Association of ghrelin dynamics with beta cell function in Japanese subjects with normal glucose tolerance.

BACKGROUND: Ghrelin is involved in feeding regulation and energy metabolism and is also known to inhibit insulin secretion (ß). However, few clinical studies have demonstrated the relationship between ß and ghrelin dynamics. This study tested the hypothesis that, in oral glucose tolerance tests (OGTT), ghrelin dynamics are associated with ß. METHODS: Subjects were 1145 healthy individuals <40 years old who tested normal on the 75-g OGTT. The following indicators and the ghrelin suppression ratio (GSR) during OGTT were calculated: insulin sensitivity (SI) [1/homoeostasis model assessment of insulin resistance, insulin sensitivity index-Matsuda and 1/fasting insulin (1/FIRI)]; and ß [Stumvoll first-phase index (Stumvoll-1), Stumvoll second-phase index and insulinogenic index]. From nine combinations of SI and ß, combinations that produce hyperbolic relationships were identified. RESULTS: Stumvoll-1 and 1/FIRI showed a hyperbolic relationship in nonobese subjects, and the product of Stumvoll-1 and 1/FIRI was used as the disposition index (DI). When analyzed by BMI quartiles, post-loading glucose and insulin levels at each time point increased from Q1 (low BMI) through Q4 (high BMI), whereas the DI, ghrelin levels at each time point, and GSR decreased from Q1 to Q4. On multivariate and bivariate analysis, GSR and DI were positive and independent, and fasting ghrelin and FIRI were negatively and independently correlated. CONCLUSIONS: Ghrelin dynamics were associated with beta cell function in subjects with normal glucose tolerance. Glucose intolerance in obesity may be due not only to insulin resistance but also to impaired beta cell function associated with abnormalities of ghrelin dynamics.

A case of pheochromocytoma with a marked decrease in catecholamine levels after rupture in which a good outcome was achieved by elective surgery.

Changes in imaging findings and hormone levels before and after pheochromocytoma rupture, as well as detailed histopathology of resected tumors, have rarely been reported. A 52-year-old woman developed hypertension and diabetes mellitus in 2014, but despite treatment with antihypertensive and hypoglycemic drugs, good control was not achieved. On April 2, 2016, the patient started to have headaches and palpitations, and on April 6, she visited our hospital. Plain computed tomography (CT) of the abdomen showed a 4-cm, isodense mass in the left adrenal gland, and the patient was hospitalized for further examination. Because the patient had hypertension, tachycardia, and hyperglycemia on admission, therapies for those were started. Catecholamine levels were markedly elevated. However, after the patient developed left flank pain on Day 4, antihypertensive and insulin therapies were no longer required. Plain CT then showed heterogeneous high density areas in the left adrenal mass. On Day 7, 3 meta-iodobenzylguanidine scintigraphy showed no abnormal uptake. On Day 8, contrast CT showed low density areas within the left adrenal tumor and contrast enhancement of the tumor margins, and catecholamine levels were markedly decreased. Elective left adrenal tumor resection was performed on Day 49. The capsule of the resected tumor was ruptured. Histopathology showed widespread hemorrhagic necrosis and viable cell components in the tumor margins. Positive chromogranin A staining of the tumor cells confirmed a diagnosis of pheochromocytoma. This patient displayed remarkable changes in imaging findings and hormone levels before and after pheochromocytoma rupture. Pheochromocytoma rupture and hemorrhagic necrosis were confirmed histopathologically.

Proprioceptive illusions created by vibration of one arm are altered by vibrating the other arm.

There is some evidence that signals coming from both arms are used to determine the perceived position and movement of one arm. We examined whether the sense of position and movement of one (reference) arm is altered by increases in muscle spindle signals in the other (indicator) arm in blindfolded participants (n = 26). To increase muscle spindle discharge, we applied 70-80 Hz muscle vibration to the elbow flexors of the indicator arm. In a first experiment, proprioceptive illusions in the vibrated reference arm in a forearm position-matching task were compared between conditions in which the indicator arm elbow flexors were vibrated or not vibrated. We found that the vibration illusion of arm extension induced by vibration of reference arm elbow flexors was reduced in the presence of vibration of the indicator elbow flexors. In a second experiment, participants were asked to describe their perception of the illusion of forearm extension movements of the reference arm evoked by vibration of reference arm elbow flexors in response to on/off and off/on transitions of vibration of non-reference arm elbow flexors. When vibration of non-reference arm elbow flexors was turned on, they reported a sensation of slowing down of the illusion of the reference arm. When it was turned off, they reported a sensation of speeding up. To conclude, the present study shows that both the sense of limb position and the sense of limb movement of one arm are dependent to some extent on spindle signals coming from the other arm.

