Mitogenic activity of insulin in the culture of a trypanosome: duration and dose response.
The effects of insulin on the in vitro growth characteristics of Trypanosoma granulosum were investigated. The insulin growth stimulus had a rapid onset with little or no lag phase but was relatively short lived, growth peaking typically on day 3 or 4 of culture. This contrasted with medium containing 10% foetal calf serum, normally used for in vitro culture of this trypanosome, which after a 3 day lag stimulated sustained log-phase growth. Insulin demonstrated a biphasic dose response with maximum growth typically occurring at 3-10 microg/ml and a much reduced effect at higher concentrations. These findings suggest a possible role for host insulin and/or trypanosomal insulin-like molecules in regulating parasite growth in vivo.
Mackintosh
David
D
Faculty of Science, School of Life Sciences, Kingston University, Penrhyn Road, Kingston, Surrey KT1 2EE, UK. d.mackintosh@kingston.ac.uk
Coleman
Kim
K
Davies
Angela J
AJ
D000818:Animals; D004305:Dose-Response Relationship, Drug; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology*; D008934:Mitogens / Q000494:pharmacology*; D014345:Trypanosoma / Q000187:drug effects* / Q000254:growth & development*
D007004:Hypoglycemic Agents; D007328:Insulin; D008934:Mitogens