Experimentally-induced diabetes reduces nocturnal pineal melatonin content in the Syrian hamster

1. 1. Male, Syrian hamsters were rendered diabetic by either alloxan (60mg/kg, i.v.) or streptozotocin (65 mg/kg, i.p.). 2. 2. Diabetic animals had reduced pineal melatonin contents during the night. Basal daytime values were not significantly altered. 3. 3. Diabetes may decrease melatonin synthesis by reducing the availability of glucose for metabolism or by decreasing the transport of tryptophan into pinealocytes for the synthesis of melatonin.