Final Injections Research Articles

Chronic treatment with paliperidone, like lithium and valproate, induces similar changes in expression and phosphorylation at the synaptoneurosomal level in rat prefrontal cortex (PFC)

Bipolar disorder is treated with mood stabilizers. mRNA data show that these drugs regulate synaptic protein expression. To determine protein levels and post‐translational processing of proteins and to determine if paliperidone (PALI), risperidone active metabolite, regulates synaptic proteins similar to mood stabilizers, we determined protein expression profiles in the PFC with chronic drug treatments. LiCl, valproate (VAL), or PALI was given daily by i.p. injections to 4 male Sprague‐Dawley rats/group for 28 d. Controls = 0.9% saline and 0.3% tartaric acid. Brains were dissected 24 h after final injections. Synaptoneurosomal proteins were extracted and separated by DIGE. Simultaneously, phosphorylation changes were determined (ProQ diamond staining). Reproducibly present data in all biological replicates were analyzed and compared with their respective controls using Interpreter (Ludesi). Proteins with differential expression and phosphorylation were identified by nano‐LC MS. PALI, LiCl, and VAL treatment resulted in similar protein expression profiles and phosphorylation patterns at the synaptoneurosomal level, suggesting that the mode of action for this drug is similar to that of mood stabilizers and supporting its use for this purpose. Interestingly, the expression profile for PALI was more similar to that of LiCl than that of VAL. Supported by a grant from Janssen Pharmaceutica, Inc.

Clinical Profile of Botulinum Toxin A in Patients with Chronic Headaches and Cervical Dystonia

Some evidence for the efficacy of botulinum toxin A as a preventive treatment for chronic primary headaches has been reported in randomized, controlled clinical studies. This study investigated the clinical profile of botulinum toxin A in a naturalistic clinical practice setting in a population of patients with cervical dystonia associated with chronic headache and a history of migraine. This was a prospective, open-label, longitudinal study. Following a prospective run-in period, eligible patients were given three sets of botulinum toxin A injections at 8- to 12-week intervals over a 16- to 24-week period and were monitored for 3 months after the final injections. Efficacy was assessed in terms of headache-related disability (using the Migraine Disability Assessment [MIDAS] questionnaire), pain and emotional function (using the Short Pain Inventory [SPI]), quality of life (QOL, using the Short-Form-36 [SF-36] questionnaire) and patient-assessed headache frequency and severity, and medication use and its effectiveness. Safety was assessed as adverse events. The primary endpoint was the change in MIDAS score from baseline following treatment with botulinum toxin A. Twenty-four patients took part in the study and 17 (71%) completed the study. There were significant improvements in headache-related disability (MIDAS score), pain and emotional function (SPI), QOL (SF-36), headache frequency and medication use following treatment with botulinum toxin A (p < 0.05 for all endpoints). An efficacy response occurred within 8 weeks of treatment initiation and was maintained throughout the study duration. Botulinum toxin A was generally well tolerated. This study demonstrated that botulinum toxin A is an effective and well tolerated preventive treatment for chronic headache in patients with cervical dystonia and a history of migraine. These results warrant further investigation in a large, randomized, controlled study.

Crystal Structure of Human Estrogen-related Receptor α in Complex with a Synthetic Inverse Agonist Reveals Its Novel Molecular Mechanism

Inverse agonists of the constitutively active human estrogen-related receptor alpha (ERRalpha, NR3B1) are of potential interest for several disease indications (e.g. breast cancer, metabolic diseases, or osteoporosis). ERRalpha is constitutively active, because its ligand binding pocket (LBP) is practically filled with side chains (in particular with Phe(328), which is replaced by Ala in ERRbeta and ERRgamma). We present here the crystal structure of the ligand binding domain of ERRalpha (containing the mutation C325S) in complex with the inverse agonist cyclohexylmethyl-(1-p-tolyl-1H-indol-3-ylmethyl)-amine (compound 1a), to a resolution of 2.3A(.) The structure reveals the dramatic multiple conformational changes in the LBP, which create the necessary space for the ligand. As a consequence of the new side chain conformation of Phe(328) (on helix H3), Phe(510)(H12) has to move away, and thus the activation helix H12 is displaced from its agonist position. This is a novel mechanism of H12 inactivation, different from ERRgamma, estrogen receptor (ER) alpha, and ERbeta. H12 binds (with a surprising binding mode) in the coactivator groove of its ligand binding domain, at a similar place as a coactivator peptide. This is in contrast to ERRgamma but resembles the situation for ERalpha (raloxifene or 4-hydroxytamoxifen complexes). Our results explain the novel molecular mechanism of an inverse agonist for ERRalpha and provide the basis for rational drug design to obtain isotype-specific inverse agonists of this potential new drug target. Despite a practically filled LBP, the finding that a suitable ligand can induce an opening of the cavity also has broad implications for other orphan nuclear hormone receptors (e.g. the NGFI-B subfamily).

