Figure 3. Neuronal RAS- A Provocative Hypothesis.

The findings reviewed herein suggest the intriguing possibility for the intracellular generation of angiotensin peptides (ANG) derived from the intracellular conversion of angiotensinogen (AGT) by renin-b or intracellular renin (icREN). The fate of intracellular angiotensin peptides synthesized in this way remains undefined. We hypothesize that some mechanism may exist for these peptides to be packaged into neurosecretory bodies and perhaps transported through axons to the synapse. Similarly, we hypothesize that the presence of the prorenin receptor [(P)RR] on the neuronal surface may provide a mechanism for prorenin or renin in the extracellular space to be concentrated in the proximity of angiotensinogen released from either glial cells or neurons. This, in the presence of other angiotensin converting enzymes may lead to the synthesis of angiotensin peptides in the proximity of neuronal angiotensin receptors (ATR).