Histochemistry of the chick esophagus and trachea. II. Enzymes, nucleic acids, proteins, carbohydrates, and fats.

Abstract

AbstractTissues of White Leghorn embryos of stages 17–45 and chicks of one day, two days, and three weeks of age were frozen, sectioned in a cryostat and, where appropriate, were fixed in cold calcium formol. Acid phosphatase, non‐specific esterase, adenosine triphosphatase, 5‐nucleotidase, non‐specific glycerophosphatase, nucleotidediphosphatase, and glucose‐6‐phosphatase were localized in these tissues. Ribonucleic acid, acid mucopolysaccharides, triglycerides, and neutral fats were localized in tissues fixed with FAA and embedded in paraffin.Positive acid phosphatase reactions were obtained in the epithelium of the trachea and esophagus at all stages of development. 5‐nucleotidase was found in the muscularis mucosae of the esophagus at all stages. Non‐specific esterase appeared with histodifferentiation of the esophageal epithelium. Ribonucleic acid was localized in the basal regions of the epithelium.Mucous glands of the esophagus are rich in ribonucleic acid and acid phosphatase at all stages of development. With histodifferentiation and the onset of secretion of sulfated acid mucopolysaccharides, the glands and their ducts become highly reactive for adenosine triphosphatase and nucleotide‐diphosphatase, indicating a role of these enzymes in secretion.