Related Experiment Videos
Progesterone receptor is constitutively expressed in chicken intestinal mesothelium and smooth muscle
S Salomaa1, A Pekki, T Sannisto
1Department of Biomedical Sciences, University of Tampere, Finland.
Insights
The progesterone receptor (PR) is constitutively expressed in the peritoneum and smooth muscle of the chicken
Area of Science:
- Reproductive Biology
- Immunohistochemistry
- Molecular Endocrinology
Background:
- Progesterone receptor (PR) expression was previously identified in the chick oviduct and ovary.
- PR is known to play a role in reproductive functions.
Purpose of the Study:
- To investigate the presence and localization of PR in various parts of the peritoneum and abdominal organs in chickens.
- To determine if estrogen influences PR expression in these tissues.
Main Methods:
- Immunohistochemical staining using monoclonal antibodies against chicken PR.
- Immunoblotting of cloacal and oviductal cytosol.
Main Results:
- PR was detected in mesothelial cells of the peritoneum and smooth muscle cells of the ileum, colon, and cloaca in both immature and mature chickens.
- Only the B form of PR was found in cloacal cytosol, while both A and B forms were present in oviduct samples.
- Estrogen treatment did not alter PR expression in the examined tissues.
Conclusions:
- The B form of PR is constitutively expressed in the mesothelial cells of the peritoneum and smooth muscle cells of the ileum, colon, and cloaca in chickens.
- PR expression in these tissues is independent of estrogen stimulation.
Abstract:
We have previously shown that progesterone receptor (PR) is expressed in the mesothelium of the chick oviduct and ovary and in the smooth muscle cells of the oviduct and the bursa of Fabricius. Here, we investigated the presence of PR in different parts of the peritoneum and abdominal organs using an immunohistochemical staining based on monoclonal antibodies against chicken PR. In 4-week-old sexually immature chicks, PR expression was located in the mesothelial cells of different parts of the peritoneum, in a thin layer of muscle cells of the ileum and throughout the muscle tissue of the colon and cloaca. In chicks of the same age treated with estrogen, PR was demonstrated similarly in the peritoneum and in the smooth muscle cells of the ileum, colon and cloaca. Using 25-week-old mature chickens, PR was also detected in identical tissues. Immunoblotting of the cloacal cytosol revealed the B form, but no A form of PR, both of which were found in the oviduct samples. Muscle cells of the duodenum and jejunum were not found to contain PR. Estrogen treatment was not needed to stimulate the production of PR in any of the tissues examined. We therefore conclude that the B form of PR is constitutively expressed in the mesothelial cells in different parts of the peritoneum and also in the smooth muscle cells of the ileum, colon and cloaca.