Effects of botulinum toxin type A and a programme of functional activity to improve manual ability in children and adolescents with cerebral palsy

We aimed to evaluate the effectiveness of a clinical programme that combined botulinum toxin injections with a functional activity programme to improve manual ability in children and adolescents with cerebral palsy. A total of 25 young people age range 2 to 19 years participated. They were given injections of botulinum toxin type A into spastic muscles in the upper extremities and participated in a functional activity training programme. Standardised clinical assessments were made before injections, one to two months after, and six months after, the final injections. To assess if the treatment had changed their ability to use the treated hand in activities of everyday life a questionnaire was given to the parents. The families thought that the ability had improved, and that the improvements took place both during the first three months after treatment and after more than six months after the final injections. The ability to extend wrist and fingers actively and the position of the thumb had improved significantly both in the short and long- term. This study supports the assumption that a programme combining botulinum toxin A injections with training in functional activity improves manual ability in young people with cerebral palsy.

Low-intensity exercise training during doxorubicin treatment protects against cardiotoxicity

Doxorubicin (Dox) is a highly effective antineoplastic antibiotic associated with a dose-limiting cardiotoxicity that may result in irreversible cardiomyopathy and heart failure. The purpose of this study was to examine the effects of low-intensity exercise training (LIET) during the course of Dox treatment on cardiac function, myosin heavy chain expression, oxidative stress, and apoptosis activation following treatment. Male Sprague-Dawley rats either remained sedentary or were exercise trained on a motorized treadmill at 15 m/min, 20 min/day, 5 days/wk (Monday through Friday) for 2 wk. During the same 2-wk period, Dox (2.5 mg/kg) or saline was administered intraperitoneally to sedentary and exercised rats 3 days/wk (Monday, Wednesday, Friday) 1-2 h following the exercise training sessions (cumulative Dox dose: 15 mg/kg). Five days following the final injections, hearts were isolated for determination of left ventricular (LV) function, lipid peroxidation, antioxidant enzyme protein expression, 72-kDa heat shock protein expression, caspase-3 activity, and myosin heavy chain isoform expression. Dox treatment significantly impaired LV function and increased caspase-3 activity in sedentary animals (P < 0.05). LIET attenuated the LV dysfunction and apoptotic signal activation induced by Dox treatment and increased glutathione peroxidase expression, but it had no significant effect on lipid peroxidation, protein expression of myosin heavy chain isoforms, 72-kDa heat shock protein, or superoxide dismutase isoforms. In conclusion, our data suggest that LIET applied during chronic Dox treatment protects against cardiac dysfunction following treatment, possibly by enhancing antioxidant defenses and inhibiting apoptosis.

Cyclosporine A‐Induced Changes to Erythrocyte Redox Balance is Time Course‐Dependent

Cyclosporine A-treated transplant recipients develop pronounced cardiovascular disease and have increased oxidative stress and altered antioxidant capacity in erythrocytes and plasma. These experiments investigated the time-course of cyclosporine A-induced changes to redox balance in plasma and erythrocytes. Rats were randomly assigned to either a control or cyclosporine A-treated group. Treatment animals received 25 mg/kg of cyclosporine A via intraperitoneal injection for either 7 days or a single dose. Control rats were injected with the same volume of the vehicle. Three hours after the final injections, plasma was analysed for total antioxidant status, alpha-tocopherol, malondialdehyde, and creatinine. Erythrocytes were analysed for reduced glutathione (GSH), alpha-tocopherol, methaemoglobin, malondialdehyde, and the activities of superoxide dismutase, catalase, GSH peroxidase, and glucose-6-phosphate dehydrogenase (G6PD). Cyclosporine A administration for 7 days resulted in a significant increase (P<0.05) in plasma malondialdehyde, methaemoglobin, and superoxide dismutase and catalase activities. There was a significant decrease (P<0.05) in erythrocyte GSH concentration and G6PD activity in cyclosporine A animals. There were no significant differences (P>0.05) between groups following a single dose of cyclosporine A in any of the measures. In summary, cyclosporine A alters erythrocyte redox balance after 7 days administration, but not after a single dose.

