The effect of methylene blue in preventing alloxan diabetes and in lowering the blood sugar of alloxan-diabetic rats.

A number of compounds have been found to prevent the diabetic action of alloxan when administered immediately before the al1oxan.l The writers have observed that the oxidation-reduction dye, methylene blue, not only is protective against the diabetogenic action of alloxan when given before the alloxan, but also exerts a marked blood sugarlowering effect when administered to rats previously made diabetic with alloxan. This paper records the blood sugar-lowering effect on twentytwo animals. Experiments to be published in more detail later will confirm the validity of this preliminary report. The following experiments illustrate the effect of methylene blue (MB) in preventing alloxan diabetes. Five non-fasted rats (240 to 267 gm.) were given 1 cc. of 1 per cent MB2 30 minutes prior to the injection of 150 mg. of alloxan per kilo of body weight. 24 hours later the blood sugar levels ranged from 28 to 124 mg. per cent (average 59 mg. per cent). Four non-fasted controls treated similarly but without MB showed 24 hour blood sugars of 113 to 299 mg. per cent (average 200 mg. per cent). When six rats (189 to 310 gm.) were fasted for 48 hours and then treated with MB and alloxan as above, the blood sugars after 48 hours ranged from 0.0 to 90 mg. per cent (average 60 mg. per cent). Five 48 hourfasted controls (187 to 232 gm.) treated with alloxan but not with MB showed 48 hour blood sugars ranging from 119 to 650 mg. per cent (average 397 mg. per cent). The effect of MB in lowering the blood sugar of alloxan-diabetic rats is shown in the table. The dye was injected into non-fasting rats, in some cases 2 days and in others 1 to 3 months after alloxan injection. In our experience MB in the dosage used does not alter the blood sugar of normal animals but causes definite hypoglycemia in rats recently made diabetic with alloxan.