View source for WBR1000

 {{WBRQuestion
|QuestionAuthor= {{YD}} (Reviewed by Serge Korjian)
|ExamType=USMLE Step 1
|MainCategory=Histology
|SubCategory=Endocrine
|MainCategory=Histology
|SubCategory=Endocrine
|MainCategory=Histology
|SubCategory=Endocrine
|MainCategory=Histology
|MainCategory=Histology
|MainCategory=Histology
|SubCategory=Endocrine
|MainCategory=Histology
|SubCategory=Endocrine
|MainCategory=Histology
|SubCategory=Endocrine
|MainCategory=Histology
|SubCategory=Endocrine
|MainCategory=Histology
|MainCategory=Histology
|SubCategory=Endocrine
|Prompt=A scientist investigating a novel antidiabetic drug injects rats with insulin antibodies to induce experimental diabetes.  Shown below is an image depicting the localization of the insulin antibodies by immunofluorescent microscopy.  The red color represents the insulin antibodies, the blue color represents the nuclei and the green color represents unspecific anti-mouse secondary antibody staining mostly the intercellular matrix.  To which of the following cells does the area in red most likely correspond to?<br>
[[File:Mouse pancreatic islet.jpg|400px]]
|Explanation=Hormones produced in the islets of Langerhans are secreted directly into the blood flow by (at least) five types of cells. In rat islets, endocrine cell subsets are distributed as follows:<br>

*[[Alpha cells]] producing [[glucagon]] (15–20% of total islet cells)
*[[Beta cells]] producing [[insulin]] and [[amylin]] (65–80%)- [[Delta cells]] producing [[somatostatin]] (3–10%)
*[[Gamma cells]] or PP cells producing pancreatic polypeptide (3–5%)
*[[Epsilon cells]] producing [[ghrelin]] (<1%)
Since insulin is produced in the beta cells, the insulin antibodies will label the beta cells in red.
|AnswerA=Alpha cella
|AnswerAExp=[[Alpha cell]]s produce glucagon.  Alpha cells form 15–20% of the total number of cells of the [[islets of langerhans]].
|AnswerB=Beta cells
|AnswerBExp=[[Beta cells]] produce [[insulin]] and [[amylin]].  Beta cells form 65–80% of the total number of cells of the [[islets of langerhans]].
|AnswerC=Delta cells
|AnswerCExp=[[Delta cells]] produce [[somatostatin]].  Delta cells form 3–10% of the total number of cells of the [[islets of langerhans]].
|AnswerD=Gamma cells
|AnswerDExp=[[Gamma cells]], or PP cells, produce pancreatic polypeptide.  Gamma cells form 3–5% of the total number of cells of the [[islets of langerhans]].
|AnswerE=Epsilon cells
|AnswerEExp=Epsilon cells produce ghrelin.  Epsilon cells form <1% of the total number of cells of the [[islets of langerhans]].
|EducationalObjectives=The [[islets of langerhans]] are formed by different types of cells.  [[Beta cells]] occupy the center of the islet of langerhans and produce [[insulin]].
|References=Gomori, George. "Observations with differential stains on human islets of Langerhans." The American journal of pathology 17.3 (1941): 395.<br>
First Aid 2015 page 313

|RightAnswer=B
|WBRKeyword=Beta cells, Insulin, Diabetes, Histology,
|Approved=Yes
}}