[A Pediatric Case of Xanthogranuloma in the Suprasellar Region Detected by a Severe Short Stature after 6 Years Growth Failure].

Here we report a case of a 12-year-old girl who was referred to our department because of marked short stature of more than -5 SD below the median. Although her growth failure began suddenly at 6 years of age, she never had an examination because she had no other symptoms. Brain MRI examination suggested a tumor in the suprasellar region, and endocrine examination revealed combined pituitery hormone deficiency due to the tumor. Before surgery, the supplementation with hydrocortisone and levothyroxine was initiated. The pathological diagnosis of the surgically removed tumor was xanthogranuloma. The pattern of her growth curve showed a growth failure with sudden onset, which is a typical pattern of short stature secondary to pituitary disfunction including growth hormone deficiency associated with brain tumors. This case suggests that growth failure could be the only symptom in pediatric cases with brain tumors. Improved awareness regarding the association of growth failure with brain tumors is needed for earlier diagnosis and treatment. Furthermore, the growth curves should be carefully evaluated in regular health examinations at school.

A Pediatric Case of Graves' Hyperthyroidism with Associated Glucose Intolerance Detected by a Urine Glucose Screening Program at School.

We report here a 13-year-old female with Graves' disease, whose diagnostic clue was glycosuria, which was detected by a urine glucose screening program at school. She had had mild general malaise, and a physical examination revealed a slightly enlarged thyroid gland. Hyperthyroidism (thyroid-stimulating hormone (TSH) < 0.01 µU/ml, free triiodothyronine (fT3) 23.57 pg/ml, free thyroxine (fT4) 3.38 ng/dl) and anti-thyroid autoantibodies (TRAb 43.6%) were detected in laboratory tests, and her plasma glucose at 120 minutes was 142 mg/dl in a 75 g oral glucose tolerance test. She was diagnosed as having borderline diabetes. These findings revealed a diagnosis of Graves' hyperthyroidism with associated impaired glucose tolerance. Although it is reported that many adults with hyperthyroidism develop disorders of glucose metabolism, pediatric patients rarely have complications of glucose intolerance or diabetes mellitus, and there are no previous reports of Graves' disease diagnosed by a urine glucose screening program at school. This case suggests a possibility of abnormalities in glucose metabolism even in pediatric cases of Graves' disease. To avoid overlooking the diagnosis of glucose intolerance associated with hyperthyroidism, a careful medical interview and examination should be performed even if the clinical features are mild.

[Evaluation of Clinical Features and Growth Hormone Deficiency in Short Children Born Small For Gestational Age].

Growth hormone (GH) therapy for short children born small for gestational age (SGA) has been approved in Japan. It is important to evaluate GH secretion ability before the initiation of GH therapy because there are some differences in dose and medical expenses between short children born SGA and GH deficiency (GHD). This study was designed to elucidate the incidence of GHD and to find a useful marker for detecting it in short SGA children. We retrospectively reviewed medical records to analyze the clinical features of short children born SGA and with GHD who had started GH therapy before the age of 6 in the University Hospital of Occupational and Environmental Health and Kyushu Rousai Hospital. Nine of 22 SGA subjects (41%) had GHD. There were no significant differences between two groups of short SGA children (GHD, non-GHD) in the median of height and serum insulin-like growth factors (IGF)-1 levels at birth or at the start of GH therapy. The probability of GHD was higher if the height standard deviation scores (SD) of the SGA children were lower than -3.2 (odds ratio, 11.6; 95% confidence interval, 1.52 - 89.1, P = 0.013). This study showed that there is an approximately 40% incidence of GHD in short SGA children needing GH treatment. We should do GH stimulation tests for short SGA children whose height SD is lower than -3 to determine the appropriate GH therapy.

CCL2 level is elevated with metabolic syndrome and CXCL10 level is correlated with visceral fat area in obese children.

