Decreased patient analgesic requirements after liver transplantation and associated neuropeptide levels.

BACKGROUND: Decreased morphine requirements have been reported after liver transplantation when compared with other types of major abdominal surgery. The aim of this study was to examine plasma concentrations of three neuropeptides involved in pain modulation-metenkephalin (ME), beta-endorphin (BE), and substance P (SP)-in patients undergoing orthotopic liver transplantation (OLT) and in control patients undergoing other liver operations. We then compared the postoperative analgesic requirements in these two groups of patients. METHODS: Plasma levels of ME, BE, and SP were measured by radioimmunoassay at preincision, preemergence, and for 3 days after operation in 13 patients undergoing OLT and in 10 control patients. Patient-controlled analgesia morphine delivery was recorded for all patients postoperatively, and plasma morphine, its metabolites, and patient pain and sedation scores were also measured. RESULTS: ME levels were elevated in all OLT patient samples when compared with control patient samples. BE levels were not significantly different at any time. SP levels were significantly decreased only in preincision and preemergence OLT patient samples. Total patient-controlled analgesia morphine delivered during the first 3 postoperative days was significantly less in OLT patients (70+/-8 mg) than in control patients (101+/-12 mg). Plasma morphine, morphine-3-glucuronide, and morphine-6-glucuronide levels were decreased in OLT patients, however, statistical significance was seen only in the morphine-6-glucuronide results. CONCLUSIONS: We have shown that postoperative analgesic requirements are decreased in OLT patients, and we suggest that associated increased peripheral ME levels may be contributing to this decreased requirement. Based on our results, circulating BE and SP are less significant factors affecting postoperative analgesic requirements.

Kyotorphin and D-kyotorphin stimulate Met-enkephalin release from rat striatum in vitro.

The release of immunoreactive Met-enkephalin (I-ME) from the rat striatum was studied in vitro using a batch technique. A basal release of the order of 2-3% of total I-ME tissue content per 10 min was found. Both dipeptides kyotorphin and D-kyotorphin produced equipotently dose-dependent I-ME release, with 0.5 mM maximal concentration causing 2-3-fold stimulation of release. This release was calcium-dependent. In concentrations up to 1 mM both dipeptides did not change the basal release of [3H]noradrenaline, [3H]GABA, [3H]D-aspartate and immunoreactive beta-endorphin from various brain structures. The results support a role of kyotorphin as a specific I-ME-releasing factor in the rat brain.

Halothane alters electrical activity and calcium dynamics in cultured mouse cortical, spinal cord, and dorsal root ganglion neurons.

Halothane inhibits neural plasma membrane Ca(2+)-ATPase, a pump that ejects Ca2+ from the cell after influx through voltage- or ligand-activated channels. Intracellular microelectrode recordings in mouse embryonic cortical and spinal cord neurons showed that halothane and eosin, a pump inhibitor, prolonged repolarization associated with spontaneous bursts of depolarization. These agents also prolonged the repolarization phases of electrically induced action potentials and of capsaicin-mediated Ca(2+)-dependent depolarization in mouse adult dorsal root ganglion neurons. In keeping with these findings, confocal microfluorimetry showed that halothane delayed clearance of intracellular Ca2+ accumulated by N-methyl-D-aspartate stimulation of single neurons.

Alcohol pretreatment alters the metabolic pattern and accelerates cocaine metabolism in pigs.

We investigated whether alcohol pretreatment would affect the disposition and metabolic pattern of intravenously (i.v.) administered cocaine in pigs. Six pigs (Group A) received alcohol (1 g/kg/day) and six pigs (control; Group D) received an equal volume of isocaloric dextrose 44% in water for 10 days via an intragastric tube. On day 11, arterial samples were taken for five hours following an intravenous administration of cocaine hydrochloride (4 mg/kg). Plasma concentrations of cocaine and its major metabolites were analyzed by HPLC method. Significant decrease in plasma half-life (10 +/- 1.2 vs. 18.7 +/- 1.4 min), and significant increases in apparent volume of distribution (73 +/- 6 vs. 51 +/- 31) and clearance (5.37 +/- 0.6 vs. 1.82 +/- 0.1 l/min) were seen in alcohol pretreated pigs as compared with control pigs (P < 0.05). Significant increases in plasma concentrations of benzoylecgonine (P < 0.05), and insignificant differences in ecgonine methyl ester and norcocaine levels were seen between the two groups. Neither ecgonine nor cocaethylene was detected in the blood samples. Our data show that alcohol administration for ten days accelerated the elimination of i.v. administered cocaine and altered its metabolic pattern in pigs.

