1. The physiological impact of proinsulin C-peptide
Thomas Kunt, Thomas Forst, Andreas Pfützner, Jürgen Beyer, John Wahren 
Pathophysiology 
Volume 5, Issue 4, Pages (January 1999)
DOI: /S (98)

2. Fig. 1
Skin microvascular blood flow was tested by assessing the capillary blood cell velocity (CBV) by means of videophotometric capillaroscopy [52]. After infusion of human proinsulin C-peptide (■), CBV increased in type 1 diabetes patients from 147±3.6 to 167±4.2 μm/s (P<0.001). (□) represent the CBV data obtained from type 1 diabetes patients after infusion of saline. (*P<0.05, ***P<0.0001).
Pathophysiology 1999 5, DOI: ( /S (98) )

3. Fig. 2
The present data are compatible with the hypothesis that C-peptide binds to a cell membrane receptor which is coupled to a G-protein. The latter either activates Ca2+-channels or causes Ca2+-release from intracellular stores resulting in increased intracellular Ca2+ and activation of Ca2+-dependent protein phosphatase IIB which, in turn, converts the inactive phosphorylated Na+, K+-ATPase to its active dephosphorylated form [60].
Pathophysiology 1999 5, DOI: ( /S (98) )