Morphology of renal parenchymal culture in collagen gels

Explants of rabbit renal parenchyma have been grown in primary tissue culture suspended within hydrated collagen gels. Light and phase contrast microscopic analysis of the first 17 days in culture is described. Pieces of NZW rabbit renal parenchyma were suspended in collagen gels and bathed in supplemented RPMI 1640 medium and incubated at 37 degrees C in 5% CO2 in air. Tubules demonstrated a fine granularity by phase contrast microscopy and glomeruli appeared as red spheres. Blebs formed at the sides and ends of the explant and a monolayer outgrowth of tightly packed polygonal cells occurred from day 4. Histologically an immediate phase of necrosis was followed by regeneration whereby tubules became lined with a confluent epithelium composed of a single layer of flat to cuboidal-shaped cells sitting on an intact tubular basement membrane (TBM). Intraluminal casts of organized cellular debris as well as material presumed to be Tamm Horsfall protein were present. Glomeruli demonstrated collapsed capillary loops. The interstitium became widened by eosinophilic material. The tissue surface contained epithelial cells arranged in places into sac-like structures enclosing a space.