Immunocytochemical evidence for growth hormone-releasing hormone in the tanycytes of the median eminence of the rat.
The current study was performed to analyse the potential existence and structure of a GHRH-transporting tuberoinfundibular system in the rat median eminence. The immunocytochemical analysis using anti-GHRH revealed an intense immunoreaction in the ependimary cells, tanycytes, at the level of the floor of the infundibular recess forming part of the median eminence. The basal processes of these cells course towards the external layer of the median eminence and reach the growth hormone-releasing hormone (GHRH) fibres of the tuberoinfundibular tract and this reaction was increased after intraventricular treatment with colchicine. Thus, these observations suggest the existence of a second or alternative cerebrospinal fluid-mediated route of GHRH transport to the median eminence and implicate the involvement of tanycytes in the regulation of this novel transport system.
Carretero
José
J
Department of Human Anatomy and Histology, Faculty of Medicine, Laboratory of Neuroendocrinology, Institute of Neuroscience of Castilla y León, University of Salamanca, Spain. jcar@usal.es
Burks
Deborah
D
Rubio
Manuel
M
Blanco
Enrique
E
Herrero
Julio J
JJ
Bodego
Pilar
P
Juanes
Juan A
JA
Hernández
Elena
E
Riesco
José M
JM
D000818:Animals; D004805:Ependyma / Q000166:cytology / Q000378:metabolism*; D005260:Female; D013007:Growth Hormone-Releasing Hormone / Q000378:metabolism*; D007031:Hypothalamus / Q000166:cytology / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D008473:Median Eminence / Q000166:cytology* / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020542:Third Ventricle / Q000166:cytology / Q000378:metabolism*
D013007:Growth Hormone-Releasing Hormone