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1.
Clin Exp Dermatol ; 46(7): 1293-1298, 2021 Oct.
Article in English | MEDLINE | ID: mdl-33763912

ABSTRACT

The effects of cigarette smoking on the risk of herpes zoster (HZ) infection remain unclear. This study aimed to examine the association between cigarette smoking and HZ. Participants were collected from four rounds (2001, 2005, 2009 and 2013) of the Taiwan National Health Interview Survey. Incident cases of HZ were identified from the Taiwanese National Health Insurance database. Of the 57 641 participants, 3346 developed HZ during the observation period. After controlling for confounders, current smokers had a lower risk of incident HZ than never-smokers (adjusted hazard ratio 0.69; 95% CI 0.62-0.77). There was a trend toward a decreased risk of HZ with increasing numbers of cigarettes per day, years of smoking and cumulative pack-years of smoking among current smokers (Ptrend < 0.001). Former smoking was not associated with risk of HZ. In conclusion, current smoking was significantly associated with a decreased risk of developing HZ.


Subject(s)
Cigarette Smoking , Herpes Zoster/epidemiology , Adult , Cohort Studies , Female , Health Surveys , Herpes Zoster/prevention & control , Humans , Male , Middle Aged , Risk Factors , Taiwan/epidemiology
2.
J Eur Acad Dermatol Venereol ; 34(7): 1510-1515, 2020 Jul.
Article in English | MEDLINE | ID: mdl-31989673

ABSTRACT

BACKGROUND: Previous studies have shown that patients with psoriasis have a higher risk of depression. However, the risk of major depressive disorder (MDD) among unaffected siblings of psoriasis probands remains unknown. This study aimed to investigate the risk of MDD among probands with psoriasis and unaffected siblings. METHODS: We selected subjects from the National Health Insurance Research Database (NHIRD) in Taiwan. Subjects were followed up from 01 January 1996 until a diagnosis of MDD, death or 31 December 2011. The Breslow-Cox model was used to calculate the adjusted relative risk (aRR). RESULTS: This study included 1094 probands with psoriasis, 1202 unaffected siblings and 4808 matched controls. Overall, 11.9% of the psoriasis probands (n = 130) and 2.5% of the unaffected siblings (n = 30) developed MDD, as compared with 1.1% of the controls (n = 52). Compared with controls, probands with psoriasis and unaffected siblings had aRRs of 10.60 [95% confidence interval (CI): 7.73-14.52] and 2.17 (95% CI: 1.44-3.28), respectively, for MDD. CONCLUSIONS: Probands with psoriasis and unaffected siblings have an increased risk of subsequently developing MDD. Further studies are needed to investigate the shared familial mechanisms underlying psoriasis and MDD.


Subject(s)
Depressive Disorder, Major , Psoriasis , Depressive Disorder, Major/epidemiology , Depressive Disorder, Major/genetics , Humans , Psoriasis/epidemiology , Psoriasis/genetics , Risk Factors , Siblings , Taiwan/epidemiology
3.
Anaesthesia ; 75(4): 464-471, 2020 04.
Article in English | MEDLINE | ID: mdl-31573678

ABSTRACT

There is conflicting evidence whether allogeneic blood transfusion influences survival or cancer recurrence after resection of hepatocellular cancer. We followed up 1469 patients who had undergone hepatocellular resection for a median (IQR [range]) of 45 (21-78 [0-162]) months, of whom 626 (43%) had had blood transfusion within 7 days of surgery. Both disease-free survival and patient survival were measured using a proportional hazards regression model and inverse probability of treatment weighting. We used restricted cubic splines for the association of the number of packed red blood cell units transfused with cancer recurrence and survival. We found that peri-operative blood transfusion was independently associated with survival and cancer recurrence after resection of hepatocellular carcinoma. Adjusted hazard ratios (95%CI) for the association of blood transfusion with cancer recurrence and all-cause mortality were 1.3 (1.1-1.4) and 1.9 (1.6-2.3), p < 0.001 for both. With more units transfused cancer recurrence was more likely and survival was shorter. The association of the number of transfused units was non-linear for cancer recurrence and linear response for all-cause mortality.


