SUFFICIENCY OF POSTPRANDIAL PLASMA-LEVELS OF ISLET AMYLOID POLYPEPTIDE FOR SUPPRESSION OF FEEDING IN RATS

Our objective was to study whether islet amyloid polypeptide (IAPP) pr oduces satiety by an endocrine mechanism. We used a rat model to deter mine whether postprandial plasma levels of IAPP are comparable to thos e required to inhibit feeding when IAPP is administered by continuous intravenous infusion. Food intake in rats with aortic catheters increa sed plasma IAPP levels from a fasting level of 10.8 +/- 0.5 pM to a pe ak level of 19.0 +/- 1.0 pM at 2.2 +/- 0.5 h. in rats with jugular vei n and aortic catheters, the threshold intravenous dose for IAPP suppre ssion of feeding was between 1 and 3 pmol . kg(-1). min(-1). The 3 pmo l . kg(-1). min(-1) dose decreased 4-h intake by similar to 25% by dec reasing meal frequency rather than meal size. This dose increased plas ma IAPP by similar to 24 pM. These results suggest that postprandial p lasma levels of IAPP are not quite sufficient to independently produce satiety.