Hyperplasia of endocrine cells, tumorlets and atypical carcinoid of the lung--a case report

The authors present an extremely rare case of endocrine cell hyperplasia, numerous tumorlets and atypical carcinoid situated in the left inferior pulmonary lobe of a 34-year old woman.

Commentary: Setting Aside Tradition When Dealing with Endocrine Disruptors

In 1996, the US Congress directed the Environmental Protection Agency to produce screens and assays to detect estrogenic and other endocrine-disrupting chemicals in food and water. To date, there are none. Years have been wasted in attempts to utilize traditional toxicological approaches to solve the problem, when in retrospect, it is now apparent that the delay in part stems from the reluctance to attack the problem with entirely new approaches. To develop new testing protocols, it is necessary to set aside much of the dogma of toxicology and to begin again with open minds. A few pertinent examples are provided concerning what has been overlooked and what needs to be done. In particular, it is necessary to give close attention to the selection of animal strain and diet, factors that were only loosely controlled historically when one takes into consideration what has been learned in the last decade. Vast numbers of animals have been sacrificed, and more will be sacrificed, in futile attempts to validate assays and to develop safety standards unless knowledge gained over the past decade concerning the sensitivity and complexity of the endocrine system is taken into consideration.

Use and Role of Invertebrate Models in Endocrine Disruptor Research and Testing

Historically, invertebrates have been excellent models for studying endocrine systems and for testing toxic chemicals. Some invertebrate endocrine systems are well suited for testing chemicals and environmental media because of the ease of using certain species, their sensitivity to toxic chemicals, and the broad choice of models from which to choose. Such assays will be useful in identifying endocrine disruptors to protect invertebrate populations and as screening systems for vertebrates. Hormone systems are found in all animal phyla, although the most simple animals may have only rudimentary endocrine systems. Invertebrate endocrine systems use a variety of types of hormones, including steroids, peptides, simple amides, and terpenes. The most well-studied hormone systems are the molting and juvenile hormones in insects, the molting hormones in crustaceans, and several of the neurohormones in molluscs and arthropods. These groups offer several options for assays that may be useful for predicting endocrine disruption in invertebrates. A few invertebrate phyla offer predictive capabilities for understanding vertebrate endocrine-disrupting chemicals. The echinoderms, and to a lesser extent molluscs, have closer evolutionary relationships with the vertebrates than the arthropods and these phyla. The recently identified estrogen receptor structure within the genome of the marine gastropod, Aplysia, indicates that the estrogens, and probably the basic steroid receptor, are quite old evolutionarily. This review of the recent literature confirms the effects of some endocrine-disrupting chemicals on invertebrates--tributyltin on snails, pesticides on insects and crustaceans, and industrial compounds on marine animals.

The neuroanatomy and neuroendocrinology of fragile X syndrome

Fragile X syndrome (FXS), caused by a single gene mutation on the X chromosome, offers a unique opportunity for investigation of gene-brain-behavior relationships. Recent advances in molecular genetics, human brain imaging, and behavioral studies have started to unravel the complex pathways leading to the cognitive, psychiatric, and physical features that are unique to this syndrome. In this article, we summarize studies focused on the neuroanatomy and neuroendocrinology of FXS. A review of structural imaging studies of individuals with the full mutation shows that several brain regions are enlarged, including the hippocampus, amygdala, caudate nucleus, and thalamus, even after controlling for overall brain volume. These regions mediate several cognitive and behavioral functions known to be aberrant in FXS such as memory and learning, information and sensory processing, and social and emotional behavior. Two regions, the cerebellar vermis, important for a variety of cognitive tasks and regulation of motor behavior, and the superior temporal gyrus, involved in processing complex auditory stimuli, are reported to be reduced in size relative to controls. Functional imaging, typically limited to females, has emphasized that individuals with FXS do not adequately recruit brain regions that are normally utilized by unaffected individuals to carry out various cognitive tasks, such as arithmetic processing or visual memory tasks. Finally, we review a number of neuroendocrine studies implicating hypothalamic dysfunction in FXS, including abnormal activation of the hypothalamic-pituitary-adrenal (HPA) axis. These studies may help to explain the abnormal stress responses, sleep abnormalities, and physical growth patterns commonly seen in affected individuals. In the future, innovative longitudinal studies to investigate development of neurobiologic and behavioral features over time, and ultimately empirical testing of pharmacological, behavioral, and even molecular genetic interventions using MRI are likely to yield significant positive changes in the lives of persons with FXS, as well as increase our understanding of the development of psychiatric and learning problems in the general population.

