In vivo and ex vivo effects of propofol on myocardial performance in rats with obstructive jaundice

Altered Expression of Differential Genes in Thoracic Spinal Cord Involved in Experimental Cholestatic Itch Mouse Model

The spinal origin of cholestatic itch in experimental obstructive jaundice mouse model remains poorly understood. In this study, the jaundice model was established by bile duct ligation (BDL) in mice, and differential gene expression patterns were analyzed in the lower thoracic spinal cord involved in cholestatic pruritus after BDL operation using high-throughput RNA sequencing. At 21st day after BDL, the expression levels of ENSRNOG00000060523, ENSRNOG00000058405 and ENSRNOG00000055193 mRNA were significantly up-regulated, and those of ENSRNOG00000042197, ENSRNOG00000008478, ENSRNOGOOOOOO19607, ENSRNOG00000020647, ENSRNOG00000046289, Gemin8, Serpina3n and Trim63 mRNA were significantly down-regulated in BDL group. The RNAseq data of selected mRNAs were validated by RT-qPCR. The expression levels of ENSRNOG00000042197, ENSRNOG00000008478, ENSRNOGOOOOOO 19607, ENSRNOG00000020647, ENSRNOG00000046289 and Serpina3n mRNA were significantly down-regulated in BDL group. This study suggested that cholestatic pruritus in experimental obstructive jaundice mouse model is related with in the changes of gene expression profiles in spinal cord.

Altered expression of differential gene and lncRNA in the lower thoracic spinal cord on different time courses of experimental obstructive jaundice model accompanied with altered peripheral nociception in rats

The spinal origin of jaundice-induced altered peripheral nociceptive response poorly understood. In the current study, we aimed to first validate rats with bile duct ligation (BDL) as a jaundice model accompanied by altered peripheral nociceptive response, and then to analyze differential gene and lncRNA expression patterns in the lower thoracic spinal cord on different time courses after BDL operation by using high-throughput RNA sequencing. The differentially expressed genes (DEGs) identified using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis, followed by clustering analysis, Gene Ontology analysis and pathway analysis. As a result, a total of 2033 lncRNAs were differentially expressed 28d after BDL, in which 1545 probe sets were up-regulated and 488 probe sets were down-regulated, whereas a total of 2800 mRNAs were differentially expressed, in which 1548 probe sets were up-regulated and 1252 probe sets were down-regulated. The RNAseq data of select mRNAs and lncRNAs was validated by RT-qPCR. 28d after BDL, the expressions of lncRNA NONRATT002335 and NONRATT018085 were significantly up-regulated whereas the expression of lncRNA NONRATT025415, NONRATT025388 and NONRATT025409 was significantly down-regulated. 14d after BDL, the expressions of lncRNA NONRATT002335 and NONRATT018085 were significantly up-regulated; the expression of lncRNA NONRATT025415, NONRATT025388 and NONRATT025409 was significantly down-regulated. In conclusion, the present study showed that jaundice accompanied with decreased peripheral nociception involved in the changes of gene and lncRNA expression profiles in spinal cord. These findings extend current understanding of spinal mechanism for obstructive jaundice accompanied by decreased peripheral nociception.

Plasma BNP level combined with surgical Apgar score to predict operative major cardiac adverse events in malignant obstructive jaundice patients

Objective:

To investigate the predictive effect of major adverse cardiac events (MACE) in malignant obstructive jaundice (OJ) patients using plasma brain natriuretic peptide (BNP) level and surgical Apgar scoring (SAS) system.

Methods:

Forty one malignant OJ patients undergoing surgical treatments were studied at a single center. Pre-and postoperative plasma BNP level, total bilirubin (TBil) and data of cardiac function (HR, CVP, CI, LVEF%) were detected, the SAS was calculated during the surgery, the relationship of both plasma BNP level and SAS with MACE after surgery was analyzed.

