology , Histiocytosis, Langerhans-Cell/pathology , Histiocytosis, Langerhans-Cell/therapy , Humans , Middle Aged , Treatment Outcome , Vertigo/pathology
8.
Peptides ; 31(11): 2089-93, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20727931

ABSTRACT

We have recently developed a new transgenic rat line expressing an arginine vasopressin (AVP)-enhanced green fluorescent protein (eGFP) fusion gene. The AVP-eGFP transgene is expressed in the paraventricular (PVN) and supraoptic (SON) nuclei and the suprachiasmatic nucleus (SCN) of the hypothalamus. Transgene expression in the PVN and SON showed an exaggerated response to salt loading and nociceptive stimulation. However, the expression of the AVP-eGFP transgene in the SCN did not change under these stressful conditions. Here, we examined daily profiles of the expression of the AVP-eGFP transgene in the SCN in comparison with the endogenous AVP and Period (Per1 and Per2) genes. While all of these genes elicited diurnal patterns of expression in the SCN, the rate of rhythmic change of transgene expression was significantly greater than that of the endogenous AVP gene. We also examined the effect of a light stimulus on the expression of the AVP-eGFP, AVP, Per1 and Per2 genes in the SCN of transgenic rats. Ninety minutes after a light stimulus, AVP-eGFP mRNA and AVP hnRNA levels in the SCN were significantly decreased, while Per2 mRNA levels were significantly increased. In addition, we observed the eGFP fluorescence in the SCN and recorded the electrophysiological properties of a dissociated SCN eGFP-positive neuron. The AVP-eGFP transgenic rat is a useful animal model to study the diurnal change and dynamics of the AVP system, and enables the facile identification of SCN AVP neurons both in vivo and in vitro.


Subject(s)
Arginine Vasopressin/biosynthesis , Green Fluorescent Proteins/biosynthesis , Recombinant Fusion Proteins/biosynthesis , Animals , Arginine Vasopressin/genetics , Circadian Rhythm , Green Fluorescent Proteins/genetics , Hypothalamus/metabolism , Paraventricular Hypothalamic Nucleus/metabolism , Period Circadian Proteins/biosynthesis , Photic Stimulation , RNA, Messenger/metabolism , Rats , Rats, Transgenic , Recombinant Fusion Proteins/metabolism , Suprachiasmatic Nucleus/metabolism , Transgenes
9.
Stress ; 13(4): 281-91, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20536330

ABSTRACT

We examined the effects of intracerebroventricular (i.c.v.) administration of colchicine on the expression of the arginine vasopressin (AVP)-enhanced green fluorescent protein (eGFP) fusion gene in rats. In rats administered i.c.v. vehicle (control), eGFP fluorescence was observed in the supraoptic nucleus (SON), the magnocellular division of the paraventricular nucleus (PVN), the suprachiasmatic nucleus (SCN), the median eminence (ME) and the posterior pituitary. Two days after i.c.v. administration of colchicine, eGFP fluorescence was markedly increased in the SON, the magnocellular and parvocellular divisions of the PVN, the SCN, the ME and the locus coeruleus (LC). Immunohistochemical staining for eGFP confirmed the distribution of fluorescence in both groups. In the colchicines-administered groups, immunohistochemistry for tyrosine hydroxylase (TH) revealed that the eGFP fluorescence was co-localised with TH-immunoreactivity in the LC. Similarly, in situ hybridization histochemistry for eGFP mRNA revealed a significant increase in gene expression in the LC, the SON and the PVN 12-48 h after administration of colchicine. Our results indicate that the synthesis of AVP-eGFP is upregulated in noradrenergic neurones in the LC after colchicine administration. This implies that AVP and noradrenaline, originating from LC neurones, might play a role in response to chronic stress.


Subject(s)
Arginine Vasopressin/genetics , Green Fluorescent Proteins/genetics , Locus Coeruleus/metabolism , Animals , Animals, Genetically Modified , Colchicine/administration & dosage , Colchicine/pharmacology , Female , Injections, Intraventricular , Osmolar Concentration , Paraventricular Hypothalamic Nucleus/metabolism , RNA, Messenger/metabolism , Rats , Rats, Wistar , Recombinant Fusion Proteins/genetics , Restraint, Physical , Sleep Deprivation , Stress, Psychological , Supraoptic Nucleus/metabolism
10.
Eur Arch Otorhinolaryngol ; 266(8): 1279-83, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19283402

ABSTRACT

Laryngotracheal separation is a simple and reliable operation for the treatment of patients with repetitive and intractable aspiration; however, it is apprehended that pooling in the tracheal blind pouch may cause postoperative complications. In the present study, we examined drainage of the blind pouch created by laryngotracheal separation. Fourteen patients aged 3-63 years with repetitive aspiration pneumonia underwent laryngotracheal separation by the modified Lindeman procedure. A barium swallow was performed 10-30 days after surgery. X-rays of the lateral view of the neck were taken at 6 and 24 h after the swallow, and then every 24 h until the contrast medium cleared. The contrast medium in the blind pouch cleared within 24 h in nine patients. In the remaining five, the clearance time was < or =48 and < or =72 h in two patients each, and 96 h in one patient. The clearance time in patients aged under 20 years was < or =24 h, while middle-aged to elderly patients showed prolonged clearance time. No late complications of the blind pouch, such as infections, were observed. The potential risk of complications caused by pooling in the tracheal blind pouch in laryngotracheal separation is prevented presumably due to the slow but continuous turnover of pooling material. This result supports the validity and usefulness of laryngotracheal separation for the treatment of intractable aspiration.


