European Journal of Anatomy

Official Journal of The Spanish Society of Anatomy
Cover Volume 8 - Number 1
Eur J Anat, 8 (1): 11-15 (2004)

Sex-related differences in pituitary GH-expressing cells induced by hypothyroidism following treatment with methimazole

Carretero J., Rubio E., Burks D.J., Blanco E., Sierra E., Herrero J.J., Torres J.L.

Dpto. de Anat. e Histologia Humanas, Facultad de Medicina, Universidad de Salamanca, Spain; Dpto. Anatomia e Histologia Humanas, Facultad de Medicina, Avda. Alfonso X el Sabio s/n, E-37007 - Salamanca, Spain

ABSTRACT An immunocytochemical and morphometric study of pituitary GH-expressing cells was carried out in adult rats following chronic treatment with methimazole. The morphological results were correlated to the basal GH serum levels. In both sexes, hypothyroidism. induced by methimazolee produced a significant decrease of GH serum levels in relation to untreated animals (p<0.05). Morphometrically, methimazole induced significant decreases in the nuclear area (p<0.05) and in the numerical density of immunoreactive cells (p<0.05). In males, these modifications were accompanied by a significant decrease in cellular and cytoplasmic size (p<0.05), but this was not seen in females. Our results confirm the existence of a physiological stimulatory role of thyroid hormones on the activity of pituitary somatotroph cells that must be modulated by gonadal steroids because the effects of hypothyroidism were more evident in male than in female rats.

Keywords: growth hormone, sex hormone, thiamazole, animal cell, animal experiment, article, cell density, cell nucleus, cell size, cell ultrastructure, controlled study, cytoplasm, drug effect, female, gender, growth hormone blood level, hormone action, hormone release, hypophysis cell, hypothyroidism, immunocytochemistry, male, morphometrics, nonhuman, rat, rat strain, sex difference, somatic cell

European Journal of anatomy
ISSN 2340-311X (Online)