Serotonin-immunoreactive nerve fibers of the rat pituitary: effects of anticatecholamine and antiserotonin drugs on staining patterns.
Serotonin-immunoreactive (5-HT-IR) nerve fibers observed in the pars intermedia and pars nervosa of the rat pituitary gland were examined after treatment of animals with antiserotonergic or anti-catecholaminergic drugs. p-Chlorophenylalanine, (PCPA), an inhibitor of 5-HT synthesis, eliminated staining in both areas of pituitary gland. p-Chloroamphetamine (PCA), a serotonin neurotoxin, did not produce a significant change in 5-HT-IR from control tissue. Unexpectedly, 6-hydroxydopamine (6-OHDA), a catecholamine neurotoxin, eliminated 5-HT staining in the pars intermedia, but not in the pars nervosa. These observations suggest that 5-HT present in fibers innervating the intermediate and neural lobes is synthesized in axons locally, or is taken up into fibers from extrinsic sources. In addition, catecholamines and 5-HT may co-exist in nerve terminals of both lobes of the pituitary gland.
L C
LC
Saland
J A
JA
Wallace
F
F
Comunas
D000818:Animals; D002395:Catecholamines / Q000037:antagonists & inhibitors*; D010134:Fenclonine / Q000008:administration & dosage / Q000031:analogs & derivatives; D006892:Hydroxydopamines / Q000008:administration & dosage; D007274:Injections, Intraperitoneal; D008297:Male; D009412:Nerve Fibers / Q000032:analysis*; D016627:Oxidopamine; D010902:Pituitary Gland / Q000032:analysis / Q000294:innervation*; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000032:analysis*; D012702:Serotonin Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D013194:Staining and Labeling / Q000379:methods; D010133:p-Chloroamphetamine / Q000008:administration & dosage
D002395:Catecholamines; D006892:Hydroxydopamines; D012702:Serotonin Antagonists; C020261:4-chlorophenylalanine methyl ester; D012701:Serotonin; D010133:p-Chloroamphetamine; D016627:Oxidopamine; D010134:Fenclonine