The Effect of Umami Stimulation on Salivary Secretion Rate and Duration

Purpose: Umami reportedly promotes salivation. We aimed to investigate the effects of taste stimuli on slow and fast salivary secretion in humans using umami, sweet, and sour stimuli. Methods: Eight healthy women participated between 14:00 and 15:00, taking the circadian rhythm of salivary secretion into account. The types and concentrations of the taste solutions were glutamic acid (1.7 × 10−3 M), inosinic acid (9.8 × 10−3 M), and guanylic acid (9.8 × 10−3 M) for umami stimulation, citric acid (6.5 × 10−3 M) for acidity stimulation, and sucrose (1.6 × 10−2 M) for sweetness stimulation. First, the unstimulated salivary flow rate was measured. Then, 3 ml of a flavor solution was dropped under the tongue using a syringe. The saliva was expelled into an aluminum cup every minute and weighed. The first minute’s value minus 3 ml flavor solution was the stimulated salivary secretion rate produced by each flavor. The time-to-return to the initial unstimulated salivary flow rate was the duration of the stimulated saliva secretion rate. Results: The mean unstimulated salivary flow rate across participants was 0.64 ± 0.25 ml/min (range: 0.23 - 1.03 ml/min). The highest amount of saliva was induced by citric acid. There were significant differences between citric acid and the other flavor solutions (p < 0.05 for glutamic acid, inosinic acid, and sucrose;p < 0.01 for guanylic acid). There were no significant differences in duration of salivation between the flavor solutions. When the participants were divided into slow (0.45 ± 0.16 ml/min) and fast groups (0.83 ± 0.15 ml/min) based on their median resting salivary secretion rate, there were no significant differences between the two groups in the amount of saliva secreted at 1 minute after stimulation and the duration of the salivary secretion rate. Conclusion: Umami stimulation was effective in slowing salivary secretion and sustaining salivary secretion after stimulation.

Mannogalactoglucan from mushrooms protects pancreatic islets via restoring UPR and promotes insulin secretion in TIDM mice

Type 1 diabetes mellitus(T1DM) lacks insulin secretion due to autoimmune deficiency of pancreaticβ-cells.Protecting pancreatic islets and enhancing insulin secretion has been therapeutic approaches.Mannogalactoglucan is the main type of polysaccharide from natural mushroom,which has potential medicinal prospects.Nevertheless,the antidiabetic property of mannogalactoglucan in T1DM has not been fully elucidated.In this study,we obtained the neutral fraction of alkali-soluble Armillaria mellea polysaccharide(AAMP-N) with the structure of mannogalactoglucan from the fruiting body of A.mellea and investigated the potential therapeutic value of AAMP-N in T1DM.We demonstrated that AAMP-N lowered blood glucose and improved diabetes symptoms in T1DM mice.AAMP-N activated unfolded protein response(UPR) signaling pathway to maintain ER protein folding homeostasis and promote insulin secretion in vivo.Besides that,AAMP-N promoted insulin synthesis via upregulating the expression of transcription factors,increased Ca^(2+) signals to stimulate intracellular insulin secretory vesicle transport via activating calcium/calmodulin-dependent kinase Ⅱ(CamkⅡ) and cAMP/PKA signals,and enhanced insulin secretory vesicle fusion with the plasma membrane via vesicle-associated membrane protein 2(VAMP2).Collectively,these studies demonstrated that the therapeutic potential of AAMP-N on pancreatic islets function,indicating that mannogalactoglucan could be natural nutraceutical used for the treatment of T1DM.

Pleomorphic rhabdomyosarcoma of the vagina: A case report

BACKGROUND Rhabdomyosarcoma(RMS)of the vagina in postmenopausal women is an extre-mely rare malignant tumor that was originally described as a unique group of soft tissue sarcomas originating from primitive mesenchymal cells.It was first re-ported in postmenopausal women in 1970,and fewer than 50 postmenopausal patients have been reported to date.CASE SUMMARY A 68-year-old multiparous female was admitted to the hospital on October 11,2023,with the chief complaint of a mass causing vaginal prolapse with incomplete urination that had persisted for 4 months.The vaginal mass was approximately the size of a pigeon egg;after lying down,the vaginal mass retracted.Complete resection was performed,and vaginal pleomorphic RMS was diagnosed based on pathology and immunohistochemical staining features.The patient is currently undergoing chemotherapy.The present study also reviewed the clinical,histolo-gical,and immunohistochemical features and latest treatment recommendations for vaginal RMS.Any abnormal vaginal mass should be promptly investigated through pelvic examination and appropriate imaging.The current initial treat-ment for vaginal RMS is biopsy and primary chemotherapy.CONCLUSION When surgery is planned for vaginal RMS,an organ-preserving approach should be considered.