Nitrous oxide and xenon enhance phospholipid-N-methylation in rat brain synaptic plasma membranes.

Halothane and isoflurane increase the rate of phospholipid methylation (PLM) in rat brain synaptosomal membranes, a process linked to the coupling of neuronal excitation to neurotransmitter release. In contrast, synaptic plasma membrane (SPM) Ca2+ ATPase (PMCA) pumping is reduced by exposure to halothane, isoflurane, xenon and nitrous oxide (N2O). To examine further the relationship between PLM, PMCA and anesthetic action, we investigated the effect of clinically relevant concentrations of two less potent anesthetic gases, N2O and xenon, on PLM in SPM. Biochemical assays were performed on SPM exposed to 1.3 MAC of N2O (2 atm), 1.3 MAC of xenon (1.23 atm) or an equivalent pressure of helium for control. N2O or xenon exposure increased PLM to 115% or 113%, respectively, of helium control (p < 0.02). Similar exposures to N2O or xenon depressed PMCA activity to 78% and 85% of control (p < 0.05). Observations that PLM and PMCA are both altered by a wide variety of inhalation anesthetic agents at clinically relevant partial pressures lend support to a possible involvement and interaction of these processes in anesthetic action.

Diminished brain synaptic plasma membrane Ca(2+)-ATPase activity in spontaneously hypertensive rats: association with reduced anesthetic requirements.

We have recently reported that plasma membrane Ca(2+)-ATPase (PMCA) pumping activity in rat brain synaptic plasma membranes (SPM) was reduced by in vitro or prior in vivo exposure to inhalation anesthetics (IA). In addition, rats with streptozocin-induced diabetes were found to have diminished brain synaptic PMCA pumping and a decrease in the partial pressures of several IA required to prevent movement in response to stimulation, defined as the minimum effective dose or MED. Diminished PMCA activity in erythrocytes of spontaneously hypertensive rats (SHR) has been noted. Because PMCA is ubiquitous, it seemed possible that PMCA pumping might be decreased in the brain of SHR and perhaps associated with decreased IA requirement. Eighteen SHR and 18 control, normotensive Wistar-Kyoto rats (WKY) were studied. PMCA activity was assessed by measurement of Ca2+ uptake into synaptic plasma membrane vesicles prepared from cerebrum and diencephalon-mesencephalon (D-M) in WKY and SHR. Ca2+ pumping was significantly less in SHR than in WKY, 85% of control in the cerebrum and 90% in the D-M (p < 0.01). The MEDs for halothane, isoflurane and desflurane were also lower in SHR than in WKY, 91%, 90% and 89%, respectively, of control (p < 0.05). Thus, an animal model of primary hypertension (SHR) manifested diminished brain synaptic PMCA activity and reduced MED for several volatile anesthetics. These findings provide further evidence for a role for PMCA in anesthetic action.

Lack of effect of flurothyl, a non-anesthetic fluorinated ether, on rat brain synaptic plasma membrane calcium-ATPase.

Plasma membrane Ca2+-ATPase (PMCA), a regulator of intracellular calcium, is inhibited by volatile anesthetics and by xenon and nitrous oxide. Response of a cellular system to anesthetics, particularly to volatile agents, raises the question of non-specific, even toxic, side effects unrelated to anesthetic action. Compounds with chemical and physical properties similar to halogenated anesthetics, but which lack anesthetic effect, have been used to address this question. We have compared the effects of halothane and flurothyl, a non-anesthetic fluorinated ether, on PMCA Ca2+ transport across isolated brain synaptic plasma membranes (SPM). Flurothyl, at concentrations predicted by the Meyer-Overton curve to range from 0.4 to 2.6 MAC (minimum alveolar concentration), had no significant on PMCA activity. In contrast halothane, 1.3 MAC, reduced Ca2+ transport 30 to 40%. These findings provide further evidence for a specific effect of inhalation anesthetics on neuronal plasma membrane Ca2+-ATPase.

