In preparation for direct vital microscopic evaluation of microcirculatory
dynamics in the diabetic pig myocardium, we were initially unsuccessful in
inducing sustained hyperglycemia in juvenile pigs using streptozotocin acco
rding to previously reported methods. Therefore, we modified the technique
in a way previously unreported in an effort to improve the success rate of
diabetes induction. In the first set of 9 pigs, we followed described metho
ds of intravenous injection with 150 mg/kg streptozotocin. In the second gr
oup of 9, the technique was modified. The change was based on human studies
with ammonium chloride and animal experiments with alloxan, and consisted
of the addition of a period of pretreatment with ammonium chloride. Of the
nine pigs not treated with ammonium chloride, only two developed sustained
hyperglycemia in excess of 17 mmol/L (300 mg/dl), and only after reinjectio
n with a full dose of streptozotocin within 7 days of the first injection.
Conversely, of the ammonium chloride pretreated pigs, eight of nine develop
ed diabetes. We conclude that the addition of ammonium chloride to produce
systemic acidosis prior to streptozotocin injection improves the efficacy o
f the drug.