Subject(s)
Blood Transfusion/methods , Carcinoma, Hepatocellular/epidemiology , Carcinoma, Hepatocellular/surgery , Liver Neoplasms/epidemiology , Liver Neoplasms/surgery , Neoplasm Recurrence, Local/epidemiology , Disease-Free Survival , Female , Humans , Male , Middle Aged
4.
Oral Dis ; 20(3): e65-75, 2014 Apr.
Article in English | MEDLINE | ID: mdl-23731011

ABSTRACT

OBJECTIVE: We aimed at studying the role of the most deregulated miR-99a, identifying its downstream targets, and exploring the clinical potential of miR-99a and its target(s) in oral cancer. SUBJECTS AND METHODS: Following confirmation of miR-99a deregulation in nine oral lines and 26 pairwise clinical specimens, miR-99a-manipulated oral cancer cells were subjected to cell proliferation, migration, invasion, and in vivo murine metastasis assays. We characterized putative miR-99a target(s) using luciferase reporter assays and genetic manipulation. The inverse relation of miR-99a and its target(s) was examined in clinical specimens using real-time PCR and Western blot analysis. RESULTS: MiR-99a down-regulation was confirmed both in tested oral cancer cell lines and clinical specimens. Ectopic miR-99a expression inhibited oral cancer cell migration and invasion. Anti-miR-99a, silencing miR-99a functions, had the opposite effect. Myotubularin-related protein 3 (MTMR3) with one evolutionarily conserved seed region in the 3'-untranslated region was a novel miR-99a target. Depleting MTMR3 expression significantly reduced cell proliferation, migration, or invasion. There was an inverse expression of miR-99a and MTMR3 protein in oral cancer lines and clinical specimens. CONCLUSION: miR-99a repressed oral cancer cell migration and invasion partly through decreasing MTMR3 expression. MTMR3 may serve as a therapeutic target for oral cancer treatment.


Subject(s)
MicroRNAs/physiology , Mouth Neoplasms/genetics , Mouth Neoplasms/pathology , Protein Tyrosine Phosphatases, Non-Receptor/antagonists & inhibitors , Protein Tyrosine Phosphatases, Non-Receptor/biosynthesis , Gene Expression Regulation, Neoplastic , Humans , Neoplasm Metastasis , Tumor Cells, Cultured
5.
Neuroscience ; 164(2): 435-43, 2009 Dec 01.
Article in English | MEDLINE | ID: mdl-19682558

ABSTRACT

Pertussis toxin (PTX) treatment results in ADP-ribosylation of Gi-protein and thus in disruption of mu-opioid receptor signal transduction and loss of the antinociceptive effect of morphine. We have previously demonstrated that pretreatment with ultra-low dose naloxone preserves the antinociceptive effect of morphine in PTX-treated rats. The present study further examined the effect of ultra-low dose naloxone on mu-opioid receptor signaling in PTX-treated rats and the underlying mechanism. Male Wistar rats implanted with an intrathecal catheter received an intrathecal injection of saline or PTX (1 microg in 5 microl of saline), then, 4 days later, were pretreated by intrathecal injection with either saline or ultra-low dose naloxone (15 ng in 5 microl of saline), followed, 30 min later, by saline or morphine (10 microg in 5 microl of saline). Four days after PTX injection, thermal hyperalgesia was observed, together with increased coupling of excitatory Gs-protein to mu-opioid receptors in the spinal cord. Ultra-low dose naloxone pretreatment preserved the antinociceptive effect of morphine, and this effect was completely blocked by the mu-opioid receptor antagonist CTOP, but not by the kappa-opioid receptor antagonist nor-BNI or the delta-opioid receptor antagonist naltrindole. Moreover, a co-immunoprecipitation study showed that ultra-low dose naloxone restored mu-opioid receptor/Gi-protein coupling and inhibited the PTX-induced mu-opioid receptor/Gs-protein coupling. In addition to the anti-neuroinflammatory effect and glutamate transporter modulation previously observed in PTX-treated rats, the re-establishment of mu-opioid receptor Gi/Go-protein coupling is involved in the restoration of the antinociceptive effect of morphine by ultra-low dose naloxone pretreatment by normalizing the balance between the excitatory and inhibitory signaling pathways. These results show that ultra-low dose naloxone preserves the antinociceptive effect of morphine, suppresses spinal neuroinflammation, and reduces PTX-elevated excitatory Gs-coupled opioid receptors in PTX-treated rats. We suggest that ultra-low dose naloxone might be clinically valuable in pain management.