Subject(s)
Drainage/methods , Larynx/surgery , Pneumonia, Aspiration/surgery , Trachea/surgery , Adolescent , Adult , Anastomosis, Surgical , Child , Child, Preschool , Deglutition Disorders/complications , Deglutition Disorders/diagnosis , Esophagus/surgery , Female , Follow-Up Studies , Humans , Male , Middle Aged , Pneumonia, Aspiration/etiology , Tracheostomy/methods , Treatment Outcome , Young Adult
11.
Neurosci Res ; 61(1): 99-105, 2008 May.
Article in English | MEDLINE | ID: mdl-18355936

ABSTRACT

Orexin-A and -B (identical to hypocretin-1 and -2) are hypothalamic neuropeptides that regulate appetite and arousal. Orexins-producing neurons project their axons to various brain regions, including the olfactory bulb. In the present study, to understand the relationship between orexins and olfaction, we investigated the distribution of the orexin-A- and -B-immunoreactive (ir) fibers in the rat olfactory bulb and the contents of orexin-A and -B in the rat olfactory bulb after food deprivation for 48 h by using immunohistochemistry and radioimmunoassay, respectively. Both orexin-A- and -B-ir fibers are similarly wide spread from the glomerular layer of the olfactory bulb where the terminals of the peripheral olfactory nerves make synapses with the mitral cells or the tufted cells, to the piriform cortex. Dense orexin-A- and -B-ir fibers were observed mainly in the granular cell layer and anterior olfactory nucleus. The contents of orexin-A and -B (pg/10 mg wet weight tissue) in fed rats (mean+/-S.E.M., n=6) were 2.72+/-0.24 and 6.31+/-0.63, respectively. Fasting for 48 h significantly reduced the contents of orexin-B, but not orexin-A. Orexins in the rat olfactory bulb may be involved in not only olfactory system but also energy balance.


Subject(s)
Intracellular Signaling Peptides and Proteins/metabolism , Nerve Fibers/metabolism , Neuropeptides/metabolism , Olfactory Bulb/cytology , Olfactory Bulb/metabolism , Animals , Cerebral Cortex/cytology , Cerebral Cortex/metabolism , Data Interpretation, Statistical , Fluorescent Antibody Technique, Indirect , Food Deprivation/physiology , Glutamate Decarboxylase/metabolism , Immunohistochemistry , Male , Neural Pathways/cytology , Neural Pathways/metabolism , Orexins , Radioimmunoassay , Rats , Rats, Wistar
12.
Peptides ; 28(8): 1596-604, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17681402

ABSTRACT

We investigated the prolactin-releasing peptide (PrRP) mRNA levels in the hypothalamus and brainstem of streptozotocin (STZ)-induced diabetic rats and fa/fa Zucker diabetic rats, using in situ hybridization histochemistry. PrRP mRNA levels in the hypothalamus and brainstem of STZ-induced diabetic rats were significantly reduced in comparison with those of control rats. PrRP mRNA levels in the diabetic rats were reversed by both insulin and leptin. PrRP mRNA levels in the fa/fa diabetic rats were significantly reduced in comparison with those of Fa/? rats. PrRP mRNA levels in the fa/fa diabetic rats were significantly increased by insulin-treatment, but did not reach control levels in the Fa/? rats. We also investigated the effect of restraint stress on PrRP mRNA levels in STZ-induced diabetic rats. The PrRP mRNA levels in the control and the STZ-induced diabetic rats increased significantly after restraint stress. The diabetic condition and insulin-treatment may affect the regulation of PrRP gene expression via leptin and other factors, such as plasma glucose level. The diabetic condition may not impair the role of PrRP as a stress mediator.


