Eur J Anat, 6 (1): 1-8 (2002)

Immunocytochemical and morphometric evidence of the existence of different cellular populations reactive to r-GHRH in the rat pituitary gland

Carretero J., Rubio M., Blanco E., Riesco J.M., Burks D., Herrero J.J., Bodego P., Perez E., Vazquez R.

Laboratorio de Neuroendocrinologia, Facultad de Medicina, Universidad de Salamanca, Avda. Alfonso X el sabio, s/n, E-37007 Salamanca, Spain

ABSTRACT In order to characterize the pituitary cells reactive for r-GRF in the adult rat, an immunocytochemicaI and morphometric study was made of the cells immunopositive for r-GHRH and those immunopositive for GH and for GHRH using a double labelling method. The existence of two populations of r-GRF-immunoreactive cells was observed; one of these was only stained with specific serum against r-GRF and the other was immunopositively stained for GH and for r-GHRH. Morphometrically, in both sexes the GH-immunoreactive cells were seen to have a cellular size that was significantly larger (p<0.01) than the r-GHRH-immunoreactive cells. The cells that were only stained for r-GHRH were significantly smaller than those immunoreactive for GH and r-GHRH. Our findings suggest the existence of at least two cellular populations in the pituitary gland of the adult rat able to react with anti-r-GHRH serum.

Keywords: growth hormone, growth hormone releasing factor, animal tissue, article, cell size, cell structure, female, hypophysis, hypophysis cell, immunocytochemistry, immunoreactivity, male, morphometrics, neuroanatomy, nonhuman, rat