Subject(s)
Analgesics, Opioid/pharmacology , Morphine/pharmacology , Naloxone/pharmacology , Narcotic Antagonists/pharmacology , Pain/drug therapy , Pain/metabolism , Analgesics, Opioid/administration & dosage , Animals , Drug Therapy, Combination , GTP-Binding Protein alpha Subunits, Gi-Go/metabolism , GTP-Binding Protein alpha Subunits, Gs/metabolism , Male , Morphine/administration & dosage , Naloxone/administration & dosage , Narcotic Antagonists/administration & dosage , Pain/chemically induced , Pertussis Toxin , Rats , Rats, Wistar , Receptors, Opioid, mu/antagonists & inhibitors , Receptors, Opioid, mu/metabolism , Spinal Cord/drug effects , Spinal Cord/metabolism
6.
Neuroscience ; 159(4): 1244-56, 2009 Apr 10.
Article in English | MEDLINE | ID: mdl-19409222

ABSTRACT

We previously demonstrated that ultra-low dose naloxone restores the antinociceptive effect of morphine in rats with pertussis toxin (PTX)-induced thermal hyperalgesia by reversing the downregulation of glutamate transporter (GT) expression and suppressing spinal neuroinflammation. In the present study, we examined the underlying mechanisms of this anti-inflammatory effect in PTX-treated rats, particularly on the expression of GTs. Male Wistar rats were implanted with an intrathecal catheter and, in some cases, with a microdialysis probe. All rats were injected intrathecally with saline (5 microl) or PTX (1 microg), then, 4 days later, were randomly assigned to receive a single injection of saline, ultra-low dose naloxone (15 ng), or the p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580 (5 microg), followed by morphine injection (10 microg) 30 min later. Our results showed that PTX injection induced activation of microglia and a significant increase in P-p38 MAPK expression in the spinal cord. Ultra-low dose naloxone plus morphine significantly inhibited the effect of PTX on P-p38 MAPK expression in the spinal cord, while the p38 MAPK inhibitor SB203580 attenuated the PTX-induced mechanical allodynia, thermal hyperalgesia, increase in spinal cerebrospinal fluid excitatory amino acids, and downregulation of GTs. These results show that the restoration of the antinociceptive effect of morphine and GT expression in PTX-treated rats by ultra-low dose naloxone involves suppression of the p38 MAPK signal transduction cascade.


Subject(s)
Hyperalgesia/drug therapy , Morphine/administration & dosage , Naloxone/administration & dosage , Narcotic Antagonists/administration & dosage , Narcotics/administration & dosage , p38 Mitogen-Activated Protein Kinases/metabolism , Amino Acid Transport System X-AG/metabolism , Animals , Enzyme Inhibitors/administration & dosage , Excitatory Amino Acids/cerebrospinal fluid , Hyperalgesia/chemically induced , Imidazoles/administration & dosage , MAP Kinase Signaling System/drug effects , Male , Microglia/drug effects , Pertussis Toxin , Pyridines/administration & dosage , Random Allocation , Rats , Rats, Wistar , Spinal Cord/drug effects , Spinal Cord/metabolism , p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors
7.
Neuroscience ; 153(3): 823-31, 2008 May 15.
Article in English | MEDLINE | ID: mdl-18400403

ABSTRACT

We previously showed that intrathecal co-administration of amitriptyline with morphine upregulates the expression of the glial glutamate transporters glutamate-aspartate transporter (GLAST) and glutamate transporter-1 (GLT-1) and restores neuronal glutamate transporter excitatory amino acid carrier 1 (EAAC1) expression in chronically morphine-infused rats. The present study examined the role of nuclear transcription factor-kappaB (NF-kappaB) in the regulation of the expression of GLAST, GLT-1, and EAAC1 following long-term amitriptyline/morphine co-infusion. Male Wistar rats were implanted with two intrathecal catheters with or without a microdialysis probe; one of the catheters was used for continuous infusion of saline (control), morphine (15 microg/h), or morphine plus amitriptyline (both 15 microg/h) for 5 days, while the other was used for a single daily intrathecal injection of the NF-kappaB inhibitor Ro106-9920 (10 microl of 10 microM) for 5 days. We found that amitriptyline co-infusion restored the antinociceptive effect of morphine (4.5-fold right-shift in the morphine dose-response curve compared with a 65-fold right-shift in its absence) and this effect was inhibited by Ro106-9920 administration (48-fold right-shift). Moreover, amitriptyline/morphine co-infusion increased IkappaBalpha phosphorylation and the translocation of NF-kappaB p65 from the cytosol to the nucleus. Daily intrathecal injection of Ro106-9920 prevented the amitriptyline/morphine-induced NF-kappaB p65 translocation and reversed the amitriptyline/morphine-induced GLAST and GLT-1 upregulation and inhibited the restoration of EAAC1 expression. The Ro106-9920 injections abolished the inhibitory effect of amitriptyline on the morphine-evoked release of excitatory amino acids into the spinal cerebrospinal fluid (CSF) dialysates. In conclusion, amitriptyline/morphine co-infusion restores the antinociceptive effect of morphine and upregulates GLAST and GLT-1 expression and restores EAAC1 expression to baseline levels, thus reducing excitatory amino acid levels in the spinal CSF dialysates. The mechanism involves activation of the NF-kappaB pathway, but may also involve other pathways.


