Related Experiment Video
Updated: Jul 29, 2026
08:37
Isolation, Fixation, and Immunofluorescence Imaging of Mouse Adrenal Glands
Published on: October 2, 2018
Zone-specific cell proliferation during compensatory adrenal growth in rats
W C Engeland1, W B Ennen, A Elayaperumal
1Departments of Surgery and Neuroscience, Box 120 UMHC, University of Minnesota, 516 Delaware Street SE, Minneapolis, MN 55455, USA. engel002@umn.edu
American Journal of Physiology. Endocrinology and Metabolism
|September 16, 2004
Summary
Compensatory adrenal growth after unilateral adrenalectomy is driven by outer fasciculata cell proliferation and growth. This response involves hyperplasia and hypertrophy, unlike sham surgeries which cause only transient hyperplasia.
Area of Science:
- Endocrinology
- Cell Biology
- Physiology
Background:
- Unilateral adrenalectomy (ULA) triggers compensatory adrenal growth, but the specific contributions of different cortical zones to this hyperplasia remain unclear.
- Understanding the cellular phenotype and zonal origins of proliferation is crucial for elucidating the mechanisms of adrenal adaptation.
Purpose of the Study:
- To characterize the phenotype of cortical cells that proliferate during compensatory adrenal growth following ULA.
- To determine the zonal contributions to adrenocortical hyperplasia and identify the primary site of cell proliferation.
Main Methods:
- Rats underwent ULA, sham surgery, or no surgery, with tissues collected at 2 and 5 days post-operation.
- Immunofluorescence histochemistry for Ki67 (proliferation), P450aldo (zona glomerulosa), and P45011beta (zona fasciculata) was performed.
- Unbiased stereology was used for zone-specific counting of proliferating cells; additional markers (PCNA, BrdU) were used for validation.
Main Results:
- Adrenal weight significantly increased after ULA compared to sham or control groups at both time points.
- Proliferating cells (Ki67-positive) were predominantly found in the outer fasciculata following ULA, correlating with adrenal weight gain.
- Compensatory growth involved both hyperplasia and hypertrophy (increased DNA, RNA, protein), whereas sham surgery induced only transient hyperplasia (increased DNA).
- Dexamethasone pretreatment blocked ULA-induced adrenal weight gain and outer fasciculata proliferation.
Conclusions:
- The outer fasciculata is the primary adrenal zone responsible for compensatory growth after ULA.
- Compensatory adrenal growth is mediated by hyperplasia and hypertrophy in the outer fasciculata, driven by steroid-suppressible signals.
- These findings clarify the zonal dynamics of adrenal adaptation and highlight the role of the outer fasciculata in responding to specific stress signals.
