Showing papers on "Intraperitoneal injection published in 1989"

Expression of c-Fos immunoreactivity in transmitter-characterized neurons after stress

Abstract: The effect of intracerebroventricular injection of the mitosis inhibitor colchicine and of immobilization stress, subcutaneous injection of capsaicin, and intraperitoneal injection of hypertonic salt solution on expression of c-Fos-like immunoreactivity was studied in the rat brain with immunohistochemistry. All the procedures induced c-Fos immunoreactivity in parvocellular neurons of the paraventricular nucleus, and many of these neurons also contained corticotropin-releasing factor immunoreactivity. c-Fos immunoreactivity was also observed, for example, in subpopulations of neurons in the locus coeruleus, the ventrolateral medulla oblongata, and the nucleus tractus solitarii. Many of these cells also expressed catecholamine-synthesizing enzymes. The results suggest that intraventricular injection of colchicine is a stressful stimulus and support the view that several catecholamine cell groups in the lower brainstem are part of the brain circuitry mediating stress reactions, as are the hypothalamic neurons that contain corticotropin-releasing factor.

Membrane docosahexaenoate is supplied to the developing brain and retina by the liver.

Abstract: Docosahexaenoic acid [22:6 omega 3; 22:6(4, 7, 10, 13, 16, 19)] is concentrated in phospholipids of cellular membranes from brain and retina. Although linolenic acid [18:3 omega 3; 18:3(9, 12, 15)] is the major omega 3 fatty acid of mouse dams' milk, 22:6 is the prevalent omega 3 fatty acid in serum and tissues. Intraperitoneal injection of [1-14C]18:3 into 3-day-old mouse pups resulted in liver and serum lipid labeling that was initially high, followed by a rapid decline. In contrast, labeling of brain and retinal lipids were initially low and increased with time. Labeled 22:6 first appeared in liver 2 hr after injection and later in brain and retina. We suggest that 22:6 synthesized from 18:3 by the liver is secreted into the bloodstream in lipoproteins, taken up by brain and retina, and incorporated into cell membranes. We hypothesize that the 22:6 requirements of membranes (e.g., during synaptogenesis, photoreceptor membrane biogenesis, or repair after ischemic injury or neurodegenerative disorders) are met by a signal that is sent by the appropriate tissues to the liver to evoke the secretion of 22:6-containing lipoproteins.

Differential regulation of lipopolysaccharide-induced interleukin 1 and tumor necrosis factor synthesis: effects of endogenous and exogenous glucocorticoids and the role of the pituitary-adrenal axis.

Abstract: Intraperitoneal injection of a sublethal dose of lipopolysaccharide (LPS) into mice resulted in the appearance of tumor necrosis factor (TNF) in the serum within 45 min. Maximal serum TNF was detected by 1 h, and by 3-4 h TNF levels were no longer significantly above baseline. Injection of mice with an additional dose of LPS at 4 h resulted in no further increase in serum TNF. The in vivo kinetics of TNF appearance correlated with in vitro studies in which TNF mRNA was detected in murine peritoneal macrophages 30 min after LPS stimulation. The increase in serum TNF was not detected in mice treated with dexamethasone, 3 mg/kg, prior to LPS stimulation. The decrease in TNF correlated with the appearance of significant amounts of endogenous serum corticosterone which were maximal by 3 h. Further evidence for the role of endogenous steroids in the modulation of serum TNF levels was obtained in studies with adrenalectomized or hypophysectomized mice. Compared to sham-operated animals, serum TNF levels remain elevated 5 h post LPS stimulation in adrenalectomized or hypophysectomized mice. In contrast with the transient increase in TNF, serum IL 1 was maximal 4 h post LPS injection and remained elevated at 24 h. In vitro studies with primary cultures of human peripheral blood monocytes and human umbilical cord vein endothelial cells demonstrated that LPS-induced monocyte IL 1 levels were reduced approximately 5-fold by 10(-7) M dexamethasone while dexamethasone had only minimal effects on endothelial cell IL 1. Therefore, the in vitro data would suggest that the maintenance of elevated IL 1 levels coincident with the appearance of endogenous corticosteroids during LPS shock is related to the synthesis of IL 1 by both monocyte-macrophages and non-myeloid cell populations including endothelial cells.