Subject(s)
Adrenergic Uptake Inhibitors/administration & dosage , Amino Acid Transport System X-AG/drug effects , Amitriptyline/administration & dosage , NF-kappa B/drug effects , Narcotics/pharmacology , Amino Acid Transport System X-AG/metabolism , Animals , Blotting, Western , Dose-Response Relationship, Drug , Drug Interactions , Drug Tolerance/physiology , Excitatory Amino Acids/metabolism , Fluorescent Antibody Technique , Gene Expression Regulation/drug effects , Image Processing, Computer-Assisted , Injections, Spinal , Male , Microdialysis , Morphine/pharmacology , NF-kappa B/metabolism , Pain Threshold/drug effects , Rats , Rats, Wistar , Sulfoxides/pharmacology , Tetrazoles/pharmacology , Up-Regulation
8.
Article in English | MEDLINE | ID: mdl-8942034

ABSTRACT

A 2-year-7-month old boy, presented with painless bloody stool was initially found to have an ulcerative, wide-based polyp in the ascending colon near the ileocecal region by colonoscopy. He received operation due to subsequent intussusception. Pathologic examination revealed an unusual case of polypoid Burkitt's lymphoma. The patient lives well 20 months later after receiving a standard chemotherapy. This case reminds us that colonic polyp and intussusception which is caused by Burkitt's lymphoma should be included in the differential diagnosis for a "wide-based polypoid" mass in the ascending colon.


Subject(s)
Burkitt Lymphoma/diagnosis , Colonic Polyps/diagnosis , Ileal Neoplasms/diagnosis , Ileocecal Valve , Intussusception/etiology , Child, Preschool , Diagnosis, Differential , Humans , Male
9.
J Membr Biol ; 149(1): 71-9, 1996 Jan.
Article in English | MEDLINE | ID: mdl-8825530

ABSTRACT

Elevation in intracellular Ca2+ acting via protein kinase C (PKC) is shown to regulate tight junction resistance in T84 cells, a human colon cancer line and a model Cl- secretory epithelial cell. The Ca2+ ionophore A23187, which was used to increase the intracellular Ca2+ concentration, caused a decrease in tight junction resistance in a concentration- and time-dependent manner. Dual Na+/mannitol serosal-to-mucosal flux analysis performed across the T84 monolayers treated with 2 microM A23187 revealed that A23187 increased both fluxes and that in the presence of ionophore there was a linear relationship between the Na+ and mannitol fluxes with a slope of 56.4, indicating that the decrease in transepithelial resistance was due to a decrease in tight junction resistance. Whereas there was no effect of 0.1 microM A23187, 1 or 2 microM produced a 55% decrease in baseline resistance in 1 hr and 10 microM decreased resistance more than 80%. The A23187-induced decrease in tight junction resistance was partially reversible by washing 3 times with a Ringer's-HCO3 solution containing 1% BSA. The A23187 effect on resistance was dependent on intracellular Ca2+; loading the T84 cells with the intracellular Ca2+ chelator BAPTA significantly reduced the decrease in tight junction resistance caused by A23187. This intracellular Ca2+ effect was mediated by protein kinase C and not calmodulin. While the protein kinase C antagonist H-7 totally prevented the action of A23187 on tight junction resistance, the Ca2+/calmodulin inhibitor W13 did not have any effect. Sphingosine, another inhibitor of PKC, partially reduced the A23187-induced decline in tight junction resistance. The PKC agonist PMA mimicked the A23187 effect on resistance, although the effect was delayed up to 1 hr after exposure. In addition, however, PMA also caused an earlier increase in resistance, indicating it had an additional effect in addition to mimicking the effect of elevating Ca2+. The effects of a phospholipase inhibitor (mepacrine) and of inhibitors of arachidonic acid metabolism (indomethacin for the cyclooxygenase pathway, NDGA for the lipoxygenase pathway, and SKF 525A for the epoxygenase pathway) on the A23187 action were also examined. None of these agents altered the A23187-induced decrease in resistance. Monolayers exposed to 2 microM A23187 for 1 hr were stained with fluorescein conjugated phalloidin, revealing that neighboring cells did not part one from another and that A23187 did not have a detectable effect on distribution of F-actin in the perijunctional actomyosin ring. The results indicate that elevation in intracellular Ca2+ decreases tight junction resistance in the T84 monolayer, acting through protein kinase C by a mechanism which does not involve visible changes in the perijunctional actomyosin ring.


