Secretion of pyruvate and lactate in pancreatic juice induced by acetazolamide or secretin

1986 ◽  
Vol 250 (4) ◽  
pp. G398-G404
Author(s):  
T. Kuroshima ◽  
S. Himeno ◽  
M. Kurokawa ◽  
K. Tsuji ◽  
S. Tarui
Keyword(s):  
Pancreatic Juice ◽  
Exocrine Pancreas ◽  
Duct Cell ◽  
In Vivo Studies ◽  
High Dose ◽  
Buffer System ◽  
Transport Pathway ◽  
Before And After ◽  
Pump Mechanism

In vivo studies using pentobarbital sodium-anesthesized dogs were performed to investigate whether a transport pathway for pyruvate and lactate is present in the exocrine pancreas. Concentrations of both acids were measured in peripheral blood and pancreatic juice before and after intravenous 15-min administration of 2.25 mmol/kg DL-lactate, superimposed on continuous intravenous infusion of 3 U X kg-1 X h-1 secretin. The concentration ratio of lactate to pyruvate in pancreatic juice was found to be approximately 1, a lower value than found in other tissues or body fluids. D-lactate, not detected in either blood or juice during basal periods, rapidly appeared in both fluids in parallel with the physiological isomer L-lactate, after the infusion of DL-lactate. Further addition of acetazolamide or a high dose of secretin caused a marked secretory response of pyruvate and lactate with no increase in juice bicarbonate levels. We conclude that these acids can be transported from blood to lumen when the transmembrane pH gradient across the duct cell membranes is augmented by stimulants via a proton pump mechanism involving a CO2-HCO3-buffer system.

scholarly journals Effect of Synchronous Versus Sequential Regimens on the Pharmacokinetics and Biodistribution of Regorafenib with Irradiation

Pharmaceutics ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 386
Author(s):  
Tung-Hu Tsai ◽  
Yu-Jen Chen ◽  
Li-Ying Wang ◽  
Chen-Hsi Hsieh
Keyword(s):  
Stereotactic Body Radiation Therapy ◽  
In Vivo Studies ◽  
Control Group ◽  
High Dose ◽  
Dependent Manner ◽  
Hep G2 ◽  
Time Curve ◽  
Dose Dependent

This study was performed to evaluate the interaction between conventional or high-dose radiotherapy (RT) and the pharmacokinetics (PK) of regorafenib in concurrent or sequential regimens for the treatment of hepatocellular carcinoma. Concurrent and sequential in vitro and in vivo studies of irradiation and regorafenib were designed. The interactions of RT and regorafenib in vitro were examined in the human hepatoma Huh-7, HA22T and Hep G2 cell lines. The RT–PK phenomenon and biodistribution of regorafenib under RT were confirmed in a free-moving rat model. Regorafenib inhibited the viability of Huh-7 cells in a dose-dependent manner. Apoptosis in Huh-7 cells was enhanced by RT followed by regorafenib treatment. In the concurrent regimen, RT decreased the area under the concentration versus time curve (AUC)regorafenib by 74% (p = 0.001) in the RT2 Gy × 3 fraction (f’x) group and by 69% (p = 0.001) in the RT9 Gy × 3 f’x group. The AUCregorafenib was increased by 182.8% (p = 0.011) in the sequential RT2Gy × 1 f’x group and by 213.2% (p = 0.016) in the sequential RT9Gy × 1 f’x group. Both concurrent regimens, RT2Gy × 3 f’x and RT9Gy × 3 f’x, clearly decreased the biodistribution of regorafenib in the heart, liver, lung, spleen and kidneys, compared to the control (regorafenib × 3 d) group. The concurrent regimens, both RT2Gy × 3 f’x and RT9Gy × 3 f’x, significantly decreased the biodistribution of regorafenib, compared with the control group. The PK of regorafenib can be modulated both by off-target irradiation and stereotactic body radiation therapy (SBRT).

scholarly journals CD44 Targeted Nanomaterials for Treatment of Triple-Negative Breast Cancer

Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 898
Author(s):  
Ghazal Nabil ◽  
Rami Alzhrani ◽  
Hashem Alsaab ◽  
Mohammed Atef ◽  
Samaresh Sau ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
In Vivo Studies ◽  
High Dose ◽  
Luminal A ◽  
Combination Strategy ◽  
Ongoing Research

Identified as the second leading cause of cancer-related deaths among American women after lung cancer, breast cancer of all types has been the focus of numerous research studies. Even though triple-negative breast cancer (TNBC) represents 15–20% of the number of breast cancer cases worldwide, its existing therapeutic options are fairly limited. Due to the pivotal role of the presence/absence of specific receptors to luminal A, luminal B, HER-2+, and TNBC in the molecular classification of breast cancer, the lack of these receptors has accounted for the aforementioned limitation. Thereupon, in an attempt to participate in the ongoing research endeavors to overcome such a limitation, the conducted study adopts a combination strategy as a therapeutic paradigm for TNBC, which has proven notable results with respect to both: improving patient outcomes and survivability rates. The study hinges upon an investigation of a promising NPs platform for CD44 mediated theranostic that can be combined with JAK/STAT inhibitors for the treatment of TNBC. The ability of momelotinib (MMB), which is a JAK/STAT inhibitor, to sensitize the TNBC to apoptosis inducer (CFM-4.16) has been evaluated in MDA-MB-231 and MDA-MB-468. MMB + CFM-4.16 combination with a combination index (CI) ≤0.5, has been selected for in vitro and in vivo studies. MMB has been combined with CD44 directed polymeric nanoparticles (PNPs) loaded with CFM-4.16, namely CD44-T-PNPs, which selectively delivered the payload to CD44 overexpressing TNBC with a significant decrease in cell viability associated with a high dose reduction index (DRI). The mechanism underlying their synergism is based on the simultaneous downregulation of P-STAT3 and the up-regulation of CARP-1, which has induced ROS-dependent apoptosis leading to caspase 3/7 elevation, cell shrinkage, DNA damage, and suppressed migration. CD44-T-PNPs showed a remarkable cellular internalization, demonstrated by uptake of a Rhodamine B dye in vitro and S0456 (NIR dye) in vivo. S0456 was conjugated to PNPs to form CD44-T-PNPs/S0456 that simultaneously delivered CFM-4.16 and S0456 parenterally with selective tumor targeting, prolonged circulation, minimized off-target distribution.

Abstract 186: Hdac7-derived 7aa Peptide May Function as a Phosphorylation Carrier

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Junyao Yang ◽  
Wen Wang ◽  
Qian Wang ◽  
Lingfang Zeng
Keyword(s):  
Endothelial Cell ◽  
Vascular Endothelial Cell ◽  
Blood Perfusion ◽  
Open Reading Frames ◽  
In Vivo Studies ◽  
Buffer System ◽  
Vascular Progenitor Cells ◽  
Upstream Kinase

Background: Histone deacetylase 7 (HDAC7) belongs to class II HDAC family, playing a pivotal role in the maintenance of endothelium integrity. There are 8 splicing variants in mouse HDAC7 mRNAs. Within the 5’ terminal non-coding area of some variants, there exist some short open reading frames (sORFs). Whether these sORFs can be translated and their potential roles in cellular physiology remain unclear. Method and results: Our previous studies suggested that one mouse HDAC7 produced a 7aa peptide from the non-coding area. In this study, we demonstrated that one sORF encoding a 7 amino acids (aa)-peptide could be translated in response to vascular endothelial cell growth factor (VEGF) in vascular progenitor cells (VPCs). The 7aa-peptide (7A) could be phosphorylated at serine residue via MEKK1. Importantly, the phosphorylated 7aa-peptide (7Ap) could transfer the phosphorylation group to the Thr residue of the 14-3-3γ protein in a cell free in-gel buffer system. The in vitro functional analyses revealed that 7A enhanced VEGF-induced VPC migration and differentiation toward endothelial cell (EC) lineage, in which MEKK1 and 14-3-3γ served as upstream kinase and downstream effector respectively. Knockdown of either MEKK1 or 14-3-3γ attenuated VEGF-induced VPC migration and differentiation. Exogenous 7Ap could rescue VEGF effect in MEKK1 but not in 14-3-3γ knockdown cells. The in vivo studies showed that 7A especially 7Ap induced capillary vessel formation within matrigel plug assays, increased re-endothelialization and suppressed neointima formation in the femoral artery injury model, and promoted the foot blood perfusion recovery in the hindlimb ischemia model. Conclusion: These results indicate that the sORFs within the non-coding area can be translated under some circumstances and that the 7aa-peptide may play an important role in cellular processes like migration and differentiation via acting as a phosphorylation carrier. Significance: As a phosphorylation carrier, 7aa possesses therapeutic potentials in tackling angiogenesis related diseases.

