This study was to observe the effect and possible mechanism of somatostatin analogue octreotide (OCT) on cross excitation of adjacent segment of spinal nerve in rat. Cutaneous branches of T9-T13 spinal dorsal rami were chosen and dissected free for the following recording and stimulation. Only single unit fiber was used for recording, and the adjacent segment of nerve stem was used for antidromic electrical stimulation. To investigate the change of discharge rate and mechanical threshold, OCT and (or) somatostatin receptor antagonist cyclo-somatostatin (c-SOM) were applied to the receptive field following the antidromic electrical stimulation. The result showed that injection of OCT inhibited the increase of discharge rate and the decrease of mechanical threshold induced by the electrical stimulation (cross excitation); c-SOM reversed the effects of OCT. Application of c-SOM alone enhanced the cross excitation effects. The results suggest local application of somatostatin analogue OCT can inhibit the cross excitation between the two segments of spinal nerve by somatostatin receptor.
Animals ; Electric Stimulation ; Octreotide ; pharmacology ; Peptides, Cyclic ; pharmacology ; Rats ; Receptors, Somatostatin ; physiology ; Somatostatin ; analogs & derivatives ; Spinal Nerves ; drug effects

To determine whether exocrine pancreatic secretion is regulated by endogenous somatostatin, somatostatin deficiency was induced by cysteamine. Rats were subcutaneously administered a single dose of cysteamine (30 mg/100 g body weight) 12 hr before experiment. Anesthetized rats were prepared with cannulation into bile duct, pancreatic duct, duodenum, and jugular vein and pancreatic juice was collected. For in vitro study, isolated pancreata of rats, pretreated with cysteamine, were perfused with an intraarterial infusion of Krebs-Henseleit solution (37 degrees C) at 1.2 mL/min, and pancreatic juice was collected in 15-min samples. In vivo experiment of the rat, the mean basal pancreatic secretions, including volume, bicarbonate, and protein output were significantly increased from 18.4+/-0.5 microL/30 min, 0.58+/-0.05 microEq/30 min, and 214.0+/-26.1 microg/30 min to 51.6+/-3.7 microL/30 min, 1.52+/-0.11 microEq/30 min, and 569.8+/-128.9 microg/30 min, respectively (p<0.05). In the isolated perfused pancreas, cysteamine also resulted in a significant increase in basal pancreatic secretion (p<0.05). Simultaneous intraarterial infusion of octreotide (10 pmol/hr) to isolated pancreata partially reversed the effect of cysteamine on basal pancreatic secretion. These findings suggest that endogenous somatostatin play an important role on the regulation of basal pancreatic exocrine secretion.
Animal ; Cysteamine/pharmacology* ; Hormone Antagonists/pharmacology* ; Hormones, Synthetic/pharmacology ; In Vitro ; Male ; Octreotide/pharmacology ; Pancreas/secretion ; Pancreas/drug effects* ; Perfusion ; Rats ; Rats, Sprague-Dawley ; Somatostatin/antagonists & inhibitors*

BACKGROUNDThe contractility of hepatic stellate cells (HSCs) may play an important role in the pathogenesis of cirrhosis with portal hypertension. The aim of this study was to research the effects of octreotide, an analogue of somatostatin, on intracellular Ca2+ and on the expression of L-type voltage-operated calcium channels (L-VOCCs) in activated HSCs, and to try to survey the use of octreotide in treatment and prevention of cirrhosis with portal hypertension complications.

METHODSHSC-T6, an activated HSCs line, was plated on small glass coverslips in 35-mm culture dishes at a density of 1 x 10(5)/ml, and incubated in DMEM media for 24 hours. After the cells were loaded with Fluo-3/AM, intracellular Ca2+ was measured by Laser Scanning Confocal Microscopy (LSCM). The dynamic changes in activated HSCs of intracellular Ca2+, stimulated by octreotide, endothelin-1, and KCl, respectively, were also determined by LSCM. Each experiment was repeated six times. L-VOCC expression in HSCs was estimated by immunocytochemistry.

RESULTSAfter octreotide stimulation, a significant decrease in the intracellular Ca2+ of activated HSCs was observed. However, octreotide did not inhibit the increases in intracellular Ca2+ after stimulation by KCl and endothelin-1. Moreover, octreotide did not significantly affect L-VOCC expression. These results suggest that neither L-VOCC nor endothelin-1 receptors in activated HSCs are inhibited by octreotide.

