1. BY NKEM UMEOKOLI MSc Neuropharmacology University of East London
GALANIN
BY NKEM UMEOKOLI
MSc Neuropharmacology
University of East London

2. Galanin is a 29 amino acid neuro-peptide isolated from porcine intestine.
It shows many interesting physiological and behavioural actions which may be relevant to some disease states and clinical therapeutics.

3. Named from the first and last amino acids in its porcine sequence - Glycine and Alanine.
The first 15 amino acids in its peptide sequence is conserved in a variety of species including Humans, rats, pigs, cows, dogs, chickens and alligators.

4. NMR analysis of Rat galanin indicates a secondary structure of two alpha-helices interrupted by a bend in the proline-13 amino acid residue.

5. Galanin is widely distributed in both the central and the peripheral nervous systems.
In the CNS: hypothalamus/hippocampus, brain stem, spinal cord.
In the peripheral organs: pancreas, adrenal gland, gastrointestinal tract, genital tract, urinary bladder

6. Galanin binds to and acts on G-protein coupled receptors.
Only one galanin receptor subtype has been cloned so far - GalR1.
Pharmacological evidence suggests more than one receptor subtype exists.

7. Purified galanin receptors from rat and human brain show a single polypeptide of 54-60 kDa.

8. The 1st antagonist for the galanin receptor has been synthesised called M15 or Galantide.
Binding of the antagonist to the galanin receptor is nM concentration.

9. Physiological functions of Galanin
In Alzheimer’s disease
galanin is elevated
galanin inhibits acetylcholine release
Galanin receptor antagonists may enhance cholinergic transmission.

10. Galanin stimulates
food consumption
release of luteinising hormone
prolactin release
growth hormone

11. Galanin serves an antinociceptive function in the spinal cord.
Galanin agonists may be clinically useful in potentiating the analgesic actions of morphine.

12. Galanin inhibits insulin release, therefore causes hyperglycemia.
Galanin may be involved in some forms of human obesity.

13. In conclusion
Galanin is a 29 amino acid neuro-peptide has inhibitory actions
Exerts biological effects in mammals such as feeding, insulin release and growth hormone release.
Is involved in the pathogenesis of Alzheimer’s disease and in antinociception.