Subject(s)
Calcimycin/pharmacology , Calcium/metabolism , Ionophores/pharmacology , Protein Kinase C/metabolism , Tight Junctions/metabolism , Arachidonic Acid/antagonists & inhibitors , Cell Membrane Permeability , Chelating Agents/pharmacology , Egtazic Acid/analogs & derivatives , Egtazic Acid/pharmacology , Humans , Mannitol/metabolism , Phospholipases/antagonists & inhibitors , Quinacrine/pharmacology , Tetradecanoylphorbol Acetate/pharmacology , Tumor Cells, Cultured
10.
Chin Med J (Engl) ; 104(9): 753-7, 1991 Sep.
Article in English | MEDLINE | ID: mdl-1935357

ABSTRACT

Since January 1984, functional reconstruction of the deltoid muscle using transfer of the upper part of the pectoralis major muscle has been performed in 7 patients with deltoid dysfunction. 5-20 months follow-up (average 11) revealed marked improvement in 6 patients. During the operation, the superior and inferior parts of the pectoralis major muscle were bluntly dissected and sectioned. The upper part of this muscle was turned over and transferred to the site normally occupied by the deltoid muscle. The transposed muscle contributed to both abduction and flexion of the shoulder. The efficacy of abduction was reinforced by the increased arm of action.


Subject(s)
Brachial Plexus/injuries , Muscles/surgery , Surgical Flaps/methods , Adolescent , Adult , Biomechanical Phenomena , Child , Female , Humans , Male , Muscles/physiology , Pectoralis Muscles , Postpoliomyelitis Syndrome/surgery , Shoulder , Tendon Transfer
11.
Am J Physiol ; 256(4 Pt 1): G721-6, 1989 Apr.
Article in English | MEDLINE | ID: mdl-2539738

ABSTRACT

To investigate the characteristics of intestinal ion and fluid secretion induced by the adherent, effacing enteropathogenic Escherichia coli strain RDEC-1, we infected weanling rabbits with 10(7)-10(8) RDEC-1 organisms and then studied cecal ion transport under short-circuit conditions in Ussing chambers. Results in tissues with confluent adherent organisms were compared with those in uninfected ceca and in ceca stimulated with dibutyryl adenosine 3',5'-cyclic monophosphate (DBcAMP). The short-circuited cecum normally absorbed Na and Cl, secreted bicarbonate (as represented by the residual ion flux), and displayed a high rate of nondiffusional Na and Cl transport. RDEC-1 infection did not alter the short-circuit current (Isc), but it increased the conductance (Gt), decreased the potential difference (PD), abolished net Na absorption, and reversed Cl absorption to secretion. The changes in Na and Cl net fluxes may be explained by inhibition of a Na-Cl linked absorptive process. In contrast, DBcAMP significantly increased the Isc, PD, and Gt, decreased net Na flux, and abolished net Cl absorption by stimulating electrogenic Cl secretion. These results suggest that RDEC-1-induced changes in cecal ion transport are not mediated by cAMP. The reduction in Na-Cl linked absorption is consistent with anatomic changes in the apical surfaces of absorptive epithelial characteristic of effacing enteroadherence, whereas the increased conductance is consistent with tight junction disruption seen with RDEC-1 infection.


