Renal nerve stimulation
[Ref: AV6:p121]
Effect of renal nerve stimulation
- Stimulates renin secretion via direct action on beta1-receptors on JG cells
- Stimulates sodium reabsorption via a direct action on tubular cells
* Including proximal tubular cells, ascending limb, and distal tubules
* [WG21:p707]
- Stimulates afferent and efferent arteriolar constriction (alpha-adrenergic receptors)
Thus,
- GFR decreases
- RBF decrease even more
Which leads to
- Decreased hydrostatic pressure in peritubular capillaries, AND
- Increased filtration fraction increases oncotic pressure in peritubular capillaries
Thus,
- Sodium reabsorption increases, mainly in proximal tubule
- Decreased GFR and increased proximal sodium resorption further leads to increase in renin
* By decreasing NaCl content at macula densa
NB:
The 3 effects of renal nerve are listed in the order of nerve impulse required
Thus,
- Renin secretion is triggered first at lower levels of renal nerve activity
- Afferent and efferent arteriolar constriction occur last