Short-Term Effects of Liraglutide versus Vildagliptin on Insulin Secretion and Sensitivity in Type 2 Diabetes: A Single Blinded Randomized Controlled Trial (LIRAVIS Study)

Background: We aimed to evaluate the short-term metabolic effects of a GLP-1a, (liraglutide) versus a DPP-4i, (vildagliptin) in a group of sub-Saharan type 2 diabetes patients. Methods: We conducted a randomized controlled single blinded clinical trial in 14 uncontrolled type 2 diabetes patients (HbA1c ≥ 53 mmol/mol) with mean duration of diabetes of 8 [1 - 12] years and median age of 57 [49 - 61] years. Baseline treatment consisted of metformin in monotherapy or metformin plus sulfonylureas. Participants were randomly allocated to 2 groups of add-on 1.2 mg/day subcutaneous liraglutide in group 1 or 100 mg/day of oral vildagliptin in group 2 for 2 weeks. In all participants, insulin secretion in response to mixed meal tolerance test, insulin sensitivity by 80 mU/m2/min hyperinsulinemic-euglycemic clamp, body composition, and lipid profile were measured before and after intervention. Results: At the end of intervention, insulin sensitivity remained unchanged both with liraglutide from 6.6 [4.2 - 7.9] to 6.9 [4.3 - 10.8] mg/kg/min;p = 0.61 and vildagliptin from 7.1 [5.3 - 9.0] to 6.5 [5.6 - 9.4] mg/kg/min (p = 0.86). The area under the C-peptide curve varied from 5.5 [1.0 - 10.9] to 14.9 [10.8 - 17.2] nmol/L/120min, p = 0.09 in group 1 and from 1.1 [0.5 - 14.1] to 13.0 [9.6 - 16.9] nmol/L/120min (p = 0.17) in group 2. LDL Cholesterol levels decreased significantly with liraglutide from 0.85 g/L [0.51 - 1.02] to 0.54 g/L [0.50 - 0.73] (p = 0.04) but not with Vildagliptin. Body weight tended to decrease in group 1 (−0.6 kg) versus modest increase in group 2 (+1.1 kg). Conclusion: Short-term metabolic effects of Liraglutide and Vildagliptin add-on therapy are comparable in sub-Saharan type 2 diabetes patients with a more favorable trend for Liraglutide on body weight, lipid profile, and insulin secretion.

Neurotransmitters regulateβcells insulin secretion:A neglected factor

βcells are the main cells responsible for the hypoglycemic function of pancreatic islets,and the insulin secreted by these cells is the only hormone that lowers blood glucose levels in the human body.βcells are regulated by various factors,among which neurotransmitters make an important contribution.This paper discusses the effects of neurotransmitters secreted by various sympathetic and parasympathetic nerves onβcells and summarizes the mechanisms by which various neurotransmitters regulate insulin secretion.Many neurotransmitters do not have a single source and are not only released from nerve terminals but also synthesized byβcells themselves,allowing them to synergistically regulate insulin secretion.Almost all of these neurotransmitters depend on the presence of glucose to function,and their actions are mostly related to the Ca^(2+)and cAMP concentrations.Although neurotransmitters have been extensively studied,many of their mechanisms remain unclear and require further exploration by researchers.