Reduced anesthetic requirements in aged rats: association with altered brain synaptic plasma membrane Ca(2+)-ATPase pump and phospholipid methyltransferase I activities.

Aging is associated with a decrease in anesthetic requirements. Animal models of aging manifest alteration of brain Ca2+ homeostasis and increased methyltransferase I (PLMTI) activity. In this study we evaluated concurrently anesthetic requirements and brain plasma membrane Ca(2+)-ATPase (PMCA) and PLMTI activities in young and aged rats. Halothane, desflurane, isoflurane and xenon MEDs (lowest partial pressures that suppress a pain response) were measured in 2 and 25 month old, male Fisher-344 rats. Halothane MED was also measured in 2 and 30 month old F344/BNF1 rats, a strain that undergoes aging with less debilitation. PMCA pumping and PLMTI activities were measured in synaptic plasma membranes (SPM) prepared from the cortex and diencephalon-mesencephalon (DM). For aged Fisher-344 rats, MEDs for halothane, desflurane, isoflurane and xenon were reduced to 81%, 82%, 67% and 86%, respectively, of young controls; PMCA activity was diminished to 91% in cortical SPM and 82% in DM SPM; and cortical and DM PLMTI activities were increased to 131% and 114% of young control. For F344/BNF1 rats, MED for halothane was reduced to 87%, PMCA activity was diminished to 90% in cortical SPM and 72% DM SPM, and PLMTI activity was increased to 133% in cortical SPM and 112% in DM SPM. The strong association between age and reduced anesthetic requirements for inhalational agents on the one hand and altered PMCA and PLMTI activity on the other lends support to the underlying hypothesis that PMCA and PLMTI may be involved in the production of the anesthetic state.

Inhibition of plasma membrane Ca(2+)-ATPase pump activity in cultured C6 glioma cells by halothane and xenon.

We have compared the effect of two inhalational anesthetics, halothane and xenon, on Ca(2+)-ATPase (PMCA) pumping activity in plasma membrane vesicles prepared from cultured rat C6 glioma cells. Halothane, at concentrations ranging from 0.5 to 1.75 vol% (equivalent to 0.5 to 1.6 MAC), significantly inhibited Ca2+ uptake (transport) by plasma membrane vesicles in a dose-related fashion. Xenon, at partial pressures ranging from 0.5 to 1.5 atm (equivalent to 0.5 to 1.6 MAC), similarly inhibited PMCA pumping activity. Additive effects on suppression of PMCA pump activity were observed when C6 cell plasma membrane vesicles were exposed to increasing partial pressures of xenon in the presence of halothane (1 vol%). Halothane also inhibited PMCA pumping in cells from two other lines of neural origin, B104 (rat neuroblastoma) and PC12 (rat pheochromocytoma). Studies described in this report support the thesis that PMCA in cells of neural origin is inhibited by quite different inhalational anesthetics at clinically relevant concentrations.

Diminished brain synaptic plasma membrane Ca(2+)-ATPase activity in rats with streptozocin-induced diabetes: association with reduced anesthetic requirements.

Recent evidence suggests that chronic hyperglycemia may inhibit plasma membrane Ca(2+)-ATPase (PMCA) in cells from several tissues. Inhalational anesthetics (IA) can inhibit brain synaptic PMCA activity. We proposed that diabetic rats may manifest chronic inhibition of brain synaptic PMCA and thus provide a model for testing the hypothesis that synaptic PMCA plays a key role in IA pharmacodynamics. Ca2+ pumping activity of PMCA was measured in cerebral synaptic plasma membrane (SPM) vesicles prepared from rats with streptozocin (STZ)-induced diabetes and from control, normoglycemic rats. Dose requirements for halothane and xenon were estimated in treated and untreated rats. Brain PMCA activity in hyperglycemic rats was depressed by about 8.4%, compared to controls. In vitro glycation also caused a significant decrease in PMCA pumping activity. Halothane requirement for STZ-hyperglycemic rats was dramatically reduced to about 65% of control. Xenon requirement was also significantly reduced, to 88% of control. Correlation of IA dose with percent glycated hemoglobin for each rat revealed a strong association between reduced requirements for halothane or xenon and increased protein glycation. These results indicate that inhibition of brain synaptic PMCA in chronically hyperglycemic rats is associated with a significant reduction in IA requirement.

