Endocrine gland size is proportional to its target tissue size

• Published in: iScience Vol. 27; no. 9; p. 110625
• Main Authors: Raz, Moriya, Milo, Tomer, Glass, David S., Mayo, Avi, Alon, Uri
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 20-09-2024; Elsevier
• Subjects: Biological sciences; Endocrinology; Natural sciences; Physiology; Biological sciences; Physiology; Natural sciences; Endocrinology
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2024.110625

Endocrine glands secrete hormones into the circulation to target distant tissues and regulate their functions. The qualitative relationship between hormone-secreting organs and their target tissues is well established, but a quantitative approach is currently limited. Quantification is important, as it could allow us to study the endocrine system using engineering concepts of optimality and tradeoffs. In this study, we collected literature data on 24 human hormones secreted from dedicated endocrine cells. We find that the number of endocrine cells secreting a hormone is proportional to the number of its target cells. A single endocrine cell serves approximately 2,000 target cells, a relationship that spans 6 orders of magnitude of cell numbers. This suggests an economic principle of cells working near their maximal capacity, and glands that are no bigger than they need to be.
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•Hormone secreting and total target cell numbers are proportional•One endocrine cell serves about 2,000 target cells•This holds across a million-fold difference in gland sizes•This suggests that cells are near maximal capacity and glands are no bigger than needed
Biological sciences; Endocrinology; Natural sciences; Physiology