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.
Fraser
R B
RB
Department of Pathology, Izaak Walton Killam Children's Hospital and Dalhousie University, Halifax, Nova Scotia, Canada.
MacAulay
M A
MA
Wright
J R
JR
Sun
A M
AM
Rowden
G
G
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