Histochemistry of glandular metaplasia at the trigone of the urinary bladder in cows.

The epithelium at the trigone of the urinary bladder showed intestinal metaplasia of a colonic type in three Holstein-Friesian cows affected with chronic polypoid cystitis. Except for Ricinus communis (RCA-I), almost all goblet cells in the whole crypt were positive to periodic acid-Schiff (PAS), alcian blue (AB) pH 2.5, AB pH 1.0, periodate borohydride-potassium hydroxide-PAS (PB-KOH-PAS), Ulex europaeus (UEA-I), Triticum vulgare (WGA) and Arachis hypogaea (PNA) after neuraminidase digestion. This result indicated that most goblet cells contained acidic and neutral glycoconjugates as O-acetylated sialomucin, L-fucose, N-acetyl-glucosamine, neuraminic acid residues and sialic acid-galactose dimers and were devoid of beta-D-galactose. The goblet cells at the surface in the upper half of the crypt contained both sulpho- and sialo-mucins with N-acetyl-galactosamine residues by AB (pH 2.5)-PAS, high iron diamine (HID)-AB (pH 2.5), Dolichos biflorus (DBA) and Glycine maximus (SBA) reactions. On the other hand, the lower goblet cells were found to contain predominantly sulphated mucins with D-mannose and D-glucose residues by AB-PAS, HID-AB and Concanavalia ensiformis (Con A) reactivities. This suggested that mucin secreted from these cells was similar to that secreted from the goblet cells of the large intestine in cattle.