The transfer of circulating 131I IgG1 and 125I IgG2 to the nasal secretions of sheep.

Ovine IgG1 and IgG2 labelled with 131I and 125I respectively were injected intravenously into four sheep. Serum and nasal secretion samples were collected and fractionated by gel filtration on columns of Sephadex G100. Results showed that in serum more than 95 per cent of the radioactivity was associated with intact IgG molecules whereas in nasal secretion samples the percentage varied from five to 47. It was found that the concentrations of IgG1 and IgG2 in the nasal secretions were similar and were approximately 2 per cent of the serum concentrations. This finding indicates a lack of selective transfer of either IgG1 or IgG2 from blood to nasal secretions in sheep.