Subject(s)
Cecum/metabolism , Chlorides/metabolism , Escherichia coli Infections/metabolism , Sodium/metabolism , Biological Transport , Bucladesine/pharmacology , Cecum/drug effects , Electric Conductivity , Intestinal Absorption/drug effects , Kinetics , Membrane Potentials
12.
Ann Surg ; 200(6): 734-41, 1984 Dec.
Article in English | MEDLINE | ID: mdl-6508404

ABSTRACT

Avascular segments of fetal rat intestine transplanted to the subcutaneous tissues of host syngeneic rats will become vascularized and grow. This study more fully characterizes this tissue, which we call "neogut," and compares it to normal rat small intestine. Anatomy was studied with light microscopy and scanning and transmission electron microscopy; transport and electrophysiologic parameters were measured in full-thickness pieces of tissue mounted in Ussing chambers; motility patterns, including slow wave and spike activity, were recorded. Subtle anatomic differences (shortened villi and microvilli) were noted in neogut compared to normal small bowel. Both neogut and normal rat ileum demonstrated net mucosal to serosal transport of d-glucose; the magnitudes of the electrophysiologic parameters (PD, Isc, and G) were less in neogut than in ileum. Slow-wave frequency of neogut was slightly less than native small bowel while spike activity was increased. These data show that neogut has structural and physiologic characteristics similar to normal rat small bowel and offers hope that this tissue may provide a nutritionally useful accessory gut for the patient with critical short-gut syndrome.


Subject(s)
Intestine, Small/transplantation , Animals , Electrophysiology , Fetus , Glucose/metabolism , Intestine, Small/anatomy & histology , Intestine, Small/metabolism , Intestine, Small/physiology , Rats , Rats, Inbred Strains
13.
Surgery ; 91(3): 293-300, 1982 Mar.
Article in English | MEDLINE | ID: mdl-6460335

ABSTRACT

Growing new mucosa from remnants of small bowel remaining in patients with short-bowel syndrome might offer a strategy for solving this clinical problem. We have performed a series of experiments investigating the possibility of growing rabbit ileal mucosa on vascularized pedicle flaps of abdominal wall musculature based on the inferior epigastric artery. By patching a defect of distal ileum with a skeletal muscle flap, we were able to demonstrate bowel augmentation by neomucosal ingrowth. Light and scanning electron microscopy confirmed the presence of essentially normal mucosa with well-developed villi atop the skeletal muscle pedicle flap. The mucosa was stripped from the skeletal muscle and compared with stripped mucosa from adjacent ileum in the Ussing chamber in 11 rabbits. The electrophysiologic studies showed no significant difference between normal mucosa and neomucosa in short-circuit current (Isc), potential difference or tissue conductance. The addition of 10 mM glucose resulted in similar unidirectional glucose flux and increase in Isc in both tissues. Bile salt absorption was also similar in both tissues. We conclude that neomucosa can be grown on flaps of skeletal muscle and is similar to normal mucosa by microscopic and electrophysiologic evaluation.


Subject(s)
Intestinal Mucosa/physiology , Malabsorption Syndromes/therapy , Regeneration , Short Bowel Syndrome/therapy , Surgical Flaps , Abdominal Muscles , Animals , Electrophysiology , Ileum/physiology , Ileum/surgery , Intestinal Mucosa/anatomy & histology , Microscopy, Electron, Scanning , Rabbits
14.
Am J Physiol ; 242(1): G65-75, 1982 Jan.
Article in English | MEDLINE | ID: mdl-6800265

ABSTRACT

The mechanism of changes in small intestinal transport due to acutely increased intraluminal hydrostatic pressure (IHP) was investigated in detail using perfused in vivo rabbit intestinal segments. IHP affected passive transport in vivo by increasing effective mucosal surface area in the small intestine (indicated by 3HOH transport and tissue architectural changes) and increasing small intestinal permeability (indicated by a proportionately greater increase in mannitol than erythritol secretory clearance). IHP did not alter ileal blood flow rate measured by radioactive microspheres, despite grossly evident venous dilatation, or active intestinal transport in the ileum as measured by a) in vitro ion transport in the absence of elevated hydrostatic pressure, b) mucosal adenylate cyclase or Na-K-ATPase activities, and c) glucose-stimulated water and electrolyte absorption. Acutely increased IHP appears to influence the hydrodynamics of the mucosal microcirculation in the rabbit ileum to produce a driving force for passive filtration-secretion, which is associated with and possibly augmented by increased tissue permeability and effective surface area.


