Neuropeptide Y in non-sympathetic nerves of the rat: changes during maturation but not after guanethidine sympathectomy.
Non-sympathetic neuropeptide Y-containing nerves were demonstrated by their persistence after destruction of sympathetic nerve terminals by acute 6-hydroxydopamine treatment for 48 h. In order to examine whether these neuropeptide Y-containing nerves reinnervate tissues following the loss of sympathetic nerves we administered guanethidine sulphate to one-week-old rat pups for three weeks to produce a complete and long-lasting sympathectomy and we monitored the innervation of the superior cervical ganglion, mesenteric vein, vas deferens and urinary bladder by noradrenaline- and neuropeptide Y-containing nerves two and 16 weeks later (assay and histochemical observations). By two weeks the reduction in neuropeptide Y content of tissues was similar to the reduction after acute sympathectomy with 6-hydroxydopamine treatment, indicating that there was no early reinnervation by non-sympathetic neuropeptide Y-containing nerve fibres at a time when sensory transmitters increase. Furthermore, there was no reinnervation by neuropeptide Y-containing nerve fibres by the time these sympathectomized animals had reached maturity, 16 weeks after cessation of treatment. Neuropeptide Y levels increased in the superior cervical ganglion with normal maturation but decreased in the prostatic end of the vas deferens. A non-sympathetic source of neuropeptide Y demonstrated in the immature rat vas deferens was no longer evident in the mature animal.
Department of Anatomy and Developmental Biology, University College London, U.K.
P
P
Milner
J
J
Lincoln
L A
LA
Corr
J A
JA
Aberdeen
G
G
Burnstock
D000375:Aging / Q000378:metabolism; D000818:Animals; D002395:Catecholamines / Q000032:analysis; D006145:Guanethidine; D006651:Histocytochemistry; D007150:Immunohistochemistry; D008856:Microscopy, Fluorescence; D009420:Nervous System / Q000737:chemistry*; D009478:Neuropeptide Y / Q000032:analysis*; D016627:Oxidopamine; D051381:Rats; D011919:Rats, Inbred Strains; D013563:Sympathectomy, Chemical; D013997:Time Factors
D002395:Catecholamines; D009478:Neuropeptide Y; D016627:Oxidopamine; D006145:Guanethidine