Recent studies revealed that obesity is a low-grade, chronic inflammatory state that is accompanied by the enhanced production of multiple chemokines. In particular, metabolic syndrome (MS) and visceral adipose tissue (VAT) accumulation are significantly associated with certain chemokines in adults. However, little is known regarding this association in obese children. The aim of this study was to investigate the relationship between circulating chemokine levels and both MS and VAT accumulation in obese children. Forty-four obese schoolchildren (26 boys) with a percentage of overweight (POW) exceeding 20 were evaluated. The median age was 11.4 years (range: 6.8-16.5 years). Blood samples were drawn after overnight fasting, and serum chemokine levels (CCL2, CCL5 and CXCL10) were quantitated. Visceral fat area (VFA) determinations were conducted using computed tomography. The results showed that the median BMI Z-score, POW, waist circumference and VFA of the subjects were 2.24 SD, 49.8%, 88.3 cm and 80.8 cm2, respectively. Eighteen were diagnosed with MS. CCL2 was significantly increased in MS subjects compared with non-MS subjects (p<0.05). CXCL10 was positively correlated with VFA (r=0.425, p<0.01). There were no significant correlations between age and chemokine levels. We showed that CCL2 levels were elevated in MS and CXCL10 levels were associated with VFA in obese children. Our results suggest that CCL2 and CXCL10 play important roles in the progression of obesity-related metabolic complications in children.

Postal contact with participating children and its impact on response rate: Japan Environment and Children's Pilot Study.

BACKGROUND: Communication with participating children and its effect on participation outcome is one of the most important but untouched issues in birth cohort studies. The purpose of this study was to assess the effect of postal communication with the participating preschool children on the response rate to postal questionnaires. METHODS: One hundred and five mother-preschool child pairs from the Japan Environment and Children's Study (JECS) pilot cohort were included. During the 6 month study period, letters addressed to the children were enclosed with our biannual questionnaires, and the response rate transition was observed. Additionally, the participants were allocated to two groups. One of these was sent the letter with the individual name of the child at the top, and the other without it. The response rates of the two groups were compared using chi-squared test. Parents' impressions of the letters and the changes in their motivation to complete the questionnaires were surveyed using an evaluation form. RESULTS: The overall response rate was 83.8%, which was lower than the previous survey period. Response rate was not significantly different between the two letter types. The duration before questionnaire return was not changed. Despite their favorable impression based on parent evaluation, the letters were not associated with the parents' motivation to respond. CONCLUSION: Letters to participating preschool children had no effect on response rate, but the long-term impact of its favorability still remains to be evaluated. A similar trial at later ages may be more effective.

Sporadic pseudohypoparathyroidism type-1b with asymptomatic hypocalcemia.

Pseudohypoparathyroidism type 1b (PHP-1b) is usually diagnosed on various symptoms of hypocalcemia. Previous studies reported a few cases of autosomal dominant pattern PHP-1b identified on familial analysis with asymptomatic hypocalcemia. Herein we report the case of a 6-year-old male patient with sporadic PHP-1b incidentally detected on preoperative examination. He had neither characteristic findings of Albright hereditary osteodystrophy nor evidence of tetany. Sporadic PHP-1b was diagnosed on the basis of clinical observation and laboratory examination. In addition, genetic testing using methylation-specific multiplex ligation-dependent probe amplification indicated broad methylation abnormalities and confirmed the sporadic form of PHP-1b. Sporadic PHP-1b might often be overlooked when diagnosis is done simply on definitive clinical features. To avoid this, DNA sequencing and methylation analysis should be performed even in the absence of definitive clinical features.

Mutation spectrum and phenotypic variation in nine patients with SOX2 abnormalities.

Multiple mutations in SOX2 have been identified in patients with ocular anomalies and/or pituitary dysfunction. Here, we identified SOX2 abnormalities in nine patients. The molecular defects included one missense, one nonsense and four frameshift mutations, and three submicroscopic deletions involving SOX2. Three of the six mutations and all deletions were hitherto unreported. The breakpoints determined in one deletion were located within Alu repeats and accompanied by an overlap of 11 bp. Three of the six mutations encoded SOX2 proteins that lacked in vitro transactivation activity for the HESX1 promoter, whereas the remaining three generated proteins with ∼15-∼20% of transactivation activity. All cases manifested ocular anomalies of various severities, together with several complications including arachnoid cyst and hamartoma. There was no apparent correlation between the residual activity and clinical severity. The results indicate that molecular defects in SOX2 are highly variable and include Alu repeat-mediated genomic rearrangements. Our data provide further evidence for wide phenotypic variation of SOX2 abnormalities and the lack of genotype-phenotype correlation in patients carrying SOX2 lesions.

Genotype-Phenotype Correlations in 30 Japanese Patients With Congenital Hypothyroidism Attributable to TG Defects.

