Diabetes Mellitus In Rabbits Research Articles

Beta-Receptor Blockade Reproduces Electrophysiological Effects of Early Diabetes Mellitus in Ventricular Myocardium

Diabetes mellitus (DM) increases the risk of sudden cardiac death, which suggests the involvement of arrhythmogenic mechanisms. Among other changes, DM causes cardiac autonomic neuropathy (CAN), but its role in electrophysiological myocardial remodeling is unclear. The objective of the present study was to test the effects of β-adrenergic blockade regarding ventricular spatiotemporal electrophysiological properties in an experimental DM model. Epicardial mapping (64-lead sock electrode array) was done in 13 control and 11 alloxan-induced DM rabbits. Activation times (AT), end of repolarization times (RT), and activation-repolarization intervals (ARI) were determined as dV/dt min during QRS, dV/dt max during T-wave, and RT-AT difference, respectively. The β-adrenergic blockade was produced by esmolol infusion (0.5 mg/kg, i.v.). It was found that the early-stage DM in rabbits was characterized by relatively mild changes in ventricular myocardium, which did not involve ventricular activation and the average duration of repolarization. The signature of this stage was the local prolongation of repolarization, which pertained to the RV apical region. The blockade of β-adrenergic receptors in healthy animals produced a ventricular spatiotemporal repolarization pattern similar to that observed in diabetic rabbits with the local apical prolongation of repolarization. On the other hand, the blockade of β-adrenergic receptors in diabetics prolonged the relatively short basal repolarization. It can be concluded that β-adrenergic blockade in healthy animals reproduced the early-stage DM effects on the spatiotemporal electrophysiological properties of the ventricular myocardium. This demonstrated the role which CAN could play in the electrical remodeling of ventricular myocardium in early-stage DM.

Evaluation of Antidiabetic Effect of Silybum marianum and Cichorium intybus extracts

Enormous efforts have recognized the importance of analyzing plant extracts for possible medical applications. In this context, Kasni (C. intybus) and Milk thistle (S. marianum), cultivated in Asia, were used to determine diabetes mellitus control. Ethanol extracts of both plants were used after induction of diabetes mellitus in rabbits (with STZ). Blood glucose was measured by the glucose oxidase method. After treatment of the injured pancreas for 60 days, Kasni and Milk thistle showed a decrease in the elevated levels of blood sugar. The coalesce effect of both plants is more than the individual plants whereas Milk thistle has demonstrated a better control than Kasni. To conclude, C. intybus and S. marianum play a positive role in controlling diabetes.

Prolonged alloxan diabetes mellitus in rabbits, an experimental model associated with increased susceptibility to reperfusion ventricular tachyarrhythmias

