Migration of macrophage-like cells within encapsulated islets of Langerhans maintained in tissue culture.
Islets of Langerhans isolated from the pancreas and encapsulated in alginate-polylysine-alginate micro-spheres can potentially serve as a self-regulating supply of insulin in response to glucose loads. A longitudinal ultrastructural and immunohistochemical study of encapsulated rat islets cultured in CMRL-1969 media at a constant glucose concentration of 5.5 mmol/L (100 mg%) allowed several observations. First, acinar cells, which remain attached to isolated islets, disappeared within 1 wk in tissue culture. Damaged endocrine cells also disappeared at this time. Phagocytic cells having ultrastructural features suggesting that they are macrophages emerged from the islets within about a week and ingested portions of the inner layer of capsule polymer. These macrophage-like cells retained these polymers until their death which occurred at around 1-2 mo after isolation; at no time did we observe phagocytic cells actually breaching the microsphere capsules. Beta cells remained well-granulated over 90 days of culture but accumulated lipofuscin-like residual bodies. Under these conditions, these bodies began to accumulate appreciably after about one week in culture.
Department of Pathology, Izaak Walton Killam Children's Hospital and Dalhousie University, Halifax, Nova Scotia, Canada.
R B
RB
Fraser
M A
MA
MacAulay
J R
JR
Wright
A M
AM
Sun
G
G
Rowden
D000818:Animals; D016923:Cell Death; D002465:Cell Movement; D046508:Culture Techniques / Q000379:methods*; D005947:Glucose / Q000378:metabolism; D007150:Immunohistochemistry; D007515:Islets of Langerhans / Q000166:cytology* / Q000254:growth & development; D008264:Macrophages / Q000502:physiology*; D010587:Phagocytosis; D051381:Rats
D005947:Glucose