Subject(s)
Intestinal Mucosa/physiology , Intestine, Small/physiology , Animals , Biological Transport/drug effects , Body Water/metabolism , Electrolytes/metabolism , Erythritol/metabolism , Glucose/pharmacology , Ileum/blood supply , Kinetics , Male , Mannitol/metabolism , Polyethylene Glycols , Pressure , Rabbits , Regional Blood Flow
15.
Am J Physiol ; 241(3): G253-8, 1981 Sep.
Article in English | MEDLINE | ID: mdl-6269439

ABSTRACT

The in vitro antisecretory effects of the alkaloid berberine (1.0 mM) on intestinal ion secretion and mucosal adenylate cyclase and Na-K-ATPase activities were studied in the rat ileum. Mucosal berberine did not alter the individual basal net ion fluxes and basal adenylate cyclase activity but decreased short-circuit current (Isc) and increased the net absorption of chloride plus bicarbonate. In the cholera toxin-treated tissue, mucosal berberine stimulated absorption of Na and Cl and inhibited the increased adenylate cyclase activity but did not change the specific Na-K-ATPase activity, whereas serosal berberine stimulated Na secretion and decreased Isc. Mucosal berberine also decreased Isc, increased Cl permeability, and reversed the ion secretion induced by dibutyryl cyclic AMP, the heat-stable enterotoxin of Escherichia coli, and methylprednisolone administration. The antisecretory effects of mucosal berberine may be explained by stimulation of a Na-Cl-coupled absorptive transport process. The mechanism of action of serosal berberine remains to be elucidated. However, it is clear that mucosal berberine affects intestinal ion transport by mechanisms different from stimulation of the Na pump and probably at a step distal to the production or degradation of cyclic AMP or cyclic GMP.


Subject(s)
Berberine Alkaloids/pharmacology , Berberine/pharmacology , Ileum/metabolism , Intestinal Mucosa/metabolism , Adenylyl Cyclases/metabolism , Animals , Biological Transport , Cholera Toxin/pharmacology , Ileum/drug effects , Ileum/enzymology , Intestinal Mucosa/drug effects , Intestinal Mucosa/enzymology , Ions , Methylprednisolone/analogs & derivatives , Methylprednisolone/pharmacology , Methylprednisolone Acetate , Rats , Sodium-Potassium-Exchanging ATPase/metabolism
16.
Am J Physiol ; 241(3): G248-52, 1981 Sep.
Article in English | MEDLINE | ID: mdl-7282933

ABSTRACT

The effect of luminal berberine hydrochloride concentration on cholera toxin-induced water and electrolyte secretion and on normal water and electrolyte transport was determined in vivo in the cannulated, perfused rat ileum using [14C]polyethylene glycol as a nonabsorbable marker. Berberine reduced the cholera toxin-induced secretion of water, Na, Cl, and calculated residual ion (primarily HCO3) in a concentration-dependent manner. The effect of berberine on cholera toxin-induced ileal secretion was evident 60-80 min after exposure and was reversed 60-80 min after removal of berberine from the perfusate. Mild changes in mucosal histology (villous tip edema) due to cholera toxin were also reversed by berberine. Berberine did not significantly alter normal ileal water and electrolyte transport.


Subject(s)
Berberine Alkaloids/pharmacology , Berberine/pharmacology , Cholera Toxin/pharmacology , Ileum/metabolism , Intestinal Mucosa/metabolism , Animals , Body Water/metabolism , Chlorides/metabolism , Ileum/cytology , Ileum/drug effects , Intestinal Mucosa/drug effects , Ions , Male , Microvilli/drug effects , Microvilli/ultrastructure , Potassium/metabolism , Rats , Sodium/metabolism
17.
J Physiol ; 318: 385-94, 1981 Sep.
Article in English | MEDLINE | ID: mdl-7320896