Minimal injection site pain and high patient satisfaction during treatment with long-acting risperidone

Long-acting injectable antipsychotic formulations of conventional antipsychotics were developed to address the problem of partial adherence among patients with schizophrenia. Injection site pain, other skin reactions and patient satisfaction with treatment were assessed in two large, multicentre studies of long-acting injectable risperidone (Risperdal CONSTA, Janssen Pharmaceutica Products, Titusville, New Jersey, USA), the first available long-acting atypical antipsychotic agent. Patients rated injection site pain using a 100-mm Visual Analogue Scale (VAS), and investigators rated injection site pain, redness, swelling and induration. Patient satisfaction with treatment was assessed with the Drug Attitude Inventory (DAI). VAS pain ratings were low at all visits across all doses in both studies, and decreased from first to final injection. In the 12-week, double-blind study, mean +/- SD VAS scores at the first and final injections were 15.6 +/- 20.7 and 12.5 +/- 18.3 for placebo-treated patients, and 11.8 +/- 14.4 (first) and 10.0 +/- 12.4 (final) for 25 mg; 16.3+/-21.9 (first) and 13.6 +/- 21.7 (final) for 50 mg; and 16.0 +/- 17.9 (first) and 9.6 +/- 16.0 (final, P<0.01) for 75 mg of long-acting risperidone. Mean VAS scores in the 50-week, open-label study at the first and final injection were: 17.9 +/- 22.2 (first) and 9.5 +/- 16.7 (final, P<0.0001) for 25 mg; 18.1 +/- 19.7 (first) and 10.4 +/- 14.8 (final, P<0.0001) for 50 mg; and 18.5 +/- 21.6 (first) and 13.6 +/- 19.9 (final, P = 0.0001) for 75 mg of long-acting risperidone. Overall, there was no or minimal injection site pain and skin reactions were rare. Mean DAI ratings were available for the 50-week study and indicated high patient satisfaction throughout the trial (baseline = 7.30; endpoint = 7.70; P<0.0001 versus baseline). These findings may positively affect patient and clinician attitudes towards long-term therapy with long-acting injectable risperidone.

The mafic potassic intrusion of Pariquera-Açu, São Paulo, Brazil

This paper describes the geological, petrographic, mineralogic and chemical characteristics of the mafic potassic intrusion of Pariquera-Acu (P-A), southern Sao Paulo. The studied rock assemblage comprises members of the high-K alkalic magma series. Nepheline, orthoclase and clinopyroxene are the essential minerals present in all samples examined microscopically. Olivine, biotite and magnetite are also present. Plagioclase is absent. The series range from nepheline syenite to alkali pyroxenite with strong dominance of shonkinites and malignites. Alkali diabase dykes were also sampled. The alkalic magma intruded Proterozoic phyllites along tensile fractures.The intrusion is conceivably shaped as sub-vertical ring dykes with internal occupancy of sub-horizontal magma sheets. Sharply discordant contacts and occurrence of low to medium angle sheets of shonkinite and of unstrained intrusion breccias, give support to the idea of a pipe-like magmatic body formed by ring-fracture, stoping of a roof slab and final magma injections. It is suggested that small degrees of partial melting of a phlogopite-bearing mantle peridotite could produce the high K2O magma responsible for the generation of the P-A rocks.

