PARP1 and Hypoinsulinemia: To attain these goals, TAU, 3-AB and NIC were tested both in vitro for PARP-1 inhibiting power and for mode of interaction with the active site of PARP-1 in rats and in vivo, using rats made diabetic with streptozotocin, (STZ), a known generator of oxygen and nitrogen reactive species, for their counteracting actions on hypoinsulinemia, hyperglycemia, hyperlipidemia and oxidative stress when administered in equimolar doses as a pretreatment to STZ.