Vascular endothelial growth factor B improves impaired glucose tolerance through insulin-mediated inhibition of glucagon secretion

BACKGROUND Impaired glucose tolerance(IGT)is a homeostatic state between euglycemia and hyperglycemia and is considered an early high-risk state of diabetes.When IGT occurs,insulin sensitivity decreases,causing a reduction in insulin secretion and an increase in glucagon secretion.Recently,vascular endothelial growth factor B(VEGFB)has been demonstrated to play a positive role in improving glucose metabolism and insulin sensitivity.Therefore,we constructed a mouse model of IGT through high-fat diet feeding and speculated that VEGFB can regulate hyperglycemia in IGT by influencing insulin-mediated glucagon secretion,thus contributing to the prevention and cure of prediabetes.AIM To explore the potential molecular mechanism and regulatory effects of VEGFB on insulin-mediated glucagon in mice with IGT.METHODS We conducted in vivo experiments through systematic VEGFB knockout and pancreatic-specific VEGFB overexpression.Insulin and glucagon secretions were detected via enzyme-linked immunosorbent assay,and the protein expression of phosphoinositide 3-kinase(PI3K)/protein kinase B(AKT)was determined using western blot.Further,mRNA expression of forkhead box protein O1,phosphoenolpyruvate carboxykinase,and glucose-6 phosphatase was detected via quantitative polymerase chain reaction,and the correlation between the expression of proteins was analyzed via bioinformatics.RESULTS In mice with IGT and VEGFB knockout,glucagon secretion increased,and the protein expression of PI3K/AKT decreased dramatically.Further,in mice with VEGFB overexpression,glucagon levels declined,with the activation of the PI3K/AKT signaling pathway.CONCLUSION VEGFB/vascular endothelial growth factor receptor 1 can promote insulin-mediated glucagon secretion by activating the PI3K/AKT signaling pathway to regulate glucose metabolism disorders in mice with IGT.

Efficacy of tolvaptan in an infant with syndrome of inappropriate antidiuretic hormone secretion associated with holoprosencephaly:A case report

BACKGROUND Holoprosencephaly(HPE)is a congenital malformation with various degrees of incomplete separation of the cerebral hemispheres due to differentiation disorders of the forebrain.Although HPE with diabetes insipidus due to associated pituitary dysfunction has been reported,HPE with the syndrome of inappropriate antidiuretic hormone secretion(SIADH)is very rare.Tolvaptan,a vasopressin V2 receptor antagonist,is effective in adults with SIADH.However,there is no report of its efficacy in infants with SIADH.The purpose of this report is to demonstrate that tolvaptan is effective for SIADH in infants and that administration of tolvaptan eliminates the need for restriction of water intake and sodium administration.CASE SUMMARY A 2414-g female infant was born at 38 wk by normal vaginal delivery.Facial anomalies and head magnetic resonance imaging indicated semilobar HPE.After birth,she had hyponatremia due to SIADH and was treated using water and sodium restriction.However,she developed an exaggerated response to the fluid restrictions,resulting in large fluctuations in serum sodium levels.Subsequent administration of tolvaptan improved the fluctuations in serum sodium levels without the need for adjustment of water or sodium administration.Serum sodium was maintained within the normal range after discontinuation of tolvaptan at 80 d of life.There were no side effects,such as hypernatremia or liver dysfunction,during the administration of tolvaptan.CONCLUSION This is the first report on the safety and efficacy of tolvaptan in an infant with SIADH associated with HPE.

Comparative Study of the Biological Activities of the Skin Secretions from Six Common Chinese Amphibians

Water soluble skin secretions of six common Chinese amphibians were studied for their biological and enzymatic activities.The skin secretions of Tylototriton verrucosus,Bombina maxima ,and Bufo andrewsi were found toxic to mice with the intraperitoneal LD 50 of 11 5?mg/kg,18 8?mg/kg,and 264?mg/kg,respectively.No acute lethal toxicities were observed for the skin secretions of Rana nigromaculata,Rana guentheri and Rana limnocharis in a dose up to 500?mg/kg.The lethal toxicities of the skin secretions of T verrucosus and B maxima to mice are in the same grade as those of Viperidae snake venoms.The toxic components in T verrucosus and B maxima skin secretions are the proteins with molecular weights ranging from 3 to 60?kDa.All the skin secretions had both proteolytic activity and trypsin inhibitory activity.The skin secretions from T verrucosus , B maxima and B andrewsi also displayed wide spectrum antimicrobial activity.On the other hand,the skin secretions from B andrewsi and B maxima showed cytotoxicity on human cancer cells.All the six samples had not significant effects on mammalian blood coagulation system.Phospholipase A 2 activity was only found in the skin secretions of T verrucosus .None of these skin secretions showed acetylcholine esterase activity.