Amphetamine modulation of paced mating behavior

The present study evaluated the effects of acute and repeated, intermittent amphetamine administration on paced mating behavior in ovariectomized (OVX) rats primed with estrogen and progesterone. In Experiment 1, female rats were tested for paced mating behavior following acute administration of amphetamine (1.0 mg/kg). Amphetamine increased the likelihood that a female would withdraw from a male following a mount or an intromission. Although this dose of amphetamine did not alter sexual receptivity or the latency to return to a male after sexual stimulation, locomotor activity was increased significantly. Experiment 2 evaluated the dose response characteristics of acute amphetamine (0.5, 1.0 and 2.0 mg/kg) administration on paced mating behavior. In agreement with Experiment 1, amphetamine at all doses increased the likelihood that a female would withdraw from a male following sexual stimulation. In Experiment 3, female rats were tested for partner preference (sexually active male vs. estrous female) following acute amphetamine administration. Amphetamine treatment augmented both social and sexual preferences. In Experiment 4, female rats were administered estrogen (20 μg/kg) and amphetamine (1.0 mg/kg) for 3 weeks and tested for paced mating behavior 1 and 4 weeks later, amphetamine free. Repeated intermittent exposure to amphetamine shortened the latency to return to a male after receiving a mount on the test conducted 1 week after the final drug injections. Collectively, these results suggest that the acute effects of amphetamine on paced mating behavior may reflect a reduction in social and sexual behaviors and an increase in locomotor activity, whereas the effects of repeated exposure may reflect a change in incentive motivation.

Placebo controlled study of an angiotensin immunotherapeutic vaccine (PMD3117) in hypertensive subjects

Immunisation against the renin system might obviate the need for daily drug administration. No previous study has determined whether a sustained antibody titre can be achieved, and whether this might have pharmacological activity. Our primary objective was to determine the antibody response to two PMD3117 vaccine dosing regimes. Secondary objectives were to assess tolerability, and to determine if immunisation changes renin and aldosterone secretion, or attenuates the BP rise after withdrawal from an ACE inhibitor. PMD3117 is a 12 amino acid analogue of angiotensin-I linked to Keyhole Limpet Haemocyanin, and adsorbed onto aluminium hydroxide (Alhydrogel™). 24 patients responsive to an ACE inhibitor or angiotensin blocker were randomly assigned to 3 or 4 subcutaneous injections over 6 weeks with 100 mg peptide equivalent of PMD3117 or Alhydrogel. Blood was drawn at each visit for estimation of renin, aldosterone, and the IgG antibodies to angiotensin. Existing treatment was withdrawn for 2 weeks before and after the 6 weeks of vaccination. 24-ABPM was performed at the start and finish of the withdrawals. (See Figure) Median titres of 6739 and 11548 respectively for the 3- and 4-dose regimen were present by day 64 (left panel), and declined thereafter with median half-life of 85 days (95% CI[44,153] days). Clinic BP did not differ between PMD3117 and Alhydrogel, but 24-hour SBP on day 64 was 7.5 mmHg lower in the 4-dose than 3-dose PMD3117 subjects (p<0.01). PMD3117 reduced 24 h aldosterone excretion at 6 weeks to 6% (95% CI[1,31]%) of control (p<0.01) (middle panel) and plasma renin was elevated ∼2-fold (right panel). Transient local swelling and itching occurred after some of the final PMD3117 injections. One patient from each group withdrew. PMD3117 offers a well tolerated means for inducing a prolonged antibody titre against the renin system. Although a higher titre is likely to be required for BP reduction, the secondary endpoints already show evidence of pharmacological blockade.

Variable Effects of Previously Untested Muscarinic Receptor Antagonists on Experimental Myopia

Atropine, pirenzepine, and himbacine prevent form-deprivation myopia (FDM) when administered intravitreously. The mechanisms and sites of action of these drugs against myopia are not clear. To shed further light on whether this mechanism is muscarinic, several other muscarinic antagonists were tested. Various concentrations of atropine, pirenzepine, dexetimide, scopolamine, tropicamide, benztropine, dicyclomine, gallamine, mepenzolate, oxyphenonium, propantheline, procyclidine, 4-diphenylacetoxy-N-methylpiperidine (4-DAMP), hexahydro-sila-difenidol (HHSiD), p-fluorohexahydro-sila-difenidol (pf-HHSiD), methoctramine, AFDX-116, and quinuclidinyl benzilate (QNB) were injected into goggled eyes of Leghorn cockerels three times at 48-hour intervals. Fellow control eyes received saline. Control animals received saline in both eyes. Twenty-four hours after final injections, refraction, eye weight, and axial length were measured, and eyes were prepared for microscopy. Other than atropine and pirenzepine, only oxyphenonium caused full rescue from FDM (goggled versus control; mean +/- SD; refraction differences: -9.50 +/- 0.22 D vs. 0.83 +/- 0.31 D, P < 0.001; wet weight differences: 75.67 +/- 3.84 mg vs. 2.33 +/- 6.14 mg, P < 0.001; axial length differences: 0.80 +/- 0.05 mm vs. 0.03 +/- 0.04 mm, P < 0.001). Oxyphenonium-treated retinas showed no damage. Of the other compounds, several elicited partial rescue and/or damaged the retina, whereas others had no effect. Oxyphenonium prevents FDM in chicks. The ineffectiveness or partial effectiveness of other compounds, coupled with the high concentrations of effective compounds required to prevent FDM, suggests that muscarinic antagonists act to prevent FDM, either at sites distant from the retina, or through a nonmuscarinic mechanism, on which only some of these drugs act.

