Response of the Pituitary-sexual Gland Chain in Female Pigs following External Gamma Irradiation

The reaction of the pituitary gland sexual glands chain is established by quantitative changes in LH, FSH and estradiol concentrations together with morphological studies of ovaries. Sexually immature female pigs, aged 2 months, were irradiated with single doses of 1.5 and 2.5 Gy. The controlled hormonal parameters were monitored up to the onset of sexual maturity. Early post-irradiation studies, following 1.5 Gy, showed a significant decrease in LH levels, compared with the control values. Three months post irradiation, its level was 0.035±0.003 IU/L vs control concentrations of 0.186±.0.07.IU/L. Subsequently, the level increased significantly to 0,210±0.003 IU/L at the end of the experimental period. 2.5 Gy irradiation triggered a peak in LH secretion 3 months post irradiation and, subsequently, by sustained suppression. The irradiation at 1.5 Gy resulted in early elevation in FSH levels which lasted to 3 months post irradiation and then remained at a value close to those in controls. The dose of 2.5 Gy provoked a lasting suppression in FSH secretion during the entire period of study. The irradiation at both doses inhibited, to different extents, 17β estradiol increase; this result was confirmed by histological examinations of ovaries.