Evidence for a paracrine role of endogenous adrenomedullary galanin in the regulation of glucocorticoid secretion in the rat adrenal gland
Previous investigations have shown that rat adrenocortical cells are provided with galanin receptors, and galanin stimulates glucocorticoid secretion from dispersed cells. The present study aimed to clarify the possible role of galanin in the physiological regulation of rat adrenal secretory activity. Reverse transcription-polymerase chain reaction detected galanin mRNA expression in the adrenal medulla, but not in the cortex. Sizeable concentrations of galanin-immunoreactivity were measured by radioimmune assay only in the adrenomedullary tissue. Galanin raised norepinephrine, but not epinephrine, release from adrenomedullary tissue. Galanin immunoneutralization (obtained with concentrations of anti-galanin antibody able to block the galanin glucocorticoid secretagogue effect on dispersed adrenocortical cells) decreased basal corticosterone production from adrenal slices containing adrenomedullary tissue, without affecting that from dispersed adrenocortical cells. The β-adrenoceptor antagonist l-alprenolol partially prevented galanin-stimulated corticosterone secretion from adrenal slices, without per se altering basal secretion. Taken together, our findings allow us to conclude that endogenous galanin, produced in adrenal medulla, is involved in the regulation of adrenocortical glucocorticoid secretion acting via a two-fold paracrine mechanism: i) direct activation of adrenocortical galanin receptors; and ii) stimulation of adrenomedullary release of catecholamines, which in turn activate β-adrenoceptors located on adrenocortical cells.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
Document Type: Research Article
Affiliations: Department of Human Anatomy and Physiology, Section of Anatomy, University of Padua, I-35121 Padua, Italy
Publication date: March 1, 2007
More about this publication?
- The International Journal of Molecular Medicine is a monthly, peer-reviewed journal devoted to the publication of high quality studies related to the molecular mechanisms of human disease. The journal welcomes research on all aspects of molecular and clinical research, ranging from biochemistry to immunology, pathology, genetics, human genomics, microbiology, molecular pathogenesis, molecular cardiology, molecular surgery and molecular psychology.
The International Journal of Molecular Medicine aims to provide an insight for researchers within the community in regard to developing molecular tools and identifying molecular targets for the diagnosis and treatment of a diverse number of human diseases.
- Editorial Board
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Information for Advertisers
- Terms & Conditions
- Ingenta Connect is not responsible for the content or availability of external websites