Related Experiment Video
Updated: Jun 25, 2025
08:21
A Modified Two Kidney One Clip Mouse Model of Renin Regulation in Renal Artery Stenosis
Published on: October 26, 2020
4.7K
Juxtaglomerular apparatus-mediated homeostatic mechanisms: therapeutic implication for chronic kidney disease
Eiji Higashihara1, Takeo Harada2, Hiroshi Fukuhara1
1Department of Urology, Kyorin University School of Medicine, Mitaka, Japan.
Expert Opinion on Pharmacotherapy
|May 22, 2024
Summary
The juxtaglomerular apparatus (JGA) mechanism influences how sodium-glucose cotransporter 2 inhibitors (SGLT2is) treat chronic kidney disease (CKD) and how tolvaptan affects autosomal dominant polycystic kidney disease (ADPKD). This understanding may improve kidney disease treatments.
Area of Science:
- Nephrology
- Pharmacology
- Physiology
Background:
- The juxtaglomerular apparatus (JGA) plays a crucial role in kidney homeostasis.
- The JGA's function is linked to tubuloglomerular feedback and the renin-angiotensin system.
- Sodium-glucose cotransporter 2 inhibitors (SGLT2is) and tolvaptan are key drugs in managing kidney diseases.
Purpose of the Study:
- To explore the JGA-mediated homeostatic mechanism.
- To assess the relationship between the JGA mechanism and the therapeutic effects of SGLT2is in chronic kidney disease (CKD).
- To evaluate the potential link between the JGA mechanism and tolvaptan's benefits in autosomal dominant polycystic kidney disease (ADPKD).
Main Methods:
- Review of clinical trials involving SGLT2is and tolvaptan.
- Analysis of the JGA-mediated homeostatic mechanism, including tubuloglomerular feedback.
- Examination of macula densa (MD) signaling in response to sodium load.
Main Results:
- Increased sodium load to the macula densa (MD) triggers adenosine production, constricting the afferent arteriole (Af-art) to protect glomeruli.
- MD signaling suppresses renin secretion and enhances sodium excretion, balancing filtration.
- In advanced CKD, increased MD adenosine production may relax the afferent arteriole (Af-art), maintaining sodium balance at the glomeruli's expense.
Conclusions:
- The JGA-mediated homeostatic mechanism is central to understanding SGLT2i efficacy in CKD.
- Tolvaptan's renal benefits in ADPKD may involve JGA-mediated mechanisms due to its action on sodium reabsorption.
- Further understanding of the JGA mechanism can guide the development of novel pharmacotherapies for kidney diseases.
Related Concept Videos
01:33Hormonal Regulation
33.1K
The renin-aldosterone system is an endocrine system which guides the renal absorption of water and electrolytes, thus managing blood pressure and osmoregulation. Activation of the system begins in the kidneys with a small cluster of cells adjacent to the afferent and efferent blood vessels of the renal corpuscle. As the nephrons are filtering blood, juxtaglomerular cells monitor blood pressure. If they detect a decrease in pressure, they release the hormone renin into the bloodstream.
33.1K
01:28Glomerular Filtration Rate and its Regulation
2.6K
The Glomerular Filtration Rate (GFR) is a measure of kidney function, reflecting the volume of filtrate formed per minute in the kidneys. On average, GFR is approximately 125 mL/min in males and 105 mL/min in females. Maintaining a relatively constant GFR is essential for the kidneys to effectively regulate body fluid homeostasis and maintain extracellular stability.
GFR regulation involves two primary intrinsic controls: the myogenic and tubuloglomerular feedback mechanisms.
The myogenic...
GFR regulation involves two primary intrinsic controls: the myogenic and tubuloglomerular feedback mechanisms.
The myogenic...
2.6K
01:26Heart Failure Drugs: Inhibitors of Renin-Angiotensin System
421
The activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system (RAAS) contributes to cardiac remodeling, and inhibiting the RAAS is a pharmacological target in heart failure management. As a result, neurohumoral modulation is a crucial treatment principle for managing heart failure. This approach involves using medications like ACE inhibitors (ACEIs), angiotensin receptor blockers (ARBs), β-blockers, mineralocorticoid receptor antagonists (MRAs), and neutral...
421
01:13Introduction to Urinary System
2.5K
The urinary system consists of two kidneys, two ureters, the urinary bladder, and the urethra.
The kidneys are bean-shaped organs located in the retroperitoneal space, on either side of the vertebral column, between the T12 and L3 vertebrae. They are partially protected by the rib cage and surrounded by perirenal fat, which provides cushioning. They are responsible for urine formation and play critical roles in regulating blood pressure, electrolyte levels, and hormone production. The ureters...
The kidneys are bean-shaped organs located in the retroperitoneal space, on either side of the vertebral column, between the T12 and L3 vertebrae. They are partially protected by the rib cage and surrounded by perirenal fat, which provides cushioning. They are responsible for urine formation and play critical roles in regulating blood pressure, electrolyte levels, and hormone production. The ureters...
2.5K
01:18Hypertension and Regulation of Blood Pressure
2.1K
Hypertension, the most common cardiovascular disease, is diagnosed through repeated measurements of elevated blood pressure. Its risks, including damage to the kidney, heart, and brain, are directly proportional to blood pressure levels. Starting from 115/75 mm Hg, the risk of cardiovascular disease doubles with each increment of 20/10 mm Hg. The diagnosis relies on blood pressure measurements, not on patient symptoms, as hypertension is often asymptomatic until end-organ damage is imminent or...
2.1K
01:30Antihypertensive Drugs: Angiotensin-Converting Enzyme Inhibitors
618
Angiotensin-converting enzyme (ACE), a vital component of the renin-angiotensin-aldosterone system, is abundant in lung endothelial cells. ACE converts the inactive decapeptide, angiotensin I, into the active octapeptide, angiotensin II. This potent vasoconstrictor narrows blood vessels, increasing resistance to blood flow and elevating blood pressure. Angiotensin II also stimulates aldosterone production, encouraging kidney cells to reabsorb more sodium and water from urine, thereby increasing...
618