Body Roundness Index Is Better Correlated with Insulin Sensitivity than Body Shape Index in Young and Middle-Aged Japanese Persons.

Aims: The present study aimed to clarify the relationships between novel and traditional anthropometric indices and insulin sensitivity (SI) in young and middle-aged Japanese persons with normal glucose tolerance (NGT), and middle-aged Japanese persons with NGT and glucose intolerance. Methods: Plasma glucose and insulin levels were measured in 1270 young (age <40 years) and 2153 middle-aged persons with NGT (n = 1531) and glucose intolerance (n = 622) during a 75-g oral glucose tolerance test. Height (Ht), weight, and waist circumference (WC) were measured. The body mass index (BMI), WC, and the WC/Ht ratio were used as traditional anthropometric indices. A body shape index (ABSI) and the body roundness index (BRI) were calculated as novel indices. Indices of SI (Matsuda index and 1/homeostasis model assessment of insulin resistance) were calculated and compared with anthropometric indices. Results: The ABSI showed a weak correlation with SI indices in all groups. The BRI showed almost the same correlation with SI indices as the BMI, WC, and WC/Ht in all groups. The inverse correlation between each of the anthropometric indices other than ABSI and SI indices was weak in young persons, at 0.16-0.27 (Spearman's ρ values), but strong in middle-aged persons, at 0.38-1.00. On receiver-operating characteristic (ROC) curve analysis for detection of insulin resistance, the ABSI had a lower area under the ROC curve (AUC) than the other anthropometric indices, and the BRI and the WC/Ht ratio showed similar AUCs. The AUCs for the BRI and WC/Ht ratio were the highest in middle-aged men with NGT and glucose intolerance. Conclusions: The BRI, not the ABSI, was better correlated with SI in young and middle-aged Japanese persons. The BRI and WC/Ht ratio were comparable in their correlations with SI and the detection of insulin resistance in the participants of the present study.

Hepatic Steatosis and High-Normal Fasting Glucose as Risk Factors for Incident Prediabetes.

Context: The role of hepatic steatosis (HS) in the initial stages of developing type 2 diabetes remains unclear. Objective: We aimed to clarify the impact of HS indexed by Fatty Liver Index (FLI) and high-normal fasting plasma glucose (FPG) as risk factors for incident prediabetes in a nonobese cohort. Methods: Data from 1125 participants with ADA-defined normal glucose metabolism (median age 52 years; BMI 23.1 kg/m2) were used for retrospective analysis. In the entire population, correlation between normal FPG and FLI was evaluated by multiple regression adjusted for age and sex. Follow-up data from 599 participants in whom 75-g OGTT was repeated 3.7 years later showed that 169 developed prediabetes. This was analyzed by the multivariate Cox proportional hazards model. Results: In the entire population, FLI was positively correlated with FPG (P < 0.01): mean FLI increased from 15.8 at FPG 4.2 mmol/L to 31.6 at FPG 5.5 mmol/L. Analysis of the 599 participants (2061 person-years) by Cox model, adjusted for sex, age, family history of diabetes, ISIMATSUDA, and Stumvoll-1, clarified an increased risk of prediabetes with high-normal FPG and FLI. Risk was increased 2.2 times with FLI ≥ 16.5 vs FLI < 16.5, P < 0.001, and increased 2.1 times in participants with FPG ≥ 5.3 mmol/L, P < 0.001. Cutoff values (unadjusted) were obtained by ROC at the point of the largest Youden's index using the entire range of the variables. Conclusion: Even among nonobese individuals, HS indexed by FLI and a high-normal FPG (≥ 5.3 mmol/L) are risk factors for prediabetes, independently from insulin.

Diabetic family history in young Japanese persons with normal glucose tolerance associates with k-means clustering of glucose response to oral glucose load, insulinogenic index and Matsuda index.