Introduction Diabetes mellitus (DM) increases the risk of ventricular arrhythmias and sudden cardiac death in patients with coronary artery disease. However, experimental studies often yield inconsistent results concerning arrhythmic outcomes in DM. Moreover, some studies reported that DM confers antiarrhythmic protection. We hypothesized that the duration of experimental diabetic conditions might be crucial in the DM-related arrhythmogenesis and evaluated myocardial electrical remodeling and susceptibility to ventricular tachyarrhythmias in rabbits with DM of different duration in the experimental ischemia/reperfusion model. Methods Ventricular epicardial contact potential 64-lead mapping and arrhythmia susceptibility burst-pacing testing were performed in 43 healthy and 55 diabetic (alloxan model) anesthetized rabbits undergoing 15-min left anterior descending coronary artery occlusion, followed by 15-min reperfusion. DM duration was from 28 to 76 days (median 42 days, interquartile range (IQR) 36-54 days). Results During ischemia, arrhythmia inducibility did not differ between the groups (14 out of 55 vs 7 out of 43 in the DM and control groups, respectively, p=0.272), but the number of reperfusion ventricular tachycardias and/or ventricular fibrillations (VT/VFs) was higher in the DM group (14 out of 55) as compared to control (3 out of 43, p=0.017). In the diabetic animals, the DM duration was an independent predictor of reperfusion VT/VF in logistic regression analysis adjusted for glucose concentration (OR 1.060; 95% CI 1.006-1.117; p = 0.029). We compared preischemic electrophysiological parameters in the control group, and groups with short and prolonged DM (cut-point 42 days of DM). The groups did not differ in dispersion of repolarization, time of epicardial activation breakthrough, duration of epicardial and total ventricular activation. Only duration of activation-repolarization intervals (ARIs, a surrogate for action potential duration) differed between the groups being increased in the prolonged DM group (Figure). Among the mapping parameters, DM duration was associated with the prolongation of total ventricular activation duration (B 0.152; 95% CI 0.049-0.255; p=0.005) and activation-repolarization intervals (ARIs) (B 0.900; 95% CI 0.315-1.484; p=0.003). The prolonged ARI was the only mapping characteristic predicting reperfusion VT/VF development in logistic regression analysis (OR 1.028; 95% CI 1.009-1.048; p = 0.004) and ROC curve analysis (AUC 0.781, p=0.001) with the optimal cut-off value ARI > 120 ms (sensitivity 0.80, specificity 0.75). Conclusions Prolongation of alloxan DM leads to the progressive lengthening of repolarization and increase in the reperfusion VT/VF inducibility.

Serum Liver Enzymes and Oxidative Stress Biomarkers in Resveratrol Treated Cholesterol Diet Induced Type 2 Diabetes Mellitus in Rabbits

Fat accumulation in the body has been implicated in the increased generation of ROS and oxidative stress which enhances hepatocellular damage. Increase in serum liver enzymes have been widely used as an index of liver dysfunction and that higher ALT concentrations predicted development of type 2 diabetes. Thirty rabbits were randomly divided into six groups, each of five animals: Group 1 = control (C), Group 2 = cholesterol diet (CD) only, Group 3 = resveratrol 200 mg/kg (R200), Group 4 = resveratrol 400 mg/kg (R400), Group 5 = CD + R200 and group 6 = CD + R400. The preparations were administered for 8 weeks of experimental protocol. Blood glucose level was measured on week zero and the 8th week of the treatment. At the end of the study period, the rabbits were placed under light anesthesia (ketamine) to remain unconscious. Blood sample of about 3ml was drawn via cardiac puncture for serum extraction which were evaluated for serum concentration of liver enzymes (alanine aminotransferase ALT, aspartate aminotransferase AST and alkaline phosphatase ALP) and oxidative stress biomarkers (superoxide dismutase SOD, catalase CAT and glutathione peroxidase GPx). Blood glucose level was significantly higher in CD group compared to groups that received resveratrol supplement. Serum Liver enzymes activities showed significant (P < 0.05) decrease in ALT, AST and ALP levels in groups that were administered resveratrol with CD compared with CD alone. Significant decrease in antioxidant enzymes activities (SOD, CAT and GPx) in resveratrol treated groups (P < 0.05) were recorded when compared to CD alone group. In conclusion, the observed decreased in blood glucose level, liver enzymes and biomarkers of oxidative stress with resveratrol administration despite CD consumptions, elucidated the therapeutic potential of resveratrol.Support or Funding Information1. SelfThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Advantages of Porous TiNi Materials for Dental Implants in Diabetes Mellitus Patients

Structural changes in osseous tissue under surgically modeled diabetes mellitus in rabbits are studied experimentally with the focus on macro- and microelemental composition. The effect of growth factors on regeneration of mucosa is analyzed in Brattlebororats with inherited diabetes insipidus. Larger animals, dogs, were used to study the morphology of osseointegration with various implant materials under experimental surgical diabetes mellitus. The advantages of porous implants over other materials are shown.