CONTEXT: Thyroglobulin (Tg), encoded by TG, is essential for thyroid hormone synthesis. TG defects result in congenital hypothyroidism (CH). Most reported patients were born before the introduction of newborn screening (NBS). OBJECTIVE: We aimed to clarify the phenotypic features of patients with TG defects diagnosed and treated since the neonatal period. METHODS: We screened 1061 patients with CH for 13 CH-related genes and identified 30 patients with TG defects. One patient was diagnosed due to hypothyroidism-related symptoms and the rest were diagnosed via NBS. Patients were divided into 2 groups according to their genotypes, and clinical characteristics were compared. We evaluated the functionality of the 7 missense variants using HEK293 cells. RESULTS: Twenty-seven rare TG variants were detected, including 15 nonsense, 3 frameshift, 2 splice-site, and 7 missense variants. Patients were divided into 2 groups: 13 patients with biallelic truncating variants and 17 patients with monoallelic/biallelic missense variants. Patients with missense variants were more likely to develop thyroid enlargement with thyrotropin stimulation than patients with biallelic truncating variants. Patients with biallelic truncating variants invariably required full hormone replacement, whereas patients with missense variants required variable doses of levothyroxine. Loss of function of the 7 missense variants was confirmed in vitro. CONCLUSION: To our knowledge, this is the largest investigation on the clinical presentation of TG defects diagnosed in the neonatal period. Patients with missense variants showed relatively mild hypothyroidism with compensative goiter. Patients with only truncating variants showed minimal or no compensative goiter and required full hormone replacement.

Guidelines for the Diagnosis and Treatment of Pediatric Familial Hypercholesterolemia 2022.

As atherosclerosis begins in childhood, early diagnosis and treatment of familial hypercholesterolemia (FH) is considered necessary. The basic diagnosis of pediatric FH (under 15 years of age) is based on hyper-low-density lipoprotein (LDL) cholesterolemia and a family history of FH; however, in this guideline, to reduce overlooked cases, "probable FH" was established. Once diagnosed with FH or probable FH, efforts should be made to promptly provide lifestyle guidance, including diet. It is also important to conduct an intrafamilial survey, to identify family members with the same condition. If the level of LDL-C remains above 180 mg/dL, drug therapy should be considered at the age of 10. The first-line drug should be statin. Evaluation of atherosclerosis should be started using non-invasive techniques, such as ultrasound. The management target level is an LDL-C level of less than 140 mg/dL. If a homozygous FH is suspected, consult a specialist and determine the response to pharmacotherapy with evaluating atherosclerosis. If the response is inadequate, initiate lipoprotein apheresis as soon as possible.

Increased plasma isoprostane is associated with visceral fat, high molecular weight adiponectin, and metabolic complications in obese children.

Oxidative stress is considered to be increased in obese subjects. However, the association of oxidative stress with visceral adiposity and adiponectin level is not fully understood in children. Forty-four obese Japanese children and adolescents, 28 boys and 16 girls, with median age of 9.9 years [5.2-13.8 years], and the 28 age-matched non-obese healthy controls, 15 boys and 13 girls, were enrolled in this study. The median BMI Z scores were +2.21 [1.31-4.38] for the obese subjects and -0.72 [-2.11-1.31] for the control. Plasma concentrations of 8-epi-prostaglandin F2α (isoprostane), a marker of oxidative stress, and adiponectin fractions were assayed using ELISA. 8-epi-PGF2α levels were significantly higher in the obese group (37.1 [4.7-112.7], median and the range) than in the control (11.5 [4.5-27.3]). In a univariate analysis, concentrations of 8-epi-PGF2α positively correlated with visceral adipose tissue area measured by computed tomography, waist circumference, serum triglycerides, alanine aminotransferase, insulin levels, and the homeostasis of minimal assessment of insulin resistance and inversely correlated with high-density-lipoprotein cholesterol and high-molecular weight (HMW) adiponectin. Total-, medium-, or low-molecular weight adiponectin fraction did not show a significant correlation with 8-epi-PGF2α Forty of 44 obese children had one or more metabolic complications. The 8-epi-PGF[Formula: see text] levels also elevated with increasing numbers of obesity-related complications. These results suggest that oxidative stress is enhanced in relation to visceral fat accumulation and decreasing HMW adiponectin level in childhood obesity. Oxidative stress may be associated with the development of obesity-related complications.

Expression of hypothalamic feeding-related peptide genes and neuroendocrine responses in an experimental allergic encephalomyelitis rat model.

