Tissue hormones
| Biogenic amines |
|---|
 histamine |
 Serotonin |
Tissue hormones are created in specialized single cells that can be distributed over a tissue . In contrast, glandular hormones , known as classical hormones, are produced in glands. Tissue hormones of the paracrine type reach their successor organs by diffusion , while those of the endocrine type are transported via the bloodstream .
Examples
- Biogenic amines such as histamine and serotonin . These arise through decarboxylation from histidine or tryptophan . Both act via receptors either as tissue hormones or as neurotransmitters . The signal transduction can take place via G proteins (cAMP, PLC, 5HT-1,2 and 4) or via the opening of cation channels (5HT-3).
- Peptide hormones such as angiotensins .
- Kinine . Kininogens are higher molecular weight plasma proteins from which peptide mediators can be released by various locally activated proteases (e.g. kallikrein ). An important product is bradykinin, a nonapeptide , which has a vasodilating, hypotensive and contracting effect on the smooth muscles of the bronchi, intestines and uterus.
- Eicosanoids , C 20 fatty acid derivatives, which can be divided into three subgroups: prostaglandins (PG), leukotrienes and epoxides . It is hardly possible to show all effects, but it is true that PG and other eicosanoids are involved in almost all signaling pathways as locally effective second messengers .
- Gases with signaling function: NO (nitrogen oxide, nitrogen monoxide ) is produced from arginine by nitroxide synthase . The gas has the following effects: regulating vascular tone, stimulating heart contraction, sometimes toxic effects. It is a neurotransmitter and affects gene expression . It is partly responsible for these effects itself, partly it is its conversion products N 2 O 3 , ONOO - ( peroxynitrite ), NO - or NO 2 .
literature
- Jeremy M. Berg, John L. Tymoczko, Lubert Stryer : Biochemistry. 6 edition, Spektrum Akademischer Verlag, Heidelberg 2007. ISBN 978-3-8274-1800-5 .
- Donald Voet, Judith G. Voet: Biochemistry. 3rd edition, John Wiley & Sons, New York 2004. ISBN 0-471-19350-X .
- Bruce Alberts , Alexander Johnson, Peter Walter, Julian Lewis, Martin Raff, Keith Roberts: Molecular Biology of the Cell , 5th Edition, Taylor & Francis 2007, ISBN 978-0815341062 .