Related Experiment Video
Updated: Aug 9, 2026
A Modified Two Kidney One Clip Mouse Model of Renin Regulation in Renal Artery Stenosis
Published on: October 26, 2020
Effects of chronic hypoxia on the circulating and pancreatic renin-angiotensin system
Siu Po Ip1, Yik Wai Chan, Po Sing Leung
1Department of Physiology and School of Chinese Medicine, The Chinese University of Hong Kong, Hong Kong.
Introduction:
The circulating renin-angiotensin system (RAS) plays a crucial role in the regulation of blood pressure, electrolytes, and fluid homeostasis. In contrast to the circulating RAS, the presence of an intrinsic RAS has been demonstrated in different tissues/organs, which may affect both local and global functions of a biologic system. Our previous studies provided solid evidence of the existence of a local RAS in rat pancreas. Our further investigation showed that such a pancreatic RAS could be activated by experimental models of chronic hypoxia and chemically induced pancreatitis. These previous findings formed the basis for the current study.
Methodology:
Adult Sprague-Dawley rats were exposed to isobaric hypoxia (10% O2), and the effects on the circulating and pancreatic RAS were documented.
Results:
The current study shows that exposure of rats to isobaric hypoxia caused a time-dependent increase in plasma renin activity. The activation of circulating RAS by hypoxia was associated with a parallel upregulation of local RAS components, including the mRNA expression of angiotensinogen and angiotensin II receptor types I and II in the pancreas.
Conclusion:
The upregulation of local pancreatic RAS, along with its counterpart circulating RAS, may be responsible for both physiologic and pathophysiologic aspects of a biologic system under chronic hypoxic stress.
Insights
Chronic hypoxia activates the body's renin-angiotensin system (RAS) in both circulation and the pancreas. This dual activation suggests a role in physiological and pathophysiological responses to low oxygen conditions.
Area of Science:
- Physiology
- Endocrinology
- Cardiovascular Research
Background:
- The renin-angiotensin system (RAS) is vital for blood pressure and fluid balance.
- Local RAS exists in organs, influencing their function independently of the circulating system.
- Previous research confirmed a local RAS in the rat pancreas, activated by hypoxia and pancreatitis.
Purpose of the Study:
- To investigate the effects of chronic hypoxia on the circulating and pancreatic RAS in rats.
- To determine if pancreatic RAS is upregulated concurrently with circulating RAS under hypoxic stress.
Main Methods:
- Adult Sprague-Dawley rats were subjected to isobaric hypoxia (10% O2).
- Measurements of plasma renin activity were performed.
- mRNA expression of pancreatic RAS components (angiotensinogen, AT1R, AT2R) was analyzed.
Main Results:
- Hypoxia induced a time-dependent increase in plasma renin activity.
- Circulating RAS activation was accompanied by parallel upregulation of pancreatic RAS components.
- Increased mRNA expression of angiotensinogen and angiotensin II receptors (types I and II) was observed in the pancreas.
Conclusions:
- Chronic hypoxia upregulates both circulating and local pancreatic RAS.
- This coordinated upregulation may contribute to physiological and pathophysiological adaptations under hypoxic stress.
Related Concept Videos
01:33Hormonal Regulation
01:18Hypertension and Regulation of Blood Pressure
01:26Heart Failure Drugs: Inhibitors of Renin-Angiotensin System
01:17Hormonal Regulation of Blood Pressure
Epinephrine and Norepinephrine
The adrenal medulla releases epinephrine and norepinephrine, catecholamines that enhance and extend the sympathetic or "fight or flight" physiological response. These hormones escalate heart rate and the force of contraction while...
01:29Hypertension II: Pathophysiology
01:28Diabetic Nephropathy