Use of the Laboratory Rat as a Model in Endocrine Disruptor Screening and Testing

The screening and testing program the US Environmental Protection Agency (EPA) is currently developing to detect endocrine-disrupting chemicals (EDCs) is described. EDCs have been shown to alter the following activities: hypothalamic-pituitary-gonadal (HPG) function; estrogen, androgen, and thyroid hormone synthesis; and androgen and estrogen receptor-mediated effects in mammals and other animals. The value and limitations of mammalian in vivo assays are described that involve the use of the laboratory rat, the EPA Endocrine Disruptor Screening and Testing Advisory Committee species of choice. The discussion includes the evaluation of high-priority chemicals positive in the Tier 1 Screening (T1S) battery, and of subsequent testing in the Tier 2 (T2) battery, with additional short-term screening assays proposed for use in T1.5 to eliminate any uncertainty about T1S results. Descriptions include the in vivo uterotropic assay, which detects estrogens and antiestrogens; the pubertal female assay, which assesses steroidogenesis, antithyroid activity, antiestrogenicity, and HPG function; and the Hershberger assay, which detects the weight of androgen-dependent tissues in castrate-immature-male rats (antiandrogens). Of the several alternative mammalian in vivo assays proposed, a short-term pubertal male rat assay appears most promising for inclusion in T1 or T1.5. An additional in utero-lactational screening protocol is being evaluated, but appears to be better suited for T1.5 or T2 due to the size, complexity, and duration of the assay. The adult intact male assay, also proposed as an alternative for T1, attempts to identify EDCs in a hormonal battery, but has limited value as a screen due to lack of sensitivity and specificity. For Tier 2 testing, the number of endocrine-sensitive endpoints and offspring (F1) examined in multigenerational tests must be thoughtfully expanded for EDCs on a mode-of-action-specific basis, with consideration given to tailoring T2 based on the results of T1S.

Animal Models and Studies of in Utero Endocrine Disruptor Effects

The rate of organ and system development in mammals, including humans, is most rapid during the prenatal period. Perturbations of the endocrine system during this period can have profound effects on later anatomy, physiology, behavior, and the onset of disease. Endocrine-disrupting compounds can cause perturbations during fetal development by mimicking or blocking natural hormones. In experimental studies, compounds that mimic estrogens and those that block androgen action have been shown to have a number of long-term effects. Among these effects are the acceleration of puberty onset, increased incidence of adult cancers such as vaginal and prostate cancers, and alterations in sexually dimorphic anatomy, physiology, and behavior. Laboratory animal models continue to play a crucial role in identifying endocrine disruptors, determining their mode of action, and demonstrating their consequences.

Carcinoids and their variant endocrinomas. An analysis of 11842 reported cases

Endocrinocarcinomas consisting of carcinoids and their variant carcinomas with endocrine features are neoplasms of relatively rare occurrence but have often been reported in many countries and regions of the world. The largest series of 13715 cases from the United States was published in 2003. A total number of 11842 reported cases of endocrinocarcinomas from the Niigata Registry were divided into two groups: the carcinoid group (n = 10804) with the typical (n = 9430) and the atypical (n = 1374) series and the variant group (n = 1038). These cases came from 64 countries and reports were written in 17 different languages. They were statistically evaluated for comparison between the two groups or series in various aspects, including gender and age, tumor-size, rate of metastases, immunohistochemistry, and survival after curative resection. In the carcinoid group, more frequent cases were found in the digestive system (64.2%) than in the extradigestive system (35.8%). Organ distribution of carcinoid cases exhibited the most frequent site to be the respiratory system (19.8%), followed by the rectum (15.0%), jejunoileum (12.0%), stomach (11.4%), appendix (9.6%) and duodenum (8.3%). An extremely small number of cases (less than 0.7%) were found in the middle ear, testicle, kidney, and several others. The highest rate of metastases was noted in the ileocecum (75.3%), followed by the jejunoileum (65.2%), pancreas (64.2%), and larynx (61.4%). Small carcinoids with invasion confined to the mucosa and submucosa, indicated an unexpectedly high metastasis rate of 13.8% for lesions 20 mm or less, and 10.0% for those 10 mm or less, and 6.1% for those 5 mm or less. The carcinoid syndrome was found to occur at the rate of 7.7% of overall 11057 cases reported between 1953 and 2002, with the highest incidence of 28.8% in the 5-year period between 1963 and 1967, gradually decreasing down to 3.7% in the last 5 years. The 5-year survival rate after curative resection of lesions showed a significant difference between the carcinoid group and the variant group (82.0% vs 41.8%: P < 0.0001). In the former group, the 5-year survival rate showed a significant difference between cases with or without metastases (61.4% vs 95.7%: P < 0.0001). In the latter group, the 5-year survival rate was 74.5% for cases without metastases and 24.1% for those with metastases (P < 0.0001). The highest 5-year survival rate in the carcinoid group was noted in the ovary (93.6%), followed by the liver (92.6%), the respiratory system (89.7%), the appendix (89.5%), and the rectum (85.4%), while poor 5-year survival rates were recorded in the pancreas (43.2%), the esophagus (43.5%) and the larynx (47.6%). It should be emphasized that there is a significant statistical difference in many aspects between the carcinoid group and the variant group. The present study confirms that the malignant nature of these endocrine tumors is well reflected in their metastasis rates, even in small lesions with submucosal invasion, resulting in the 5-year survival rates of a significant difference among the groups or series.