Subject(s)
Brain Stem/metabolism , Diabetes Mellitus, Experimental/genetics , Hypothalamic Hormones/genetics , Hypothalamus/metabolism , Neuropeptides/genetics , Animals , Diabetes Mellitus, Experimental/drug therapy , Diabetes Mellitus, Experimental/metabolism , Dorsomedial Hypothalamic Nucleus/metabolism , Down-Regulation , In Situ Hybridization , Insulin/pharmacology , Leptin/pharmacology , Male , Medulla Oblongata/metabolism , Obesity/drug therapy , Obesity/genetics , Obesity/metabolism , Prolactin-Releasing Hormone , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Rats, Wistar , Rats, Zucker , Restraint, Physical/adverse effects , Restraint, Physical/physiology , Solitary Nucleus/metabolism
13.
Peptides ; 28(5): 1104-12, 2007 May.
Article in English | MEDLINE | ID: mdl-17386959

ABSTRACT

Central administration of either adrenomedullin 2 (AM2) or adrenomedullin (AM) activates hypothalamic oxytocin (OXT)-secreting neurons in rats. We compared AM2 with AM, given intracerebroventricularly (icv), across multiple measures: (1) plasma OXT levels in conscious rats; (2) blood pressure, heart rate and circulating catecholamine levels in urethane-anesthetized rats; and (3) the expression of the c-fos gene in the supraoptic (SON) and the paraventricular nuclei (PVN). We also tested the effects of the AM receptor antagonist, AM(22-52) and calcitonin gene-related peptide (CGRP) antagonist, CGRP(8-37) on these measures. Plasma OXT levels at 10 min after icv injection of AM (1 nmol/rat) were increased (compared with vehicle), but OXT levels after AM2 (1 nmol/rat) were nearly double the levels seen after AM injection. OXT levels remained elevated at 30 min. Pretreatment with AM(22-52) (27 nmol/rat) and CGRP(8-37) (3 nmol/rat), nearly abolished the increase in plasma OXT level after AM injection, but partially blocked OXT level changes due to AM2. Increases in blood pressure, heart rate and circulating catecholamines were all greater in response to central AM2 than to AM at the same dose. In situ hybridization histochemistry showed that both AM2 and AM induced expression of the c-fos gene in the SON and the PVN, but AM(22-52)+CGRP(8-37) could only nearly abolish the effects of centrally administered AM. These results suggest that the more potent central effects of AM2 and only partial blockade by AM/CGRP receptor antagonists may result from its action on an additional, as yet unidentified, specific receptor in the central nervous system.


Subject(s)
Adrenomedullin/pharmacology , Hypothalamus/drug effects , Neurons/drug effects , Neuropeptides/pharmacology , Oxytocin/metabolism , Adrenomedullin/administration & dosage , Adrenomedullin/chemistry , Animals , Calcitonin Gene-Related Peptide/administration & dosage , Calcitonin Gene-Related Peptide/pharmacology , Gene Expression/drug effects , Genes, fos/genetics , Hypothalamus/cytology , Hypothalamus/metabolism , In Situ Hybridization , Male , Neurons/cytology , Neurons/metabolism , Neuropeptides/administration & dosage , Neuropeptides/chemistry , Oxytocin/blood , Paraventricular Hypothalamic Nucleus/drug effects , Paraventricular Hypothalamic Nucleus/metabolism , Peptide Fragments/administration & dosage , Peptide Fragments/pharmacology , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Rats, Wistar , Receptors, Adrenomedullin , Receptors, Peptide/antagonists & inhibitors , Supraoptic Nucleus/drug effects , Supraoptic Nucleus/metabolism , Sympathetic Nervous System/drug effects , Sympathetic Nervous System/physiology , Time Factors
14.
Endocrinology ; 148(4): 1638-47, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17255209

ABSTRACT

Ghrelin is known as a potent orexigenic hormone through its action on the brain. In this study, we examined the effects of intracerebroventricular (icv) and iv injection of ghrelin on water intake, food intake, and urine volume in rats deprived of water for 24 h. Water intake that occurred after water deprivation was significantly inhibited by icv injection of ghrelin (0.1, 1, and 10 nmol/rat) in a dose-related manner, although food intake was stimulated by the hormone. The antidipsogenic effect was as potent as the orexigenic effect. Similarly, water intake was inhibited, whereas food intake was stimulated dose dependently after iv injection of ghrelin (0.1, 1, and 10 nmol/kg). The inhibition of drinking was comparable with, or even more potent than, atrial natriuretic peptide (ANP), an established antidipsogenic hormone, when administered icv, although the antidipsogenic effect lasted longer. ANP had no effect on food intake. Urine volume decreased dose relatedly after icv injection of ghrelin but not by ANP. Intravenous injection of ghrelin had no effect on urine volume. Because drinking usually occurs with feeding, food was withdrawn to remove the prandial drinking. Then the antidipsogenic effect of ghrelin became more potent than that of ANP and continued longer than when food was available. Expression of Fos was increased in the area postrema and the nucleus of the tractus solitarius by using immunohistochemistry after icv and iv injection of ghrelin. The present study convincingly showed that ghrelin is a potent antidisogenic peptide in rats.


Subject(s)
Drinking/drug effects , Peptide Hormones/administration & dosage , Animals , Brain/drug effects , Brain/metabolism , Dose-Response Relationship, Drug , Eating/drug effects , Ghrelin , Injections, Intravenous , Injections, Intraventricular , Male , Proto-Oncogene Proteins c-fos/metabolism , Rats , Rats, Wistar , Time Factors , Urine
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