The following signalling mechanisms are in place:
| Hormone | Stimulus | Site of action | Effect |
| Angiotensin II or ß adrenergics via renin release | Low ECF volume | Proximal convoluted tubule | Increased reabsorption of NaHCO3 & NaCl |
| Aldosterone | Angiotensin II Hyperkalaemia |
Cortical distal nephron | Reabsorption of NaCl Secretion of K+ |
| Atrial natriuretic peptide | Vascular volume expansion | GFR Medullary collecting duct |
Increased GFR Reduced reabsorption of NaCl |