Small bowel motility in diabetics

Neostigmine-induced contraction and nitric oxide-induced relaxation of isolated ileum from STZ diabetic guinea pigs

Both delayed gastrointestinal transit and autonomic neuropathy have been documented in patients with diabetes mellitus. The mechanism of neostigmine, an agent that mimics release of acetylcholine from autonomic neurons by prokinetic agents, to contract smooth muscle, despite dysfunctional enteric neural pathways, was determined using isolated ilea from STZ-treated and control guinea pigs. Both bethanechol- and neostigmine-induced contractions were stronger in diabetic ileum. Bethanechol-induced contractions of control but not diabetic ileum were increased by low dose scopolamine suggesting reduced activation of presynaptic muscarinic autoreceptors in diabetic ileum. The muscarinic receptor antagonist 4-DAMP strongly, but the nicotinic receptor antagonist hexamethonium only weakly, reduced neostigmine-induced contractions of control and diabetic ilea. The amount of acetylcholine, inferred from tissue choline content, was increased in diabetic ileum. Nicotinic neural and noncholinergic postjunctional smooth muscle receptors contributed more strongly to neostigmine-induced contractions in diabetic than control ileum. Relaxation of diabetic ileum by exogenous nitric oxide generated from sodium nitroprusside was comparable to control ileum, but smooth muscle relaxation by l-arginine using neuronal nitric oxide synthase to generate nitric oxide was weaker in diabetic ileum with evidence for a role for inducible nitric oxide synthase. Despite autonomic neuropathy, neostigmine strongly contracted ileum from diabetic animals but by a different mechanism including stronger activation of postjunctional muscarinic receptors, greater synaptic acetylcholine, stronger activation of noncholinergic excitatory pathways, and weaker activation of inhibitory pathways. A selective medication targeting a specific neural pathway may more effectively treat disordered gastrointestinal transit in patients with diabetes mellitus.

Role of inflammation in gastrointestinal tract in aetiology and pathogenesis of idiopathic parkinsonism

Idiopathic parkinsonism (IP) is a common disorder, conventionally regarded as neurodegenerative. Its cardinal features, poverty and slowness of movement, muscle rigidity, postural abnormality and a characteristic tremor, are associated with loss of dopaminergic neurones in the substantia nigra of the brain. Genetic factors explain only a minority of cases, and a common toxic environmental insult remains elusive. We propose that IP is a systemic disorder resulting from a ubiquitous peripheral infection, and that only the tip of the iceberg comes to diagnosis. There is evidence for inflammatory/immune activation peripherally and in the brain. We have used statistical modelling to explore links with non-specific and specific systemic markers of inflammation/infection in IP probands, and explore whether their partners and siblings have a frank or pre-presentation parkinsonian state. Critical to this approach is continuous objective measures of the facets of IP. Hypotheses on causality and mechanism are based on the statistical models. There is pathological and clinical evidence for direct involvement of the gastrointestinal tract in IP. The candidacy of Helicobacter pylori infection as a trigger event or driving infection is relatively high. We have found that eliminating infection in late parkinsonism with cachexia, a stage usually considered intractable, can result in a U-turn. However, eradication therapy may not provide a complete solution. Persistence of antibody against cytotoxin-associated antigen (CagA), increases the predicted probability of being labelled as having parkinsonism. Evidence for autoimmunity and immunocompromise is used to build schemes for the natural history. We conclude that current classifications of neuropsychiatric disease may not prove the best with respect to defining sub-clinical disease, prophylaxis or halting progression.

Streptozotocin-induced diabetes modulates presynaptic and postsynaptic function in the rat ileum

Altered gastrointestinal motility frequently occurs in diabetic patients and also in animal models of diabetes but the underlying causes are not clear. In the present study, contractile responses to agonists and electrical field stimulation (EFS) and the inhibitory actions of an adenosine A(1) receptor agonist were investigated on ilea from 8-week streptozotocin (STZ)-induced diabetic rats. Contractile responses to carbachol, prostaglandin F(2 alpha) (PGF(2 alpha)), the calcium ionophore A23187 and to EFS were increased in diabetic tissues compared to controls. In contrast, the inhibitory effects of a potent and selective adenosine A(1) receptor agonist N(6)-cyclopentyladenosine (CPA) on electrical field stimulation-evoked contractions were decreased in diabetic tissues compared to controls but its ability to relax carbachol-contracted tissues was unaltered. These results suggest that diabetes may cause alterations at both pre- and postsynaptic sites and this may lead in turn to the gastrointestinal complications seen in diabetic patients.