Effects of Fermented Soya Bean Supplements on Thyroid Profile and Serum Electrolytes of High Fat Diet-induced Type 2 Diabetes Mellitus in Rabbits

The aim of this study was to evaluate the effects of fermented soya bean supplements on thyroid profile and serum electrolytes of high fat diet-induced type 2 diabetes in rabbits. Twenty rabbits weighing between 1 kg – 1.5 kg were used for the study. Diabetes was induced by feeding the animals with high fat diet for eight weeks. Rabbits having fasting blood glucose levels of 7.2 mmol/L and above after the induction were used for the study. The animals were grouped into four groups of five rabbits each: Group 1 (diabetic control) received distilled water ad libitum for six weeks; Groups 2, 3 and 4 were fed with 12.5%, 25% and 50% fermented soya bean supplements respectively for six weeks. At the end of the treatment period, the rabbits were euthanized by cervical dislocation and blood samples were collected through cardiac puncture. The serum was extracted after clotting and centrifugation for the determination of thyroid profile and electrolyte levels. The results showed a significant decrease (P ≤ 0.05) in serum T3 and T4 concentrations, and a significant increase (P ≤ 0.05) in the serum TSH concentration in the groups fed with the supplements when compared with the diabetic control. Furthermore, as regards to the serum electrolytes concentrations there was a significant increase (P ≤ 0.05) in sodium ion concentration in the group fed 12.5% soya bean supplement when compared with the control and a significant decrease (P ≤ 0.05) in potassium ion concentrations in all the groups fed with the soya beans supplements, as compared to control. Chloride ion concentrations were significantly decreased (P ≤ 0.05) in groups fed 25% and 50 % supplement as compared to control, while bicarbonate ion concentrations were significantly increased (P ≤ 0.05) in groups fed with 25% and 50% supplement when compared with the control. In conclusion fermented soya bean supplementation suppressed thyroid activity and improved serum electrolyte concentrations; it may be used to alleviate hyperthyroidism and electrolyte disturbances in diabetes patients.

An Experimental Study of Drug Interactions of Diclofenac with Commonly Used Drugs for Diabetes Mellitus in Rabbits

Insulin, Glibenclamide and Tolbutamide are some of the frequently used drugs for the most common metabolic disorders, diabetes mellitus. Along with hypoglycaemic drugs diabetic patient is exposed to variety of drugs. NSAIDs are one of the commonly used drugs in this metabolic syndrome. When a patient on hypoglycaemic drugs receives NSAIDs there are chances of drug interactions. This study was undertaken in the department of Pharmacology, GSVM medical college, Kanpur (UP) after approval by the institutional animal ethics committee to find out the interaction if any between Diclofenac and three hypoglycaemic drugs i.e. insulin, glibenclamide and tolbutamide.<p>Young healthy rabbits were divided into six groups: five rabbits in each group. First group received Insulin 1 u/kg subcutaneously; second Glibenclamide 0.05 mg/kg orally; third Tolbutamide 40 mg/kg orally; fourth Diclofenac 1mg/kg orally and insulin 1mg/kg s.c. simultaneously; fifth glibenclamide 0.05mg/kg orally at 0 hour and diclofenac 1mg/kg orally at 2 hours and sixth tolbutamide 40mg/kg orally at 0 hour and diclofenac 1mg/kg orally at 2 hours. Blood samples were taken at 0, 1, 2, 4 and 6 hours for blood sugar estimation. Mean blood sugar levels reduced significantly from their fasting levels when insulin, glibenclamide and tolbutamide were administered. However blood sugar levels did not showed any significant changes when diclofenac was administered along with insulin, glibenclamide and tolbutamide in comparison to when insulin, glibenclamide and tolbutamide were given alone. The results showed that diclofenac does not interact with insulin, glibenclamide and tolbutamide on blood sugar levels in rabbits.No Abstract.</p>

Sinusoidal Constriction and Vascular Hypertrophy in the Diabetes-Induced Rabbit Penis

