Table 1.

Physical constants and the number of receptors for the binding of IGF-I to Leishmania (L) mexicana promastigotes and amastigote-like forms

Parameter	Promastigotes	Amastigotes
Ka, liter/mol	3  × 107	1  × 107
Kd, mol/liter	4  × 10−8	10  × 10−8
Receptor number/parasite	2  × 106	6  × 106

The values were obtained from the computer program ligand as described in Materials and Methods.