Aims: The present study aimed to clarify the relationships between diabetic family history (FH), and dysglycemic response to the oral glucose tolerance test (OGTT), insulin secretion, and insulin sensitivity in young Japanese persons with normal glucose tolerance (NGT). Methods: We measured plasma glucose (PG) and immunoreactive insulin levels in 1,309 young Japanese persons (age <40 years) with NGT before and at 30, 60, and 120 min during a 75-g OGTT. Dysglycemia during OGTT was analyzed by k-means clustering analysis. Body mass index (BMI), blood pressure (BP), and lipids were measured. Insulin secretion and sensitivity indices were calculated. Results: PG levels during OGTT were classified by k-means clustering analysis into three groups with stepwise decreases in glucose tolerance even among individuals with NGT. In these clusters, proportion of males, BMI, BP and frequency of FH were higher, and lipid levels were worse, together with decreasing glucose tolerance. Subjects with a diabetic FH showed increases in PG after glucose loading and decreases in insulinogenic index and Matsuda index. Conclusions: Dysglycemic response to OGTT by k-means clustering analysis was associated with FH in young Japanese persons with NGT. FH was also associated with post-loading glucose, insulinogenic index, and Matsuda index.

Glucose Effectiveness Decreases in Relationship to a Subtle Worsening of Metabolic Parameters in Young Japanese with Normal Glucose Tolerance.

Background: The aim of the study was to investigate the relationship between glucose effectiveness (Sg) and some metabolic parameters in male and female young Japanese. Methods: We measured plasma glucose and immunoreactive insulin levels in 1309 young Japanese persons (age <40 years) with normal glucose tolerance (NGT) before and at 30, 60, and 120 min during a 75 gram oral glucose tolerance test. We also measured serum adiponectin and high-sensitivity C-reactive protein (hsCRP) levels and oral glucose effectiveness (SgIO), and investigated factors related to SgIO. Results: The results of Spearman correlation analysis revealed that high-density lipoprotein cholesterol (HDL) and adiponectin were positively correlated with SgIO, whereas the proportion of males, body mass index, waist circumference (WC), systolic blood pressure (SBP), diastolic blood pressure, triglycerides (TG), and hsCRP were inversely correlated with SgIO. The results of multiple regression analysis indicated negative correlations between SgIO and the proportion of males, WC, and SBP and a positive correlation with HDL. The results of multiple regression analysis excluding WC indicated negative correlations between SgIO and the proportion of males, SBP, and TG and positive correlations with HDL and adiponectin. Conclusions: Sg decreased with a subtle worsening of metabolic parameters, even in young persons with NGT. Decreased Sg may be involved in the development of glucose intolerance in individuals with worse metabolic parameters.

Postloading insulinemia is independently associated with arterial stiffness in young Japanese persons.

Associations of arterial stiffness with glucose, insulin, and proinsulin dynamics during the oral glucose tolerance test (OGTT) remain under debate. The aim of this study was to investigate whether plasma glucose (PG), insulin, and proinsulin (Pro) contribute to arterial stiffness, measured by pulse wave velocity (PWV), in young Japanese persons. PG, immunoreactive insulin (IRI), and Pro levels were determined in 1193 young Japanese subjects (<40 years of age) with normal glucose tolerance or nondiabetic hyperglycemia before and at 30, 60, and 120 min during a 75-g OGTT. Participants were divided into two groups according to the median PWV. Background factors, PG, IRI, and Pro levels during the OGTT, and insulin sensitivity (SI) indices in each group were compared. Several multiple regression analysis models were used to evaluate factors contributing to PWV. All IRI and Pro levels before and after glucose loading and the area under the curve (AUC) values for IRI and Pro increased with higher PWV. 1/HOMA-IR and ISI-Matsuda as measures of SI decreased with higher PWV. The IRI AUC and Pro level before glucose loading (Pro0) were independently associated with PWV, in addition to male sex, heart rate, and mean blood pressure. The IRI AUC had a stronger relationship with PWV than Pro0. The IRI AUC had an independent relationship with PWV, whereas both SI indices did not. Postloading insulinemia, but not reduced SI, was independently associated with arterial stiffness in young Japanese persons.