To assess the morphological changes of penile vascular structures and the corpus cavernosum area in alloxan-induced diabetic rabbits. Twenty male rabbits (2 months old) were divided into two groups with 10 rabbits each, the control group (CG) and the diabetic group (DG). The animals from DG received an intravenous injection of alloxan (100mg/kg) to induce the diabetes. Ten weeks after the induction of diabetes, all animals were euthanized. Two fragments of the penile shaft were harvested and samples were processed and paraffin embedded. Sections (5 µm) were cut and stained for histological and immunohistochemical markers. Nuclear protrusion toward the lumen, and cytoplasmic vacuolization were observed in the tunica intima of the dorsal artery of the penis in DG. The thicknesses of the tunica media increased significantly in DG (p = 0.0350). It was also observed a significant increase in the area of the tunica media (p = 0.0179). There was no significant change in smooth muscle cell density in the tunica media of the dorsal artery of the penis (p = 0.0855). The collagen fiber pattern of the tunica adventitia of the dorsal artery of the penis was different between the control and diabetic groups. There was a significant decrease in the area occupied by the cavernous sinuses in DG (p = 0.0013). Alloxan-induced diabetes mellitus in rabbits promotes important changes in penile vascular structures, thereby decreasing blood supply and affecting penile hemodynamics, leading to erectile dysfunction.

Histopathological abnormalities of prolonged alloxan‐induced diabetes mellitus in rabbits

The objective of this study was to investigate the prolonged complications of untreated diabetes on histomorphology of rabbits. Diabetes mellitus was experimentally induced in one group of New Zealand white male rabbits by intraperitoneal administration of four doses of alloxan @ 80 mg/kg b.w. at weekly intervals following 12 h fasting. Other group of rabbits served as healthy controls that received isotonic saline in a similar manner. The establishment of diabetes mellitus was confirmed by fasting blood glucose levels. For histomorphological study of different organs, 50% of the animals were killed after 7 weeks and the rest after 26 weeks. Routine haematoxylin and eosin stain and Gomori's modified stain were used. The blood glucose level of diabetic rabbits increased significantly throughout the experimental period. The peak values for blood sugar were on the sixth week of the study. Further, histomorphological alterations were recorded in pancreas, kidneys, lungs, heart and brain in diabetic rabbits. However, mild changes were observed in gastrointestinal tract with proliferation of yeasts in the stomach. With the progress of untreated diabetes, the histoanatomical alterations intensify and extend to almost all organs of the body and appear to increase the susceptibility of gastric mucosa to yeast cell proliferation.

L-Asparaginase diabetes mellitus in rabbits: differing effects of two different schedules of L-asparaginase administration.

The diabetogenic effect of daily injections of 1000 i.u./kg body wt. E coli L-asparaginase was studied in male New Zealand white rabbits and compared with the diabetogenic effect of a single bolus of 10,000 I.U. E coli L-asparaginase/kg body wt. to determine whether the schedule of administration of the drug altered the diabetic syndrome produced. A daily injection of 1000 i.u. L-asparaginase/kg. body wt. was continued for 30 days. During this time glucose levels in rabbits allowed free access to food rose steadily, reaching levels of 717 +/- 63 mg/dl the day after the last injection. Levels of immunoreactive insulin fell, reaching their nadir, 53 +/- 4 pg/ml (approximately 50% of baseline) at 25 days. Glucose levels declined when therapy was discontinued, but remained significantly above control levels 46 days after insulin injections were stopped. (Glucose levels in L-asparaginase-treated groups vs. those in controls on day 46 after discontinuation: 116 +/- 3 vs. 104 +/- 1 mg/dl; P less than 0.0025.) Levels of immunoreactive insulin rose when therapy ended, reaching control levels 17 days after discontinuation. In contrast, a single bolus injection of 10,000 I.U. L-asparaginase/kg resulted in hyperglycemia with hyperinsulinemia. These data suggest that L-asparaginase can induce either a hypoinsulinemic or a hyperinsulinemic diabetic syndrome depending on the schedule of administration of the L-asparaginase and that a mild abnormality in glucose homeostasis persists after discontinuation of L-asparaginase therapy.