Results:

Thirteen patients out of 41 (31.71%) experienced MACE without cardiac death. OJ patients had a higher plasma BNP level than baseline before operation (191.61±105.76 pg/ml VS 175 pg/ml, P<0.05), the cardiac function data was improved (CVP: t=4.761, p=0.000; CI: t=3.539, p=0.001; LVEF%: t=3.632, p=0.001) after the operation. Patients with lower SAS had increasing incidence of MACE after surgery.

Conclusion:

Malignant OJ patients with higher preoperative BNP level and lower surgical Apgar score were identified at high risk of MACE after surgery.

Propofol ameliorates hyperglycemia-induced cardiac hypertrophy and dysfunction via heme oxygenase-1/signal transducer and activator of transcription 3 signaling pathway in rats

OBJECTIVES

Heme oxygenase-1 is inducible in cardiomyocytes in response to stimuli such as oxidative stress and plays critical roles in combating cardiac hypertrophy and injury. Signal transducer and activator of transcription 3 plays a pivotal role in heme oxygenase-1-mediated protection against liver and lung injuries under oxidative stress. We hypothesized that propofol, an anesthetic with antioxidant capacity, may attenuate hyperglycemia-induced oxidative stress in cardiomyocytes via enhancing heme oxygenase-1 activation and ameliorate hyperglycemia-induced cardiac hypertrophy and apoptosis via heme oxygenase-1/signal transducer and activator of transcription 3 signaling and improve cardiac function in diabetes.

DESIGN

Treatment study.

SETTING

Research laboratory.

SUBJECTS

Sprague-Dawley rats.

INTERVENTIONS

In vivo and in vitro treatments.

MEASUREMENTS AND MAIN RESULTS

At 8 weeks of streptozotocin-induced type 1 diabetes in rats, myocardial 15-F2t-isoprostane was significantly increased, accompanied by cardiomyocyte hypertrophy and apoptosis and impaired left ventricular function that was coincident with reduced heme oxygenase-1 activity and signal transducer and activator of transcription 3 activation despite an increase in heme oxygenase-1 protein expression as compared to control. Propofol infusion (900 μg/kg/min) for 45 minutes significantly improved cardiac function with concomitantly enhanced heme oxygenase-1 activity and signal transducer and activator of transcription activation. Similar to the changes seen in diabetic rat hearts, high glucose (25 mmol/L) exposure for 48 hours led to cardiomyocyte hypertrophy and apoptosis, both in primary cultured neonatal rat cardiomyocytes and in H9c2 cells compared to normal glucose (5.5 mmol/L). Hypertrophy was accompanied by increased reactive oxygen species and malondialdehyde production and caspase-3 activity. Propofol, similar to the heme oxygenase-1 inducer cobalt protoporphyrin, significantly increased cardiomyocyte heme oxygenase-1 and p-signal transducer and activator of transcription protein expression and heme oxygenase-1 activity and attenuated high-glucose-mediated cardiomyocyte hypertrophy and apoptosis and reduced reactive oxygen species and malondialdehyde production (p < 0.05). These protective effects of propofol were abolished by heme oxygenase-1 inhibition with zinc protoporphyrin and by heme oxygenase-1 or signal transducer and activator of transcription 3 gene knockdown.

CONCLUSIONS

Heme oxygenase-1/signal transducer and activator of transcription 3 signaling plays a critical role in propofol-mediated amelioration of hyperglycemia-induced cardiomyocyte hypertrophy and apoptosis, whereby propofol improves cardiac function in diabetic rats.

Bilirubin modulates acetylcholine receptors in rat superior cervical ganglionic neurons in a bidirectional manner

