Abstract
Pituitary portal blood was collected from urethane-anesthetized rats and examined for the presence of neuropeptide Y (NPY) using high-performance liquid chromatography and radioimmunoassay. Other rats were perfused with fixative, and coronal sections through the hypothalamus and median eminence were processed for immunohistochemical localization of NPY. Combined high-performance liquid chromatography and radioimmunoassay analysis of pituitary portal plasma and systemic plasma revealed a single peak of NPY immunoreactivity which corresponded in retention time to synthetic porcine NPY. Increasing amounts of portal or systemic plasma produced displacement curves which were parallel to the NPY standard curve. The concentration of NPY immunoreactivity in portal plasma (52.0 +/- 4.0 ng/ml, mean +/- SEM) was three times greater (p less than 0.005) than in systemic plasma (16 +/- 4.5 ng/ml). NPY-labeled fibers were observed in the external zone of the median eminence in the vicinity of hypothalamo-hypophyseal portal vessels. The observation of significantly higher concentrations of NPY immunoreactivity in the portal plasma supports the hypothesis that NPY may be released from the hypothalamus to affect pituitary function.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