The Anabolic Effects of Vitamin D-Binding Protein- Macrophage Activating Factor (DBP-MAF) and a Novel Small Peptide on Bone

Vitamin D-binding protein-macrophage activating factor (DBP-MAF) has previously been shown to stimulate bone resorption and correct the skeletal defects associated with osteopetrosis in two nonallelic mutations in rats. This same protein and a small fragment of the protein have now been shown to demonstrate an anabolic effect on the skeleton of both newborn and young adult, intact rats. The novel peptide fragment was synthetically produced based on the human amino acid sequence at the site of glycosylation in the third domain of the native protein (DBP). The peptide tested is 14 amino acids in length and demonstrates no homologies other than to that region of DBP. Newborn rats were injected i.p. with saline, peptide (0.4 ng/g body wt.) or DBP-MAF (2 ng/g body wt.) every other day from birth to 14 days of age. On day 16 the rats were euthanized and the long bones collected for bone densitometry by pQCT. After 2 weeks of treatment with either the whole protein (DBP-MAF) or the small peptide, bone density was significantly increased in the treated animals compared to the saline controls. Young adult female rats (180 grams) were given s.c. injections of saline or peptide (0.4 ng/g body wt. or 5 ng/g body wt.) every other day for 2 weeks; 2 days after the final injections, the rats were euthanized and the femurs and tibias collected for bone densitometry. Both doses of the peptide resulted in significant increases in bone density as determined by pQCT. Young adult rats were injected locally with a single dose of the peptide (1 microg) or saline into the marrow cavity of the distal femur. One week after the single injection, the bones were collected for radiographic and histological evaluation. The saline controls showed no evidence of new bone formation, whereas the peptide-treated animals demonstrated osteoinduction in the marrow cavity and osteogenesis of surrounding cortical and metaphyseal bone. These data suggest that DBP-MAF and the synthetic peptide represent therapeutic opportunities for the treatment of a number of bone diseases and skeletal disorders. Systemic administration could be used to treat osteoporosis and a number of other osteopenias, and local administration could be effective in fractures, bony defect repairs, spinal surgery, and joint replacement.

Administration of recombinant porcine somatotropin (rpST) changes hormone and metabolic status during early pregnancy

The objective of this study was to examine the effects of somatotropin (ST) on porcine reproductive and metabolic statuses during early pregnancy. Four pregnant crossbred gilts received 6 mg of recombinant porcine somatotropin (rpST) daily from days 10 to 27 after artificial insemination while six pregnant gilts served as controls. Blood samples were taken on days 8, 10, 12, 14, 18, 22, and 27 prior to rpST injections (8:00 h) and subsequently at 9:00, 10:00, 12:00, 14:00, 16:00, 18:00, and 20:00 h. On all remaining days of treatment, samples were taken once daily before injections (8:00 h). The samples were assayed for the metabolic hormones: ST, insulin-like growth factor I (IGF-I), insulin, thyroxine (T 4), triiodothyronine (T 3), and cortisol; for metabolites: free fatty acids (FFA) and glucose; and for the reproductive hormones: luteinizing hormone (LH), progesterone, estradiol-17β, estrone sulfate, and prostaglandin F 2α. Delivery of rpST daily induced a 20- to 40-fold increase in plasma ST concentrations. Moreover, repeated administration of rpST resulted in a continuous increase in plasma IGF-I concentration ( P<0.001), from 191.0±22.3–340.0±15.3 ng/mL 24 h after initial injection to 591.3±46.8 ng/mL after final injections. Mean serum insulin tended to be greater in rpST-treated gilts. Blood concentrations of T 4 were reduced ( P<0.05) from day 14 of gestation in treated gilts while T 3 concentrations remained unchanged. Concentrations of both glucose and FFA were greater ( P<0.01) and cortisol concentrations were unchanged in treated gilts. Changes in reproductive steroid hormones were minimally affected. Circulating progesterone ( P=0.078), and estradiol-17β ( P=0.087) concentrations tended to be lower in treated animals. These data show that treatment of pregnant gilts with rpST during early gestation mainly impacts metabolic rather than reproductive status.