Uncertainties for endocrine disrupters: our view on progress

The hypothesis that hormonally active compounds in the environment--endocrine disrupters--are having a significant impact on human and ecological health has captured the public's attention like no other toxicity concern since the publication of Rachel Carson's Silent Spring 1962. In the early 1990s, Theo Colborn and others began to synthesize information about the potential impacts of endocrine-mediated toxicity in the scientific literature (Colborn and Clement, 1992) and the popular press (Colborn et al., 1997). Recognizing the possibility of an emerging health threat, the U.S. Environmental Protection Agency (EPA) convened two international workshops in 1995 (Ankley et al., 1997; Kavlock et al., 1996) that identified research needs relative to future risk assessments for endocrine-disrupting chemicals (EDCs). These workshops identified effects on reproductive, neurological, and immunological function, as well as carcinogenesis as the major endpoints of concern and made a number of recommendations for research. Subsequently, the EPA developed a research strategy to begin addressing the recommendations (EPA, 1998a), and the federal government as a whole, working through the White House's Committee on the Environment and Natural Resources, increased funding levels and coordinated research programs to fill the major data gaps (Reiter et al., 1998). In parallel with these research efforts that were attempting to define the scope and nature of the endocrine disruptor hypothesis, the U.S. Congress added provisions to the Food Quality Protection Act (FQPA) and the Safe Drinking Water Act of 1996 to require the testing of food-use pesticides and drinking water contaminants, respectively, for estrogenicity and other hormonal activity. These bills were enacted into law, giving the EPA the mandate to implement them. The EPA, with the help of an external advisory committee, the Endocrine Disruptor Screening and Testing Advisory Committee (EDSTAC), determined that other hormonal activity should include androgens and compounds that affect thyroid function, and expanded the mandate to include all chemicals under EPA's jurisdiction, potentially including the 70,000 chemicals regulated under the Toxic Substances Control Act (Endocrine Disruptor Screening and Testing Advisory Committee [EDSTAC], 1998). EDSTAC recommended an extensive process of prioritization, screening, and testing of chemicals for endocrine-disrupting activity, including a screening battery that involves a combination of at least eight in vitro and in vivo assays spanning a number of taxa (EDSTAC, 1998). What started out as a hypothesis has become one of the biggest testing programs conceived in the history of toxicology and the only one that has ever been based on mechanism of action as its premise. As we pass the 10th anniversary of the emergence of the endocrine disruptor hypothesis, it is useful to look back on the progress that has been made in answering the nine questions posed as data gaps in the EPA's research strategy (EPA, 1998a)--not only to see what we have learned, but also to examine whether the questions are still appropriate for the goal, what gaps remain, and what directions should be emphasized in the future.

Angiogenesis in endocrine glands: special reference to the expression of vascular endothelial growth factor

Recent studies have shown that several angiogenic growth factors are produced and secreted by normal endocrine cells and are increased in pathological states of endocrine glands, including inflammation, hyperplasia, and neoplasia. Expression of corresponding receptors on epithelial cells and/or endothelial cells enables these angiogenic factors to influence growth and function of the endocrine tissues by auto- or paracrine mechanisms. Some of the angiogenic factors are also considered to be involved in angiogenesis, which is a critical process in tumor formation and progression. Vascular endothelial growth factor (VEGF) is regarded as one of most important angiogenic factors with specific effects on endothelial cell growth and vascular permeability, and is isolated from a variety of normal and neoplastic endocrine cells. In this article, recent studies on angiogenic factors, especially on expression of VEGF, are reviewed in the field of endocrine systems.

