Octreotide and its effects on portal circulation

Microarray analysis demonstrates up-regulation of the endothelin-1 gene with compensatory down-regulation of the ETA receptor gene in human portal vein

High blood pressure in the portal vein, portal hypertension (PH), is the final common pathway in liver cirrhosis regardless of aetiology. Complications from PH are the major cause of morbidity and mortality in these patients. Current drug therapy to reduce portal pressure is mainly limited to β-adrenergic receptor blockade but approximately 40% of patients do not respond. Our aim was to use microarray to measure the expression of ∼20,800 genes in portal vein from patients with PH undergoing transplantation for liver cirrhosis (PH, n=12) versus healthy vessels (control, n=9) to identify potential drug targets to improve therapy. Expression of 9,964 genes above background was detected in portal vein samples. Comparing PH veins versus control (adjusted P-value < 0.05, fold change > 1.5) identified 548 up-regulated genes and 1,996 down-regulated genes. The 2,544 differentially expressed genes were subjected to pathway analysis. We identified 49 significantly enriched pathways. The endothelin pathway was ranked the tenth most significant, the only vasoconstrictive pathway to be identified. ET-1 gene (EDN1) was significantly up-regulated, consistent with elevated levels of ET-1 peptide previously measured in PH and cirrhosis. ETA receptor gene (EDNRA) was significantly down-regulated, consistent with an adaptive response to increased peptide levels in the portal vein but there was no change in the ETB gene (EDNRB). The results provide further support for evaluating the efficacy of ETA receptor antagonists as a potential therapy in addition to β-blockers in patients with PH and cirrhosis.

[Pulmonary Complications in Patients with Liver Cirrhosis]

Portal hypertension is a clinical syndrome defined by an increased portal venous pressure. The most frequent cause of portal hypertension is liver cirrhosis, and many of the complications of cirrhosis, such as ascites and gastroesophageal variceal bleeding, are related to portal hypertension. Portal hypertension is a pathological condition caused by the accumulation of blood flow in the portal system. This blood flow retention reduces the effective circulation volume. To compensate for these changes, neurotransmitter hormone changes and metabolic abnormalities occur, which cause complications in organs other than the liver. A hepatic hydrothorax is fluid accumulation in the pleural space resulting from increased portal pressure. Hepatopulmonary syndrome and portopulmonary hypertension are the pulmonary complications in cirrhosis by deforming the vascular structure. Symptoms, such as dyspnea and hypoxia, affect the survival and the quality of life of patients. These lung complications are usually underestimated in the management of cirrhosis. This review briefly introduces the type of lung complications of cirrhosis.

Necrotising enterocolitis in newborns receiving diazoxide

BACKGROUND

Frequent and severe gastrointestinal disturbances have been reported with the use of diazoxide in adults and older children. However, no studies have investigated the incidence of necrotising enterocolitis (NEC) in diazoxide-exposed newborns.

OBJECTIVE

To evaluate a possible association between diazoxide treatment for neonatal hypoglycaemia and the occurrence of NEC.

DESIGN

Multicentre retrospective cohort study.

SETTING

Three tertiary neonatal intensive care units in Toronto, Canada.

PATIENTS

All patients treated with diazoxide for persistent hypoglycaemia between July 2012 and June 2017 were included. Overall incidence of NEC during those years on the participating units was obtained for comparison from the Canadian Neonatal Network database.

MAIN OUTCOME

Incidence of NEC after diazoxide exposure.

RESULTS

Fifty-five neonates were exposed to diazoxide during the study period. Eighteen patients (33%) showed signs of feeding intolerance, and 7 developed NEC (13%). A diagnosis of NEC was more prevalent in the diazoxide-exposed, as compared with non-exposed infants of similar gestational age (OR 5.07, 95% CI 2.27 to 11.27; p<0.001), and greatest among infants born at 33-36 weeks' gestation (OR 13.76, 95% CI 3.77 to 50.23; p<0.001). All but one of the neonates diagnosed with NEC developed the disease within 7 days from initiation of diazoxide treatment.

CONCLUSION

The present data suggest a possible association between diazoxide exposure and the development of NEC in neonates. Further evaluation of the diazoxide-associated risk of NEC in neonates treated for persistent hypoglycaemia is warranted.

Effects of a Long-Acting Formulation of Octreotide on Patients with Portal Hypertension

Objective

This study aimed to determine whether the treatment of a long-acting formulation of octreotide (OCT-LAR) exerted a similar effect on improving the prognosis of patients with portal hypertension compared with placement of transjugular intrahepatic portosystemic shunts (TIPSs).

Methods

A total of 24 patients with portal hypertension who underwent TIPS placement or OCT-LAR treatment from January 2010 to January 2015 were reviewed. Hemodynamic studies, biological values, live functions, and treatment complications before and during the treatment were evaluated.

Results

Baseline clinical characteristics were similar between two groups. Hepatic venous pressure gradient (HVPG) was improved in OCT-LAR groups (15.9 ± 2.4 to 12.8 ± 1.6 mmHg). Both groups showed a slight decrease in endothelin-1 (ET-1) and urotensin II and a slight increase in oxide metabolite (NOx) concentrations with no significant difference. Aspartate aminotransferase and alanine aminotransferase increased one week after TIPS placement when they improved in the OCT-LAR treatment group. The complications of OCT-LAR treatment were minor and transient. However, one patient who received TIPS placement presented procedure-related complications and required rehospitalization, and 2 patients had developed hepatic encephalopathy during the follow-up period.

