Effects of insulin and hydrocortisone on lung tissue phosphatidyl choline and disaturated phosphatidyl choline in fetal rabbits in vivo.

To determine the effects of insulin and hydrocortisone on lung tissue surfactant, the fetuses of New Zealand White rabbits were injected with insulin, saline (0.154 mol/l), insulin+hydrocortisone, insulin+saline or saline+hydrocortisone, or were sham-operated on day 27 of gestation. Twenty-four hours later (on day 28 of gestation) delivery was accomplished by Caesarian hysterectomy. The lung tissues were analysed for phosphatidyl choline and disaturated phosphatidyl choline. Both were higher in fetuses injected with insulin than in sham-operated control animals. The phosphatidyl choline and disaturated phosphatidyl choline were also higher in the fetuses injected with insulin+hydrocortisone than in fetuses injected with insulin or hydrocortisone alone. These results suggest that insulin increases the phosphatidyl choline and disaturated phosphatidyl choline content in lung tissue in fetal rabbits in vivo, and that in the presence of hydrocortisone, insulin appears to have an additive effect.