Experimental allergic encephalomyelitis (EAE) is considered to be a useful animal model of human multiple sclerosis (MS). However, among the various symptoms of MS, the mechanisms contributing to inflammatory anorexia remain unclear. In the present study, we used an EAE rat model to examine changes in expression levels of hypothalamic feeding-related peptide genes and neuroendocrine responses such as the hypothalamo-neurohypophysial system and the hypothalamo-pituitary-adrenal (HPA) axis. The weight gain and cumulative food intake in EAE rats in the early days after immunization was significantly lower than that of the control group. The expression of orexigenic peptide genes Npy and Agrp were significantly increased, whereas the levels of anorectic peptide genes (Pomc and Cart) were significantly decreased in the hypothalamus of EAE rats. There was also a significant increase in the mRNA and plasma oxytocin (OXT) but not of arginine vasopressin (AVP) in the supraoptic and paraventricular nuclei (PVN) of EAE rats at days 12 and 18 after immunization. The expression of corticotropin-releasing hormone (Crh) and Avp was downregulated and upregulated, respectively, in the parvocellular division of the PVN at day 12 after immunization. The expression level of Pomc in the anterior pituitary significantly increased, accompanied by increased plasma corticosterone levels, at days 6, 12, and 18 after immunization. These results suggest that inflammatory anorexia in rat EAE may be caused by activation of the OXT-ergic pathway and HPA axis via changes in the expression of hypothalamic feeding-related peptides, including Avp but not Crh.

The effect of environmental factors in childcare facilities and individual lifestyle on obesity among Japanese preschool children; a multivariate multilevel analysis.

Lifestyle in preschool children is associated with the onset of childhood obesity. However, the effect of environmental factors in childcare facilities on lifestyle and obesity in preschool children is unknown. The aim of this study was to determine the effect of environmental factors in childcare facilities on the association between obesity and individual lifestyle in preschool children.Subjects included 2902 infants, aged 4 to 6 years old in Kitakyushu City, Japan. A stratified multilevel analysis was conducted with 2 strata: factors related to individual lifestyle and maternal factors as the individual level and factors related to the childcare facility as the environmental level. Two-level multilevel regression analysis was conducted with the presence or absence of obesity.The proportion of infants with obesity was 4.2%. The childhood obesity was significantly associated with the mastication, nutritional methods during infancy, absence of breakfast, presence of skipping meals due to overeating of snacks, usual play activity, screen time on weekdays, maternal body mass index, and maternal weight increase during pregnancy at the individual level. On the other hand, childhood obesity had a significantly negative association with the receiving snacks in facilities by using multilevel analysis.The present study revealed that establishing and maintaining environmental factors in childcare facilities may play important roles in the prevention of obesity from early childhood.

Correction to: Inhibition of ghrelin-induced feeding in rats by pretreatment with a novel dual orexin receptor antagonist.

The article Inhibition of ghrelin-induced feeding in rats by pretreatment with a novel dual orexin receptor antagonist, written by Mariko So, Hirofumi Hashimoto.

Status and trends in the use of insulin analogs, insulin delivery systems and their association with glycemic control: comparison of the two consecutive recent cohorts of Japanese children and adolescents with type 1 diabetes mellitus.

Background Treatment for type 1 diabetes mellitus (T1DM) has greatly changed by the general use of insulin analogs and continuous subcutaneous insulin infusion (CSII). To investigate whether these advances have been translated into continued improvement in glycemic control in Japanese children and adolescents, we analyzed the registration data of the two consecutive recent cohorts of Japanese childhood-onset T1DM patients. Methods The registration data including hemoglobin A1c (HbA1c), hypoglycemia and insulin regimen were compared between the two cohorts (862 patients in the 2008 cohort and 1090 in the 2013 cohort). Results The proportion of subjects with multiple daily insulin injection therapy (MDI) and CSII significantly increased (p<0.0001) from 67.4% and 9.7% to 71.8% and 23.4%, respectively. In the 2013 cohort, almost all patients were treated with basal-bolus treatment using insulin analogs. The use of CSII increased in all age groups, especially in the age group 0-5 years. The rates of overall, moderate and severe hypoglycemia significantly declined from 10.24, 10.18 and 0.056 events/100 persons/period in the 2008 cohort to 0.66, 0.62 and 0.033 in the 2013 cohort (p<0.0001, <0.0001, 0.04), respectively. Contrarily, there were no significant changes in HbA1c values between the two cohorts. Conclusions The popularization of the basal-bolus treatment using insulin analogs hascontributed to a significant decrease in hypoglycemia. In contrast, the intensive insulin treatment may not be enough for the satisfactory improvement of glycemic control in Japanese children and adolescents with T1DM. Considerable points remain, such as diabetic education and support to motivate patients.

Centrally administered kisspeptin suppresses feeding via nesfatin-1 and oxytocin in male rats.

