-tropin

-tropin

also -trophin
suff.
Hormone affecting the growth or function of a certain kind of cell, tissue, or organ: gonadotropin
[Variant -tropin : -trop(ic) + -in. Variant -trophin : -troph(ic) + -in (with subsequent mutual influence between the two suffixes, with the result that that modern scientific usage treats them as variants of a single suffix).]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.