CONCLUSIONSOctreotide may decrease portal hypertension and intrahepatic vascular tension by inhibiting activated HSCs contractility through decreases in intracellular Ca2+. The somatostatin receptors in activated HSCs may be inhibited by octreotide.

Calcium ; analysis ; Calcium Channels, L-Type ; analysis ; Cells, Cultured ; Hepatocytes ; chemistry ; cytology ; drug effects ; Microscopy, Confocal ; Octreotide ; pharmacology

To investigate the effects of sorafenib and octreotide combination treatment on cellular proliferation and explore the underlying molecular mechanisms by using an in vitro cell culture system with the human hepatoma cell line, HepG2. HepG2 cells were treated with different concentrations of sorafenib and octreotide alone or in combination. Untreated HepG2 cells were used as controls. Treatment-induced cytotoxicity was determined with the cell counting kit-8 by Sigma-Aldrich, and rate of apoptosis was detected by flow cytometry. Fluorescent microscopy was used to observe rates of cell growth under the various treatments. Treatment-induced changes in protein expressions were detected by enzyme-linked immunosorbent assay (for vascular endothelial growth factor (VEGF)) and Western blotting (for the Mcl-1 apoptosis mediator and the ERK1/2 and PERK1/2 kinases). Sorafenib and octreotide, used alone or in combination, inhibited proliferation and induced apoptosis in HepG2 cells. Combination treatment was more effective than either mono-treatment (F = 200.398, P less than 0.05). Fluorescent microscopy showed that combination treatment stimulated phosphatidylserine, the marker of early apoptosis, better than either mono-treatment. VEGF expression in cultures exposed to combination treatment was also significantly lower than in mono-treatment or untreated control cultures (F = 1019.725, P less than 0.05). Western blotting showed that octreotide mono-treatment had no effect on Mcl-1 expression (vs. control group; P more than 0.05) and that combination treatment significantly lowered Mcl-1 expression (vs. mono-treatment and control groups; P less than 0.05). None of the treatments affected ERK1/2 expression (all, P more than 0.05), while all treatments significantly lowered PERK1/2 expression (vs. control group; F = 2.401, P less than 0.05) and the combination treatment lowered PERK1/2 significantly more than either mono-treatment (P less than 0.05). Sorafenib and octreotide can inhibit proliferation and induce apoptosis in the human hepatoma cell line, HepG2. Combination treatment is significantly more efficacious (P less than 0.05) and produced synergistic effects. The mechanism underlying this phenomenon may depend on synergistic inhibition of VEGF, the anti-apoptotic protein Mcl-1, and the proliferation-inducing PERK1/2.
Apoptosis ; drug effects ; Benzenesulfonates ; pharmacology ; Cell Proliferation ; drug effects ; Hep G2 Cells ; drug effects ; Humans ; Niacinamide ; analogs & derivatives ; Octreotide ; pharmacology ; Phenylurea Compounds ; Pyridines ; pharmacology

OBJECTIVE: To explore the protective effect of octreotide on liver warm ischemia-reperfusion injury and its possible mechanism. METHODS: Pringle's maneuver liver ischemia-reperfusion models were established. Forty eight male Sprague Daweley rats were randomly divided into a sham operation group (S group, n=16), an ischemia-reperfusion group (I/R group, n=16) and an octreotide preconditioning group (OPC group, n=16). ALT and AST in the serum were measured at 30 min after the ischemia and 120 min after the reperfusion. The histomorphological changes and ultrastructure of hepatocellular were observed by optic and transmission electronic microscope. Hepatic adenine nucleotide levels and energy changes (EC) were determined by high performance liquid chromatography (HPLC). RESULTS: (1) At 30 min after the ischemia and 120 min after the reperfusion, the levels of ALT and AST in the serum of OPC group was lower than those in I/R group, whereas the levels of ATP and EC in the hepatic tissue were higher than those in the I/R group (P<0.01 or P<0.05). Compared with the I/R group, the injury of hepatocellular histomorphology and ultrastructure in the OPC group was abated. (2) At 30, 60, and 120 min after the reperfusion, the levels of ATP and EC in the OPC groups were higher than those in the I/R group. During the ischemia, the levels of ATP and EC in the OPC group dropped more slowly than those in the I/R group, but ATP and EC in the OPC groups rose more quickly than those in the I/R group during the reperfusion. CONCLUSION Octreotide precondition can improve the hepatocellular energy reserve, and protect the liver from warm ischemia-reperfusion injury. The protective of octreotide on warm ischemia-reperfusion injury may be related to its influence on endocrine secretion.
Animals ; Hot Temperature ; Liver ; blood supply ; Male ; Octreotide ; pharmacology ; therapeutic use ; Protective Agents ; pharmacology ; therapeutic use ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; prevention & control

