In situ analysis of adenohypophysis proliferative activity in beagle dogs

Kolopp, Maryelle; Poirel, G.; Vit, P.; Perentes, Elias

doi:10.1016/s0344-0338(11)80076-2

Cited by 5 publications

(1 citation statement)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The proliferative activity of canine hypophyseal cells in vivo is 0.05% (40), which is lower than the proliferation rate in vitro. We found FCS to have a stimulating effect on the proliferation of canine corticotrophic adenoma cells in vitro.…”

Section: Discussionmentioning

confidence: 72%

Effects of corticotrophin-releasing hormone, vasopressin and insulin-like growth factor-I on proliferation of and adrenocorticotrophic hormone secretion by canine corticotrophic adenoma cells in vitro

Wijk

Rijnberk²,

Croughs³

et al. 1998

European Journal of Endocrinology

View full text Add to dashboard Cite

Extrinsic factors such as hypothalamic hormones or intrapituitary growth factors may stimulate clonal expansion of a genomically altered cell and therefore play a role in pituitary tumorigenesis. Here we report on the effects of the hypophysiotrophic hormones corticotrophin-releasing hormone (CRH) and vasopressin (AVP) and the intrapituitary growth factor insulin-like growth factor-I (IGF-I) on the proliferation of, as measured by the bromodeoxyuridine labelling index, and ACTH secretion by normal canine pituitary cells and corticotrophic adenoma cells of dogs with pituitary-dependent hyperadrenocorticism. The sensitivity to inhibition by cortisol was analysed under various conditions.Under basal conditions, no signi®cant differences were found in the bromodeoxyuridine labelling indices between control cells and tumour cells. CRH, AVP, IGF-I and cortisol had no effect on the proliferation of canine pituitary cells or canine corticotrophic adenoma cells. In contrast with normal pituitary cells, the proliferation of corticotrophic adenoma cells was stimulated by fetal calf serum (FCS). This FCS-induced proliferation was not inhibited by cortisol.The CRH-induced ACTH secretion by corticotrophic adenoma cells was signi®cantly (P < 0.05) lower than that by normal pituitary cells after 4 h incubation with CRH. Incubation with cortisol for 24 h resulted in reduced ACTH secretion under basal and AVP-or IGF-I-stimulated conditions. The relative inhibition was, however, signi®cantly (P < 0.05) lower in ACTH-producing tumour cells than in normal pituitary cells. Cortisol did not inhibit the CRH-induced ACTH secretion in normal pituitary cells after 24 h.In conclusion, canine corticotrophic adenomas are less sensitive to stimulation by CRH and less sensitive to inhibition by glucocorticoids. These tumours have an aberrant sensitivity to a growthpromoting factor present in FCS. This factor may have an important role in the growth promotion of canine corticotrophic tumours. European Journal of Endocrinology 138 309±315

show abstract

Section: Discussionmentioning

confidence: 72%

Effects of corticotrophin-releasing hormone, vasopressin and insulin-like growth factor-I on proliferation of and adrenocorticotrophic hormone secretion by canine corticotrophic adenoma cells in vitro

Wijk

Rijnberk²,

Croughs³

et al. 1998

European Journal of Endocrinology

View full text Add to dashboard Cite

show abstract

A brief review of modern toxicologic pathology in regulatory and explanatory toxicity studies of chemicals

et al. 1991

View full text Add to dashboard Cite

Macroscopic and histologic evaluation of animal studies for general toxicity and carcinogenicity are cornerstones of the risk assessment of new chemical entities. Standard toxicopathologic evaluation is mainly based on the study of paraffin sections stained with hematoxylin and eosin. There are, however, a number of new approaches and techniques which have improved the objectivity of evaluation and the accuracy of cell identification, and provided deeper insight into the molecular biological mechanisms of toxicity and carcinogenicity. Such approaches include the standardization of the nomenclature, the creation of data banks for morphological alterations, the use of computers to register pathological findings in toxicity studies and to statistically evaluate incidences, and the use of morphometry. Other modern techniques are immunohistochemistry, in situ hybridization, and the assessment of cell kinetics.

show abstract

Mitosis and apoptosis in the pituitary gland: tumour formation or hyperplasia?

Levy

1999

Best Practice & Research Clinical Endocrinology & Metab

View full text Add to dashboard Cite

In situ analysis of adenohypophysis proliferative activity in beagle dogs

Cited by 5 publications

References 16 publications

Effects of corticotrophin-releasing hormone, vasopressin and insulin-like growth factor-I on proliferation of and adrenocorticotrophic hormone secretion by canine corticotrophic adenoma cells in vitro

Effects of corticotrophin-releasing hormone, vasopressin and insulin-like growth factor-I on proliferation of and adrenocorticotrophic hormone secretion by canine corticotrophic adenoma cells in vitro

A brief review of modern toxicologic pathology in regulatory and explanatory toxicity studies of chemicals

Mitosis and apoptosis in the pituitary gland: tumour formation or hyperplasia?

Contact Info

Product

Resources

About