Spermine-induced alteration of small intestine in suckling rat - Involvement of apoptosis or Zn2+ enzymes?

Polyamines are of great importance in several physiological processes, such as cell proliferation and differentiation. The ingestion of spermine by su ckling rats induces precocious maturation of their small intestine. Shortly after ingestion, spermine produces cell elimination at the villous top. Th e origin of this exfoliation was investigated to determine whether it was d ue to apoptosis. Wistar rats were orally treated with spermine. Apoptosis w as analyzed in their small intestine by Tdt-mediated dUTP-fluorescein nick- end labeling reaction, caspase-3-like analysis, and DNA laddering. Polyamin e content was measured by HPLC. The intestinal transitory alteration appear ed as soon as 2 hr after spermine administration. Apoptosis events increase d strongly at the same moment in the small intestine. They were evidenced b y Tdt-mediated dUTP-fluorescein nick-end labeling analysis, DNA laddering, and caspase-3-like activity. Changes observed are consistent with apoptosis , but caspase inhibitor did not reduce intestinal alteration, as did Zn2+ c helator.