Intracrine refers to a hormone that acts inside a cell, regulating intracellular events. Steroid hormones act through intracellular (mostly nuclear) receptors and, thus, may be considered to be intracrines. In contrast, peptide or protein hormones, in general, act as endocrines, autocrines, or paracrines by binding to their receptors present on the cell surface. Several peptide/protein hormones or their isoforms also act inside the cell through different mechanisms. These peptide/protein hormones, which have intracellular functions, are also called intracrines. The term 'intracrine' is thought to have been coined to represent peptide/protein hormones that also have intracellular actions.
The biological effects produced by intracellular actions are referred as intracrine effects, whereas those produced by binding to cell surface receptors are called endocrine, autocrine, or paracrine effects, depending on the origin of the hormone. The intracrine effect of some of the peptide/protein hormones are similar to their endocrine, autocrine, or paracrine effects; however, these effects are different for some other hormones.
Examples of intracrine peptide hormones: There are several protein/peptide hormones that are also intracrines. Notable examples that have been described in the references include:
• Fibroblast Growth Factor -2
• Parathyroid Hormone Related Protein
- "intracrine - definition of intracrine in the Medical dictionary - by the Free Online Medical Dictionary, Thesaurus and Encyclopedia". Medical-dictionary.thefreedictionary.com. Retrieved 2011-11-08.
- Re, RN (Apr 2003). "The intracrine hypothesis and intracellular peptide hormone action". BioEssays. 25 (4): 401–9. doi:10.1002/bies.10248. PMID 12655647.
- Re, RN (Jan 2002). "The origins of intracrine hormone action". Am J Med Sci. 323 (1): 43–8. doi:10.1097/00000441-200201000-00008. PMID 11814142.
- Kumar R, Singh VP, Baker KM. "The intracellular renin-angiotensin system: a new paradigm. Trends Endocrinol Metab. 2007 May 15. doi:10.1016/j.tem.2007.05.001 PMID 17509892.
- Fiaschi-Taesch, NM; Stewart, AF (Feb 2003). "Minireview: parathyroid hormone-related protein as an intracrine factor--trafficking mechanisms and functional consequences". Endocrinology. 144 (2): 407–11. doi:10.1210/en.2002-220818. PMID 12538599.
- Sorensen, V; Nilsen, T; Wiedlocha, A (May 2006). "Functional diversity of FGF-2 isoforms by intracellular sorting". BioEssays. 28 (5): 504–14. doi:10.1002/bies.20405. PMID 16615083.
- Singh, VP; Baker, KM; Kumar, R (Apr 2008). "Activation of the intracellular renin-angiotensin system in cardiac fibroblasts by high glucose: role in extracellular matrix production". Am J Physiol Heart Circ Physiol. 294 (4): 1675–84. doi:10.1152/ajpheart.91493.2007. PMID 18296558.