ABSTRACT

1. The electrical potential difference, short-circuit current, tissue conductance, and fluxes of sodium and chloride were measured in rat small intestine in an in vitro chamber preparation in the presence and absence of 100 mM-mannitol on either the mucosal or serosal surface. 2. Mucosal mannitol generally decreased potential difference, short-circuit current, and tissue conductance while serosal mannitol increased the electrical variables. 3. Mucosal mannitol decreased unidirectional movement of sodium and chloride but did not change the net transport of these ions. The change in short-circuit current was therefore ascribed to changes in fluxes of ions other than sodium and chloride. 4. Serosal mannitol increased the unidirectional fluxes of sodium, but not the new transport of this ion. The transport of chloride increased only in the serosal to mucosal direction yielding a net secretion of chloride equal to the change in short-circuit current. 5. The changes in potential difference and short-circuit current caused by mucosal mannitol were dependent on the presence of sodium. The changes due to serosal mannitol were dependent on both sodium and chloride. 6. Changes in undirectional transport of ions, small non-electrolytes, and water due to an osmotic gradient were attributed to changes in the dimension of the lateral intercellular spaces observed in earlier studies. 7. No evidence suggesting that the electrical changes due to the mannitol gradients could be attributed to diffusive or convective flows of fluid, but instead the changes were ascribed to perturbations in the cellular transport mechanisms.


Subject(s)
Intestine, Small/physiology , Animals , Biological Transport , Chlorides/metabolism , Electric Conductivity , In Vitro Techniques , Intestinal Mucosa/metabolism , Intestinal Mucosa/physiology , Intestine, Small/metabolism , Male , Membrane Potentials , Osmotic Pressure , Rats , Sodium/metabolism
19.
Am J Physiol ; 240(5): G365-70, 1981 May.
Article in English | MEDLINE | ID: mdl-6112881

ABSTRACT

Administration of the glucocorticoid methylprednisolone (MP) (30 mg/kg body wt for 3 days) to rats increased intestinal mucosal guanylate cyclase and Na-K-ATPase activities, short-circuit current (Isc), electrical potential difference (PD), net Na absorption, and net Cl secretion and reversed HCO3 transport from secretion to absorption. In the MP-treated animals, removal of HCO3 from both the mucosal and serosal bathing solutions increased Cl secretion but did not alter the Isc, PD, and net Na flux. Removal of Cl abolished the MP-induced increase in Isc but did not affect the MP-induced changes in net Na and HCO3 fluxes. At 6 h, after a single dose of MP, stimulation of guanylate cyclase activity was already maximal, whereas Na-K-ATPase activity was not detectably altered. The changes in intestinal transport properties present 6 h after MP treatment and associated with the increased guanylate cyclase activity were an increase in Isc and PD and a reversal of net Cl absorption to net secretion. These results suggest that an initial response to MP administration is a persistent increase in intestinal guanylate cyclase activity that mediates an electrogenic Cl secretory process, then is followed by a superimposed effect of increased Na-K-ATPase activity that mediates an increase in net Na absorption.


Subject(s)
Electrolytes/metabolism , Intestinal Mucosa/metabolism , Methylprednisolone/pharmacology , Animals , Biological Transport, Active/drug effects , Electrophysiology , Epithelium/metabolism , Guanylate Cyclase/metabolism , Ileum/metabolism , Intestinal Mucosa/enzymology , Intestines/drug effects , Male , Models, Biological , Rats , Sodium-Potassium-Exchanging ATPase/metabolism
20.
J Membr Biol ; 59(3): 173-7, 1981 Apr 30.
Article in English | MEDLINE | ID: mdl-7241580

ABSTRACT

The relationships among ion current, membrane potential difference, and resistance of an epithelium are studied. The short-circuit technique introduced by Ussing and Zerahn does not completely short circuit the epithelium if the series resistance parallel to the cell layer between the voltage electrodes is not properly compensated. The residual potential difference across the epithelial cell layer in the "short-circuit state" is proportional to both the measured short-circuited small intestinal mucosa the villus and crypt areas are hypo-polarized to different degrees rather than simultaneously hyper- and hypo-polarized. Short-circuiting the whole tissue reduces but does not abolish the passive net ion movement across the tissue. Measurements of the electrical properties of the whole and denuded rat distal small intestine in HCO3-Ringer solution containing 10 mM glucose reveal that the measured short-circuit current has under-estimated approximately 33% of the true short-circuit current and that the passive net Na flux from serosa to mucosa and Cl flux from mucosa to serosa are not negligible in the "short circuit state."


Subject(s)
Electrophysiology/methods , Epithelium/pathology , Intestinal Mucosa/physiology , Ions/physiology , Animals , Chlorides/physiology , Electric Conductivity , In Vitro Techniques , Intestine, Small/physiology , Rats , Sodium/physiology
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