Undernutrition does not alter the activation of beta-cell neogenesis and replication in adult rats after partial pancreatectomy.
In previous work, we demonstrated that a 65% protein calorie food restriction started during the third trimester of gestation in rats caused a reduced beta-cell mass at 4 days of life that persisted until adult age. In this study with adult undernourished (U) rats, we investigated 1) whether undernutrition affects the beta-cell growth potential and both beta-cell proliferation and differentiation and 2) the implication of the IGFs, highly responsive to nutritional status, in these processes. To this end, we used the 90% pancreatectomy (Px) procedure in U and control (C) adult rats. The results show that, on day 2 after Px, beta-cell replication was significantly higher in C rats, whereas the beta-cell neogenesis was markedly increased in U/Px rats. Both the serum levels of IGF-I and the liver IGF-I mRNA expression were reduced in adult U rats before and after Px compared with C rats. Pancreatic IGF-I mRNA expression was reduced in U animals on day 0. However, on day 2 after Px, the increase of pancreatic IGF-I mRNA expression was significantly higher in U rats than in C rats. These data suggest that beta-cells still have the capacity to regenerate in the adult U rats, with a higher efficiency than C rats on day 2, and that both beta-cell neogenesis and beta-cell replication are stimulated. The increased pancreatic IGF-I mRNA may be instrumental in these processes.
Fernández
E
E
Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad Complutense, Ciudad Universitaria, 28040 Madrid, Spain.
Martín
M A
MA
Fajardo
S
S
Bailbé
D
D
Gangnerau
M N
MN
Portha
B
B
Escrivá
F
F
Serradas
P
P
Alvarez
C
C
D000367:Age Factors; D000818:Animals; D031204:Caloric Restriction; D002454:Cell Differentiation; D002455:Cell Division; D005260:Female; D048070:Fetal Nutrition Disorders / Q000473:pathology* / Q000503:physiopathology; D015870:Gene Expression / Q000502:physiology; D005865:Gestational Age; D007334:Insulin-Like Growth Factor I / Q000235:genetics / Q000378:metabolism; D007335:Insulin-Like Growth Factor II / Q000235:genetics / Q000378:metabolism; D050417:Insulin-Secreting Cells / Q000166:cytology*; D007515:Islets of Langerhans / Q000166:cytology / Q000196:embryology* / Q000601:surgery; D008099:Liver / Q000196:embryology / Q000502:physiology; D008297:Male; D010180:Pancreatectomy; D010183:Pancreatic Ducts / Q000166:cytology / Q000196:embryology; D011247:Pregnancy; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D012038:Regeneration / Q000502:physiology*
D012333:RNA, Messenger; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II