Identification and localization of insulin-like growth factor receptors in human infant pituitary gland-similar distribution to somatotrophs

Human fetal ovaries and uteri: developmental expression of genes encoding the insulin, insulin-like growth factor I, and insulin-like growth factor II receptors

OBJECTIVE

To study the messenger ribonucleic acid (mRNA) expression of receptors for insulin, insulin-like growth factor I (IGF-I), and insulin-like growth factor II (IGF-II) in human fetal ovaries and uteri at 10, 15, 19, and 22 weeks' gestation. Insulin, IGF-I, and IGF-II are postulated to have paracrine and autocrine functions in the development of fetal tissues, but receptors for these growth factors have never been studied in reproductive organs of the human female fetus.

DESIGN

Ribonucleic acid extracted from human fetal reproductive tissues underwent reverse transcription and polymerase chain reaction (PCR) amplification. The amplified complementary deoxyribonucleic acid (cDNA) fragments were analyzed by gel electrophoresis and restriction enzyme mapping.

RESULTS

Messenger RNA expression consistent with both known forms of the insulin receptor, the IGF-I receptor, and the IGF-II receptor was observed in human fetal ovaries and uteri at 10, 15, 19, and 22 weeks' gestation. The identity of the PCR amplified ovarian and uterine DNA fragments were confirmed by digestion with the restriction endonucleases AvaII, DdeI, and BamHI, respectively.

CONCLUSIONS

This study demonstrates that mRNA for receptors for insulin, IGF-I, and IGF-II are expressed in the fetal human female genital tract. These receptors may have roles in fetal reproductive tract development.