The Effect of μ-Opioid Receptor Antisense on Morphine Potency and Antagonist-Induced Supersensitivity and Receptor Upregulation

The present study examined the effect of in vivo antisense oligodeoxynucleotide treatment on naltrexone (NTX)-induced functional supersensitivity and μ-opioid receptor upregulation in mice. On day 1 mice were implanted SC with a NTX or placebo pellet and injected IT and ICV with dH2O or oligodeoxynucleotides. The oligodeoxynucleotides were designed so that they were either perfectly complementary to the first 18 bases of the coding region of mouse μ-opioid receptor mRNA, or had one (Mismatch-1) or four (Mismatch-4) mismatches. On days 3, 5, 7, and 9, mice were again injected IT and ICV with dH2O or one of the oligodeoxynucleotides. After the final injections on day 9, placebo and NTX pellets were removed, and 24 h later mice were tested for morphine analgesia or sacrificed for saturation binding studies ([3H]DAMGO). Naltrexone increased the analgesic potency of morphine in dH2O treated mice by ≈ 70%. In binding studies, NTX significantly increased density of brain (≈ 60%) and spinal cord (≈ 140%) μ-opioid receptors without affecting affinity. The μ-opioid antisense and the oligodeoxynucleotide with one mismatch (Mismatch-1) significantly reduced the potency of morphine by ≈ twofold in placebo-treated mice. The oligodeoxynucleotide with four mismatches (Mismatch-4) did not significantly alter morphine potency. When placebo-treated mice were treated with either the antisense to the mouse μ-opioid receptor, Mismatch-4 or Mismatch-1 there were no significant changes in the density of μ-opioid receptors. Thus, μ-opioid antisense significantly reduced morphine potency without changing μ-opioid receptor density. When NTX and oligodeoxynucleotide treatments were combined, there was no change in NTX-induced supersensitivity and μ-opioid receptor upregulation. These data suggest that opioid antagonist-induced supersensitivity and upregulation of μ-opioid receptors does not involve changes in gene expression.

Tolerability of Multiple Administration of Intramuscular Meloxicam: A Comparison with Intramuscular Piroxicam in Patients with Rheumatoid Arthritis or Osteoarthritis

This multicentre, randomized, open controlled study compared the local and overall tolerability of i.m. meloxicam with i.m. piroxicam in 211 patients with rheumatoid arthritis (RA) (n = 95) or osteoarthritis (OA) (n = 116). Of these, 210 patients were randomized (2:1) to receive meloxicam 15 mg (n = 144) or piroxicam 20 mg (n = 66) for 7 days. Local tolerability of meloxicam was significantly better than piroxicam with respect to occurrence of redness after the first injection (P = 0.03) and global assessment after the first and final injections (P < 0.05). No rise in creatinine phosphokinase levels (a marker of muscle fibre damage) was observed with meloxicam, in contrast to piroxicam (P = 0.0001). The overall tolerability of both treatments was good. Significant differences in favour of meloxicam were observed for global efficacy assessed by the patient in RA (P < 0.05) and for overall pain intensity in OA patients (P = 0.02). In conclusion, i.m. meloxicam is safe and effective for the treatment of acute rheumatic pain and shows some superiority over piroxicam.

Calcitonin decreases corticosterone-induced skeletal muscle calpain activity.

