Influence of Hypoxia and Hyperoxia on the Cardiovascular and Lethal Effects of Ethanol

et al. 2019

Preprint

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 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 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, 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.

Section: Discussioncontrasting

confidence: 74%

Section: Study Protocolmentioning

confidence: 99%

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

et al. 2019

Preprint

“…Even continuous exposure to hypoxia in conscious animals may decrease both heart rate and systolic blood pressure [58]. However, in our study, the reduced mBP by hypoxic gas was much pronounced as compared with our previous study and some other works in male rats [38,43]. Sex differences in blood pressure response to hypoxia may explain partly this different response [45].…”

Section: Discussioncontrasting

confidence: 73%

“…Animals were anesthetized by intraperitoneal injection of 60 mg/kg sodium thiopental [38,42]. It is important to emphasize that barbiturates have protective effects on the cardiovascular system, and has been preferred compared to other anesthetics like ketamine during hemodynamic measurements [43,44]. One point five ml of tail blood sample was taken in micro tubes containing ethylenediaminetetraacetic acid (Sigma) and centrifuged at 1200 rpm for 3 min.…”

Section: Study Protocolmentioning

confidence: 99%

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

et al. 2020

BMC Cardiovasc Disord

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.

“…Animals were anesthetized by intraperitoneal injection of 60 mg/kg sodium thiopental [35,39]. It is important to emphasize that barbiturates have protective effects on the cardiovascular system, and has been preferred compared to other anesthetics like ketamine during hemodynamic measurements [40,41]. 1.5 ml of tail blood sample was taken in micro tubes containing ethylenediaminetetraacetic acid (Sigma) and centrifuged at 1200 rpm for 3 minutes.…”

Section: Study Protocolmentioning

confidence: 99%

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

et al. 2019

Preprint

Background : Liver disorders may lead to a wide spectrum of pulmonary complications from hepatopulmonary syndrome to portopulmonary hypertension. In this study, we aimed to investigate the effect of severity of liver dysfunctions on blood-borne variables, and pulmonary hemodynamic during repeated ventilation of animals with hypoxic and hyperoxic gases. Methods: Female Sprague Dawley rats were divided into four groups of Sham, common bile duct ligation (CBDL), portal vein ligation (PPVL), and combination of them (CBDL+ PPVL). Twenty-eight days later, right ventricular systolic pressure (RVSP) and systemic blood pressure were recorded in anesthetized animals. Besides, we assessed blood parameters in parallel with liver histology. Results: Data of liver histology and enzymes indicated a larger liver damage in the CBDL+PPVL group as compared with the other groups. Moreover, low platelet level was only observed in the CBDL+PPVL group. Besides, the enhancement of serum estradiol in the CBDL+PPVL group was less pronounced than that in the CBDL group. The baseline RVSP in the CBDL groups were significantly higher than those in the Sham and PPVL groups, and in the CBDL+PPVL group was higher than the ones in the other groups. Hypoxic pulmonary vasoconstriction (HPV) were eliminated in both CBDL groups, whereas, it was recovered in the PPVL group. Conclusion: In this study, we presented, for the first time, ligations of both CBDL and PPVL as a possible animal model for POPH. High RVSP in this model may be linked to ROS production, serum estradiol level, low platelet level or a combination of them.