Research

The role of apoptosis in early embryonic development of the adenohypophysis in rats

Jens Weingärtner¹ , Kristina Lotz² , Andreas Faltermeier³ , Oliver Driemel⁴ , Johannes Kleinheinz⁵ , Tomas Gedrange⁶ and Peter Proff³

¹Department of Anatomy and Cell Biology, Ernst Moritz Arndt University Greifswald, Friedrich Löffler Straße 23c, D-17487 Greifswald, Germany

²Department of Gynecology and Obstetrics, Ernst Moritz Arndt University Greifswald, Wollweberstr. 1, D-17487 Greifswald, Germany

³Department of Orthodontics, University of Regensburg, F.J. Strauss-Allee 11, D-93042 Regensburg, Germany

⁴Department of Oral and Maxillofacial Surgery, University of Regensburg, F.J. Strauss-Allee 11, D-93042 Regensburg, Germany

⁵Department of Oral and Maxillofacial Surgery, University of Münster, Waldeyerstraße 30, D-48129 Münster, Germany

⁶Department of Orthodontics, Preventive and Pediatric Dentistry, Ernst Moritz Arndt University Greifswald, Rotgerberstr. 8, D-17489 Greifswald, Germany

author email corresponding author email

Head & Face Medicine 2008, 4:13doi:10.1186/1746-160X-4-13

Published:	23 July 2008

Abstract

Background

Apoptosis is involved in fundamental processes of life, like embryonic development, tissue homeostasis, or immune defense. Defects in apoptosis cause or contribute to developmental malformation, cancer, and degenerative disorders.

Methods

The developing adenohypophysis area of rat fetuses was studied at the embryonic stage 13.5 (gestational day) for apoptotic and proliferative cell activities using histological serial sections.

Results

A high cell proliferation rate was observed throughout the adenohypophysis. In contrast, apoptotic cells visualized by evidence of active caspase-3, were detected only in the basal epithelial cones as an introducing event for fusion and closure of the pharyngeal roof.

Conclusion

We can clearly show an increasing number of apoptotic events only at the basic fusion sides of the adenohypophysis as well as in the opening region of this organ. Apoptotic destruction of epithelial cells at the basal cones of the adenohypophysis begins even before differentiation of the adenohypophyseal cells and their contact with the neurohypophysis. In early stages of development, thus, apoptotic activity of the adenohypophysis is restricted to the basal areas mentioned. In our test animals, the adenohypophysis develops after closure of the anterior neuroporus.