The effects of calcitonin (CT) administration on calcium (Ca) concentrations in plasma and skeletal muscle as well as the calpain activity of skeletal muscle were examined in young growing male rats treated with corticosterone (CTC). The rats received subcutaneous injections of CTC (5 mg/100 g body weight/day), or both CTC and CT (100 m unit/100 g body weight/day) for four days. Control rats received placebos. The rats were sacrificed 24 h after the final injections, and blood was taken followed by dissections to remove gastrocnemius and extensor digitorum longus muscles. Plasma Ca concentration was increased and muscle Ca concentration and its calpain activity tended to be increased by CTC. The CTC-induced increases in muscle Ca concentration and its calpain activity were significantly minimized by the simultaneous injection of CT. However, CTC-induced hypercalcemia was not minimized by CT. The present observations indicate that CT decreases Ca concentration in skeletal muscle cell and its calpain activity, followed by a suppression of muscle proteolysis in rats treated with CTC.

Alteration of intestinal microbial ecology in mice by recombinant interleuken-2

In addition to its beneficial immunostimulatory properties, interleukin-2 (IL-2) has many significant side effects including gastrointestinal (GI) toxicities. Preliminary studies of the effects of IL-2 on GI bacterial translocation suggested that IL-2 altered intestinal bacterial population levels. In order to further define the effects of IL-2 on intestinal microecology, groups of specific pathogen-free C57BL/6 mice were injected subcutaneously twice daily for 5 days with various dosages of human recombinant IL-2 (up to a maximum of 1.6 mg/kg injection) or an equal volume of sterile buffer. One day after the final injections, IL-2 had significantly (P<.05) increased in a dose-dependent fashion the mean cecal population levels of indigenousEscherichia coli, other gram-negative bacilli, streptococci, and staphylococci. Maximum increases above control cecal population levels were more than 10,000-fold forE. coli and streptococci, 209-fold for gram-negative bacilli other thanE. coli, and 93-fold for staphylococci. These changes were completely reversible, with normal cecal population levels 12 days after the last IL-2 injection. IL-2 did not change the total cecal population levels of strictly anaerobic bacteria. Ileal and cecal structures, as assessed by light microscopy, were not altered by the highest dose of IL-2. When incubated in vivo with 1.6 mg/ml of IL-2, the growth of an indigenous strain ofE. coli was not different from growth in broth alone. Thus, IL-2 treatment caused the intestinal overgrowth of common opportunistic aerobic and facultatively anaerobic bacterial pathogens, without altering total population levels of strict anaerobes or affecting intestinal histology.

Regulation of striatonigral prodynorphin peptides by dopaminergic agents

The primary purpose of this study was to examine the regulation of prodynorphin peptides by dopaminergic agents in the central nervous system. The indirectly acting catecholamine agonistd-amphetamine sulfate (AMPH) and the dopamine receptor antagonist haloperidol (HAL) were administered to rats across a variety of treatment schedules and drug doses. The striatum, substantia nigra and hippocampus were dissected and examined by radioimmunoassay for 5 different prodynorphin peptides, covering all 3 opioid domains in the prodynorphin precursor: dynorphin A(1–8) and dynorphin A(1–17) of the dynorphin A domain, dynorphin B(1–13) of the dynorphin B domain, and α-neo-endorphin and ß-neo-endorphin of the neo-endorphin domain. In addition, the proenkephalin peptide Met-enkephalin-arg6-gly7-leu8 (MERGL) was examined in the striatum. AMPH administered one hour prior to sacrifice caused a dose-dependentdepletion of prodynorphin peptides in both the striatum and substantia nigra. In animals treated with AMPH once each day for 7 days and sacrificed 24 h later, a dramatic dose-dependentincrease in prodynorphin peptides was observed in these brain regions. Animals treated with AMPH once each day for 7 days and sacrificed one hour after the final injections showed no changes in prodynorphin peptides. In addition to changes in individual prodynorphin peptides, AMPH treatment caused alterations in the relationships between intermediate peptides (dynorphin A(1–17) and α-neo-endorphin) and their immediate products (dynorphin A(1–8) and ß-neo-endorphin). AMPH caused no consistent changes in prodynorphin peptides in the hippocampus, or in MERGL in the striatum. Taken together these data suggest that acute dopaminergic activation causes depletion of dynorphins from striatonigral prodynorphin neurons, presumably due to dopamine-dependent release of these peptides; repeated activation causes repeated release, with a rebound increase in biosynthesis. HAL, in contrast to AMPH caused relatively subtle changes in striatonigral prodynorphin peptides. Although no significant changes in individual prodynorphin peptides were observed, HAL treatment caused a change in the relationship between dynorphin A(1–17) and dynorphin A(1–8), a change in direction to that observed with AMPH treatment. As has been previously reported, repeated HAL administration caused a dose-dependent increase in the proenkephalin peptide MERGL. The relatively subtle effects of HAL on prodynorphin peptides suggests that tonic dopamine activity is not important in the regulation of striatonigral prodynorphin neurons. The potential functional and behavioral significance of the present results are discussed.