Autonomic dysfunction as a partial contributing factor to cardiovascular instability in jaundiced patients is often associated with increased serum bilirubin levels. Whether increased serum bilirubin levels could directly inhibit sympathetic ganglion transmission by blocking neuronal nicotinic acetylcholine receptors (nAChRs) remains to be elucidated. Conventional patch-clamp recordings were used to study the effect of bilirubin on nAChRs currents from enzymatically dissociated rat superior cervical ganglia (SCG) neurons. The results showed that low concnetrations (0.5 and 2 μM) of bilirubin enhanced the peak ACh-evoked currents, while high concentrations (3 to 5.5 µM) of bilirubin suppressed the currents with an IC₅₀ of 4 ± 0.5 μM. In addition, bilirubin decreased the extent of desensitization of nAChRs in a concentration-dependent manner. This inhibitory effect of bilirubin on nAChRs channel currents was non-competitive and voltage independent. Bilirubin partly improved the inhibitory effect of forskolin on ACh-induced currents without affecting the action of H-89. These data suggest that the dual effects of enhancement and suppression of bilirubin on nAChR function may be ascribed to the action mechanism of positive allosteric modulation and direct blockade. Thus, suppression of sympathetic ganglionic transmission through postganglionic nAChRs inhibition may partially contribute to the adverse cardiovascular effects in jaundiced patients.

Proteinase-activated Receptor 1 Contributed to Up-regulation of Enkephalin in Keratinocytes of Patients with Obstructive Jaundice

Background:

Skin synthesis of endogenous opioids such as enkephalin is considered to be increased in cholestatic rodents, which may induce antinociception in cholestatic liver disease. No studies have reported yet the expression of skin enkephalin in patients with cholestasis.

Methods:

Electrical pain threshold, postoperative morphine consumption, and skin enkephalin expression were measured in patients with jaundice (n = 18) and control patients (n = 16). Male Sprague–Dawley rats (n = 52) and human keratinocyte cell line HaCaT were used in vivo and in vitro studies, respectively. Nociceptive thresholds and plasma and skin levels of methionine-enkephalin were compared in protease-activated receptors-1–antagonized and control bile duct–ligated rats. In in vitro study, the effect on thrombin-induced enkephalin expression was examined and the role of extracellular regulated protein kinases 1/2 and p38 was investigated.

Results:

The authors found that: (1) the electrical pain threshold (mean ± SD) was 1.1 ± 0.1 mA in control patients, whereas it was significantly increased in patients with jaundice (1.7 ± 0.3 mA); 48-h postoperative morphine consumption was approximately 50% higher in the control group than that in the group with jaundice; (2) Skin keratinocytes enkephalin expression was increased in the patients with jaundice; (3) Protease-activated receptors-1 antagonist 1 μg·kg−1·day−1 treatment to the bile duct–ligated rats significantly reduced plasma levels of methionine-enkephalin, nociceptive thresholds, and keratinocytes enkephalin expression; and (4) protease-activated receptors-1 activation induced enkephalin expression through phosphorylation of extracellular regulated protein kinases 1/2 and p38 in keratinocytes.

Conclusion:

Protease-activated receptors-1 activation in peripheral keratinocytes may play an important role in the local synthesis of enkephalin during cholestasis.

Obstructive jaundice and perioperative management

The causes of obstructive jaundice are varied, but it is most commonly due to choledocholithiasis; benign strictures of the biliary tract; pancreaticobiliary malignancies; and metastatic disease. Surgery in patients with obstructive jaundice is generally considered to be associated with a higher incidence of complications and mortality. Therefore, it poses a considerable challenge to the anesthesiologist, surgeons, and the intensive care team. However, appropriate preoperative evaluation and optimization can greatly contribute to a favorable outcome for perioperative jaundiced patients. This article outlines the association between obstructive jaundice and perioperative management, and reviews the clinical and experimental studies that have contributed to our knowledge of the underlying pathophysiologic mechanisms. Pathophysiology caused by obstructive jaundice involving coagulopathies, infection, renal dysfunction, and other adverse events should be fully assessed and reversed preoperatively. The depressed cardiovascular effects of obstructive jaundice are worth noticing because it has complicated mechanisms and needs to be further explored. Alterations of anesthesia-related drugs induced by obstructive jaundice are varied and clinicians should be aware of the possible need for a decrease in the anesthetic dose. Recommendations concerning the perioperative management of the patients with obstructive jaundice including preoperative biliary drainage, anti-infection, nutrition support, coagulation reversal, cardiovascular evaluation, perioperative fluid therapy, and hemodynamic optimization should be taken.