ABSTRACT
<p><b>OBJECTIVES</b>To study the effect of testicular local heating on spermatogenic cell apoptosis in rat.</p><p><b>METHODS</b>Seventy male SD rats were divided into heat treatment group (43 degrees C) and control group (22 degrees C). Each group was further divided into seven sub-groups respectively according to the time of 12 hours and 1 days, 3 days, 6 days, 10 days, 50 days and 80 days after testicular local treatment. The spermatogenic cell apoptosis in all sub-groups was examined by means of electron microscopy, flow cytometry and terminal deoxynucleotidyl transferase-mediated dUDP-nick end labeling(TUNEL) method.</p><p><b>RESULTS</b>In the groups of heat treatment, spermatogenic cell apoptosis was detected by electron microscopy; flow cytometry showed that the percentage of cells with sub-haploid increased(P < 0.01); the percentage of positive TUNEL cells in the heat treatment groups was higher than that in the control group(P < 0.01). Initiation of spermatogenic cell apoptosis after testicular heating was not random but was highly selective.</p><p><b>CONCLUSIONS</b>Local testicular heating could increase the spermatogenic cell apoptosis. The most sensitive cell is spermatocyte. Spermatid and sperm also display apparent changes. Heating can increase the apoptosis of spermatogonia in a long period.</p>