Participation Of Enhanced Intestinal Permeability And Reduced Intestinal Butyrate Availability In The Vascular Remodeling Of Hypertensive Rats Resistance Arteries

Participation Of Enhanced Intestinal Permeability And Reduced Intestinal Butyrate Availability In The Vascular Remodeling Of Hypertensive Rats Resistance Arteries

• Autor
• Patrizia Dardi
• Co-autores
• Gisele Kruger Couto , Rosangela Aparecida dos Santos Eichler , Marco Aurélio Ramirez Vinolo , Niels Olsen Saraiva Câmara , Luciana Venturini Rossoni
• Resumo

• Introduction: gut commensal bacteria produce short-chain fatty acids (SCFAs), molecules that contribute to a balanced intestinal environment and preservation of intestinal permeability (IP). In spontaneously hypertensive rats (SHR), gut bacteria show changes in its composition/function, a phenomenon termed dysbiosis and associated with reduced SCFA production/increased IP. These changes are related to impaired arterial vascular function, but no associations were described with vascular remodeling in resistance arteries.Aim: Correlate structural and mechanical remodeling of mesenteric resistance arteries (MRAs) with intestinal changes in hypertension. Methods: Systolic blood pressure (SBP) of male 6 months old SHR and Wistar rats were measured by tail-cuff method. Animals were anesthetized and killed, and serum, fecal samples and MRAs were collected. Arteries were mounted in a pressure myograph, submitted to a pressure response-curve (3 - 140mmHg) in Ca2+-free solution. Internal diameter (Di) was measured and cross sectional area (CSA), wall/lumen ratio (W/L) and distensibility were evaluated. Serum zonulin (IP biomarker) were quantified by ELISA and fecal SCFAs (acetate, propionate and butyrate) by chromatography. Analysis: Student’s t test or ANOVA (p<0,05 *vs. Wistar) and Pearson correlation coefficient (r). Ethical approval n. 1946260318. Results: SHR had higher SBP (Wistar: n=13, 122±1.7 vs. SHR: n=8, 180±2.5 mmHg*), increased zonulin (Wistar: 116±5.1 vs. SHR: 154±2.9 ng/mL*) and reduced fecal butyrate (Wistar: 40±2.9 vs. SHR: 27±2.4 ?mol/g*). Di were reduced in SHR MRAs with elevated W/L ratio (Di, 40mmHg - Wistar: 285±7.1 vs. SHR: 226±9.4 ?m*; W/L - Wistar: 0.155 vs. SHR: 0.262±0.01*), preserved CSA and reduced distensibility (40mmHg - Wistar: 1.28±0.03 vs. SHR: 0.99±0.04 %mmHg-1*). Zonulin showed positive correlation with SBP and MRA W/L ratio, and negative correlation with vascular distensibility; while butyrate showed the opposite correlations with these variables. Conclusion: Intestinal changes associated with dysbiosis are related to structural and mechanical remodeling in MRAs, contributing to maintenance of hypertension in SHR.
   

   

• Palavras-chave
• Hypertension, SCFAs, Vascular Remodeling
• Modalidade
• Pôster
• Área Temática
• Inflamação e doenças vasculares