Influence of gastric inhibitory polypeptide on pentagastrinstimulated gastric acid secretion in patients with type 2 diabetes and healthy controls

AIM： Gastric inhibitory polypeptide is secreted from intestinal K-cells in response to nutrient ingestion and acts as an incretin hormone in human physiology. While animal experiments suggested a role for GIP as an inhibitor of gastric secretion, the GIP effects on gastric acid output in humans are still controversial. METHODS： Pentagastrin was administered at an infusion rate of 1 μg . kg^-1 . h^-1 over 300 min in 8 patients with type 2 diabetes （2 female, 6 male, 54± 10 years, BMI 30.5 ± 2.2 kg/m^2; no history of autonomic neuropathy） and 8 healthy subjects （2/6, 46 ± 6 years., 28.9 ± 5.3 kg/ m^2）. A hyperglycaemic clamp （140 mg/dl） was performed over 240 min. Placebo, GIP at a physiological dose （1 pmol . kg^-1 . min^-1）, and GIP at a pharmacological dose （4 mol . kg^-1 . min^-1） were administered over 60 min each. Boluses of placebo, 20 pmol GIP/kg, and 80 pmol GIP/kg were injected intravenously at the beginning of each infusion period, respectively. Gastric volume, acid and chloride output were analysed in 15-min intervals. Capillary and venous blood samples were drawn for the determination of glucose and total GIP. Statistics were carried out by repeated-measures ANOVA and one-way ANOVA. RESULTS： Plasma glucose concentrations during the hyperglycaemic clamp experiments were not different between patients with type 2 diabetes and controls. Steady-state GIP plasma levels were 61 ±8 and 79 ± 12 pmol/I during the low-dose and 327±35 and 327± 17 pmol/I during the high-dose infusion of GIP, in healthy control subjects and in patients with type 2 diabetes, respectively （P= 0.23 and p 0.99）. Pentagastrin markedly increased gastric acid and chloride secretion （P〈 0.001）. There were no significant differences in the rates of gastric acid or chloride output between the experimental periods with placebo or any dose of GIP. The temporal patterns of gastric acid and chloride secretion were similar in patients with type 2 diabetes and healthy controls （P= 0.86 and P= 0.61, respectively）. CONCLUSION： Pentagastrin-stimulated gastric acid secretion is similar in patients with type 2 diabetes and healthy controls. GIP administration does not influence gastric acid secretion at physiological or pharmacological plasma levels. Therefore, GIP appears to act as an incretin rather than as an enterogastrone in human physiology.

Atopobium vaginae与细菌性阴道病关系的研究

目的:应用非培养方法研究Atopobium vaginae与细菌性阴道病的关系。方法:根据Nugent评分标准从15例健康妇女及17例BV患者的其阴道分泌物中提取细菌总DNA。分别选择健康妇女及BV患者样本各3例,构建16S rRNA基因克隆文库并进行测序分析。应用Atopobium vaginae16S rRNA基因的特异性引物对32例样本进行PCR扩增。结果:Atopobium vaginae是BV患者阴道菌群中的优势菌种,它存在于大部分(14/17)BV患者阴道中,健康妇女阴道中(1/15)则很罕见。结论:Atopobium vaginae与细菌性阴道病的发生有一定的相关性。

