Posterior pituitary to release vasopressin.
Adrenal medulla to release adrenaline.
Adrenal medulla to release aldosterone.
Juxta glomerular cells to release renin.
A fall in glomerular filtration rate (GFR) activates juxtaglomerular of kidney cells to release renin, which activates the renin-angiotensin-aldosterone system (RAAS), is a signaling pathway responsible for regulating the body's blood pressure. As the blood pressure is regulated the GFR is also regulated.