11 research outputs found
Analytical Validation of a Flow Cytometric Protocol for Circulating Platelet Microparticle Quantification in Dogs
Serotonin concentrations in platelets, plasma, mitral valve leaflet, and left ventricular myocardial tissue in dogs with myxomatous mitral valve disease
HYPOTHESIS/OBJECTIVES: Altered serotonin (5âhydroxytryptamine, 5HT) signaling is postulated in development and progression of canine myxomatous mitral valve disease (MMVD). Little is known regarding platelet, plasma, valvular, or myocardial 5HT concentration ([5HT]) in affected dogs. We quantified [5HT] in plateletârich plasma (PRP), plateletâpoor plasma (PPP), mitral valve leaflets (MV), and left ventricular myocardium (LV). ANIMALS: Fortyâfive dogs comprised 4 plasma groups of Cavalier King Charles Spaniels (CKCS) or nonâCKCS, either healthy (CON) or MMVD affected: CKCS CON (n = 12); nonâCKCS CON (n = 8); CKCS MMVD (n = 14); nonâCKCS MMVD (n = 11). Twentyâfour dogs comprised 3 tissue groups: MMVD (n = 8); otherâHD (heart disease) (n = 7); nonâHD, extracardiac disease (n = 9). METHODS: Highâperformance liquid chromatography measured PRP, PPP, MV, and LV [5HT]. RESULTS: Plateletârich plasma platelet [5HT] was greater in CKCS CON (1.83 femtograms/platelet [fg/plt]; range, 0.20â4.76; P = .002), CKCS MMVD (1.58 fg/plt; range, 0.70â4.03; P = .005), and nonâCKCS MMVD (1.72 fg/plt; range, 0.85â4.44; P = .003) versus nonâCKCS CON (0.92 fg/plt; range, 0.63â1.30). There was no group difference in PPP [5HT]. MV [5HT] was significantly higher in MMVD (32.4 ng/mg; range, 8.4â106.7) versus nonâHD (3.6 ng/mg; range, 0â28.3; P = .01) and LV [5HT] was significantly higher in MMVD (11.9 ng/mg; range, 4.0â104.8) versus otherâHD (0.9 ng/mg; range, 0â10.1; P = .011) and nonâHD (2.5 ng/mg; range, 0â6.9; P = .001). CONCLUSIONS AND CLINICAL IMPORTANCE: Platelet [5HT] was highest in healthy CKCS and both MMVD groups, but plasma [5HT] showed no group differences. Tissue [5HT] was highest in MV and LV of MMVDâaffected dogs, suggesting altered 5HT signaling as a potential feature of MMVD. Interactions of platelet, valvular, and myocardial 5HT signaling warrant further investigation