Atropine decreases drinking but not feeding and induces less hypothalamic acetylcholine release in diabetic rats

Drinking, feeding and hypothalamic extracellular acetylcholine (ACh) release was measured before and after the administration of several doses of atropine sulfate in streptozotocin (STZ)-diabetic and normal rats. Drinking but not feeding was dose-relatedly decreased by i.p. or intrahypothalamic injections of atropine in STZ-diabetic rats. Hypothalamic ACh release, as measured by microdialysis, increased less (dose-related) in diabetic than normal rats following an i.p. administration of atropine. Ach basal levels were the same in both groups. These results are discussed in terms of a hyperactive hypothalamic cholinergic (muscarinic) system involved in the diabetic polydipsia.

Duration-dependent changes in calcium responsiveness in the alloxan-diabetic rat intestine

Disturbances of the gastrointestinal tract that are common in diabetes mellitus seem to be related to intestinal motility. In experimental models of diabetes, decreased calcium sensitivity has been demonstrated in various smooth muscles including those in the gastrointestinal tract. The main purpose of the present study was to examine further the calcium sensitivity in diabetic rat intestine and to understand if changes in the calcium sensitivity occur at an earlier stage of the disease. For this purpose, the effects of potassium and calcium were evaluated on nondepolarized and depolarized duodenum from rats with alloxan diabetes for 1 and 8 weeks and their age-matched controls. To evaluate the calcium sensitivity in rat duodenum, apparent affinity constants (pD2 values) and intrinsic activities (alpha E values) were calculated for every experimental conditions examined in this study. Both values (pD2 and alpha E) for the effects of potassium and calcium on the nondepolarized and depolarized duodenum, respectively, were not changed in 1-week diabetic rats. In contrast, intrinsic activities for the effects of potassium and calcium were found to be significantly decreased (p < 0.001) in the nondepolarized and depolarized duodenum from rats with alloxan diabetes for 8 weeks, whereas apparent affinity constants were not altered in this case. Taking into consideration all these experimental findings, the decreased calcium sensitivity in gastrointestinal tract seems to be closely related to decreased calmodulin levels and may occur at a later stage of diabetes as a linkage to long-term gastrointestinal complications.

Basal and histamine-induced gastric acid secretion in alloxan diabetic rats

1. Effects of alloxan-induced diabetes on the rat gastric acid secretion were investigated using a number of biostatistical models described earlier. 2. Histamine-induced gastric acid secretion was found to be decreased in alloxan-diabetic rats when compared with their age-matched controls. 3. Basal acid secretion was also decreased depending on experimentally-induced diabetes. 4. The above results strongly suggest that alloxan-induced diabetes depresses vagal activity and H2-receptor activity in the stomach.

β-Adrenergic Responsiveness of the Gastrointestinal Tract in Diabetic Rats

Recently, decreased gastrointestinal beta-adrenergic responses in experimental diabetes have been demonstrated. Gastrointestinal responses to beta-adrenoceptor agonists are impaired in both insulin-dependent and non-insulin-dependent diabetic rat. Insulin treatment improves the impaired gastrointestinal beta-adrenergic responsiveness of diabetic rats. The improvement seen with insulin treatment on beta-adrenergic responsiveness is closely related to protein biosynthesis. The decreased beta-adrenergic responses in diabetic rat gastrointestinal tract seem to result from a decrease in the number of beta-adrenoceptors. It is most likely that the decreased gastrointestinal beta-adrenergic responsiveness is related to an impairment in the turnover of beta-adrenoceptors as a consequence of diabetes and that insulin has a beneficial effect on the impaired receptor turnover.

Decreased beta-adrenergic responses of rat small intestine due to non-insulin-dependent diabetes

Relaxing responses to salbutamol of duodenum, jejunum and ileum isolated from alloxan-induced non-insulin-dependent diabetic rats were investigated by means of pharmacodynamic analysis using pD2 (apparent receptor affinity) and alpha E (intrinsic activity) values. beta-Adrenergic responses of these three intestinal parts of diabetic rats were found to be significantly decreased when compared to controls. The decreased responses may be attributable to a decrease in the number of beta-adrenergic receptors. The gastro-intestinal manifestations reported in diabetic patients are possibly linked to the occurrence of a decrease in beta-adrenergic receptors. Furthermore, this model seems to be useful for the investigations of gastro-intestinal complications resulting from non-insulin-dependent diabetes.

