The effect of alloxan-induced diabetes on triamine lesions in the ventromedial hypothalamus.

It has been demonstrated that the ventromedial hypothalamus (VMH) of alloxan-induced diabetic mice is protected from subsequent gold thioglucose (GTG)-induced lesions. Another compound, 3,3'-methyliminobis-(N-methylpropylamine) (MIMPA), a triamine structurally unrelated to GTG, has been shown to cause similar VMH lesions in mice. We chose to investigate the effect of alloxan-induced diabetes on VMH lesion formation in MIMPA-treated mice. In this study CF-1 female mice were made diabetic by a simple intravenous (IV) injection of alloxan and subsequently treated with MIMPA by subcutaneous injection (SC). Contrary to studies which showed that GTG-induced VMH lesions are insulin dependent, an insulin deficiency did not inhibit MIMPA-induced lesions in the VMH of mice. Our data suggests, albeit GTG is suspected to induce VMH necrosis by attaching to glucoreceptors and insulin-sensitive neurons, MIMPA works by a different and as yet unknown mechanism. We conclude that MIMPA-induced lesions in the VMH of mice are not insulin dependent.