Neuropeptide Y in the human prenatal and mature gonads

In the present paper we have examined the distribution and identity of neuropeptide Y (NPY) immunoreactivity in the prenatal and mature human gonads. Tissue specimens were obtained from prenatal gonads (gestational age < 42 weeks) of induced abortions, premature birth and stillbirths. Specimens were also taken from infants who died aged less than 4 days. Tissue from mature gonads was obtained during surgery. The distribution and concentration in tissue extracts were determined by immunohistochemistry and radioimmunoassay. NPY-immunoreactivity (NPY-IR) was demonstrated in both the prenatal and mature human gonads. In the gonads from fetuses at 16-25 weeks the NPY-IR was scarce and could only be demonstrated by radioimmunoassay. In the female gonads from fetuses at 40 weeks of gestation, distinct nerve fibres were detected in relation to blood vessels and primordial follicles. In the prenatal male gonads at the same gestational length as well as in the mature testis, the NPY-IR nerves were detected in relation to blood vessels and seminiferous tubules. The gel filtration profile from the prenatal gonads and from the mature ovary revealed a single peak corresponding to the elution position of bioactive synthetic human NPY. The gel filtration profile from the mature testis demonstrated an additional peak at Kd of 0.17. The presence of NPY-IR in relation to the developing and mature gonads suggests that NPY participates in gonadal functions from an early point in life.