Mechanism involved in Danshen-induced fluid secretion in salivary glands

AIM:Danshen's capability to induce salivary fluid secretion and its mechanisms were studied to determine if it could improve xerostomia.METHODS:Submandibular glands were isolated from male Wistar rats under systemic anesthesia with pentobarbital sodium.The artery was cannulated and vascularly perfused at a constant rate.The excretory duct was also cannulated and the secreted saliva was weighed in a cup on an electronic balance.The weight of the accumulated saliva was measured every 3 s and the salivary flow rate was calculated.In addition,the arterio-venous difference in the partial oxygen pressure was measured as an indicator of oxygen consumption.In order to assess the mechanism involved in Dansheninduced fluid secretion,either ouabain(an inhibitor of Na+/K+ ATPase) or bumetanide(an inhibitor of NKCC1) was additionally applied during the Danshen stimulation.In order to examine the involvement of the main membrane receptors,atropine was added to block the M3 muscarinic receptors,or phentolamine was added to block the α1 adrenergic receptors.In order to examine the requirement for extracellular Ca2+,Danshen was applied during the perfusion with nominal Ca2+ free solution.RESULTS:Although Danshen induced salivary fluid secretion,88.7 ± 12.8 μL/g-min,n = 9,(the highest value around 20 min from start of DS perfusion was significantly high vs 32.5 ± 5.3 μL/g-min by carbamylcholine,P = 0.00093 by t-test) in the submandibular glands,the time course of that secretion differed from that induced by carbamylcholine.There was a latency associated with the fluid secretion induced by Danshen,followed by a gradual increasein the secretion to its highest value,which was in turn followed by a slow decline to a near zero level.The application of either ouabain or bumetanide inhibited the fluid secretion by 85% or 93%,and suppressed the oxygen consumption by 49% or 66%,respectively.These results indicated that Danshen activates Na+/K+ ATPase and NKCC1 to maintain Cl- release and K+ release for fluid secretion.Neither atropine or phentolamine inhibited the fluid secretion induced by Danshen(263% ± 63% vs 309% ± 45%,227% ± 63% vs 309% ± 45%,P = 0.899,0.626 > 0.05 respectively,by ANOVA).Accordingly,Danshen does not bind with M3 or α1 receptors.These characteristics suggested that the mechanism involved in DS-induced salivary fluid secretion could be different from that induced by carbamylcholine.Carbamylcholine activates the M3 receptor to release inositol trisphosphate(IP3) and quickly releases Ca2+ from the calcium stores.The elevation of [Ca2+]i induces chloride release and quick osmosis,resulting in an onset of fluid secretion.An increase in [Ca2+]i is essential for the activation of the luminal Cl- and basolateral K+ channels.The nominal removal of extracellular Ca2+ totally abolished the fluid secretion induced by Danshen(1.8 ± 0.8 μL/g-min vs 101.9 ± 17.2 μL/g-min,P = 0.00023 < 0.01,by t-test),suggesting the involvement of Ca2+ in the activation of these channels.Therefore,IP3-store Ca2+ release signalling may not be involved in the secretion induced by Danshen,but rather,there may be a distinct signalling process.CONCLUSION:The present findings suggest that Danshen can be used in the treatment of xerostomia,to avoid the systemic side effects associated with muscarinic drugs.

New therapeutic perspectives in irritable bowel syndrome: Targeting low-grade inflammation, immuno-neuroendocrine axis, motility, secretion and beyond

Irritable bowel syndrome(IBS)is a chronic,recurring,and remitting functional disorder of the gastrointestinal tract characterized by abdominal pain,distention,and changes in bowel habits.Although there are several drugs for IBS,effective and approved treatments for one or more of the symptoms for various IBS subtypes are needed.Improved understanding of pathophysiological mechanisms such as the role of impaired bile acid metabolism,neurohormonal regulation,immune dysfunction,the epithelial barrier and the secretory properties of the gut has led to advancements in the treatment of IBS.With regards to therapies for restoring intestinal permeability,multiple studies with prebiotics and probiotics are ongoing,even if to date their efficacy has been limited.In parallel,much progress has been made in targeting low-grade inflammation,especially through the introduction of drugs such as mesalazine and rifaximin,even if a better knowledge of the mechanisms underlying the low-grade inflammation in IBS may allow the design of clinical trials that test the efficacy and safety of such drugs.This literature review aims to summarize the findings related to new and investigational therapeutic agents for IBS,most recently developed in preclinical as well as Phase 1 and Phase 2clinical studies.

