Distribution and coexistence of chromogranin A-, serotonin- and pancreastatin-like immunoreactivity in endocrine-like cells of the human anal canal

Cell Tissue Res. 1992 Apr;268(1):109-16. doi: 10.1007/BF00338059.


The comparative distribution and coexistence of chromogranin A (CGA)-, serotonin (5-hydroxytryptamine; 5-HT)- and pancreastatin (PST)-like immunoreactivity in endocrine-like cells of the human anal canal was investigated by light-microscopic immunocytochemistry. The largest population of colorectal endocrine-like cells consisted of CGA-immunoreactive (ir) cells, followed by the 5-HT-ir and PST-ir cell population. In the anal transitional zone (ATZ), CGA- and 5-HT-immunoreactivity was equally distributed; ir-PST was confined to a smaller endocrine-like cell population. In the squamous zone and the perianal skin, Merkel cells in the basal layer of the epidermis and hair follicles exhibited ir-CGA and ir-PST but no ir-5-HT. Double immunofluorescence on identical sections revealed distinct coexistence patterns. In the colorectal zone, about 2/3 of the CGA-ir endocrine-like cells also stained for 5-HT, whereas in the ATZ epithelium, CGA- and 5-HT-immunoreactivity completely overlapped. No 5-HT-immunoreactivity could be detected in CGA-ir Merkel cells of the squamous zone of the anal canal and the perianal skin. PST-immunoreactivity was present in about 1/3 of the CGA-ir colorectal and anal transitional endocrine-like cells and in about 1/4 of the Merkel-cell population staining for CGA. These chemically heterogeneous phenotypes of the anal endocrine-like and Merkel cells may reflect a specific regulatory role of these cells in the various epithelial linings of the human anal canal and the perianal skin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anal Canal / cytology*
  • Cell Count
  • Chromogranin A
  • Chromogranins / analysis*
  • Fluorescent Antibody Technique
  • Humans
  • Neurosecretory Systems / chemistry
  • Neurosecretory Systems / cytology*
  • Pancreatic Hormones / analysis*
  • Serotonin / analysis*
  • Skin / cytology


  • CHGA protein, human
  • Chromogranin A
  • Chromogranins
  • Pancreatic Hormones
  • pancreastatin
  • Serotonin