Increased anesthetic requirements for isoflurane, halothane, enflurane and desflurane in obese Zucker rats are associated with insulin-induced stimulation of plasma membrane Ca(2+)-ATPase.

A wide spectrum of structurally disparate inhalational anesthetics reduce brain synaptic plasma membrane Ca(2+)-ATPase (PMCA) activity, whereas phospholipid methyltransferase I (PLMTI) is enhanced by anesthetics. Several rat models with incidental or disease-induced reduction of PMCA and enhancement of PLMTI activities manifest increased sensitivity to inhalational anesthetics. Because insulin is known to stimulate PMCA, anesthetic requirements in hyperinsulinemic obese Zucker rats (fa/fa) and in normoinsulinemic lean Zucker heterozygotes (fa/+) were examined, and brain synaptic PMCA and PLMTI activities were determined in both genotypes. Significantly higher partial pressures of halothane, enflurane, isoflurane, and desflurane were required to inhibit the pain response in obese rats compared to lean Zucker rats. Dose dependent stimulation of PMCA pumping was observed in synaptic membranes from both types, but insulin concentrations in extracts of diencephalon-mesencephalon, cerebellum, and medulla (but not cortex) were higher in obese than in lean Zucker rats. Microdialysis of three subcortical regions showed marked increases in insulin levels with halothane exposure in obese rats, compared to lean controls. These observations in an anesthetic resistant rat model lend further support to the hypothesis that the calcium pump plays a functional role in production of the anesthetic state.

Reduced anesthetic requirements, diminished brain plasma membrane Ca(2+)-ATPase pumping, and enhanced brain synaptic plasma membrane phospholipid methylation in diabetic rats: effects of insulin.

We have recently reported that streptozocin (STZ)-induced diabetes in rats was associated with i) reduced Ca2+ pumping by rat brain synaptic plasma membrane Ca(2+)-ATPase (PMCA) and ii) a substantial reduction in the partial pressures of halothane and xenon required to prevent movement in response to stimulation (minimum effective dose or MED). MED for both agents correlated well with the degree of hemoglobin glycation and with PMCA activity. We now report that MEDs for isoflurane, enflurane, and desflurane were also substantially reduced in STZ-diabetic rats, compared with placebo-injected controls. In addition, we examined the effect of insulin treatment, begun 2 weeks after induction of diabetes and continued for 3 more weeks, on isoflurane MED and on brain synaptic PMCA and phospholipid-N-methyltransferase I (PLMT I), another enzyme altered by inhalation anesthetics (IA). Partial treatment of diabetes, as indicated by decreased glycated hemoglobin (GHb) compared to untreated diabetic rats, was associated with an isoflurane MED of 1.05 vol%, intermediate between a control mean of 1.57 vol% and an untreated diabetic mean of 0.82 vol% (p < 0.01), with a trend toward normalization of both PMCA and PLMT I activity. We also examined isoflurane MED and PMCA activity in the cerebrum and diencephalon-mesencephalon (D-M) of control and diabetic rats 2 and 12 weeks after induction of diabetes. Isoflurane MED was substantially reduced in diabetic rats from both treatment periods. Cerebral and D-M PMCA activities were each reduced to about 90% of control values 2 weeks after STZ induction. At 12 weeks, cerebral PMCA pumping in SPM from diabetic rats did not differ from control values, but PMCA pumping in SPM from the D-M was reduced to about 85% of control levels. Good correlation (r = 0.89, p < 0.01) was found between isoflurane MED and GHb in all treatment groups. These findings provide further evidence for an important role for PMCA in IA action. They also suggest that anesthetic effects on the calcium pump at specific anatomic sites may be of major importance in producing anesthesia.

Infrared laser diode irradiation has no behavioral or biochemical effect on pain in the sciatic nerve ligation-induced mononeuropathy in rat.

