Effects of epidermal growth factor (EGF) on fetal islet B cells in vitro.
ABSTRACT. It has been reported that when the rat fetus is treated with streptozotocin (STZ) in vivo, islet B cells are destroyed but later recover. To investigate the process of the recovery of B cells after in vitro treatment of the fetal pancreas with STZ and the role of epidermal growth factor (EGF) in the recovery of B cells, we measured the level of insulin released from the cultured fetal pancreas and examined it histologically. As a result, we immunohistologically confirmed the regeneration of B cells in the pancreas that had been cultured for 48 hr after destruction of islet B cells by STZ treatment. An immunohistologic study using proliferating cell nuclear antigen (PCNA) showed that without the addition of EGF, the cell division index was significantly higher in the STZ-treated group (STZ group) than in the untreated group (intact group), whereas with the addition of EGF, the cell division index increased in both groups, but EGF did not have a significant cell division-promoting effect on the pancreas in the STZ group. The addition of EGF caused a significant decrease in the concentration of insulin in culture medium in both groups. These results indicate that EGF has a cell growth-promoting effect on intact fetal pancreas in vitro but has the effect of inhibiting the release of insulin, and thus suggest that EGF does not trigger the regeneration of islet B cells.
Yasuda
Masahiko
M
Department of Anatomy II, Azabu University School of Veterinary Medicine, Sagamihara, Kanagawa, Japan.
Yamamoto
Masako
M
Arishima
Kazuyoshi
K
Eguchi
Yasunobu
Y
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D046508:Culture Techniques; D004815:Epidermal Growth Factor / Q000494:pharmacology / Q000502:physiology*; D005260:Female; D007150:Immunohistochemistry / Q000662:veterinary; D007328:Insulin / Q000378:metabolism; D007329:Insulin Antagonists; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000166:cytology* / Q000187:drug effects* / Q000196:embryology; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013311:Streptozocin / Q000494:pharmacology*
D007328:Insulin; D007329:Insulin Antagonists; D013311:Streptozocin; D004815:Epidermal Growth Factor