Factors involved in body weight loss and its maintenance in morbidly obese inpatients.

BACKGROUND: Body weight loss in patients with obesity improves abnormal glucose tolerance, dyslipidemia and hypertension; however, it is difficult to maintain this loss of body weight. The objective of this study was to examine factors involved in body weight loss and its maintenance in morbidly obese inpatients. METHOD: The subjects were 31 patients (11 males and 20 females) who were admitted to hospital for obesity management. Factors involved in body weight changes during hospitalization and after discharge were examined retrospectively. The mean age was 58.1 ± 13.6 years and body mass index (BMI) was 40.2 ± 10.2 kg/m2. Twenty-four patients were complicated with type 2 diabetes mellitus. Diet therapy was 23.8 ± 3.9 kcal/kg ideal body weight/day. RESULTS: Excess weight loss (EWL) during hospitalization varied from 4.2 to 61.7%. Since EWL was affected by duration of hospital stay, the subjects were divided by the median of EWL per day. The subjects with greater EWL per day had lower body weight, BMI and fat mass on admission in the entire (n = 31), diabetic (n = 24), and non-diabetic subjects (n = 7), respectively. EWL per day was not different between diabetic and non-diabetic subjects. Follow-up data revealed that BMI remained unchanged 3 months after discharge but modestly increased 1 year after discharge, irrespective of EWL per day during hospitalization. In diabetic subjects followed up 1 year after discharge (n = 15), the increase in body weight was smaller than that in non-diabetic subjects (n = 3). CONCLUSION: These results suggest that EWL in morbidly obese inpatients is greater than those with lower baseline BMI and fat mass. The presence of diabetes had no effects on EWL during hospitalization. EWL during hospitalization was not correlated with its maintenance after discharge. Diabetic patients displayed lesser degree of body weight gain after discharge, possibly due to the effects of anti-diabetic medications.

Analysis of the Relationships between Multiple Endocrine Hormones and Return of Spontaneous Circulation (ROSC) in Cardiac Arrest Patients: Possible Association of the Serum Free T4 Level with ROSC.

BACKGROUND: Endocrine hormones are closely associated with homeostasis, so it is important to clarify hormone secretion dynamics in shock. Few reports, however, have examined the dynamics of endogenous hormone secretion relative to prognosis in cardiac arrest patients. Therefore, to clarify the roles of endocrine hormones in out-of-hospital cardiac arrest (OHCA) patients, the concentrations of anterior pituitary, thyroid, and adrenocortical hormones were measured, and their associations with return of spontaneous circulation (ROSC) were examined. METHODS: The subjects were OHCA patients transported to our Emergency Department. In addition to conventional clinical laboratory tests, the following were measured: serum TSH, serum free T3, serum free T4 (F-T4), plasma ACTH, serum cortisol, serum GH, serum IGF-1, plasma aldosterone concentration (PAC), and plasma renin activity. The primary endpoint was the presence or absence of ROSC, and the secondary endpoint was 24-hour survival. RESULTS: A total of 29 patients, 17 in the ROSC group and 12 in the non-ROSC group, were studied. There were associations between ROSC and low serum potassium, high F-T4, low cortisol, and low PAC on bivariate analyses. There were associations between ROSC and serum potassium, F-T4, and GH using the step-wise method. On multiple logistic regression analysis, a relationship between ROSC and high serum F-T4 level was identified by both methods. There were also associations between 24-hour survival and both low serum potassium and elevated blood glucose levels. CONCLUSIONS: The present findings suggest a possible relationship between the serum F-T4 level and ROSC in OHCA patients. A higher serum F-T4 level might cause an increase in the ß-adrenergic response in cardiomyocytes and increased responsiveness to catecholamines and was possibly associated with ROSC.

Insulin and Proinsulin Dynamics Progressively Deteriorate From Within the Normal Range Toward Impaired Glucose Tolerance.

