Lack of satiety effect of cholecystokinin (CCK) in a new rat model not expressing the CCK-A receptor gene.
This work expands recent observations that Otsuka Long-Evans Tokushima Fatty (OLETF) rats show little or no pancreatic expression of the cholecystokinin (CCK)-A receptor gene. We examined whether the CCK-A and -B receptor genes were expressed in the brain (hypothalamus) of OLETF rats in comparison with control (Long-Evans Tokushima Otsuka = LETO) rats. CCK-A receptor mRNA was detected in the hypothalamus of LETO rats but not OLETF rats. The CCK-B receptor gene was expressed in the hypothalamus in both strains. Cerebroventricular administration of CCK-8 sulfate inhibited daily food intake in LETO rats, but not in OLETF rats. These results show that in OLETF rats the absence of CCK-A receptor gene expression in the hypothalamus results in hyperphagia because of lack of satiety.
Miyasaka
K
K
Department of Clinical Physiology, Tokyo Metropolitan Institute of Gerontology, Japan.
Kanai
S
S
Ohta
M
M
Kawanami
T
T
Kono
A
A
Funakoshi
A
A
D000818:Animals; D001483:Base Sequence; D002766:Cholecystokinin / Q000502:physiology*; D003919:Diabetes Insipidus / Q000235:genetics / Q000503:physiopathology; D006963:Hyperphagia / Q000150:complications / Q000235:genetics* / Q000503:physiopathology; D007031:Hypothalamus / Q000503:physiopathology*; D008297:Male; D008969:Molecular Sequence Data; D009765:Obesity / Q000209:etiology / Q000235:genetics / Q000503:physiopathology; D016133:Polymerase Chain Reaction; D051381:Rats; D011922:Rats, Mutant Strains; D043886:Receptor, Cholecystokinin A; D011949:Receptors, Cholecystokinin / Q000172:deficiency* / Q000235:genetics; D012527:Satiation / Q000502:physiology*; D012844:Sincalide / Q000494:pharmacology*
D043886:Receptor, Cholecystokinin A; D011949:Receptors, Cholecystokinin; D002766:Cholecystokinin; D012844:Sincalide