The aim of this study was to evaluate the effect of acute and repeated (5 days) treatment with various types of infrared (IR) diode lasers and probes (single- vs cluster-beam) on the pain response in rats with peripheral mononeuropathy produced by sciatic nerve ligation. Male Sprague-Dawley rats were anesthetized with sodium pentobarbital, and the mid-thigh was surgically exposed to reveal the sciatic nerve, around which four ligatures were loosely tied. On postoperative day 5, the skin over the sciatic nerve lesion was subjected to a 30-min daily local exposure from a 904-nm IR diode laser (700 Hz, average output power 10 mW) with a single-beam probe, a 830-nm IR diode laser (700 Hz) with either a single-beam (average output power 50 mW) or cluster-beam probe (average output power 15 mW), or placebo for 5 consecutive days. Two pain responses (foot-withdrawal time and the hind-paw elevation time) were measured on both sides using the radiant heat method on days 5 and 9. In addition, cold allodynia was measured on day 9 of treatment by placing the rats on a chilled metal plate (4 degrees C) and measuring the duration of elevation of either of the hind paws. On day 9, the animals were sacrificed for collection of the samples of brain and lumbar spinal cord for the determination of the tissue concentrations of dynorphin A1-8-like immunoactivity (DYN) using specific radioimmunoassay (RIA). The hind-paw withdrawal and elevation times on the right side in all groups subjected to the various methods of IR laser irradiation did not differ significantly as compared with the placebo-treated group when measured on days 5 and 9 after surgery. No statistically significant differences in withdrawal response and elevation time of the unaffected left hind paw were noted either. The measurement of cold allodynia similarly failed to reveal any effect in laser-treated groups versus placebo. The RIA analysis found that tissue concentrations of DYN were significantly elevated in the spinal cord ipsilaterally to the ligation side, as compared with the contralateral side, in all rats with sciatic nerve ligation. All modalities of IR diode laser treatment did not produce any significant difference in the brain and spinal cord level of DYN on postoperative day 9 in all treatment groups. It is concluded that repeated IR diode laser treatment did not reduce hyperalgesia induced by sciatic nerve ligation in rats.

[Interactions between herbicides and various of the most frequently used drug groups. I. Interactions between chronically administered herbicides: carbendazyme, 2,4-dichlorophenoxyacetic acid and 2,4,5-trichlorophenoxyacetic acid and drugs affecting the circulatory system]. / Interakcje herbicydów i niektórych najczesciej stosowanych grup leków. I. Interakcje herbicydów: Karbendazymu, kwasu 2,4-dichlorofenoksyoctowego i kwasu 2,4,5-trichlorofenoksyoctowego podawanych przewlekle z lekami dzialajacymi na uklad krazenia.

The influence of chronically administered (6 weeks) herbicides (KAR, 2,4-D and 2,4,5-T) on pharmacological effects of quinidine, reserpine and strophantin K in mice and rats was examined in vivo. The investigated herbicides produced in mice an increase in acute toxicity of strophantin K, the acute toxicity of either reserpine oro quinidine being unchanged. The herbicides alone, after 6 weeks administration, significantly increased mean arterial pressure of rats, however the hypotensive response to reserpine was not statistically influenced in these animals as compared with controls. The prolonged administration of investigated herbicides produced also the increased sensibility of heart to the arrhythmic effects of quinidine and ouabain as observed in the ecg pattern in rats treated with increasing doses of these agents. The studies indicate the significance of the possible pharmacological interactions between the drugs affecting cardiovascular system and commonly used herbicides in men.

Perioperative use of continuous renal replacement therapy for orthotopic liver transplantation.

