Figure 1: Body weight and testicular development in unilateral nephrectomized rats treated with cyclosporine, tacrolimus or sirolimus. Male Sprague-Dawley rats were randomly divided into 5 experiment groups of eight animals each. All animals except for the control group were subjected to left unilateral nephrectomy. After recovery from surgery, animals received daily oral gavage of either drinking water or one of the drugs diluted in water for 8 weeks and were weighed twice a week. The testes were harvested at the end of the study and weighed, and the testicular coefficient was calculated as the percentage of total body weight (testicular coefficient = bilateral testicular weight/total body weight). UN, unilateral nephrectomy; CsA, cyclosporine; FK506, tacrolimus; Rapa, sirolimus. compared with UN group; compared with UN+FK506 group; compared with UN+Rapa group.