In vitro motor activity of intestinal segments of streptozotocin diabetic rats

The spontaneous motor activity of the isolated segments of the gut of streptozotocin-diabetic rats was studied in vitro. In normal preparations, the frequency of intraluminal pressure changes was little influenced by raising the intraluminal pressure. In contrast, in diabetic preparations, the frequency tended to increase with a rise of the intraluminal pressure, and the pressure waves were more irregular than in controls. The motor frequency with a pressure load of 3 cm H2O in the duodenum was 33/min in control rats and 21/min in diabetic rats. The motor frequencies in the other intestinal segments were also higher in normal preparations than in diabetic ones, although these differences were statistically not significant. The amplitude of intraluminal pressure changes increased according to the increase of pressure load, both in normal and diabetic preparations. These amplitudes were higher in normal than in diabetic preparations; however, the differences were statistically significant only in the jejunum. Insulin treatment (5 U/day) for one month, one to two months after streptozotocin injection, lowered the plasma glucose level to nearly normal and increased the body weight up to 80% of the normal but did not re-establish the normal motor frequency in the duodenum. Moreover, treatment of diabetic rats with aldose reductase inhibitor, ONO-2235 (per os, 50 mg/kg b.w./day for one month, one to two months after streptozotocin injection) did not re-establish the normal rhythms in duodenum. The pacemaker activity as well as mechanical properties in the intestinal tract may be disturbed in diabetic preparations.

Insulin action on different smooth muscle preparations

1. The importance of insulin in diabetic gastro-intestinal complications has been postulated. The present study was designed to investigate short-term effect of insulin on different smooth muscles isolated from non-diabetic animals. 2. The contractile responses of isolated guinea-pig ileum to acetylcholine and histamine and the serotonin-induced contractions of rat stomach fundus strips were inhibited by insulin in a non-competitive manner. The contractions of rat vas deferens elicited by noradrenaline and tyramine were also inhibited in the presence of insulin. 3. Insulin caused dose-dependent relaxation on the isolated rat duodenum. The relaxing response to insulin was not affected in the presence of atropine, phentolamine, propranolol, nicotinic acid, tetrodotoxin, tetraethylammonium, ouabain and nifedipine. The relaxing effect of insulin on the isolated rat duodenum was inhibited by sodium orthovanadate, trifluoperazine, verapamil, aspirin and dexamethasone, non-competitively. 4. The above results strongly suggest that the relaxing or inhibitory effect of insulin on the smooth muscles is closely related with prostanoid metabolism. Furthermore, it is concluded that this effect of insulin on the smooth muscles may be due to activation of Ca2+-pump ATPase(s).

Electrophysiological principles of motility disturbances in the small and large intestines--review of the literature and personal experience

Motility disturbances of the small and large intestines are based on changes in the smooth-muscle potential, whereby the number of amplitudes and configuration of slow waves and of spike potentials as well as pattern, speed of propagation, and duration of the MMC are of crucial importance. Whereas the electromechanical principles of intestinal motility are sufficiently known, changes in the electromechanical activity in clinically manifest motility disturbances have as yet not been given due regard. Only recently, electromechanical measurements in the upper gastrointestinal tract and colon were performed in several gastrointestinal diseases of internal medicine. In the small intestine, changes in slow waves, spike potentials, and the MMC could be disclosed which are typical for hyperthyrosis, hypothyrosis, irritable bowel syndrome, bacterial diarrhea, primary and secondary intestinal pseudo-obstruction, short-bowel syndrome, postoperative bowel atonia, mechanical bowel obstruction, vagotomy, and diabetic enteropathy with disturbed gastric emptying. Regarding the colon, a disturbance in the electromechanical characteristics was found in irritable bowel syndrome, bacterial overgrowth in the small bowel, chronic constipation, and idiopathic intestinal pseudo-obstruction, which is probably identical with the clinical picture of adynamic ileus. Based on a thorough examination of the literature and on own results from electromechanical measurements in children, electromechanical disturbances have been narrowly defined.

