U. Arnelo et al., CHRONIC INFUSION OF ISLET AMYLOID POLYPEPTIDE CAUSES ANOREXIA IN RATS, American journal of physiology. Regulatory, integrative and comparative physiology, 40(6), 1996, pp. 1654-1659
Islet amyloid polypeptide (IAPP) is a hormonal peptide that at high do
ses has been shown to reduce food intake. In the present study, the do
se-response effects of subcutaneous infusion of IAPP (0, 2, 7, and 25
pmol . kg(-1). min(-1)) for 8 days on food intake and meal patterns in
rats were investigated. At the end of the experiment, plasma was obta
ined and levels of IAPP were measured by radioimmunoassay. IAPP dose-d
ependently and transiently inhibited food intake. The minimal effectiv
e dose (2 pmol . kg(-1). min(-1)) caused a small but significant (up t
o 14%, P < 0.01) inhibition of food intake that lasted 5 days. The hig
hest dose administered (25 pmol . kg(-1). min(-1)) had the greatest ef
fect (up to 44%, P < 0.001), which lasted throughout the 8-day period.
Reductions in feeding during light and dark phases occurred through a
decrease in number of meals consumed rather than meal size or meal du
ration. IAPP also decreased body weight gain and water intake dose dep
endently. IAPP infusion of 2, 7, and 25 pmol . kg(-1). min(-1) increas
ed plasma IAPP concentrations from a basal level of 10.3 +/- 0.7 pM to
35.1 +/- 5.4, 78.1 +/- 11.2, and 236.6 +/- 23.6 pM, respectively, val
ues that are likely to be close to physiological and within the pathop
hysiological ranges. Thus IAPP may play an important physiological or
pathophysiological role in control of food intake.