Recent study has demonstrated that the long-acting somatostatin analogue administration effectively prevented initial renal growth in diabetic and uninephrectomized rats. In the present study we examined long-term effect of somatostatin analogue (Sandostatin) on renal enlargement in uninephrectomized-diabetic rat5. Animals were divided into 4 groups: (1) normal control rats (C) (n = 7), (2) uninephrectomized rats (NPX) (n = 7), (3) uninephrectomized-diabetic rats (NPX + DM) (n = 7) and (4) NPX + DM rats treated with Sandostatin (NPX + DM + Tx) (n = 9). All animals had free access to diet (50% protein) and water during the experimental period. To the NPX + DM + Tx rats, 2.5 micrograms of Sandostatin was given subcutaneously twice a day for 8 weeks. Periodic observations were done at 0, 4 and 8 weeks. After 8 weeks. NPX rats (0.540 +/- 0.017 (SEM)) had higher fractional kidney weights (FKW) (wet kidney wt/body wt) compared to C rats (0.410 +/- 0.014) (p < 0.0005), and both NPX + DM rats (0.983 +/- 0.098) and NPX + DM + Tx rats (1.091 +/- 0.042) had higher FKW compared to C rats (p < 0.0001) and NPX rats (p < 0.005), respectively. But no significant change of FKW was observed between NPX + DM rats and NPX + DM + Tx rats. Systolic blood pressure, BUN, serum creatinine, glomerular filtration rate and 24 hour urine protein excretion in NPX + DM rats were not different from those in NPX + DM + Tx rats.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals ; Blood Pressure/drug effects ; Diabetes Mellitus, Experimental/*pathology ; Kidney/*drug effects/pathology ; Male ; *Nephrectomy ; Octreotide/*pharmacology ; Organ Size/drug effects ; Proteinuria/etiology ; Rats ; Rats, Wistar

OBJECTIVETo study the effect of Modified Dachengqi Decoction (MDD) as whole course therapy on mediators of inflammation in severe acute pancreatitis (SAP) model rats, and to compare interventional advantages over intestinal mucosal barrier (IMB) of SAP rats between whole course therapy of MDD and early stage therapy of MDD.

METHODSTotally 190 SD rats were divided into five groups according to random digit table, i.e., the sham-operation group, the model group, the octreotide (OT) group, the early stage MDD treatment group, the whole course MDD treatment group, 38 in each group. SAP models were established with retrograde injection of 5% sodium taurocholate into the pancreaticobiliary duct. Three hours after modeling normal saline (NS) was administered to rats in the sham-operation group and the model group by gastrogavage, once per 12 h.1.35 µg/100 g OT was subcutaneously injected to rats in the OT group, once every 8 h. 0.4 mL/100 g MDD was administered to rats in the early stage MDD treatment group, and 6 h later changed to NS (once per 12 h).0.4 mL/100 g MDD was administered to rats in the whole course MDD treatment group, once every 12 h. The accumulative survival rate and morphological manifestations of pancreas and small intestine were observed under microscope 48 h after modeling. Pathologic scores of the pancreas and small intestine were conducted at 4, 6, 24, and 48 h after modeling. Contents of serum amylase (AMY), alanine transaminase (ALT), and TNF-α were also detected. The expression of high mobility group box protein 1 (HMGB1) in the small intestine tissue was also detected by Western blot. The positive rate of bacterial translocation in mesenteric lymph nodes (MLNs) was observed within 48 h. Correlations between serum TNF-α or HMGB1 in small intestinal tissue and pathological scores of the pancreas or the small intestine were analyzed.