Kisspeptin (KP), known as a hypothalamic neuropeptide, plays a critical role in the regulation of not only reproduction but also food intake. The anorectic neuropeptides, nesfatin-1 and oxytocin (OXT), are expressed in central nervous system, particulaly in various hypothalamic nuclei, and peripheral tissue. We examined the effects of the intracerebroventricular (icv) administration of KP-10 on feeding and nesfatin-1-immunoreactive (ir) or OXT-ir neurons in the rat hypothalamus, using Fos double immunohistochemistry in male rats. Cumulative food intake was remarkably decreased 0.5-3 h after icv administration of KP-10 (6.0 µg) compared to the vehicle treated and the KP-10 (3.8 µg) treated group. The icv administration of KP-10 significantly increased the number of nesfatin-1-ir neurons expressing Fos in the supraoptic nucleus (SON), paraventricular nucleus (PVN), arcuate nucleus (ARC), dorsal raphe nucleus, locus coeruleus, and nucleus tractus solitarius. The decreased food intake induced by KP-10 was significantly attenuated by pretreatment with the icv administration of antisense RNA against nucleobindin-2. After icv administration of KP-10, the percentages of OXT-ir neurons expressing FOS were remarkably higher in the SON and PVN than for vehicle treatment. The KP-10-induced anorexia was partially abolished by pretreatment with OXT receptor antagonist (OXTR-A). The percentage of nesfatin-1-ir neurons expressing Fos-ir in the ARC was also decreased by OXTR-A pretreatment. These results indicate that central administration of KP-10 activates nesfatin-1- and OXT neurons, and may play an important role in the suppression of feeding in male rats.

Postnatal development of galanin-like peptide mRNA expression in rat hypothalamus.

We examined the developmental change of GALP mRNA in male and female rat hypothalamus during postnatal day 1 to 60, using in situ hybridization histochemistry. Neuropeptide Y (NPY) and proopiomelanocortin (POMC) mRNA in the hypothalamus were also examined because they are important in the regulation of food intake. GALP mRNA was first detected in the arcuate nucleus (ARC) on day 8. GALP mRNA was gradually increased between day 8 and 14 and markedly increased between day 14 and 40, which is the weaning and pubertal period in rats. After day 40, there were no significant differences in GALP mRNA. In contrast to GALP, NPY and POMC mRNAs were detected in the ARC from day 1 and lasted to day 60. There was no sexual dimorphism in GALP, NPY and POMC mRNAs during postnatal development. Next, we examined the effect of the milk deprivation for 24 h on GALP, NPY and POMC mRNA in pups. GALP mRNA did not change by milk deprivation on day 9 and 15, while milk deprivation had a significant effect on NPY and POMC mRNA on day 15. These results suggest that the development of GALP may be associated with developmental changes such as weaning, feeding and maturation of reproductive functions. The regulatory mechanism of GALP mRNA is different from that of the NPY and POMC genes during postnatal development.

Hydroxymethylglutaryl--CoA reductase inhibitor inhibits induction of nitric oxide synthase in 3T3--L1 preadipocytes.

Preadipocytes are considered to play a role in adipose tissue inflammation in obesity. The purpose of this study was to determine whether hydroxymethylglutaryl-CoA reductase inhibitor (statin) modulates the nitric oxide (NO) production via inducible NO synthase (iNOS) in preadipocytes. Undifferentiated 3T3-L1 cells, a model of preadipocytes, significantly produced NO by the treatment with the combination of lipopolysaccharide (L), tumor necrosis factor-alpha (T) and interferon-gamma (I). Pre-incubation with simvastatin, a lipophilic statin, or pravastatin, a hydrophilic one, dose-dependently inhibited the NO production in the LTI-treated cells. The effect of simvastatin was offset by mevalonate or geranylgeranyl pyrophosphate (GGPP) but not by squalene. The mRNA level for iNOS paralleled the NO production. The nuclear factor-kappaB (NF-kappaB) was activated by the LTI-treatment, and was inhibited by addition of simvastatin or pravastatin. Mevalonate or GGPP completely offset the effect of simvastatin. Simvastatin or pravastatin also decreased the LTI-stimulated interleukin-6 (IL-6) secretion. These effects of pravastatin were relatively weak compared with those of simvastatin. Y27632, an inhibitor of Rho kinase, also inhibited the LTI-induced NF-kappaB activation and iNOS expression, and decreased the production of NO and IL-6 in 3T3-L1 preadipocytes. These results suggest that statins, especially lipophilic types, inhibit induction of iNOS by inhibiting the small GTP-binding protein signal in preadipocytes.