New insight in expression, transport, and secretion of brain-derived neurotrophic factor: Implications in brainrelated diseases

Brain-derived neurotrophic factor(BDNF) attracts increasing attention from both research and clinical fields because of its important functions in the central nervous system. An adequate amount of BDNF is critical to develop and maintain normal neuronal circuits in the brain. Given that loss of BDNF function has beenreported in the brains of patients with neurodegenerative or psychiatric diseases, understanding basic properties of BDNF and associated intracellular processes is imperative. In this review, we revisit the gene structure, transcription, translation, transport and secretion mechanisms of BDNF. We also introduce implications of BDNF in several brain-related diseases including Alzheimer's disease, Huntington's disease, depression and schizophrenia.

Anti-diabetic effects of Caulerpa lentillifera:stimulation of insulin secretion in pancreatic β-cells and enhancement of glucose uptake in adipocytes

Objective:To evaluate anti-diabetic effect of Caulrpa kntillifera(C.lentillifera).Methods:The inhibitory effect of C.lentillifera extract on dipeptidyl peptidase-IV and a-glucosidase enzyme was measured in a cell free system.Then,interleukin-1βand interferon-γinduced cell death and insulin secretion were measured in rat insulinoma(RIN)cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and ELISA kit,respectively.Glucose uptake and glucose transporter expression were measured by fluorometry and western blotting,using 3T3-Ll adipocytes.Results:C.lentillifera extract significantly decreased dipeptidyl peptidase-IV and a-glucosidase enzyme activities,and effectively inhibited cell death and iNOS expression in interleukin-1βand interfcron-γinduced RIK cells.Furthermore,C.lntillifera extract significantly enhanced insulin secretion in RTN cells and glucose transporter expression and glucose uptake in 3T3-L1adipocytes.Conclusions:Thus,our results suggest that C.lentillifera could be used as a potential antidiabetic agenl.

Increased secretion of pro inflammatory cytokines by circulating polymorphonuclear neutrophils and regulation by interleukin 10 during intestinal inflammation

Abstract AIM To investigate whether PMN from patients with IBD or infectious colitis, respectively, secrete increased amounts of pro inflammatory cytokines and can be regulated by IL 10. METHODS Secretion (ELISA) as well as corresponding mRNA levels (semiquantitative RT PCR) of pro inflammatory cytokines (IL 1β, TNF α) and of IL 1 receptor antagonist were assessed in peripheral PMN. RESULTS PMN from patients with IBD are primed to secrete enhanced amounts of pro inflammatory cytokines accompanied by detection of corresponding mRNAs in comparison with normal controls. This finding is not specific for IBD but rather reflects intestinal inflammation in general. IL 10 markedly inhibited proinflammatory cytokine secretion as well as corresponding mRNA concentrations. CONCLUSION PMN are an important source of pro inflammatory cytokines in patients with intestinal inflammation and can be downregulated by IL 10.

Peripheral mechanism of inhibitory effect of centrally administrated histamine on gastric acid secretion

AIM To study the peripheral mechanism of the inhibitory effect of intra third ventricular administration (icv) of histamine (HA) on gastric acid secretion in rats. METHODS Gastric acid was continuously washed with 37℃ saline by a perfusion pump in male adrenalectomized SD rats. Drugs were injected intravenously (iv) by a syringe pump and their effect on pentagastrin induced (10μg·kg·h, iv) gastric acid secretion was observed. RESULTS The inhibitory effect of HA (1μg, icv) on gastric acid secretion was blocked by subdiaphragmatic vagotomy, and pretreatment with atropine (0 005mg·kg·h, iv). Pretreatment with somatostatin antagonist, cyclo [7 aminoheptanoyl Phe D Trp Lys Thr(Bzl)], ( 2μg - 4μg ·kg· 100min , iv) could also block the inhibitory effect of HA on gastric acid secretion in a dose dependent manner. CONCLUSION The inhibitory effect of centrally administrated HA on gastric acid secretion may be mediated by vagi, acetylcholine M receptor and somatostatin.

Root secretion stimulating ash growth in larch-ash mixed forest

Allelopathic effect of larch (Larix gmelini ) on the ash growth (Fraximus mandshurica) was studied in artificial cultivation tests. The results revealed that the larch root secretion obviously stimulated the ash growth. In order to determine the main stimulation allelochemicals, the chemical composition was analyzed. By contrasting the contents of carbohydrate and aminoacid in root secretion of larch and ash, it was concluded that the carbohydrate and aminoacid were not important stimulation allelochemicals. The organic acid and other components in root secration of larch and ash were analyzed by GC and GC-MS analysis. The sand culture tests were carried out ed selected model compounds. The results showed that benzeneacetic acid, benzenepropionic acid and phenolic acids in root secretion of larch were the main stimulation allelochemicals.