RESULTSThe accumulative survival rate was 100. 0% in the sham-operation group, 79. 2% in the whole course MDD treatment group, 70. 8% in the OT group, 45. 8% in the early stage MDD treatment group, and 37.5% in the model group. At 6 h after modeling, pathological scores decreased more in the whole course MDD treatment group, the early stage MDD treatment group, the OT group than in the model group (P < 0.05). At 24 and 48 h after modeling, pathological scores of the pancreas and the small intestine decreased more in the whole course MDD treatment group and the OT group than in the early stage MDD treatment group (P <0. 05). At 6, 24, and 48 h after modeling, serum contents of AMY and ALT both decreased more in the whole course MDD treatment group, the early stage MDD treatment group, the OT group than in the model group (P < 0.05). At 48 h after modeling serum contents of AMY and ALT both decreased more in the whole course MDD treatment group and the OT group than in the early stage MDD treatment group (P < 0.05). At 6 h after modeling serum TNF-α levels decreased more in the whole course MDD treatment group, the early stage MDD treatment group, the OT group than in the model group (P < 0.05). At 6, 24, and 48 h after modeling the level of HMGB1 in the small intestinal tissue decreased more in the whole course MDD treatment group, the early stage MDD treatment group, the OT group than in the model group (P < 0.05). Of them, HMGB1 levels at 24 and 48 h were lower in the whole course MDD treatment group and the OT group than in the early stage MDD treatment group (P < 0.05). The number of MLNs bacterial translocation at 48 h after modeling was lower in the whole course MDD treatment group and the OT group than in the early stage MDD treatment group and the model group (P < 0.05). Serum TNF-α contents within 6 h were positively correlated with pathological scores of pancreas (r = 0.579, P < 0.01). ROC curve showed that serum TNF-α contents could predict the severity of SAP (ROC = 0.990, 95% Cl: 0.971 to 1.000). HMGB1 in the small intestine was positively correlated with pathological scores of the small intestine (r = 0.620, P < 0.01).

CONCLUSIONSEarly stage use of MDD could effectively reduce the release of TNF-α, while whole course use of MDD could effectively inhibit the expression of HMGB1. The latter could preferably attenuate injuries of the pancreas and the small intestine, lower MLNs bacterial translocation, and elevate the survival rate.

Animals ; Bacterial Translocation ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; HMGB1 Protein ; Intestinal Mucosa ; drug effects ; Octreotide ; Pancreas ; Pancreatitis ; drug therapy ; Plant Extracts ; pharmacology ; therapeutic use ; Rats ; Rats, Sprague-Dawley ; Taurocholic Acid ; Tumor Necrosis Factor-alpha

A 47-yr-old man with hepatitis B virus associated liver cirrhosis was admitted to our hospital with diarrhea and generalized edema and diagnosed as protein-losing enteropathy due to intestinal lymphangiectasia by intestinal biopsy and 99mTc albumin scan. During hospitalization, he received subcutaneous octreotide therapy. After 2 weeks of octreotide therapy, follow-up albumin scan showed no albumin leakage, and the serum albumin level was sustained. We speculate that liver cirrhosis can be a cause of intestinal lymphangiectasia and administration of octreotide should be considered for patients with intestinal lymphangiectasia whose clinical and biochemical abnormalities do not respond to a low-fat diet.
Adolescent ; Adult ; Duodenum/pathology ; Female ; Hepatitis B/complications ; Hepatitis B Virus/metabolism ; Human ; Intestinal Diseases/*drug therapy/virology ; Jejunum/pathology ; Liver Cirrhosis/*drug therapy/virology ; Lymphangiectasis, Intestinal/*drug therapy/virology ; Male ; Middle Aged ; Octreotide/*pharmacology ; Protein-Losing Enteropathies/*drug therapy

OBJECTIVETo investigate the effect of somatostatin analogue-octreotide (OCT) on expression of connective tissue growth factor (CTGF) gene of murine hepatic stellate cells (HSCs) in vitro.

METHODSHSCs separated from Sprague Dawley rats by in situ perfusion and Nycodenz gradient were divided into 5 groups. HSCs in 4 out of 5 groups were co-cultured with octreotide at different dosages, and the remaining group served as control. The expression of CTGF and TGF-beta mRNA were assessed by reverse transcription-polymerase chain reaction (RT-PCR).

RESULTSOCT down-regulates the expression of CTGF and TGF-beta mRNA in HSCs. The effect is increased with a dose dependent manner.

CONCLUSIONSOCT could exert the inhibitory effect on HSCs by down-regulating the expression of CTGF and TGF-beta. This provides a potential for the prevention and management of hepatic fibrosis.

Animals ; Cells, Cultured ; Connective Tissue Growth Factor ; Gene Expression ; drug effects ; Hepatocytes ; drug effects ; metabolism ; Immediate-Early Proteins ; genetics ; Intercellular Signaling Peptides and Proteins ; genetics ; Male ; Octreotide ; pharmacology ; RNA, Messenger ; genetics ; Rats ; Rats, Sprague-Dawley ; Reverse Transcriptase Polymerase Chain Reaction ; Somatostatin ; analogs & derivatives ; Transforming Growth Factor beta ; genetics