Hemodynamic effects of leukotriene C4 in ovine fetus

1990 ◽  
Vol 259 (6) ◽  
pp. E851-E855
Author(s):  
B. A. Meyer ◽  
S. W. Walsh ◽  
V. M. Parisi
Keyword(s):  
Blood Flow ◽  
Vena Cava ◽  
Cardiovascular Effects ◽  
In Vivo Studies ◽  
Leukotriene C4 ◽  
Blood Flows ◽  
Before And After ◽  
Placental Blood ◽  
Near Term

Leukotrienes are synthesized during pregnancy and produce cardiovascular effects in adults. We hypothesized that leukotriene C4 would cause vasoconstriction in the fetus and placenta. Eight near-term, unanesthetized ovine fetuses were studied before and after infusion of 10 micrograms leukotriene C4 (LTC4) into the fetal vena cava. Cardiovascular monitoring of maternal and fetal arterial pressures and heart rates was performed. Fetal blood flows were measured by the radioactive-microsphere technique. Sustained elevations in systolic and diastolic blood pressure and decreased fetal heart rate began by 1 min and returned to baseline by 30 min. Arterial pH fell from 7.33 +/- 0.01 to 7.29 +/- 0.01 at 15 min (P less than 0.05) and to 7.29 +/- 0.01 at 30 min (P less than 0.05), with a significant increase in base deficit from 0.7 +/- 0.7 to 3.5 +/- 0.7 at 15 min (P less than 0.05) and to 2.9 +/- 1.0 at 30 min (P less than 0.05). Fetal PO2 and PCO2 were unchanged. Significant decreases in blood flow and resistance were seen in the umbilical placental circulation as well as in fetal skeletal muscle and intestine. Blood flow and resistance were unchanged in the renal and adrenal vascular beds. Fetal administration of LTC4 caused no changes in maternal cardiovascular parameters. These findings represent the first in vivo studies of the effects of a lipoxygenase metabolite on fetal-placental blood flow.

PANCREATIC CANNULATION OF YOUNG PIGS FOR LONG-TERM STUDY OF EXOCRINE PANCREATIC FUNCTION

1988 ◽  
Vol 68 (3) ◽  
pp. 953-959 ◽  
Author(s):  
S. G. PIERZYNOWSKI ◽  
B. R. WESTRÖM ◽  
B. W. KARLSSON ◽  
B. NILSSON ◽  
J. SVENDSEN
Keyword(s):  
Pancreatic Juice ◽  
Exocrine Pancreas ◽  
Exocrine Pancreatic Function ◽  
Hormonal Stimulation ◽  
Long Term Study ◽  
Young Pigs ◽  
Before And After ◽  
Key Words Pig ◽  
Adaptation Processes