CONTEXT: Slight elevations in plasma glucose (PG) manifest in advance of diabetes onset, but abnormalities in immunoreactive insulin (IRI), proinsulin (Pro), and adiponectin dynamics during this stage remain poorly understood. OBJECTIVE: The objective of this work is to investigate whether IRI and Pro dynamics become abnormal as glucose tolerance deteriorates from within the normal range toward impaired glucose tolerance (IGT), as well as the relationship between PG, and these dynamics and serum adiponectin levels. DESIGN: A cross-sectional study was designed. SETTING: This study took place at Jichi Medical University in Japan. PARTICIPANTS AND MEASUREMENTS: PG, IRI, and Pro levels were determined in 1311 young Japanese individuals (age < 40 years) with normal or IGT before and at 30, 60, and 120 minutes during a 75-g oral glucose tolerance test. Participants were assigned to 4 groups according to glucose tolerance, and then background factors, adiponectin levels, insulin sensitivity (SI), and insulin secretion (ß) indexes were determined. RESULTS: PG levels as well as IRI and Pro levels 60 and 120 minutes after glucose-loading increased incrementally with deteriorating glucose tolerance. All measures of ß and the SI measure index of insulin sensitivity (ISI)-Matsuda decreased incrementally. Serum adiponectin levels were not significantly different among the glucose tolerance groups, but were independently and negatively correlated with fasting glucose. CONCLUSIONS: Early ß decreased and postloading Pro levels became excessive in a progressive manner as glucose tolerance deteriorated from within the normal range toward IGT.

Continuous Hemodiafiltration for Pheochromocytoma Crisis with a Positive Outcome.

A 38-year-old woman who consulted a local doctor with chief complaints of sudden palpitations, headaches, and chest pain is herein presented. After admission, pheochromocytoma crisis was suspected. Since the patient had a history of acute heart failure and had once survived an episode of cardiac arrest, a rapid decrease in the catecholamine levels was needed. After resuscitation, pharmacological therapy with agents such as phentolamine and landiolol was administered, and continuous hemodiafiltration (CHDF) was performed to reduce the catecholamine levels. Elective surgery was then performed, and a positive outcome was achieved. This case suggests that the preoperative use of CHDF to control pheochromocytoma crisis may therefore be effective.

Alcohol flushing is independently associated with lesser degree of carotid atherosclerosis in Japanese type 2 diabetic patients.

BACKGROUND: Type 2 diabetes mellitus is a well-known risk factor for atherosclerosis. Intima media thickness (IMT) of the carotid arteries has been widely used for assessing atherosclerotic changes representing cerebro-cardiovascular disease risk. Previous studies have associated the presence of inactive aldehyde dehydrogenase with progression of atherosclerosis and alcohol flushing. However, reports conflict on whether alcohol flushing could potentially modify the degree of atherosclerosis in type 2 diabetic patients. METHODS: We retrospectively assessed the relationships among alcohol flushing, IMT, and clinical characteristics in 123 consecutive Japanese type 2 diabetic patients. Alcohol flushing was assessed by standardized questionnaires. RESULTS: Patients with alcohol flushing had lower mean IMT [0.7 (0.65-0.80) vs. 0.8 (0.73-0.90) mm, p < 0.05], despite having higher triglycerides [132 (94-169) vs. 98 (70-139) mg/dL, p < 0.01] and lower high-density lipoprotein cholesterol [52 (44-60) vs. 59 (49-67) mg/dL, p < 0.05] concentration. Patients with alcohol flushing had lower frequency of alcohol intake (45 vs. 76%, p < 0.0001). Mean IMT was positively associated with age and low-density lipoprotein cholesterol concentration, and negatively with alcohol flushing according to stepwise multiple regression analysis. Alcohol flushing was also independently associated with mean IMT by multivariate analysis. CONCLUSIONS: These findings suggest that alcohol flushing is independently associated with lesser degree of carotid atherosclerosis in Japanese type 2 diabetic patients.

Intrapancreatic injection of human bone marrow-derived mesenchymal stem/stromal cells alleviates hyperglycemia and modulates the macrophage state in streptozotocin-induced type 1 diabetic mice.