[Prevalence of 'obesity disease' and 'metabolic syndrome' in obese pediatric outpatients at the University Hospital of Occupational and Environmental Health, Japan].

'Obesity Disease for Japanese Children' was defined in 2002, and very recently 'Metabolic Syndrome (MS) for Japanese Children' was also defined. We therefore aimed to determine the prevalence of these two among the obese pediatric outpatients at our university hospital. The subjects were 97 children, 58 boys and 39 girls, ranging in age from 5 to 15 years. A child was considered to be obese when the body weight exceeded 120% of the standard body weight. All the subjects exceeded 120% overweight, and 58 children (35 boys and 23 girls) were over 150% overweight. Eighty five children (53 boys and 32 girls) were diagnosed with obesity disease (87.6%). Sixteen children (12 boys and 4 girls) were diagnosed with metabolic syndrome, which was 16.5% of all the subjects and 18.8% of the children with obesity disease. Fourteen of the 16 children with MS were over 10 years old. Obesity disease is diagnosed when the child has an obesity disease score of more than 6. The obesity disease score was significantly correlated with the waist circumference and the visceral adipose tissue area measured by computed tomography. The mean score of the children with MS was significantly higher than that of the non-MS group (30.2 vs. 12.3 points). In this study, it was clear that about 90% of our clinic patients are in the obesity disease group, and need therapeutic interventions. The prevalence of MS in the pediatric age is very low compared with that of adults, but MS is a high-risk category of obesity disease.

Inhibition of ghrelin-induced feeding in rats by pretreatment with a novel dual orexin receptor antagonist.

Orexin-A and -B, and ghrelin are potent orexigenic peptides. The effects of ACT462206, a novel dual orexin receptor antagonist (DORA), on ghrelin-induced feeding were examined in adult male Wistar rats. Hyperphagia induced by the intracerebroventricular (icv) administration of ghrelin was significantly suppressed for at least 2 h by pretreatment with icv administration of DORA. A marked increase was observed in the number of neurons showing Fos immunoreactivity in the paraventricular nucleus, arcuate nucleus and lateral hypothalamic area (LHA), 90 min after icv administration of ghrelin. Pretreatment with DORA significantly decreased the number of Fos-immunoreactive (IR) neurons; however, Fos immunoreactivity remained significantly increased. Double-immunostaining for Fos and orexin-A showed that many orexin-A-IR neurons in the LHA coexisted with Fos immunoreactivity after icv administration of ghrelin, but their number was reduced significantly by DORA pretreatment. These results suggest that centrally administered ghrelin may activate the orexinergic and non-orexinergic pathways responsible for the regulation of feeding.

N-acetylcysteine inhibits induction of nitric oxide synthase in 3T3-L1 adipocytes.

The present study was designed to determine whether N-acetylcysteine (NAC), a potent antioxidant, modulates nitric oxide (NO) production stimulated by lipopolysaccharide (LPS) and tumor necrosis factor-alpha (TNF-alpha) in adipocytes. Stimulation by the combination of 5 microg/ml of LPS and 100 ng/ml of TNF-alpha (LT) significantly enhanced NO production in 3T3-L1 adipocytes. Preincubation of the cells with NAC (5-20 mM) for 24 h suppressed the increased NO production in a dose-dependent manner. The production of NO was decreased by 49% at the concentration of 20 mM of NAC. The decrease in NO production by NAC was accompanied by a decrease in inducible nitric oxide synthase (iNOS) protein, detected by immunoblot analysis, and iNOS mRNA, determined by real-time reverse-transcriptase coupled polymerase chain reaction analysis. Nuclear factor-kappa B (NF-kappa B) was significantly activated by LT-treatment, while the pretreatment with 20 mM of NAC prevented the activity by 42%. Pyrrolidine dithiocarbamate (PDTC), a NF-kappaB inhibitor, also inhibited the LT-mediated NO production dose-dependently. One hundred microM of PDTC inhibited the NO production by 46%. We also investigated the effect of NAC and PDTC on the production of interleukein-6 (IL-6), which is regulated transcriptionally by NF-kappa B in 3T3-L1 adipocytes. IL-6 production was markedly increased by LT stimulus, and the enhanced secretion of IL-6 was suppressed in a dose-dependent manner by pretreatment with NAC or PDTC. These results suggest that NAC regulates iNOS expression and NO production in adipocytes through the modulating activation of NF-kappa B.