A surgical model and an experimental procedure were developed in the pig to enable the long-term collection of pancreatic juice under natural conditions from the first week of life until several weeks after weaning. Purebred Swedish Landrace pigs of varying ages were operated on as follows: at 3–4 d of age (n = 3) and returned to the sow; at 3 wk of age (n = 5), returned to the sow for 1 wk and then weaned; at 4–5 wk of age (n = 3), weaned on the day of surgery, and at 8–9 wk of age (n = 6). The pancreatic duct was catheterized; the catheter was exteriorized through an abdominal cannula and connected to a re-entrant perforated duodenal T-cannula. Using this model, long-term experiments were performed on alternate days for periods of 1–12 wk, and pancreatic juice was collected before and after feeding. The growth of the pigs did not appear to be seriously disturbed; postmortem examination did not reveal any major problems at the operation sites. The procedure permitted the collection of pure unactivated pancreatic juice, and did not appear to interfere with normal physiological responses to both feeding and hormonal stimulation with cholecystokinin (CCK) and secretin. Our observations indicated that this animal model may be used to study the postnatal development of the exocrine pancreas and the adaptation processes taking place when the feeding regime is changed at weaning. Key words: Pig, exocrine pancreas, chronic cannulation, development

Effect of Single Dose In Vivo Propranolol Therapy on In Vitro Adhesion of Human SS RBC.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1234-1234 ◽  
Author(s):  
Laura M. De Castro ◽  
Jude C. Jonassaint ◽  
Jennifer G. Johnson ◽  
Milena Batchvarova ◽  
Marilyn J. Telen
Keyword(s):  
Safety Data ◽  
Study Drug ◽  
Flow Chamber ◽  
In Vivo Studies ◽  
Dependent Manner ◽  
Number Of Patients ◽  
Significant Difference ◽  
Before And After

Abstract Sickle red blood cells (SS RBC) are abnormally adhesive to both endothelial cells (ECs) and components of the extracellular matrix (ECM). Epinephrine (epi) has been shown to elevate cAMP in SS RBC and increase adhesion of SS RBC to ECs in a protein kinase A-dependent manner. In vitro and in vivo studies performed in our lab have led to the hypothesis that adrenergic stimuli such as epi may initiate or exacerbate vaso-occlusion and thus contribute to the association of vaso-occlusive events with physiologic stress. We are conducting a prospective, dose-escalation pilot clinical study to investigate whether in vivo administration of one dose of propranolol either down-regulates baseline SS RBC adhesion in vitro or prevents its upregulation by epi. In addition, this study will provide additional safety data regarding the use of propranolol in normotensive patients with sickle cell disease (SCD). Figure Figure To date, we have completed the first two dose cohorts. 11 subjects (9 SS and 1 Sβ° thalassemia; 7 females, 3 males) have participated. No severe adverse events were noted. Cohorts 1 and 2 had mean pre-propranolol blood pressure (BP) of 116 (5.9 SD)/ 60.4 (3.98 SD) and 106.8 (4.68 SD)/ 58 (3.9 SD), respectively; this difference was not statistically significant. Minimal and asymptomatic changes in BP were noted in both cohorts after drug administration, with biphasic systolic and diastolic BP nadirs at 45 and 240 minutes. No clinically significant changes in heart rate were observed. Adhesion studies were performed using a graduated height flow chamber on the day of RBC collection. RBC adhesion to ECs was studied before and after epi stimulation and was measured at sheer stresses ranging from 1 to 3 dyne/cm2. Baseline adhesion measurements were validated by comparing percent (%) adhesion assayed at 2 different times within 7 days—at screening and before propranolol dose on the study drug day. We observed no significant difference in adhesion at the 2 different time points without propranolol. Comparison of % adhesion of epi-stimulated RBC to ECs before and 1 hour after propranolol showed that propranolol given in vivo significantly inhibited both non-stimulated and epi-stimulated SS RBC adhesion (p=0.04 and p=0.001, respectively). Lastly, comparison of SS RBC adhesion at both drug doses confirmed the drug-related inhibition of adhesion (p<0.004). We conclude that propranolol administered in vivo decreases SS RBC baseline adhesion to ECs and substantially abrogates epi-stimulated adhesion to ECs, as measured in vitro. Although we have thus far studied only a small number of patients and low propranolol doses, we expect to confirm these results with the 3rd cohort, in which a higher dose of propranolol will be used. If our findings continue to show that propranolol can decrease both SS RBC baseline and epi-stimulated adhesion to ECs, study of propranolol on a larger scale would be warranted in order to ascertain its safety and efficacy as an anti-adhesive therapy in SCD.

