title: Ultrastructure of somatotrophs of rats with median eminence lesions: studies in basal conditions and after thyrotropin-releasing hormone stimulation.
abstract: Anterior pituitaries from female Sprague-Dawley rats (160-200 g b.w) bearing electrolytic lesions of the median eminence were qualitatively and quantitatively investigated by electron microscopy and the findings compared with those from intact animals or sham-operated controls. This study was performed in basal conditions and after stimulation with thyrotropin-releasing hormone. Animals with lesions showed a reduction of both the number of somatotrophic cells and growth hormone granules. After injection of thyrotropin-releasing hormone exocytosis of growth hormone granules from somatotrophs was frequent in rats with lesions of the median eminence but rare in sham-operated animals. The differences were statistically significant.
mesh_terms: D000818:Animals; D005260:Female; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology*; D008473:Median Eminence / Q000502:physiology*; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000187:drug effects / Q000648:ultrastructure*; D051381:Rats; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology*
chemical_list: D013973:Thyrotropin-Releasing Hormone