Biochemical and Histomorphological Study of Streptozotocin-Induced Diabetes Mellitus in Rabbits

This study was designed to investigate the biochemical and histomorphological changes occurring due to streptozotocin-induced diabetes mellitus in rabbits. Twelve New Zealand male rabbits of uniform age were divided into two Groups. Group I was made diabetic by single intravenous injection of streptozotocin (@ 65mg/kg.b.w.) whereas Group II served as control. Significant increase in blood sugar (P<0.01), blood urea (P<0.10) and serum creatinine (P<0.10) was recorded in Group I rabbits compared to Group II rabbits. Further, histomorphological alterations of pancreas, kidneys, liver, heart, lungs and brain were observed. However, no pathological features were observed in alimentary canal. From the study, it is concluded that streptozotocin-induced diabetes causes disturbances in biochemical and histological features in rabbits and serves as a model in studying the various complications arising due to this illness.

Altered hypoxia-induced coronary vasodilatation in diabetic rabbit heart

The effect of type 1 diabetes mellitus on hypoxia-induced coronary vasodilation was studied in isolated perfused rabbit hearts. Four groups of hearts were compared: control hearts from normal rabbits perfused with physiological buffer (5 mM glucose and 2 mM pyruvate added), hearts from alloxan-induced diabetic rabbits (same perfusion as control), hyperglycemic hearts from normal rabbits perfused with 22 mM glucose and 2 mM pyruvate, and hyperosmotic hearts from normal rabbits perfused with 5 mM glucose, 2 mM pyruvate, and 8.5 mM choline chloride. Hypoxia was produced by perfusion with a mixture of N2- and O2- saturated solutions. Endothelium-dependent and -independent dilators were also tested. Papaverine-induced coronary vasodilatation was unaltered, whereas that of serotonin and adenosine was significantly reduced in hyperglycemic and hyperosmotic hearts but not in diabetic hearts perfused with normoglycemic buffer. Hypoxia (PO2 from 515 +/- 86 to 131 +/- 24 mmHg; 1 mmHg = 133.3 Pa) caused a significant coronary vasodilatation in normal hearts (-66 +/- 3%). This vasodilatation was reduced slightly in diabetic (-45 +/- 7%, p < 0.05) and severely in hyperglycemic (-21 +/- 5%, p < 0.05) and hyperosmotic (-24 +/- 5%, p < 0.05) hearts. The adenosine-receptor antagonist 8-phenyltheophylline (10 microM) reduced hypoxia-induced vasodilatation in normal and diabetic hearts. However, inhibition of prostaglandin synthesis with diclofenac (1 microM), which reduces hypoxia-induced vasodilatation in normal hearts, had no effect in diabetic hearts. In conclusion, alloxan-induced type 1 diabetes mellitus in rabbits is accompanied by a reduced coronary vasodilator response to hypoxia. The contribution of adenosine in this response is unaffected. However, the abated contribution of cyclooxygenase products may account for the reduced vasodilatation during hypoxia in this particular model.

Selective attenuation of neuropeptide-Y-mediated contractile responses in blood vessels from patients with diabetes mellitus.