PURPOSE: We present a retrospective study describing the perioperative use of continuous renal replacement therapy (CRRT) for orthotopic liver transplantation (OLT). MATERIALS AND METHODS: We retrospectively reviewed the clinical course of patients who underwent OLT with the perioperative use of CRRT. The following variables were recorded: Gender, age, indication for transplantation, time when CRRT was initiated, postoperative need for CRRT, and the patient and organ (liver, kidneys) outcome up to 1 year after transplantation. RESULTS: Among 105 patients who underwent OLT from 2006 to 2010; we used CRRT in 12 cases (11.4%) perioperatively, including 9 (8.3%) patients intraoperatively. Perioperative CRRT was employed for volume, electrolyte, and/or pH management. All patients who underwent CRRT perioperatively were alive at 1 month, 10 (83.3%), at 3 and 6 months and 9 (75%) at 1 year after OLT. Only 1 surviving patient (8.3%) required renal replacement therapy at 1 month after surgery. Renal replacement therapy was not required in any surviving patient up to 12 months posttransplantation. CONCLUSION: Perioperative and especially intraoperative use of CRRT therapy can potentially improve the outcomes of patients undergoing OLT.

Genetic determinants of platelet reactivity during acetylsalicylic acid therapy in diabetic patients: evaluation of 27 polymorphisms within candidate genes.

AIMS: Decreased platelet responsiveness to acetylsalicylic acid (ASA) reported previously in diabetic patients could be attributed to patient-based, clinical, genetic and cellular factors. The objective of the present study was to investigate the effect of the genomic polymorphism on the platelet reactivity in diabetic patients treated with ASA. METHODS AND RESULTS: The study cohort consisted of 295 Caucasians with diabetes type 2 who had been taking ASA tablets at the dose of 75 mg per day for at least 3 months for primary or secondary prevention of myocardial infarction (MI). Platelet reactivity analyzes were performed using VerifyNow ASA and PFA-100 assays. Genotyping for the selected 27 single nucleotide polymorphisms (SNPs) within 19 genes was performed using a Sequenom iPLEX platform. The results indicate that the statistically significant differences in platelet reactivity were observed in the PFA-100 assay for SNPs in following genes: TXBA2R (rs1131882), ADRA2A (rs4311994), PLA2G7 (rs7756935) and 9p21.3 (rs10120688) (P = 0.02, P = 0.03, P = 0.02, P = 0.03, respectively, all significance levels corrected for multiple comparisons). When using the VerifyNow ASA test, a weak nominal statistical significance (i.e. before multiple comparison testing) was observed for two SNPs in the GPVI gene: rs1671152 and rs1613662 [P = 0.025 (0.5) for both SNPs, corrected for multiple comparisons test]. CONCLUSIONS: The results from the present study suggest that the four analyzed genes may contribute to platelet reactivity measured with the PFA-100 assay in the diabetic population treated with ASA.

Fatal hyperammonemia after renal transplant due to late-onset urea cycle deficiency: a case report.

We present a case of severe hyperammonemia with subsequent brain herniation in an adult man after renal transplantation. After successful surgery and an initially uneventful postoperative course, the patient developed significant mental status changes associated with seizure activity. His condition rapidly deteriorated, requiring mechanical ventilation and cardiovascular support. Laboratory studies at that time demonstrated an increased serum ammonia level without evidence of liver or kidney dysfunction. Further investigation revealed an increased orotic acid level in the urine, suggesting a urea cycle disorder (UCD). Despite aggressive therapy, the patient's condition continued to deteriorate. Magnetic resonance imaging demonstrated severe brain edema with no cerebral perfusion; after consultation with the family, care was withdrawn. The combination of hyperammonemia and elevated urine orotic acid with normal liver and kidney function suggested a UCD. It is important to note that patients with a UCD may be free of symptoms for many years. Several factors are able to trigger the disease in adulthood, leading to encephalopathy and death. In this case, the patient's seizures were initially assumed to be a side effect of immunosuppressive therapy. Further diagnostic measures were only performed late in the course of the disease, which delayed the diagnosis of UCD.

Binding of human alpha-interferon in the brain tissue membranes of rat.

The receptor binding characteristics of human lymphoblastoid alpha-interferon (IFN) to human Daudi cell line was compared with its binding to membrane homogenates derived from various regions of rat brain. Rat brain membranes bound specifically a detectable amount of I-125 alpha interferon revealing the receptor affinity constant (Kd) of 3.9-4.2 x 10(-10) M and the Bmax was 0.9-1.7 fmoles/mg wet weight tissue depending on the analyzed brain region (the highest Bmax was obtained in the membranes from the hypothalamus region, the lowest one from the spinal cord membranes).