Modulation of peripheral markers of the serotoninergic system in healthy horses.
To evaluate the changes in plasma and platelet serotonin (5-HT) as markers of the serotoninergic system in equines, 5-HT content was measured by high performance liquid chromatography (HPLC) in deproteinized plasma obtained from peripheral blood samples of 12 clinically healthy horses, before and after feeding. 5-HT was measured in platelet rich plasma (PRP) and in platelet poor plasma (PPP). 5-HT in platelets (p5-HT) was obtained by subtracting free 5-HT in PPP (f5-HT) from 5-HT in PRP. After food ingestion, significant increases in p5-HT and f5-HT (p < 0.001), and no changes in the f5-HT/p5-HT ratio were recorded. Increase in the total circulating 5-HT might account both for initiating peristaltic activity and for increasing the f5-HT levels. Augmented 5-HT uptake by platelets could reflect the hypothetical increased activity of the serotoninergic neurons. Besides showing the feasibility to obtain f5-HT and p5-HT through HPLC determination of 5-HT in PRP and PPP equine plasma, these findings are consistent with the postulation that 5-HT is released from enterochromaffin cells following a mechanical and chemical stimulation.
Alberghina
D
D
Department of Experimental Sciences and Applied Biotechnology, Faculty of Veterinary Medicine, University of Messina, Viale Annunziata, 98100 Messina, Italy.
Amorini
A M
AM
Lazzarino
G
G
D000818:Animals; D015415:Biomarkers / Q000097:blood; D001792:Blood Platelets / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000662:veterinary; D005260:Female; D006736:Horses / Q000097:blood* / Q000502:physiology; D008297:Male; D012701:Serotonin / Q000031:analogs & derivatives / Q000097:blood* / Q000502:physiology
D015415:Biomarkers; C008494:N-methylserotonin; D012701:Serotonin