Octreotide and the Novel Multireceptor Ligand Somatostatin Receptor Agonist Pasireotide (SOM230) Block the Adrenalectomy-Induced Increase in Mitotic

LA Nolan, HA Schmid, A Levy

Research output: Contribution to journalArticle (Academic Journal)peer-review

13 Citations (Scopus)

Abstract

The novel somatostatin receptor agonist pasireotide binds with high affinity to somatostatin receptors SSTR1, 2, 3, and 5. Acting principally through the latter, it inhibits basal and CRH-stimulated ACTH secretion from the AtT20 corticotroph cell line and ACTH release from a proportion of human corticotroph adenomas both in vitro and in vivo. Data supporting an additional antiproliferative effect has led to pasireotide being explored as a potential therapy for patients with Cushing’s disease. We have compared the effects of pasireotide and octreotide on adrenalectomy-induced mitotic and apoptotic activity in the male rat anterior pituitary. Adrenalectomized rats were treated with daily sc injections of vehicle, pasireotide, or octreotide. Changes in proliferation and apoptosis were determined 2–6 d postoperatively. Pasireotide and octreotide had no effect on baseline pituitary cell turnover and no measurable effects on apoptosis. However, the wave of increased mitotic activity normally seen in the pituitary after adrenalectomy was completely abolished. Nevertheless, pasireotide and octreotide did not diminish the increase in ACTH-immunopositive cell index after adrenalectomy, indicating that cell division and differentiation of hormonally null cells in the pituitary are under independent control. In conclusion, basal cell turnover in the pituitary is not inhibited by pasireotide or octreotide. Bilateral adrenalectomy stimulates differentiation of preexisting null cells into ACTH-positive cells. Cell division after bilateral adrenalectomy occurs in a specific subpopulation of hormonally null cells that are equally sensitive to the antiproliferative effects of pasireotide and octreotide, implicating SSTR2 receptors in this antimitotic response.
Translated title of the contributionOctreotide and the Novel Multireceptor Ligand Somatostatin Receptor Agonist Pasireotide (SOM230) Block the Adrenalectomy-Induced Increase in Mitotic
Original languageEnglish
Pages (from-to)2821 - 2827
Number of pages7
JournalEndocrinology
Volume148 (6)
DOIs
Publication statusPublished - Jun 2007

Bibliographical note

Publisher: Endocrine Society

Fingerprint

Dive into the research topics of 'Octreotide and the Novel Multireceptor Ligand Somatostatin Receptor Agonist Pasireotide (SOM230) Block the Adrenalectomy-Induced Increase in Mitotic'. Together they form a unique fingerprint.

Cite this