Effect of diabetes on the enzymes of the cholinergic system of the rat brain

Choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) activities were determined in several brain regions of normal and streptozotocin-induced diabetic rats. The diabetic rats exhibited significant increase in ChAT activity (p less than 0.05) in all brain regions studied except for the cortex and the midbrain. Meanwhile, the diabetes condition was associated with significant increase (p less than 0.05) in AChE activity of the bulbus olfactorius, medulla oblongata and cerebellum. These data suggest that uncontrolled diabetes is associated with significant alterations in the brain cholinergic systems.

Adrenergic, but not cholinergic or purinergic, responses are potentiated in the cecum of diabetic rats

Electrophysiologic properties of smooth muscle strips from the circular muscle of the cecum were compared in streptozocin-treated diabetic (8 wk) and untreated control rats using the sucrose-gap technique. Changes in membrane potential elicited by field stimulation (0.03-32 Hz) and by exogenously applied adenosine triphosphate (10-1000 microM) and noradrenaline (0.03-10 microM) were measured. Nonadrenergic, noncholinergic inhibitory junction potentials were the predominant response to field stimulation. However, in some preparations from both diabetic and control tissues, the inhibitory junction potential was preceded by a small nonadrenergic, noncholinergic excitatory junction potential. In nonatropinized preparations, a cholinergic excitatory junction potential was occasionally elicited; there was no difference between these cholinergic responses in diabetic and control tissues. The inhibitory junction potentials and the hyperpolarization in response to adenosine triphosphate were similar in diabetic and control tissues, although the rate of hyperpolarization of the single inhibitory junction potential was slower in the diabetic tissues. In contrast, exogenous application of noradrenaline revealed significantly greater hyperpolarizing responses in diabetic compared with control tissues. This increase in potency appeared to be due, in part, to an increased sensitivity of alpha-adrenoceptors on smooth muscle. There was no evidence for beta-adrenoceptor activation by noradrenaline. Prejunctional inhibition of the nonadrenergic, noncholinergic neuromuscular transmission by noradrenaline was not affected by streptozocin-induced diabetes. The induced changes in adrenoceptor activity were selective for the postjunctional alpha-adrenoceptors.

Abnormalities of the migrating motor complex in diabetics with autonomic neuropathy and diarrhea

Diarrhea is a common symptom in long-standing diabetes. The pathogenesis of this diarrhea remains obscure, although it appears to be related to the development of autonomic neuropathy, which may cause several abnormalities including altered gut motility. We studied fasting gastrointestinal motility for a mean of 210 min in a group of 12 type-II diabetics with diarrhea. All patients had peripheral neuropathy and symptoms of autonomic neuropathy. Their motor activity was compared with that of a group of six normal volunteers. In addition, gastrointestinal transit time was assessed by the hydrogen breath test. The presence of bacterial overgrowth was assessed by the hydrogen breath test and culture of jejunal secretions. The diabetics showed grossly disordered motor activity. There was a complete absence of phase-III activity in two patients. Most phase III's commenced in the distal duodenum or jejunum. The phase-III component was often of short duration at each recording site. There was increased velocity of propagation between sites. Continuous phase-II activity was noted in some patients. Antral activity was absent or reduced during phase II. Gastrointestinal transit time was significantly prolonged in the diabetics. Bacterial overgrowth was demonstrated in three diabetic subjects. These motility abnormalities are nonspecific and are unlikely to play a major role in the pathogenesis of diabetic diarrhea.

Decreased gastro-intestinal responses to salbutamol and serotonin in streptozotocin-induced diabetes: improving effect of insulin in vivo and in vitro

1. Decreased gastro-intestinal responses to salbutamol (sal) and serotonin (5-HT) in experimental diabetes have been postulated. The present study was designed to investigate whether in vivo and in vitro insulin treatments improve the decreased gastro-intestinal responses. 2. In vivo insulin treatment (166.7 micrograms/kg/day i.p.) for 6 weeks is able to improve both decreased gastro-intestinal beta-adrenergic and serotonergic responses. 3. Insulin incubation in bathing medium for 4-5 hr enhances the decreased gastro-intestinal responses to sal, but not to 5-HT. 4. The above results strongly suggest that the improving effect of insulin on the gastro-intestinal beta-adrenergic responses is direct in nature. In contrast, the improving effect on insulin on the serotonergic responses occurs via an indirect mechanism.