Vascular smooth muscle contractile responses to neuropeptide Y, alpha,beta-methyleneATP and noradrenaline were studied in circular segments of isolated vessels with intact endothelium in vitro from 12 patients with diabetes mellitus type 2 (NIDDM) and 12 control subjects. The dilatory effect of acetylcholine was used to test the function of the endothelium. Subcutaneous arteries and veins (diameter 0.1-1.1 mm) were obtained during surgery. There was no difference in contractile responses to noradrenaline or alpha,beta-methyleneATP between diabetic and control vessels. The contractile response to neuropeptide Y, however, was markedly reduced in the diabetic group. The maximal contractile effect (46.0 +/- 14.0%, p < 0.05) but not the sensitivity to neuropeptide Y was significantly less in diabetic veins compared to control (107.5 +/- 19.6%). Thus, the attenuation of neuropeptide Y responses was present in humans as previously observed in alloxan-induced diabetes mellitus in rabbits. There was no difference in the dilator effect of acetylcholine between the diabetic and the control group in any of the vessel types, indicating that the difference in vascular reactivity to neuropeptide Y was not endothelium-dependent. In conclusion, the present study has shown that the postjunctional effects of neuropeptide Y, a co-transmitter of the peripheral sympathetic nervous system, is selectively attenuated in diabetes mellitus.

Hypolipidemic effect of water extract ofFicus bengalensis in alloxan induced diabetes mellitus in rabbits

Hypolipidemic effect of the water extract of the bark ofFicus bengalensis was investigated in alloxan induced diabetes mellitus in rabbits. Treatment for one month (50 mg/kg body weight/day) brought down the level of total serum cholesterol (TC) in subdiabetic and diabetic rabbits (five in each group) from 82±11 mg% and 118±10.6 mg% to 42.7±3.1 mg% and 51.7±4.7 mg% respectively. Low density lipoprotein cholesterol and very low density lipoprotein cholesterol values came down from 34±10 mg% and 95±24 mg% to 16±3 mg% and 29±4 mg% in subdiabetic and diabetic rabbits. Triacylglycerol level before treatment was 121±21.6 mg% and 416±70 mg% in subdiabetic and diabetic rabbits. Treatment brought it down to 45±5 mg% and 81±27.5 mg%. Glycosylated hemoglobin was brought down from 2.1±0.3% to 1.5±0.1% in subdiabetic group and from 4.28±0.5% to 2±0.3% in diabetic group, indicating that treatment with water extract effectively controlled blood sugar.

L-Asparaginase-induced diabetes mellitus in rabbits.

Twenty-seven male New Zealand White rabbits were injected with a single dose of 10,000 IU E. coli L-asparaginase per kilogram body wt to document the diabetogenic activity of this antitumor agent. Significant weight loss was observed by day 1, and a loss continued until day 9. After day 16, weight steadily increased. Random serum glucose levels increased steadily after the injection of L-asparaginase, reaching a peak value of 344 +/- 32 mg/dl (x- +/- SEM) on day 10. From day 12, levels declined, but they remained significantly higher than basal levels. Serum immunoreactive insulin (IRI) levels had a similar pattern of response. By day 2 the IRI was significantly above baseline. The IRI levels increased daily, reaching a peak level of 1,379 +/- 587 pg/ml (x- +/- SEM). Thereafter the levels fell gradually. However, the IRI levels remained significantly higher than basal levels. Intravenous regular insulin decreased glucose levels in L-asparaginase-treated animals at 3 h by only 7.7 +/- 3.2%, while it decreased them in controls by 34.0 +/- 6.7% (P less than 0.0025). These data demonstrate that, acutely, a single intravenous dose of 10,000 IU E. coli L-asparaginase per kilogram body wt induces a hyperinsulinemic. Insulin-resistant, diabetic syndrome in rabbits.

L-Asparaginase-induced diabetes mellitus in rabbits

L-Asparaginase-induced diabetes mellitus in rabbits

Diabetes mellitus in rabbits immunized with insulin.