Conclusion

Prolonged administration of OCT-LAR exerted a virtually similar effect on improving hemodynamic parameters and liver function in patients with portal hypertension compared with placement of TIPS, with no apparent serious adverse effects.

Octreotide bolus injection and azygos blood flow in patients with cirrhosis: is the effect really predictable?

BACKGROUND

Octreotide (OCT) improves the management of variceal bleeding, but the pattern of administration is not clearly defined. Available data show a transient decrease in portal pressure and azygos blood flow (AzBF) after OCT bolus injection with desensitization at readministration.

AIM

To explore the sustained hemodynamic effects of OCT and changes associated with readministration at 60 minutes on AzBF in patients with portal hypertension.

PATIENTS AND METHODS

AzBF was measured invasively (thermodilution technique) in 12 patients at baseline and at 10 minutes intervals after OCT 50-μg IV bolus for a total of 60 minutes. Readministration of OCT was followed by AzBF measurement for another 15 minutes. Patients [age 51.4 y (30 to 69)] had cirrhosis (alcoholic in 9 patients; Pugh's score 8.8±0.3), portal hypertension (HVPG 19±1 mm Hg), and elevated AzBF (658±138 mL/min).

RESULTS

The bolus of OCT was followed at 10 minutes by a 34% decline in AzBF as compared with baseline value. This AzBF reduction was sustained over the 60-minute study period (-36%±1.4%) with the values that remained decreased as compared with baseline (P<0.01). Mean arterial pressure remained stable. At 60 minutes, the repeat OCT bolus induced a further significant (P<0.01) decline in AzBF, although the response was blunted (-18%±1.2%).

CONCLUSION

The AzBF showed a sustained decrease of value after a bolus injection of 50-μg OCT. A further hemodynamic response is detectable at OCT readministration after 60 minutes. The pattern of hemodynamic response to OCT may not be uniform among cirrhotics.

The effect of 1 month of therapy with midodrine, octreotide-LAR and albumin in refractory ascites: a pilot study

BACKGROUND

The pathogenesis of refractory ascites (RA) is linked to splanchnic vasodilation. We hypothesized that a combination of midodrine, octreotide long-acting release (LAR) and albumin would result in increased natriuresis, better control of ascites and an improvement in renal function in patients with RA+/-Type 2 hepatorenal syndrome.

METHODS

A prospective pilot study in patients with RA as defined by the International Ascites Club. Consecutive patients received an intramuscular injection of octreotide-LAR, 50 g of albumin three times per week and midodrine titrated to increase the systolic blood pressure for 1 month.

RESULTS

Ten patients with RA were enrolled and eight with complete data to 1 month post-treatment were included in the analysis. There was no change in renal function but there was a trend towards a reduction in the volume of ascites removed by paracentesis (P=0.08) and a significant reduction in the plasma renin (P=0.01) and aldosterone concentrations (P=0.01). Interestingly, there was a transient worsening in the model for end-stage liver disease (MELD) score (P=0.01). The deterioration in MELD was completely reversible after discontinuation of therapy.

CONCLUSIONS

To our knowledge, this is the first study of prolonged midodrine, octreotide and albumin therapy in RA. We observed a significant reduction in the plasma renin and aldosterone concentrations and a trend towards a reduction in the volume of ascites removed by paracentesis without an effect on renal function. The beneficial effects are at the expense of a reversible deterioration in the MELD score. Large controlled trials are needed before this therapy can be routinely recommended.

Somatostatin suppresses endothelin-1-induced rat hepatic stellate cell contraction via somatostatin receptor subtype 1

BACKGROUND & AIMS

Hepatic stellate cells (HSCs) are considered therapeutic targets to decrease portal hypertension. To elucidate some of the hemodynamic effects of somatostatin (SST) on portal pressure, the presence and function of SST receptors (SSTRs) on HSCs were investigated.

METHODS

SSTR messenger RNA expression, and SSTR presence was investigated using reverse-transcription polymerase chain reaction, real-time quantitative polymerase chain reaction, Western blotting, and immunohistochemistry. The function of SSTRs was studied by examining the effects of SST and specific SSTR agonists on endothelin-1(ET-1)-induced HSC contraction.

RESULTS

Specific amplicons for SSTR subtypes 1, 2, and 3 were demonstrated in rat liver and in activated HSCs. The presence of SSTR subtypes 1, 2, and 3 was confirmed by Western blotting. With immunohistochemistry, a strong staining of HSCs was obtained for SSTR subtypes 1, 2, and 3 in CCl4-treated rats, but not in normal rat liver. Incubation of HSCs on collagen gels with buffer, 10(-8) mol/L SST, and 2 x 10(-8) mol/L ET-1 resulted in collagen surface area decreases of 5.5% +/- 3.3%, 6.8% +/- 4.4%, and 49.8% +/- 8.3%, respectively. Relative contraction of gels preincubated with 10(-8) mol/L SST followed by 2 x 10(-8) mol/L ET-1 or vice versa as compared with maximal contraction (100%) with 2 x 10(-8) mol/L ET-1 were 72.6% +/- 17.9% and 76.2% +/- 12.6%, respectively (P < 0.05). SSTR agonist 1, but not SSTR agonist 2 or 3, was able to counteract the contractile effect of ET-1. CONCLUSIONA: Activated rat HSCs bear SSTR subtypes 1, 2, and 3. SST causes significant partial inhibition of ET-1-induced contraction of activated HSCs, mainly by stimulation of SSTR subtype 1.