Abstract
The sympathetic perivascular innervation has long been suggested to exert trophic influences on cerebral arteries, particularly during hypoxic adaptation. Although most of this effect has been attributed to the actions of norepinephrine, sympathetic nerves also co‐release NPY together with norepinephrine. This study tests the hypothesis that NPY released from sympathetic nerves also contributes to hypoxic remodeling of fetal lamb cerebral arteries. Hypoxic acclimatization for 110 days increased NPY levels by 230% in nerve intact arteries. Whereas sympathectomy (SANX) had no significant effect in normoxic arteries, it decreased NPY levels in hypoxic arteries (25%). Hypoxia also increased Y1 receptor levels (70%) but only in nerve intact arteries. SANX decreased Y1 levels (30%) in hypoxic arteries. Confocal microscopy revealed that organ culture with 100 nM NPY potently decreased the colocalization of Non‐Muscle Myosin with Smooth Muscle Alpha‐Actin, indicating increased contractile differentiation. In nerve intact arteries, NPY decreased myogenic tone whereas in SANX arteries NPY increased myogenic tone. Co‐culture with the Y1 antagonist BIBP‐3226 (5 µM) reversed these effects of NPY. Taken together, these results suggest that NPY released from sympathetic nerves contributes to remodeling of the fetal cerebral vasculature during hypoxic acclimatization.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: 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.