Normal rabbits immunized with bovine insulin in adjuvant produce circulating autoantibodies that bind large amounts of endogenous insulin (measured by an immunoassay which distinguishes endogenous and exogenous insulin). In a series of nine immunized animals, two not only produced autoantibody but also, as a result of the autoimmune phenomenon, became acutely diabetic. Their blood sugar, circulating antibody, endogenous insulin bound to antibody and morphologic lesions in the islets of Langerhans observed by light and electron microscopy were compared to those of immunized but nondiabetic rabbits for a period of sixty-five weeks. Diabetes was characterized by weight loss, lipemia and blood sugar levels maintained at 350 to 600 mg. per 100 ml. throughout an experimental period of twenty-one weeks after immunization with insulin. Although circulating antibody levels were unusually high in the diabetic animals, little antibody-bound insulin was evidenced in contrast to the nondiabetic immunized rabbits whose bound endogenous insulin ranged fiom 390 to 2,340 μU. per ml. Histologic examination by light and electron microscopy at twenty-one weeks revealed absence of beta cell granules and severe damage to the beta cells. Lymphocytic infiltration of the islets was noted in the less severe diabetic in which some beta cells remained, but neither lymphocytes nor beta cells could be detected in the most severely diabetic animal. Alpha cells in each rabbit were normal. Significantly, the nondiabetic immunized rabbits also showed specific changes in their beta cells detectable by electron microscopy. The surviving, less severely diabetic rabbit remained diabetic and had detectable antibody until sacrificed fourteen months after immunization. Improvement of the animal at this time was indicated by a blood sugar level of 174 mg. per 100 ml., an increase in antibody-bound endogenous insulin, extractable pancreatic insulin in an amount two thirds of normal, and demonstrable granules in most of the beta cells. It was concluded thai an autoimmune diabetes that closely resembles the early juvenile form can be created in rabbits by immunization with insulin. The possibility that autoimmunity can not only contribute to the diabetic state in insulin-treated subjects but may prove important as an underlying cause in some forms of diabetes is discussed.

Diabetes Mellitus in Rabbits Injected with Dialuric Acid.

SummaryDialuric acid when injected intravenously into rabbits produces diabetes which is indistinguishable clinically or pathologically from alloxan diabetes.

Alloxan Diabetes in Rabbits. Production of Hypercholesterolemia, Hyperlipemia and Adrenal Cortical Lesions

SummaryA transient period of hypercholesterolemia and hyperlipemia may accompany the early stage of severe diabetes mel-litus in rabbits following the injection of alloxan. It occurred in varying degrees in many rabbits that survived with persistent diabetes and always occurred if the diabetes was severe enough to cause death. A dosage of 50 mg/kg of alloxan failed to cause hyperlipemia or hypercholesterolemia, 100 mg/kg produced it in one of 3 rabbits, while 125 mg/kg was effective in 29 of 32 animals. Lesions were found in the adrenal cortices of 12 of 25 animals dying after receiving 125 mg/kg of alloxan.

Some Experiments on the Etiology of Diabetes Mellitus.

About a year ago, an interesting report was published by Bergey in which the author claimed that he had been able to produce diabetes mellitus in rabbits by a single intravenous injection of a Berkefeld filtrate of the urine of diabetic patients. A striking feature in his observations was the time interval, suggestive of an incubation period, which elapsed between the injection of the urine filtrate and the onset of the glycosuria. Of no little interest also was the observation that filtrates inoculated into serum-broth and incubated for 56 days, or longer, even at room temperature “produced glycosuria in rabbits more promptly and to a more marked degree than freshly filtered urine.” The observations suggested to Bergey that the cause of diabetes mellitus may be represented by a filtrable, ultra-visible organism. These observations stimulated our interest to the extent that we immediately afterward undertook to repeat these studies. During the course of the work some 30 rabbits were inoculated intravenously with filtrates of diabetic urine in the doses (2 cc.) employed by Bergey. Most of the animals received Chamberland L3 filtrates. Some were injected with L1, others with L2 filtrates, of the same specimen of diabetic urine. Specimens from different patients were employed. The urine samples were collected from the animals by placing them over night in thoroughly cleaned and dry metabolism cages, with no food, but with water before them. The animals were kept on a fairly uniform mixed diet, though this was not strictly standardized. They were for the most part kept under observation for periods of at least 2 months and in some instances as long as 6 months. The urine tests were carried out daily on some animals, others were tested at intervals of several days.