Altered responses to calcium and trifluoperazine in K+-depolarized duodenum from alloxan diabetic rats

Contractile responses to calcium were examined in the K+-depolarized duodenum from normal and alloxan-diabetic rats. In addition, verapamil and trifluoperazine which are well-known calcium channel blocker and calmodulin inhibitor respectively were used as tools in order to approach to the mechanism of changes resulting from diabetes. Decreased contractile responses to calcium were observed in the alloxan diabetic rat duodenum compared to normals. Trifluoperazine-induced non-competitive inhibition was significantly affected depending on diabetes, while verapamil-induced competitive inhibition was not changed. The non-competitive inhibition affinity constant for trifluoperazine was significantly elevated in the K+-depolarized duodenum from alloxan-diabetic rats. On the basis of findings obtained in this study, possible mechanism of the effect of experimental diabetes on the calcium-induced contraction is discussed.

Evidence for abnormal cholinergic neuromuscular transmission in diabetic rat small intestine

Proximal and distal rat small intestine from control, diabetic, and insulin-treated diabetic rats was cut into strips measuring 6.0 X 10.0 mm. Strips cut along the oral-caudal axis were called longitudinal strips, while those cut 90 degrees to that axis were called circular strips. The strips were stretched to their optimum lengths and subjected to electrical field stimulation (0.1-1.0-ms pulse duration, 30-270 mA, 1-26 Hz) in the presence of Krebs' solution and Krebs' solution plus 10(-6) M atropine. Field stimulation produced atropine-sensitive and atropine-resistant contractions in all strips. Significant differences among the three groups were found in the amplitudes of atropine-sensitive contractions in strips from distal longitudinal muscle. Controls showed the highest amplitude contractions and diabetics the lowest, whereas the insulin-treated diabetics showed contractions intermediate in amplitude. No significant differences were noted among the atropine-resistant contractions. Field stimulation delivered at pulse durations of 5.0 and 50.0 ms in the presence of neural blockade with tetrodotoxin (5 X 10(-6) M) produced similar contraction amplitudes among the three groups. These results suggest that streptozotocin-induced diabetes mellitus is associated with defective cholinergic neuromuscular transmission in the myenteric plexus of the distal small intestine. Insulin therapy seems to improve the abnormality.

A form of necrobiosis and atrophy of smooth muscle in diabetic gastric autonomic neuropathy

Pathological changes identified in the muscular wall of the stomach from two young insulin-dependent diabetic patients suffering from severe gastric autonomic neuropathy are presented. Scattered smooth muscle cells appearing as homogeneous round eosinophilic bodies ("M" bodies) among areas of sub-total smooth muscle cell atrophy together with intercellular collagen proliferation were identified in the muscularis propria of the stomach. Ultrastructurally, the "M" bodies are transformed smooth muscle cells undergoing a form of necrobiosis with peculiar intracellular features. These changes appear characteristic of end-stage diabetic gastric autonomic neuropathy when compared with other pathological conditions involving the gastric wall. The degree and extent of involvement of the various components of the gastric wall are discussed.

Gastro-intestinal phytobezoars in Zimbabwean Africans

The clinical features of 10 African patients with gastro-intestinal phytobezoars are described. These were similar to those described with persimmon bezoars and we postulate that the fruit of locally found trees, also of the genus Diospyros, are responsible.

Quantitative study of mucosal structure, enzyme activities and phenylalanine accumulation in jejunal biopsies of patients with early and late onset diabetes

A study of the three-dimensional structure of the upper jejunal mucosa in diabetics has been carried out. The structural findings were related to 14C-L-phenylalanine uptake in vitro, sucrase activity in mucosal homogenates, and the enzyme content of the absorptive cells as measured cytophotometrically. A low grade mucosal transformation of the sprue-type was found, which was associated with decreased sucrase activity, and with no reduction in phenylalanine accumulation. On the other hand the specific activities of alkaline phosphatase, non-specific esterase, and succinic dehydrogenase in the surface cells remained unchanged.

