Effects of Salmon Calcitonin on the Concentrations of Monoamines in Periaqueductal Gray in Formalin Test

Abstract

Background:

The receptors of salmon calcitonin, located on certain areas of the brain such as the periaqueductal gray matter, are responsible for pain modulation.

Aims:

The effects of intracerebroventricular injection of salmon calcitonin on the behavioral response to pain and on the levels of monoamines in the periaqueductal gray were explored using a biphasic animal model of pain.

Study Design:

Animal experiment.

Methods:

A total of 45 male rats were divided into four groups (n=6). Salmon calcitonin was injected into the lateral ventricle of the brain (1.5 nmol, with a volume of 5 μL). After 20 min, 2.5% formalin was subcutaneously injected into the right leg claw, and pain behavior was recorded on a numerical basis. At the time of the formalin test, the periaqueductal gray area was microdialized. High-performance liquid chromatography method was used to gauge the levels of monoamines and their metabolites.

Results:

Intracerebroventricular injections of salmon calcitonin resulted in pain reduction in the formalin test (p<0.05). The dialysate concentrations of serotonin, dopamine, norepinephrine, 5-hydroxyindoleacetic acid, 3,4-dihydroxyphenylacetic, and 4-hydroxy-3-methoxyphenylglycol increased in the periaqueductal gray area in different phases of the formalin pain test (p<0.05).

Conclusion:

Salmon calcitonin reduced pain by increasing the concentrations of monoamines and the metabolites derived from them in the periaqueductal gray area.

• Authors: Kaveh Rahimi, Javad Sajedianfard, Ali Akbar Owji
• Journal: Balkan medical journal (Balkan Med J) Vol. 36 Issue 5 Pg. 263-269 (08 22 2019) ISSN: 2146-3131 [Electronic] Turkey
• PMID: 31218879 (Publication Type: Journal Article)

Chemical References

• Biogenic Monoamines
• Calcitonin

Topics

• Analysis of Variance
• Animals
• Biogenic Monoamines (analysis, physiology)
• Calcitonin (administration & dosage, pharmacology)
• Pain Measurement (methods)
• Periaqueductal Gray (chemistry, pathology)
• Rats
• Rats, Sprague-Dawley (metabolism, physiology)
• Salmon (blood, physiology)