Distribution and Accumulation of Neodymium and Its Effect on Secretion of Progesterone in Mice

Distribution and accumulation of Nd, and its effect on secretion of progesterone in mice were studied using radioisotope tracer ((()^(147)Nd)) technique. Following single intraperitoneal administration of neodymium traced with (()^(147)Nd) at a dose of 200 mg·kg^(-1), uneven distribution of the radioactive Nd occurred in various tissues and organs. Much amount of (()^(147)Nd) accumulates in the bone, and the residue increases with the lapse of time. Some amount of radioactivity was also detected in eyes, blood and brain, but the accumulation decreased with the time due to excretion and re-distribution in mice. In comparison with controls, concentration of progesterone is found to be significantly lower in the serum of administered mice, indicating a significantly inhibitory effect of Nd on secretion of progesterone.

Ghrelin and gastric acid secretion

Ghrelin, a novel growth hormone-releasing peptide, was originally isolated from rat and human stomach. Ghrelin has been known to increase the secretion of growth hormone (GH), food intake, and body weight gain when administered peripherally or centrally. Ghrelin is also known to stimulate the gastric motility and the secretion of gastric acid. In the previous studies, the action of ghrelin on acid secretion was shown to be as strong as that of histamine and gastrin in in-vivo experiment. In the studies, the mechanism for the action of ghrelin was also investigated. It was shown that vagotomy completely inhibited the action of ghrelin on the secretion of gastric acid suggesting that vagal nerve is involved in the mechanism for the action of ghrelin on acid secretion. As famotidine did not inhibit ghrelin-in-duced acid secretion in the study by Masuda et al, they concluded that histamine was not involved in the action of ghrelin on acid secretion. However, we have shown that famotidine completely inhibited ghrelin-induced acid secretion and histidine decarboxylase (HDC) mRNA was increased in gastric mucosa by ghrelin injection which is inhibited by vagotomy Our results indicate that histamine is involved in the action of ghrelin on acid secretion. Furthermore synergistic action of gastrin and ghrelin on gastric acid secretion was shown. Although gastrin has important roles in postprandial secretion of gastric acid, ghrelin may be related to acid secretion during fasting period or at night. However, further studies are needed to elucidate the physiological role of ghrelin in acid secretion.

Effects of Chinese herbs on salivary fluid secretion by isolated and perfused rat submandibular glands

AIM： TO determine whether Chinese herbs （CHs） relieve xerostomia （dry mouth） by increasing salivary secretion. METHODS： The submandibular glands of Wistar rats were surgically isolated and perfused arterially with buffered salt solution. After control perfusion, recording started 5 min prior to the start of stimulation. After fluid secretion was induced by 0.2 μmol/L carbamylcholine （CCh） in the perfusate for 10 min, Chinese herb （CH） was added in the perfusion for 5 min. CCh was then overloaded at 0.2 μmol/L in the perfusion for 20 min. The volume of salivary fluid secretion was recorded by a computer-controlled balance system. RESULTS： Saliva secretion formed an initial ephemeral peak at 30 s followed by a gradual increase to a sustained level. CH alone induced no or little saliva in all types of CH selected. During perfusion with CH,overloading of CCh promoted fluid secretion in 1S of 20 CHs. This promotion was classified into four patterns, which were eventually related to the categories of CH： Overall sustained phase was continuously raised （Yin-nourishing, fluid production-promoting and heatclearing agents）; The sustained secretion rose to reach a maximum then decreased （Qi-enhancing agent）; Sustained secretion rose to reach the highest maximum and was then sustained with a slight decline （swelling-reducing, phlegm-resolving and pus-expelling agents）; Stimulation of salivary secretion without any added stimulants. Addition of CCh raised the fluid secretion to reach the highest maximum then sharply decreased to a lower sustained level （blood activating agent）. CONCLUSION： The present findings lead to the conclusion that various CHs have different promotional effects directly on the salivary gland.