Endocrine pathology in translational medicine: an overview of current and future prospects

With applications of recent development of molecular techniques, endocrine pathology, as a scientific discipline, has been expanding its field to cover not only the pathologic diagnosis but also molecular mechanisms of hormone production and secretion as well as implementation for appropriate therapeutic approaches. In this review, the discussion includes molecular markers for the diagnosis of neuroendocrine (NE) tumors focusing on various proteins for the transport of secretory granules. MIB-1, proliferative indices, is particularly useful to access biologic activities of NE tumors. The specific hormone production relies on the expression of combination of transcription factors and proteolytic digestion (processing) of prohormones by specific enzymes, prohormone convertases PC1/3 and PC2. Inappropriate processing of prohormones sometimes are related to neoplastic conditions. Endocrine therapeutics have been focusing on the compensation of deficient hormones by transplanting specific hormone producing cells including embryonic stem (ES) cells. The endocrine pathology is expected to play a major role in translational medicine.

Autopsy case of multiple anomalies with hypoplastic cerebrum, eyes, and endocrine organs, mimicking Micro syndrome

We report an autopsy case of multiple anomalies with severe micrencephaly, bilateral microphthalmos, and hypoplastic endocrine organs. We examined expressions of calcium-binding proteins and hypothalamic and pituitary hormones. A female proband presented with microcephaly, microphthalmia, and psychomotor development delay. At the age of 23 years, she died of cardiorespiratory failure. The endocrine organs demonstrated severe underdevelopment, and the hypoplastic eyeballs had remnant lens, vitreous hemorrhage, and retinal detachment. The brain weighed 260 g; the cerebrum, cerebellum, and brain stem were extremely small; and the tertiary sulci were absent in the cerebral surface. The cross-sectional area of cerebral cortex was reduced to about one third of those in the control, although six-layered lamination, density of pyramidal neurons, and expressions of calcium-binding proteins were comparatively preserved in the cerebral cortex. The third ventricle was hypoplastic, and the bilateral thalami appeared to be fused and the hippocampus was unrolled, whereas the corpus callosum was preserved. In the hypothalamus, the paraventricular nucleus was only identified, and the adenohypophysial somatotrophs were reduced. This may be the first autopsy report of Micro syndrome, which is characterized by microcephaly, brain malformations, optic atrophy, and hypogenitalism, although the case lacked agenesis of the corpus callosum.

Scientific issues associated with the validation of in vitro and in vivo methods for assessing endocrine disrupting chemicals

The assays required to assess the potential of chemicals to act as endocrine disrupting (ED) agents are either in place or are under current development. However, the validation and utilisation of these assays is currently being hampered by uncertainties regarding their purpose and required sensitivity, and uncertainties as to the intrinsic variability of the parameters being measured. This article discusses these several sources of uncertainty and the intrinsic variability of many of the key assay parameters. It is concluded that current uncertainties regarding the use of ED assays, and the extrapolation of rodent effects to humans, are due to the absence of an extensive agreed rodent control database for the developmental parameters under study, coupled to the established intrinsic variability of these parameters between strains/species of test animals and test protocols. Only when these factors are generally accepted, well studied and controlled for, will it be possible to employ ED assays with confidence and to relate assay data to effects likely to be seen in humans.