Effects of Chronic Ochratoxin A and Citrinin Toxicosis on Kidney Function of Single Comb White Leghorn Pullets

The objectives of the present study were to examine the effects of repeated or chronic ochratoxin A (OA) and citrinin exposure, and to determine if severe ochratoxicosis permanently alters renal function in pullets. The OA-treated birds were injected intramuscularly (breast muscle) with a 1 mg/mL solution of OA at a dose of .25 mg/kg BW or .5 mg/kg BW. Citrinin-treated birds were injected with a 6 mg/mL solution of citrinin at a dose of 6 mg/kg BW. Control birds received an equal volume injection of the citrinin and OA solvent, 100% ethanol, at a dose of 1 mL/kg BW. Kidney function was evaluated after 10 consecutive days of OA, citrinin, or ethanol injection, and 2 wk following the final injections. Venous blood gas measurements were taken after the seventh day of injection.The OA increased urine flow rate, decreased urine osmolality, increased ion excretion (Na, K, Ca, P), increased water consumption, increased manure moisture, and caused a relative alkalosis when measured immediately after 10 days of OA injection. These effects of OA were not detected 2 wk later. Citrinin increased manure moisture, decreased plasma P, increased the clearance of para-aminohippuric acid, and had no consistent effect on blood acid-base parameters. The results suggest that OA may cause an osmotic diuresis by inhibiting tubular reabsorption of electrolytes. The data also suggest that the effects of OA may be reversible simply by discontinuing toxin administration. Although the citrinin-induced increase in manure moisture indicates that citrinin had an effect on renal function, renal function analysis suggests that even repeated exposure to high doses of citrinin may only have a short duration of diuretic action on the kidneys.

Effects of chronic lithium, amitriptyline and mianserin on glucoregulation, corticosterone and energy balance in the rat

Major negative side-effects reported for mood-stabilizing and antidepressant drugs in humans are excess weight gain and carbohydrate craving. The aim of the present study was to establish whether the rat could usefully be employed in investigation of these phenomena. Three experiments investigated the effects of chronic lithium (40 mg/kg LiCl), amitriptyline (2.5 mg/kg), mianserin (2.5 mg/kg) and saline administration (15–20 days, one subcutaneous injection/day) on body weight, food intake and fluid intake. Water and food cubes were provided in all experiments. Additionally available, as separate fluid sources, in Experiment 2 were 24% sucrose and 0.6% saccharin and in Experiment 3, 0.6% saccharin. Blood was collected for plasma glucose and insulin determinations 20–24 hours after the final injections. Lithium administration resulted in a marked increase in weight gain but only if both sucrose and saccharin were available (Experiment 2). Saccharin intake was increased with lithium treatment as was total caloric intake with sucrose available. Amitriptyline induced a sweetness craving; however, weight gain was somewhat depressed with just cubes available (Experiment 1) and only normalised by the additional availability of sucrose and saccharin (Experiment 2). With amitriptyline, total caloric intake was never different from controls. Weight gain was slightly suppressed and caloric intake slightly elevated by mianserin but importantly the two effects combined for a decrease in metabolic efficiency which was particularly exaggerated under the condition of carbohydrate availability (Experiment 2). Lithium and amitriptyline both produced hyperinsulinemia with normoglycemia whether or not the rate of weight gain was changed and whether or not intake was increased. Corticosterone levels were elevated by all drug treatments in Experiment 1. However, additional availability of carbohydrate dramatically suppressed corticosterone levels to saline control levels in all drug-treated groups. Further, carbohydrate availability in saline treated animals further reduced corticosterone levels to 50% of chow-fed saline controls. The results demonstrate the usefulness of the rat for the study of the energy balance perturbations attendant upon the use of some mood-stabilizing and antidepressant drugs and focus on carbohydrates as a major contributing factor.