Studies on the Protective Effect of Diphenylhydantoin Against Alloxan Diabetes in Mice

Abstract

An earlier communication from these laboratories described the protective effect of diphenylhydantoin (DPH) against the diabetogenic action of alloxan in mice ( l ) . The intraperitoneal injection of from 10 to 45 mg/kg of DPH, one hour prior to the intravenous injection of alloxan, prevents pancreatic beta cell necrosis and the development of chronic hyperglycemia.Although the mechanism through which alloxan produces its pancreotoxic effect remains obscure, certain structural requirements have been recognized for this action. One of these requirements is the presence of an unsubstituted ureido group on the alloxan molecule. Alkyl substitutions on one or both of the nitrogens of alloxan results in decreased pancreotoxic activity (2). The DPH molecule also possesses an Ensubstituted ureido moiety and this drug is known to influence pancreatic function (3-5). This structural similarity between alloxan and DPH has led us to hypothesize that DPH-induced protection against alloxan may be a reflection of a competition between the two compounds for the same binding site on the pancreatic beta cell (1).An alternative explanation for the protective effect of DPH against alloxan is suggested by the results reported by Scheynius and Taljedal (6). These workers have shown that the intravenous injection of D-glucose prior to the administration of alloxan prevents the development of diabetes. Since DPH is known to produce hyperglycemia (1, 3-5) it is possible that the protective effect of DPH is mediated by this action.The objectives of the experiments reported This research was supported by grants from the National Institutes of Health (AM-14134 and CA-13285) and the Dreyfus Medical Foundation.in this communication were to determine if the protective effect of DPH could be correlated to the hyperglycemic action of the drug, and the effect of alkyl substitution in the ureido group of DPH on the ability of the drug to prevent alloxan-induced diabetes.Methods. Male albino mice (Laboratory Supply Co., Indianapolis) weighing 18 to 24 g were used in these experiments. The animals were housed in groups of ten with free access to food and water at all times.Blood samples for glucose analysis were obtained by the orbital sinus puncture technique. Glucose analyses were performed by a glucose oxidase method (Beckman Glucose Analyzer). Since only small blood samples are required for this method (10 pl of serum) repeated samples were taken from the animals and each mouse served as its own control.All drug solutions were prepared at concentrations which allowed for the administration of volume doses of 10 ml/kg. Alloxan monohydrate was dissolved in distilled water no more than 10 min prior to injection. Diphenylhydantoin sodium and D-glUCOSe were dissolved in distilled wster and 3-methyl diphenylhydantoin (3-M-DPH) was suspended in 10% Tween 80.The intraperitoneal dosage levels of DPH and 3-M-DPH used in these experiments were selected on the basis of the anticonvulsant potency and time of peak activity in the supramaximal electroshock tes...

The comparative effects of barbituric acid and phenobarbital on blood glucose and insulin secretion in mice

“…The structural similarities between alloxan, barbituric acid, tolbutamide and diphenylhydantoin have led to an earlier suggestion that the observed interactions may be reflections of competition for binding sites on the pancreatic B-cell membrane [1,4]. All of these chemicals possess unsubstituted ureido groups in their structural configurations and the importance of this portion of the molecules of alloxan and diphenylhydantoin have been shown in earlier in vivo experiments [4,10].…”

“…The demonstration of the in vivo interactions between DPH, alloxan and tolbutamide has led to the hypothesis that these agents compete for binding sites on the pancreatic B-cell membrane [4]. Evidence in support of this hypothesis, however, is indirect and does not rule out the possible role of the known membrane stabilizing action of DPH.…”