De novo purine synthesis inhibition and antileukemic effects of mercaptopurine alone or in combination with methotrexate in vivo

Blood ◽  
2002 ◽  
Vol 100 (4) ◽  
pp. 1240-1247 ◽  
Author(s):  
Thierry Dervieux ◽  
Timothy L. Brenner ◽  
Yuen Y. Hon ◽  
Yinmei Zhou ◽  
Michael L. Hancock ◽  
...  
Keyword(s):  
De Novo ◽  
Lymphoblastic Leukemia ◽  
Initial Therapy ◽  
High Dose ◽  
Purine Synthesis ◽  
Percentage Decrease ◽  
Before And After ◽  
Leukocyte Counts ◽  
B Lineage

Methotrexate (MTX) and mercaptopurine (MP) are widely used antileukemic agents that inhibit de novo purine synthesis (DNPS) as a mechanism of their antileukemic effects. To elucidate pharmacodynamic differences among children with acute lymphoblastic leukemia (ALL), DNPS was measured in leukemic blasts from newly diagnosed patients before and after therapy with these agents. Patients were randomized to receive low-dose MTX (LDMTX: 6 oral doses of 30 mg/m2) or high-dose MTX (HDMTX: intravenous 1 g/m2) followed by intravenous MP; or intravenous MP alone (1 g/m2), as initial therapy. At diagnosis, the rate of DNPS in bone marrow leukemia cells was 3-fold higher in patients with T-lineage ALL compared with those with B-lineage ALL (769 ± 189 vs 250 ± 38 fmol/nmol/h;P = .001). DNPS was not consistently inhibited following MP alone but was markedly inhibited following MTX plus MP (median decrease 3% vs 94%; P < .001). LDMTX plus MP and HDMTX plus MP produced greater antileukemic effects (percentage decrease in circulating leukocyte counts) compared with MP alone (−50% ± 4%, −56% ± 3%, and − 20% ± 4%, respectively;P < .0001). Full DNPS inhibition was associated with greater antileukemic effects compared with partial or no inhibition (−63% ± 4% vs −37% ± 4%; P < .0001) in patients with nonhyperdiploid B-lineage and T-lineage ALL. HDMTX plus MP yielded 2-fold higher MTX polyglutamate concentrations than LDMTX plus MP (2148 ± 298 vs 1075 ± 114 pmol/109 cells;P < .01) and a higher percentage of patients with full DNPS inhibition (78% vs 53%; P < .001). Thus, the extent of DNPS inhibition was related to in vivo antileukemic effects, and a single dose of intravenous MP produced minimal DNPS inhibition and antileukemic effects, whereas MTX plus MP produced greater antileukemic effects and DNPS inhibition, with full inhibition more frequent after HDMTX.

scholarly journals In vivo studies of the role of factor VII in hemostasis

Blood ◽  
1985 ◽  
Vol 65 (5) ◽  
pp. 1197-1200
Author(s):  
AR Giles ◽  
S Tinlin ◽  
L Brosseau ◽  
H Hoogendoorn
Keyword(s):  
Alternative Pathway ◽  
Factor Xa ◽  
In Vivo Studies ◽  
Factor Vii ◽  
High Dose ◽  
Factor X ◽  
Clotting Factors ◽  
Dose Warfarin ◽  
Factor X Activation

