Impact of liver damage on blood-borne variables and pulmonary hemodynamic responses to hypoxia and hyperoxia in anesthetized rats

Abstract

Background: Liver disorders may be associated with normal pulmonary hemodynamic, hepatopulmonary syndrome (HPS), or portopulmonary hypertension (POPH). In this study, we aimed to investigate the effect of the severity of liver dysfunctions on blood-borne variables, and pulmonary hemodynamic during repeated ventilation with hyperoxic and hypoxic gases. Methods: Female Sprague Dawley rats were assigned into four groups of Sham (n = 7), portal vein ligation (PPVL, n = 7), common bile duct ligation (CBDL, n = 7), and combination of them (CBDL+ PPVL, n = 7). Twenty-eight days later, right ventricular systolic pressure (RVSP) and systemic blood pressure were recorded in anesthetized animals subjected to repeated maneuvers of hyperoxia (O 2 50%) and hypoxia (O 2 10%). Besides, we assessed blood parameters and liver histology. Results: Liver histology score, liver enzymes, WBC and plasma malondialdehyde in the CBDL+PPVL group were higher than those in the CBDL group. Also, the plasma platelet level in the CBDL+PPVL group was lower than those in the other groups. On the other hand, the serum estradiol in the CBDL group was higher than that in the CBDL+PPVL group. All the above parameters in the PPVL group were similar to those in the Sham group. During ventilation with hyperoxia gas, RVSP in the CBDL+PPVL group was higher than the ones in the other groups, and in the CBDL group, it was more than those in the PPVL and Sham groups. Hypoxic pulmonary vasoconstriction (HPV) was not detected in both CBDL+PPVL and CBDL groups, whereas, it retained in the PPVL group. Conclusion: Severe liver damage increases RVSP in the CBDL+PPVL group linked to the high level of ROS, low levels of serum estradiol and platelets or a combination of them. Furthermore, the high RVSP at the noted group could present a reliable animal model for POPH in female rats.

Características clínicas y complicaciones de la cirrosis hepática en una población de altura (Huancayo, 3250 m s. n. m.)

“…Los pacientes cirróticos presentan hipoxia crónica en los sinusoides hepáticos (18) , lo que induce a mayor producción de factor inducido por la hipoxia 1 (HIF-1, de sus siglas en inglés) y óxido nítrico, lo que conduce a una mayor vasodilatación de la arteria hepática. Esta elevación del HIF-1 es un componente normal de la adaptación a la altura (7) y se asocia a mayor eritropoyesis, hipertensión pulmonar e hipertensión en el ventrículo derecho, este último componente se incrementa en paralelo a la severidad del daño hepático (19) . Estos datos nos indican que el paciente cirrótico en la altura tendría mayores niveles de HIF-1, óxido nítrico y presión ventricular derecha, pero queda por definir las consecuencias de estos cambios fisiopatológicos.…”

Roles of alpha-7 nicotinic acetylcholine receptors and spleen in the lung injury induced by a repeated saline lavage in rat

“…Briefly, 100 μl of plasma, supernatant samples, or standard solutions (1, 1,3,3-tetraethoxy propane, Merck, Germany) was mixed with 400 μl of combinations of 0.25 N, HCl (Sigma, Germany), 20% trichloroacetic acid (Sigma, Germany) and 0.8% tribarbituric acid (Sigma, Germany), incubated at 90 °C for 60 min, cold in ice, and centrifuged at 4000 rpm for 10 min. Then, 200 μl of prepared solutions was added to each well, and the absorbance of the well-plate was read at 532 nm using a microplate reader (Biotek, USA) [ 35 ].…”

Effects of pioglitazone on electrocardiogram parameters and heart rate variability in isoproterenol- induced cardiac ischemia in rat

“…We measured MDA in plasma using a TBARS assay as previously described [42]. Brie y, 100 µl of plasma, supernatant samples, or standard solutions (1, 1,3,3-tetraethoxy propane, Merck, Germany) were mixed with 400 µl of 0.25 N, HCl (Sigma, Germany), 20% tricholoro acetic acid (Sigma, Germany) and 0.8% tribarbituric acid (Sigma, Germany) incubated at 90°C for 60 minutes, cold in ice, and centrifuged at 4000 rpm for 10 minutes.…”