Type 1 diabetes mellitus is a progressive disease caused by the destruction of pancreatic ß-cells, resulting in insulin dependency and hyperglycemia. While transplanted bone marrow-derived mesenchymal stem/stromal cells (BMMSCs) have been explored as an alternative therapeutic approach for diseases, the choice of delivery route may be a critical factor determining their sustainability. This study evaluated the effects of intrapancreatic and intravenous injection of human BMMSCs (hBMMSCs) in streptozotocin (STZ)-induced type 1 diabetic mouse model. C57/BL6 mice were intraperitoneally injected with 115 mg/kg STZ on day 0. hBMMSCs (1 × 106 cells) or vehicle were injected into the pancreas or jugular vein on day 7. Intrapancreatic, but not intravenous, hBMMSC injection significantly reduced blood glucose levels on day 28 compared with vehicle injection by the same route. This glucose-lowering effect was not induced by intrapancreatic injection of human fibroblasts as the xenograft control. Intrapancreatically injected fluorescence-labeled hBMMSCs were observed in the intra- and extra-lobular spaces of the pancreas, and intravenously injected cells were in the lung region, although the number of cells mostly decreased within 2 weeks of injection. For hBMMSCs injected twice into the pancreatic region on days 7 and 28, the injected mice had further reduced blood glucose to borderline diabetic levels on day 56. Animals injected with hBMMSCs twice exhibited increases in the plasma insulin level, number and size of islets, insulin-positive proportion of the total pancreas area, and intensity of insulin staining compared with vehicle-injected animals. We found a decrease of Iba1-positive cells in islets and an increase of CD206-positive cells in both the endocrine and exocrine pancreas. The hBMMSC injection also reduced the number of CD40-positive cells merged with glucagon immunoreactions in the islets. These results suggest that intrapancreatic injection may be a better delivery route of hBMMSCs for the treatment of type 1 diabetes mellitus.

Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) Is Involved in Adult Mouse Hippocampal Neurogenesis After Stroke.

In the subgranular zone (SGZ) of the hippocampus, neurogenesis persists throughout life and is upregulated following ischemia. Accumulating evidence suggests that enhanced neurogenesis stimulated by ischemic injury contributes to recovery after stroke. However, the mechanisms underlying the upregulation of neurogenesis are unclear. We have demonstrated that a neuropeptide, pituitary adenylate cyclase-activating polypeptide (PACAP), exerts a wide range of effects on neural stem cells (NSCs) during neural development. Here, we examined the effects of endogenous and exogenous PACAP in adult NSCs of the SGZ. Immunostaining showed expression of the PACAP receptor PAC1R in nestin-positive NSCs of adult naive mice. PACAP injection into the lateral ventricle increased bromodeoxyuridine (BrdU)-positive proliferative cells in the SGZ. These data suggest that PACAP promoted the proliferation of NSCs. In global ischemia model mice, the number of BrdU-positive cells was increased in wild-type mice but not in PACAP heterozygous knockout mice. The BrdU-positive cells that increased in number after ischemia were immunopositive for SOX2, a marker of NSCs, and differentiated into NeuN-positive mature neurons at 4 weeks after ischemia. These findings suggest that PACAP contributes to the proliferation of NSCs and may be associated with recovery after brain injury.

Pituitary adenylate cyclase-activating polypeptide (PACAP) contributes to the proliferation of hematopoietic progenitor cells in murine bone marrow via PACAP-specific receptor.

Pituitary adenylate cyclase-activating polypeptide (PACAP, encoded by adcyap1) plays an important role in ectodermal development. However, the involvement of PACAP in the development of other germ layers is still unclear. This study assessed the expression of a PACAP-specific receptor (PAC1) gene and protein in mouse bone marrow (BM). Cells strongly expressing PAC1(+) were large in size, had oval nuclei, and merged with CD34(+) cells, suggesting that the former were hematopoietic progenitor cells (HPCs). Compared with wild-type mice, adcyap1(-/-) mice exhibited lower multiple potential progenitor cell populations and cell frequency in the S-phase of the cell cycle. Exogenous PACAP38 significantly increased the numbers of colony forming unit-granulocyte/macrophage progenitor cells (CFU-GM) with two peaks in semi-solid culture. PACAP also increased the expression of cyclinD1 and Ki67 mRNAs. These increases were completely and partially inhibited by the PACAP receptor antagonists, PACAP6-38 and VIP6-28, respectively. Little or no adcyap1 was expressed in BM and the number of CFU-GM colonies was similar in adcyap1(-/-) and wild-type mice. However, PACAP mRNA and protein were expressed in paravertebral sympathetic ganglia, which innervate tibial BM, and in the sympathetic fibers of BM cavity. These results suggested that sympathetic nerve innervation may be responsible for PACAP-regulated hematopoiesis in BM, mainly via PAC1.