Endocrine aspects of neurosarcoidosis

The involvement of the hypothalamus and/or pituitary gland by granulomatous, infiltrative or autoimmune diseases is a rare condition of non-tumoral-non-vascular acquired hypothalamic dysfunction and hypopituitarism. In this paper, we present the case of a 26-year-old woman, who showed an amenorrhea-galactorrhea syndrome with hypogonadotropic hypogonadism due to an isolated hypothalamic-peduncular localization of neurosarcoidosis. Acquired GH deficiency was also demonstrated. This clinical case provided the opportunity for a review of the endocrine aspects linked to brain infiltrative diseases that may affect the hypothalamic-pituitary function, with a focus upon neurosarcoidosis. Sarcoidosis is a pathogen-free granulomatous disease that affects both the central and peripheral nervous system in 5-16% of patients. In most cases, such involvement by sarcoidosis occurs within a multi-systemic disease, but disease localization limited to the nervous system may also be observed. Endocrine manifestations of neurosarcoidosis disclose "chameleon-like" clinical pictures, which are usually expressed by the evidence of hypothalamic dysfunction, diabetes insipidus, adenopituitary failure, amenorrhea-galactorrhea syndrome, in isolated fashion or variedly combined. More rarely, inappropriate anti-diuretic hormone secretion, isolated secondary hypothyroidism, adrenal insufficiency or altered counter-regulation of glucose homeostasis have been reported. Neurosarcoidosis is often hard to diagnose, especially when the neurological localization of the disease is not accompanied by other systemic localizations or by specific signs of the disease, and when the lesion is too deep to obtain bioptic confirmation. The study of cerebrospinal fluid and blood lymphocyte sub-populations, integrated by MRI and nuclear scans (67GalIium uptake and 111Indium-pentetreotide, Octreoscan), may be helpful for a correct diagnosis. Therapy with corticosteroid and immunosuppressive drugs, such as cyclosporine A, and other treatment approaches to neurosarcoidosis are also accounted for.

Approaches to the assessment of toxicity data with endpoints related to endocrine disruption

There has been a substantial proliferation in the number of studies reporting endocrine effects as an endpoint. The vast majority have focused on oestrogenicity in vitro but, with recent recommendations by the USEPA Endocrine Disrupter Screening and Testing Advisory Committee, tests are now being developed for (anti)-androgenicity and effects on the thyroid, largely because of the potential for altering reproduction or development via these mechanisms. Despite being a vital organ and involved in reproduction and development, there is currently no provision for assessing adrenocortical function. Similarly, the entire process of steroidogenesis poses multiple molecular targets for toxic disruption that are not included in current test strategies and at present there is no clear position on the significance of the data being generated. This review provides a framework for approaching endocrine data: that all the glands, tissues, receptors, transporter proteins and enzymes that comprise the endocrine system are targets for toxicity. They should be considered in much the same way as other target organs, with appropriate provision for the special cases of carcinogenesis and teratogenesis, and a pragmatic weight of evidence approach should be adopted considering all available data and recognizing its limitations. In this approach, structure-activity relationships and in vitro and targeted in vivo screens provide useful data but repeat-dose regulatory studies with defined endpoints provide the most powerful tools for hazard assessment. Pragmatic consideration should be given to exposure issues (which may highlight the practical irrelevance, for example, of very low potency oestrogens) and subsequently whether endocrine disruption is the critical or most sensitive endpoint for a compound. Finally, endocrine disruption may be considered a mechanism and, as with other toxic endpoints, knowledge of effect and no-observable-effect levels and reversibility is as important as identifying the target tissue or any inherent hormone-like property.

Hyperplasia versus adenoma in endocrine tissues: are they different?

The traditional view holds that hyperplasia of endocrine glands is secondary to oversecretion of a trophic hormone. However, in most cases, the mechanism underlying this growth is the spontaneous proliferation of benign neoplasias. Pathologists still depend on subtle morphological criteria to delineate and further classify these tumours. Owing to their variable architecture, a bewildering nomenclature has emerged for these tumours, exemplified by the many names applied to the goitrous thyroid gland: hyperplasia, adenomatous goitre, adenomatoid nodules, benign nodular thyroid disease, adenoma, etc. This article reviews the evidence suggesting that: (1) the varied types of benign neogeneration of endocrine tissue, the spectrum of which ranges from 'simple hyperplasia' to 'true adenoma', involve the same process; (2) even clonality of a growing lesion cannot distinguish hyperplasia from neoplasia; and (3) the basic processes in both cases are not different from those that cause benign tumours in other organs.

Endocrine disruption caused by two common pollutants at "acceptable" concentrations

This report focuses on the impact of low concentrations of two purported endocrine-disrupting xenobiotic compounds, nonylphenol and methoxychlor, on two freshwater teleosts of the genus Xiphophorus, X. maculatus, commonly known as the platyfish, and X. helleri, commonly known as the swordtail. Nonylphenol exposure increased mortality rates, elicited stress behaviors, decreased body weight and significantly hampered gonadal development and reproductive function. Methoxychlor exposure elicited stress behaviors, decreased body weight and significantly retarded sexual development. This report demonstrates that, even at "acceptable" concentrations, these compounds pose a serious threat to our aquatic ecosystems.