Diabetic autonomic neuropathy

This review attempts to outline the present understanding of diabetic autonomic neuropathy. The clinical features have been increasinly recognised but knowledge of the localization and morphology of the lesions and their pathogenesis remains fragmentary. A metabolic causation as postulated in somatic nerves accords best with clinical observations. Most bodily systems, particularly the cardiovascular, gastrointestinal and urogenital, are involved with added disturbances of thermoregulatory function and pupillary reflexes. Possible effects on neuroendocrine and peptidergic secretion and respiratory control await definition. Current interest centres around the development of a new generation of tests of autonomic nerve function that are simple, non-invasive, reproducible and allow precision in diagnosis and accurate quantitation. Most are based on cardiovascular reflexes and abnormality in them is assumed to reflect autonomic damage elsewhere. Probably no single test suffices and a battery of tests reflecting both parasympathetic and sympathetic function is preferable. Little is known of the natural history. The prevalence may be greater than previously suspected and although symptoms are mild in the majority, a few develop florid features. The relation of control and duration of diabetes to the onset and progression of autonomic neuropathy is not clearly established. Once tests of autonomic function become abnormal they usually remain abnormal. Symptomatic autonomic neuropathy carries a greatly increased mortality rate possibly due to indirect mechanisms such as renal failure and direct mechanisms such as cardio-resiratory arrest. Improved treatment of some of the more disabling symptoms has been possible in recent years.

Radiologic abnormalities and autonomic neuropathology in the digestive tract of the ketonuric diabetic Chinese hamster

Barium x-ray patterns of ketonuric diabetic Chinese hamsters displayed marked dilatation of the stomach, small and large intestine. Hypomotility was manifested by flocculation of barium in the small and large bowel. Impaired transit time was further characterized by prolonged emptying of the stomach (mean 570 min diabetics; 200 min controls) and delayed stool formation (mean 230 min diabetics; and 100 min controls) and passage (mean 457 min diabetics; 210 min controls). Ultrastructural analysis of Auerbach's myenteric plexuses of the small intestine indicated acute degeneration in certain distal, unmyelinated axons. Swelling, deposition of glycogen, aggregation of neurofilaments and dense accumulation of lamellar bodies were observed. The severity and frequency of barium flocculation, glycogen deposition, aggregation of neurofilaments and lamellar inclusion bodies in axons were directly related to duration of ketonuria. The data strongly suggest that autonomic neuropathology in the plexuses of Auerbach may be a critical factor underlying gastrointestinal dysfunction in the ketonuric diabetic Chinese hamster.

Intact removal of phytobezoar using fibreoptic endoscope in patient with gastric atony

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Bile lipid composition and bile acid pool size in diabetes

Since the prevalence of gallstones is higher in diabetics than in controls and since cholelithiasis is often associated with supersaturated bile, we measured bile lipid composition and bile acid pool size in 8 patients with juvenile diabetes, 16 with maturity-onset diabetes, and 10 control subjects. Bile lipid composition was expressed as "saturation index." In the maturity-onset diabetics the saturation index (1.60 +/- 0.45 SDM) was significantly higher (P less than 0.005) than that in the controls (0.82 +/- 0.20) and in patients with juvenile diabetes (0.75 +/- 0.24). The absolute values for biliary bile acid concentration were significantly lower (P less than 0.01) in the maturity-onset diabetics than in the other two groups. There were no differences in either the proportion of the individual biliary bile acids or the size of the bile acid pool between the three groups. The results suggest that the incidence of cholelithiasis in diabetes is associated with the secretion of a supersaturated bile only in the maturity-onset subgroup.

Small intestinal transit in diabetics

Small intestinal transit was assessed in diabetic patients and healthy controls by measuring the breath hydrogen appearance time after the ingestion of lactulose. Transit in diabetics with autonomic neuropathy was significantly slower than in diabetics without neuropathy and controls. Delayed transit is probably due to vagal denervation. These slower transit times would allow bacteria to proliferate, which might explain why some diabetics have diarrhoea. The test cannot be used in patients with bacteria in the small bowel because these may metabolise lactulose and release hydrogen prematurely.

A study of the morphological changes in the small intestine of the spontaneously diabetic Chinese hamster

Several morphological changes were observed microscopically in the small intestine of some diabetic Chinese hamsters. Although some alterations lacked statistical significance due to variation, most diabetics displayed a greater incidence and severity compared with nondiabetic controls. The following structural deviations were seen in the small intestines of some diabetics: increased surface area, elevated number of goblet cells per villus, decreased muscle thickness with connective tissue infiltration, reduced number of Auerbach's plexuses, lymphocyte aggregations accompanied by blunted villi, blood vascular lesions and deformed villi due to excessive loss of epithelial cells.