Intrauterine Device and Pitutary Follicle-Stimulating Hormone and Luteinizing Hormone in the Rat

Abstract

To obtain direct evidence of the intrauterine devices possible systemic effect on the mechanism of the pituitary luteinizing hormone (LH) and follice-stimulating hormone (FSH) levels in Holtzman rats were measured in the presence of a nylon IUD under 3 different experimental situations. In the first group (intact) rats with an IUD in place for 1 month were killed and studied. In the second group (unilaterally spayed) rats had their right ovary (opposite the IUD) removed after the IUD had been in place for 1 month; 10 days later the other ovary was removed. In the third group (bilaterally spayed) rats had an IUD implanted 5 weeks after the opposite ovary had been removed. 43 days later the remaining ovary was also removed. Each group had a set of sham-operated controls. Autopsies revealed that the uterine horn with the IUD was significantly heavier than the horn without the IUD in all 3 groups and heavier than the controls in Groups 1 and 3. The adrenal weights in the IUD-fitted rats were also significantly higher than the respective weights in the controls. No significant effect of the IUD was found on ovarian weight or number of corpora lutea in Group 1 nor on ovarian compensatory hypertrophy in Group 2. No significant effect of the IUD was found on pituitary LH and FSH content in any group nor on the rise in these hormone stores induced by bilateral ovariectomy. The heavier organ weights caused by the IUD should be investigated and further research into the mechanism of the IUD is indicated.