Evidence for suppression of immune function by insulin-like growth factor-1 in dwarf rats in vivo.
These studies were undertaken to investigate the effects of increasing or decreasing IGF-1 levels on aspects of immune function in rats. Female dwarf rats were treated with recombinant human IGF-1 or with a potent sheep anti-IGF-serum. Body weight, thymus weight and spleen weight increased with IGF-1 treatment (p < 0.001), while there was no effect of anti-IGF-1 treatment when compared with the appropriate normal sheep serum (NSS) treated controls. IGF-1 treatment significantly decreased WBC and RBC counts, but increased the ratio of CD4+:CD8+ T-cells. Anti-IGF-1 serum had no effect on these parameters compared with NSS. However anti-IGF-1 was associated with increased T-cell numbers, decreased natural killer cells, and enhancement of the animals' ability to produce specific IgG in response to injection of keyhole limpet haemocyanin (KLH). These results indicate that IGF-1 may suppress immune function although increasing the size of immune organs such as spleen.
Schurmann
A
A
Ruakura Agricultural Centre, Hamilton, New Zealand.
Spencer
G S
GS
Berry
C J
CJ
Decuypere
E
E
Goddeeris
B
B
D000818:Animals; D001772:Blood Cell Count / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D004392:Dwarfism / Q000276:immunology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007165:Immunosuppression Therapy; D007334:Insulin-Like Growth Factor I / Q000008:administration & dosage*; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D011917:Rats, Inbred Lew; D011994:Recombinant Proteins / Q000008:administration & dosage
D011994:Recombinant Proteins; D007334:Insulin-Like Growth Factor I