Pancreatic Endocrine Effects of Dopamine Receptors in Human Islet Cells.
OBJECTIVE
To date, there are no reports on the cellular localization of dopamine receptors in the human pancreas. In our study, we determined the localization and expression of 5 dopamine receptors (D(1), D(2), D(3), D(4), and D(5)) in normal human pancreas tissue.


METHODS
Human nonpathological pancreas tissues were fixed with 4% paraformaldehyde, paraffin-embedded, and processed for immunohistochemical analysis to detect dopamine receptors in the human pancreas tissue by using double immunofluorescent labeling and confocal microscopy.


RESULTS
We found that the D(1) receptor is present in β cells; the D(2) receptor is expressed by α, δ, and pancreatic polypeptide cells; the D(4) receptor is expressed by β and polypeptide cells; whereas the D(5) receptor is expressed only by δ cells.


CONCLUSIONS
Our results identify the dopamine receptors (D(1)-D(5)) in normal pancreas tissue and provide a morphological basis for studying the pancreatic endocrine effects of dopamine and suggest a new target for the clinical treatment of diabetes.
From the *Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing; and †School of Medicine, Nankai University, Tianjin, China.
Ying
Y
Zhang
Ruipan
R
Zheng
Xiangzhi
X
Meng
Lulu
L
Wang
Li
L
Liu
Yan
Y
Gao
D005455:Fluorescent Antibody Technique; D050416:Glucagon-Secreting Cells / Q000737:chemistry; D006801:Humans; D050417:Insulin-Secreting Cells / Q000737:chemistry; D007515:Islets of Langerhans / Q000737:chemistry* / Q000166:cytology; D018613:Microscopy, Confocal; D050418:Pancreatic Polypeptide-Secreting Cells / Q000737:chemistry; D016612:Paraffin Embedding; D011954:Receptors, Dopamine / Q000032:analysis*; D017447:Receptors, Dopamine D1 / Q000032:analysis; D017448:Receptors, Dopamine D2 / Q000032:analysis; D050637:Receptors, Dopamine D3 / Q000032:analysis; D050638:Receptors, Dopamine D4 / Q000032:analysis; D050641:Receptors, Dopamine D5 / Q000032:analysis; D019864:Somatostatin-Secreting Cells / Q000737:chemistry
C583260:DRD1 protein, human; C581293:DRD2 protein, human; C493593:DRD3 protein, human; C493599:DRD4 protein, human; C493605:DRD5 protein, human; D011954:Receptors, Dopamine; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D050638:Receptors, Dopamine D4; D050641:Receptors, Dopamine D5