The effect of both congenital and acquired factor VII deficiency on the cuticle bleeding time (CBT) was evaluated in dogs. The CBT has been previously documented to be a sensitive indicator of factor VIII:C deficiency in hemophilic dogs. Serial CBT determinations were made on normal dogs treated with high-dose warfarin. At 48 hours post- treatment, the CBT was normal, although the factor VII level was less than 1%, whereas the levels of factors II, IX, and X were 44%, 25%, and 17%, respectively. At 120 hours the CBT became abnormal when all vitamin K-dependent clotting factors had dropped to less than 18%. Administration of a plasma concentrate of factors II, IX, and X corrected the CBT, despite the factor VII level remaining at less than 1%. Similar studies in a congenitally factor VII-deficient dog (factor VII less than 2%) confirmed that this deficiency state was not associated with an abnormality of the CBT. Administration of heparin to both normal and factor VII-deficient animals was associated with prolongation of the CBT, but the heparin dose required in the normal animals was substantially higher than in the factor VII-deficient animals. These data do not suggest that factor VII/VIIa has an exclusive role in generating factor Xa, either directly or indirectly, by way of factor IXa generation, in vivo. However, the increase in heparin sensitivity of the factor VII-deficient animals does suggest that factor VII/VIIa may, in some circumstances, present a significant alternative pathway of factor X activation, although the activation pathway involved cannot be determined from the studies performed.

scholarly journals Doxorubicin-induced myocardial failure in rats with malignant neoplasm: Protective role of fullerenol C60(OH)24

2008 ◽  
Vol 62 (3) ◽  
pp. 197-204 ◽  
Author(s):  
Rade Injac ◽  
Aleksandar Djordjevic ◽  
Borut Strukelj
Keyword(s):  
Untreated Control ◽  
Malignant Neoplasm ◽  
In Vivo Studies ◽  
Control Group ◽  
High Dose ◽  
Sprague Dawley ◽  
Untreated Control Group ◽  
Cardiac Damage

The therapeutic utility of the anthracycline antibiotic doxorubicin is limited due to its cardiotoxicity. Our aim was to investigate the efficacy of fullerenol C60(OH)24 in preventing single, high-dose doxorubicin-induced cardiotoxicity in rats with malignant neoplasm. In vitro and in vivo studies have shown that fullerenol C60(OH)24, has strong antioxidative potential. Experiment was performed on adult female Sprague Dawley rats with chemically induced mammary carcinomas. All 32 rats (2-5 groups) received i.p. applications of 1-methyl-l-nitrosourea (MNU; 50 mg/kg body weight) on the 50th and 113th day of age. Animals were randomly divided into five groups as follows: (1) Untreated control group - rats received saline only; (2) Cancer control group - rats received MNU and saline; (3) Dox group - rats received MNU and Dox 8 mg/kg; (4) Full/Dox group -rats received MNU and Full 100 mg/kg 30 min before Dox 8 mg/kg; (5) Full group - rats received MNU and Full 100 mg/kg. Tumor incidence was 4.94 +- 0.576 per rat. The animals were sacrificed 2 days after the application of doxorubicin and/or fullerenol, and the serum activities of CK, LDH and ?-HBDH, as well as the levels of MDA, GSH, GSSG, GSH-Px, SOD, CAT, GR and TAS in the heart, were determined. The results obtained from the enzymatic activity in the serum show that the administration of a single dose of 8 mg/kg in all treated groups induces statistically significant damage. There are significant changes in the enzymes of LDH and CK (p < 0.05), after an i.p. administration of doxorubicin/fullerenol and fullerenol. Comparing all groups with untreated control group, point to the conclusion that in the case of a lower oc-HBDH/LDH ratio, results in more serious the liver parenchymal damage. The results revealed that doxorubicin induced oxidative damage and that the fullerenol antioxidative influence caused significant changes in MDA, GSH, GSSG, GSH-Px, SOD, CAT, GR and TAS level in the heart (p < 0.05). Ultra structural analysis of heart tissues from rats treated with doxorubicin and indicated that the hearts of the rats were protected from doxorubicin-induced subcellular damage. Doxorubicin/fullerenol rats did not appear to show significant cardiac damage although occasional focal loss of cristae in the mitochondria was observed. Therefore, it is suggested that fullerenol might be a potential cardioprotector in doxorubicin-treated individuals.

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