Figure 1.

(A) In vitro proliferative response of Leishmania (L.) amazonensis and Leishmania (L.) mexicana promastigotes to IGF-I. Stationary-phase Leishmania (L) amazonensis and Leishmania (L.) mexicana promastigotes were tested for proliferative response ([³H]thymidine incorporation) with IGF-I in the presence of 4% FCS: control (open bar); with 50 ng/ml IGF-I (hatched bar). Each point represents data from triplicate determinations with less than 5% SD of the mean. (B) In vitro proliferative response of Leishmania (L.) mexicana amastigote-like forms to IGF-I ([³H]thymidine incorporation). Stationary-phase Leishmania (L) mexicana amastigote-like forms were tested for proliferative response with IGF-I in the presence of 0% FCS (circle), 4% FCS (square), or 8% FCS (triangle). (C) In vitro proliferative response of Leishmania (L.) mexicana amastigote-like forms to IGF-I (parasite counting). Stationary-phase Leishmania (L) mexicana amastigote-like forms were tested for proliferative response to IGF-I in the presence of 4% FCS. Parasite index = number of parasites in cultures with IGF-I/number of parasites in cultures without IGF-I. For further details see Materials and Methods.