Food intake and meal pattern in IAPP knockout mice with and without infusion of exogenous IAPP.
OBJECTIVE
The current study used islet amyloid polypeptide (IAPP) knockout mice (KO mice) to investigate the physiological role of IAPP in the regulation of food intake (FI).


METHODS
FI and body weight were measured in KO and wild-type (WT) mice for 27 weeks. In an additional short-term experiment, IAPP (25 pmol·kg(-1)min(-1)) was infused subcutaneously for 3 days in KO and WT mice, and FI, meal pattern, and body weight were analyzed.


RESULTS
In the long-term experiment, no significant differences in body weight were seen between WT and KO mice at any point. FI, meal number, and meal size did not differ significantly between the groups in any of the five selected weeks that were studied. In the short-term experiment, FI decreased significantly during IAPP infusion in both WT and KO groups. FI was significantly lower in the KO mice compared with WT on days 1 and 2 (p < 0.05 and p < 0.01, respectively).


CONCLUSIONS
The data showing no differences in FI and body weight were seen between KO and WT mice, indicating that FI can be controlled in the absence of IAPP. The more marked anorectic effect seen in the KO mice during IAPP infusion suggests that IAPP receptors and/or IAPP post-receptor signaling pathways are up-regulated in mice lacking endogenous IAPP.
Department for Clinical Science, Intervention and Technology (CLINTEC), Division of Surgery, Karolinska Institutet at Karolinska University Hospital, Huddinge, Stockholm, Sweden.
Madelene
M
Olsson
Margery K
MK
Herrington
Roger D
RD
Reidelberger
Johan
J
Permert
Samuel
S
Gebre-Medhin
Urban
U
Arnelo
D000818:Animals; D001067:Appetite Depressants / Q000494:pharmacology*; D001835:Body Weight; D004435:Eating / Q000187:drug effects*; D005247:Feeding Behavior / Q000187:drug effects*; D058228:Islet Amyloid Polypeptide / Q000235:genetics / Q000494:pharmacology* / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D015398:Signal Transduction; D013997:Time Factors
D001067:Appetite Depressants; D058228:Islet Amyloid Polypeptide