Regeneration of beta-cells in response to islet inflammation.
Subtotal pancreatectomy (90%) in Lewis rats induces chronic islet inflammation and tissue damage in the remaining pancreas 4 months after surgery. Concomitantly, significant enlargement of the islets of Langerhans was observed (90% pancreatectomy: islet/pancreas area: 25.6 +/- 9.6 x 10(-3), beta-cell/pancreas area: 12.4 +/- 4.4 x 10(-3); n = 4; controls without pancreatectomy: islet/pancreas area: 5.5 +/- 1.7 x 10(-3), beta-cell/pancreas area: 4.6 +/- 1.5 x 10(-3); n = 4; p < 0.05, respectively). Islet growth is mainly due to an increase in beta-cell mass. Beta-cell regeneration was not caused by the surgical manipulations or by metabolic stress. The former was ruled out by performing 10% pancreatectomy which did not cause islet enlargement after 4 months (islet/pancreas area: 13.6 +/- 11.3 x 10(-3), beta-cell/pancreas area: 7.1 +/- 2.0 x 10(-3); n = 3). An influence of metabolic stress was excluded by continuous substitution of syngenic islet antigens, which inhibits insulitis. In the absence of islet inflammation, despite persistent metabolic stress, beta-cell regeneration did not occur (islet/pancreas area: 7.0 +/- 5.5 x 10(-3), beta-cell/pancreas area: 5.5 +/- 4.1 x 10(-3); n = 4). Continuous treatment of animals after 90% pancreatectomy by insulin implants (1.5 U/day) avoided insulitis and beta-cell growth (islet/pancreas area: 9.2 +/- 1.1 x 10(-3), beta-cell/pancreas area: 6.8 +/- 1.0 x 10(-3), n = 3): All enlarged islets observed 4 months after 90% pancreatectomy without further treatment were infiltrated. Thus, beta-cell growth appears to be a response to insulitis. The stimulus for beta-cell growth could result from tissue damage caused by infiltrating cells or from cytokines secreted by the infiltrating cells, or both.
Lampeter
E F
EF
Diabetes Research Institute at Heinrich-Heine-University of Düsseldorf, Germany.
Gurniak
M
M
Brocker
U
U
Klemens
C
C
Tubes
M
M
Friemann
J
J
Kolb
H
H
D000818:Animals; D005260:Female; D007150:Immunohistochemistry; D007515:Islets of Langerhans / Q000473:pathology* / Q000502:physiology*; D010180:Pancreatectomy; D010195:Pancreatitis / Q000473:pathology*; D051381:Rats; D011917:Rats, Inbred Lew; D012038:Regeneration; D013312:Stress, Physiological / Q000473:pathology