Lower plasma levels of some gastrointestinal peptides in Raynaud's disease. Influence of transcutaneous nerve stimulation.

In a previous study it was shown that Raynaud patients during ischemic attacks displayed significantly lower levels of vasoactive intestinal polypeptides (VIP) in cubital vein plasma than did normal subjects in the same relatively cold environments. Low-frequency transcutaneous nerve stimulation (TNS), producing widespread cutaneous vasodilatation, was associated with a 30-35% increase in plasma VIP in both groups. In the present study parallel observations were made in some of the same subjects under the same experimental conditions with regard to six other gastrointestinal peptides: somatostatin, motilin, pancreatic polypeptide (PP), secretin, gastric inhibitory polypeptide (GIP), and cholecystokinin (CCK), determined radioimmunochemically. Except for CCK, the mean plasma levels of all these gut peptides were similarly lower in the Raynaud patients than in the normal subjects in cold environments. However, TNS did not induce significant increases in the plasma levels of any of these 6 peptides. These findings appear to place VIP in a different functional category than the other gut peptides.