Immunocytochemical evidence of hypothalamic regulation of adenohypophyseal VIP in the male rat.
In order to check whether hypothalamic stimulatory or inhibitory factors exert any kind of modulation on the morphology of VIP-immunoreactive cells in the rat hypophysis, the transport of these towards the hypophyseal portal system was blocked by intraventricular administration of colchicine in adult male rats, thereafter performing a morphometric study after characterizing the VIP-immunoreactive adenohypophyseal cells by immunocytochemical techniques. Colchicine administration led to a significant increase (p < 0.01) in the number of reactive cells observed. These cells were characterized by a larger cellular area (p < 0.01), owing to increases in nuclear area (p < 0.05) and cytoplasmic area (p < 0.05). Their morphology became more regular, with a predominance of polygonal and oval cells. The results suggest that the VIP-reactive cells of the rat hypophysis are subject to a hypothalamic inhibitory influence and their activity increasing when the hypothalamic effect is interrupted by intraventricular administration of colchicine.
Carretero
J
J
Departamento de Anatomía e Histología Humanas, Facultad de Medicina, Universidad de Salamanca, Spain.
Sánchez
F
F
Rubio
M
M
Lorenzo
M J
MJ
Francos
M
M
Cacicedo
L
L
Sánchez-Franco
F
F
Vázquez
R
R
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D003078:Colchicine / Q000008:administration & dosage; D007031:Hypothalamus / Q000473:pathology / Q000502:physiology*; D007124:Immunoenzyme Techniques; D007276:Injections, Intraventricular; D008297:Male; D010903:Pituitary Gland, Anterior / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism*
D014660:Vasoactive Intestinal Peptide; D003078:Colchicine