A nucleoprotein-enriched diet suppresses dopaminergic neuronal cell loss and motor deficit in mice with MPTP-induced Parkinson's disease.

Parkinson's disease (PD) is an obstinate progressive neurodegenerative disease and characterized by locomotor impairment and dopaminergic neuronal degeneration in the substantia nigra pars compacta (SNc). We examined in here the dietary effect of nucleoprotein (NP) extracted from salmon soft roe on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-injected PD-like mice model to prevent the symptom as an alternative medicine. Male C57/BL6 mice were given either an artificially modified NP-free diet (NF) or NF supplied with 1.2% NP for 1 week. Then, mice were injected intraperitoneally four times with 20 mg/kg MPTP. Seven days later, locomotor activity was examined, and the brains were immunostained with tyrosine hydroxylase (TH) and Iba1 antibodies. Moreover, in situ detection of superoxide anion (O2(-)) and gene expression of mitochondrial electron transfer chain gene, Cox8b was evaluated in midbrains. NP-fed animals showed significantly reduced locomotor impairment and an increased number of TH-positive cells in the SNc compared with NF animals. The NP-fed animals also showed reduced lower levels of O2(-) and up-regulation of Cox8b levels and Iba1 immunoreactivity, suggesting that inflammation and oxidative stress were suppressed and mitochondrial impairment was relieved in these animals. Supplementation of the diet with NP may serve as a useful preventive measure to slow the onset of PD.

Ghrelin suppresses proliferation of fetal neural progenitor cells, and induces their differentiation into neurons.

Although considerable progress has been made in understanding how the temporal and regional control of neural progenitor cells (NPCs) dictates their fate, their key regulators during neural development are still unknown. Ghrelin, which is isolated from porcine stomach extract, is an endogenous ligand for the growth hormone secretagogue receptor (GHS-R). The widespread expression of ghrelin and GHS-R in the central nervous system during development suggests that ghrelin may be involved in developmental neural growth. However, its role in regulating fetal NPCs is still unclear. In this study, we investigated the effects of ghrelin on primary cultured NPCs derived from fetal mouse telencephalon. The expressions of both ghrelin and its receptor were observed in NPCs using RT-PCR, immunoblotting and immunocytostaining. Interestingly, the exposure of fetal NPCs to ghrelin at concentrations of 10(-7) and 10(-9)M suppressed their proliferation, and caused them to differentiate into neurons and to extend neurites. These results strongly suggest that ghrelin plays an autocrine modulatory role in fetal neural development.

PACAP38 suppresses cortical damage in mice with traumatic brain injury by enhancing antioxidant activity.

The production of reactive oxygen species (ROS) and the resulting oxidative stress in mice in response to a controlled cortical impact (CCI) are typical exacerbating factors associated with traumatic brain injury (TBI). Pituitary adenylate cyclase-activating polypeptide 38 (PACAP38) is a multifunctional peptide that has been shown to exhibit neuroprotective effects in response to a diverse range of injuries to neuronal cells. We recently reported that PACAP38 might regulate oxidative stress in mice. The aim of the present study was to determine whether PACAP38 exerts neuroprotective effects by regulating oxidative stress in mice with TBI. Reactive oxidative metabolites (ROMs) and biological antioxidant potential (BAP) were measured in male C57Bl/6 mice before and 3, 4, and 24 h after CCI. PACAP38 was administered intravenously immediately following CCI, and immunostaining for the oxidative stress indicator nitrotyrosine (NT), and for neuronal death as an indicator of the area affected by TBI, was measured 24 h later. Western blot experiments to determine antioxidant activity [as indicated by superoxide dismutase-2 (SOD-2) and glutathione peroxidase 1 (GPx-1)] in the neocortical region were also performed 3 h post-CCI. Results showed that plasma BAP and ROM levels were dramatically increased 3 h after CCI. PACAP38 suppressed the extent of TBI and NT-positive regions 24 h after CCI, and increased SOD-2 and GPx-1 levels in both hemispheres. Taken together, these results suggest that increasing antioxidant might be involving in the neuroprotective effect of PACAP38 in mice subjected to a CCI.