Endocervicosis of the small intestine

A case of endocervicosis of the small intestine incidentally found as a mass lesion during a gastric bypass surgery is reported. No previous cases of intestinal endocervicosis have been reported in the literature.

[Endocrine glands in alcohol drinkers and patient with alcoholism]

Chronic alcoholic intoxication results in atrophic and sclerotic changes of the endocrine glands, as was demonstrated by 225 autopsies of subjects who suffered from heavy drinking (165 cases) and alcoholism (60 cases). Morphometry and statistical data processing showed that alcoholism leads to irreversible changes, while heavy drinking causes changes that are reversible and compensated. The testes and ovaries are the most sensitive to ethanol and acetaldehyde, while the adrenals are the least sensitive. The pancreas retains its function for a long time despite pronounced changes.

Reproductive endocrinology and toxicological pathology over the life span of the female rodent

Understanding the pathology of the female reproductive system with respect to toxicology requires a basic understanding of morphology and function of the system over time because the nature of the female reproductive system is cyclical. Thus, the morphology and the endocrinology is dependent on age and time, as form follows function and function follows form. The life span of the rodent is used as an outline to present an overview of key morphological and endocrinological events important for toxicologic pathologists to consider in study evaluations. Environmental and pharmaceutical compounds differentially impact the organs individually and/or the system in its entirety in a time- and dose-dependent way. Examples are used to illustrate the consequences of exposures at different times and with different outcomes.

Preliminary immunohistochemical study of C cells of the thyroid and endocrine cells of the parathyroid glands in rats after prolonged exposure to cadmium

The effect of cadmium (Cd) on the thyroid and parathyroid glands was examined following a 12-week exposure of rats to 5 or 50 mg Cd/dm3. Immunohistochemical methods were used to determine calcitonin (CT), calcitonin-gene related peptide (GGRP), parathormone (PTH), somatostatin (ST), synaptophysin (SPh) and neuron-specific enolase (NSE). Calcium and cadmium concentrations in the femoral bone were assayed. The animals exposed to cadmium showed attenuation of all reactions, which was most distinct after 50 mg Cd/dm3. Exposure-dependent cadmium accumulation and a decrease in calcium concentration in the femoral bone were noted.

Overview of structural and functional lesions in endocrine organs of animals

The objective of this review is to summarize the pathogenic mechanisms responsible for perturbations of endocrine function and development of structural lesions that result in important diseases in domestic and laboratory animals. For each major category, several specific disease problems have been selected to illustrate the functional and morphologic lesions that are characteristic for either a naturally occurring endocrinopathy or endocrine disturbances induced by the administration of large doses of xenobiotic chemicals. The major pathogenic mechanisms responsible for disruption of endocrine function include primary hyperfunction, secondary hyperfunction, primary hypofunction, secondary hypofunction, endocrine hyperactivity secondary to other conditions, hypersecretion of hormones by nonendocrine tumors, failure of target cells to respond to a hormone, failure of fetal endocrine function, abnormal degradation (increased or decreased rate) of hormone, and iatrogenic syndromes of hormone excess (direct and indirect). Disorders of the endocrine system are encountered in a wide variety of domestic and laboratory animal species and often present challenging diagnostic problems. The development of proliferative lesions, usually hyperplasia and benign tumors, in endocrine organs and hormone-responsive tissues are common findings in chronic studies with high doses of many nongenotoxic xenobiotic chemicals administered to sensitive rodent species and may have limited significance for human safety assessment.

Gastric emptying in an animal model of human diabetes type 1: relation to endocrine cells

Gastric emptying was measured in female non-obese diabetic (NOD) mice with a duration of diabetes of 28-35 days. As controls, age- and sex-matched BLAB/cJ mice were used. Gastric emptying of diabetic mice was significantly slower than that of controls. The faeces weight and water content were significantly higher in diabetic mice than controls. The endocrine cells known to correlate with gastric emptying, namely secretin, serotonin, peptide YY (PYY) and enteroglucagon cells, were identified by immunocytochemistry and quantified by computer image analysis. The densities of duodenal secretin, serotonin and colonic PYY cells in NOD mice were significantly higher than that of control mice. Changes in these three endocrine cell types may play a role in delayed gastric emptying and in the manifestation of diarrhoea in this animal model of human diabetes type 1.