The key difference between Alpha and Beta cells is that the Alpha cells (or A cells) produce and secrete glucagon hormone whereas the Beta cells (or B cells) produce and secrete insulin hormone.
The pancreas is one of the major organs located in the abdomen of our body. Pancreas fulfils two major functions namely endocrine (regulation of blood sugar) and exocrine (digestion of foods) functions. Exocrine pancreas secretes essential enzymes such as pepsin, trypsin, chymotrypsin, amylase, lipase, etc. that aid in the digestion of foods we consume. The endocrine pancreas has cells that produce and secrete hormones such as glucagon, insulin, somatostatin, etc. These cells exist as small cell clusters called islets. There are roughly one million islets in human pancreas. Pancreas islets have three types of cells that produce different endocrine products. They are alpha cells (A cells), beta cells (B cells) and delta cells (D cells).
CONTENTS
1. Overview and Key Difference
2. What are Alpha Cells
3. What are Beta Cells
4. Similarities Between Alpha and Beta Cells
5. Side by Side Comparison – Alpha vs Beta Cells in Tabular Form
6. Summary
What are Alpha Cells?
Pancreas islets house three types of cells, and among them, alpha cells or A cells are one type. Out of the total cells in the islets, alpha cells account for 33 – 46 %. Alpha cells synthesize and secrete glucagon hormone.
Figure 01: Alpha Cells
Glucagon is a peptide hormone that is responsible for increasing the blood glucose level. Glucagons bind with receptors in the liver cells or kidney cells. The bonding of glucagons with receptors activates the enzyme called glycogen phosphorylase. Glycogen phosphorylase catalyzes the hydrolysis of glycogen into glucose. This conversion increases the blood glucose level.
What are Beta Cells?
Beta cells are the second type of cells in the islets of the pancreas. They are the most abundant cell type and they account for 65 – 80% of the total cells. These cells occupy the central area of the islets and alpha and delta cells surround them. Beta cells synthesize and secrete insulin hormone. Insulin hormone is responsible for reducing the blood glucose level.
Furthermore, beta cells secrete another two hormones namely C-peptide and Amylin. Amylin’s slow down the rate of glucose entering into the bloodstream while C – peptides help to prevent neuropathy and other vascular deterioration related symptoms of diabetes mellitus.
What are the Similarities Between Alpha and Beta Cells?
- Alpha and Beta cells are two types of cells located in the pancreas.
- They reside in the pancreas islets.
- Both produce and secrete hormones.
What is the Difference Between Alpha and Beta Cells?
Alpha and beta cells are two endocrine pancreas cell types. They secrete hormones glucagon and insulin respectively. This is the key difference between Alpha and Beta cells. Furthermore, Beta cells are the most abundant cells in islets. They occupy more than 70% of the total cells. Alpha cells account for about 20 %.
Summary – Alpha vs Beta Cells
Out of the three major cell types present in islets of the pancreas, alpha and beta cells are two types. Alpha cells synthesize and secrete the hormone called glucagon while beta cells produce and release insulin hormone. Beta cells are the most abundant cell type in the islets, and they locate in the central area of the islets surrounding by the alpha and delta cells. This is the difference between alpha and beta cells.
Reference:
1.“Beta Cell.” Wikipedia, Wikimedia Foundation, 30 July 2018. Available here
2.“Functional Anatomy of the Endocrine Pancreas.” The Parietal Cell: Mechanism of Acid Secretion. Available here
Image Courtesy:
1.”Langerhanssche Insel”By User:Polarlys – Own work, (CC BY 2.5) via Commons Wikimedia