5‐HT3 receptor antagonists injected into the area postrema inhibit cisplatin‐induced emesis in the ferret

Abstract: 1. The purpose of the present study was to identify and investigate the role of 5-hydroxytryptamine3 (5-HT3) receptors in the area postrema in the control of cisplatin-induced emesis in the ferret. 2. Homogenate binding and autoradiography experiments using the high affinity 5-HT3 receptor ligand, [3H]-GR65630, identified the presence of a high concentration of 5-HT3 receptors in the area postrema of the ferret. 3. Intraperitoneal injection of the 5-HT3 receptor antagonists, GR38032F, GR65630A and MDL72222, at doses of 1, 0.1 and 1 mg kg-1 respectively, inhibited emesis induced by cisplatin, 9 mg kg-1 i.p. 4. Discrete injection of low doses of the 5-HT3 receptor antagonists directly into the area postrema region also inhibited cisplatin-induced (9 mg kg-1 i.p.) emesis. The dose ranges used were: GR38032F, 0.01-1 microgram; GR65630A, 0.001-0.1 microgram; MDL72222, 0.1-10 micrograms. 5. Cisplatin-induced emesis was not inhibited by discrete injection of ketanserin (30 micrograms) or methiothepin (30 micrograms) into the area postrema. Injection of the 5-HT3 receptor agonist, 2-methyl-5-HT, directly into the area postrema produced an incomplete emetic response. 6. These results confirm a role of 5-HT, and in particular 5-HT3 receptors, in the control of cisplatin-induced emesis, and show that at least one functional site for these receptors in modulating the emetic response is the area postrema, the locus of the chemoreceptor trigger zone.

Long-lasting skin allograft tolerance in adult mice induced across fully allogeneic (multimajor H-2 plus multiminor histocompatibility) antigen barriers by a tolerance-inducing method using cyclophosphamide.

Abstract: A new method of cyclophosphamide (CP)-induced skin allograft tolerance in mice that can regularly overcome fully allogeneic (major H-2 plus non-H-2) antigen barriers in mice has been established. The components of the method are intravenous or intraperitoneal administration of 50-100 micrograms of anti-Thy-1.2 mAb on day -1, intravenous injection of 90 x 10(6) allogeneic spleen cells mixed with 30 x 10(6) allogeneic bone marrow cells from the same donor on day 0, and intraperitoneal injection of 200 mg/kg CP on day 2. In each of four fully allogeneic donor\---|-recipient combinations, including C3H/HeJ (C3H; H-2k)\---|-C57BL/6J(B6; H-2b), B6\---|-C3H, BALB/cByJ (BALB; H-2d)\---|-B6, and BALB\---|-C3H, long-lasting survival of skin allografts was induced in most of the recipient mice. The specific tolerant state induced was dependent on the doses of the antibody and bone marrow cells used. The optimal timing of CP treatment to induce tolerance was found to be 1-3 d after the stimulating cell injection. Treatment with the anti-Thy-1.2 antibody together with CP on day 2 after the cell injection on day 0 also induced profound tolerance. In the B6 mice made tolerant of C3H with antibody, C3H spleen cells plus C3H bone marrow cells, and then CP, a minimal degree of stable mixed chimerism was established and the antitolerogen (C3H) immune responses examined here, including delayed footpad reaction (DFR), CTL activity, and capacity for antibody production against donor-strain antigens were abrogated in a tolerogen-specific manner. From cell transfer experiments, the mechanism of tolerance could be largely attributed to reduction of effector T cells reactive against the tolerogen, and strong suppressive influences that might prolong skin allograft survival directly were not detected in the tolerant mice. Moreover, pretreatment with anti-Thy-1.2 antibody or anti-L3T4 (CD4) antibody was more effective than pretreatment with anti-Lyt-1 (CD5) antibody or anti-Lyt-2 (CD8) antibody as an initial step in tolerance induction. These results suggest that permanent tolerance to fully allogeneic skin grafts may be induced because antibody given before the stimulating cell injection reduces the number of reactive T cells in the recipient mice. This antibody treatment may facilitate an antigen-stimulated destruction of responding and thus proliferating cells with CP by preventing a possibly less proliferative, more rapid maturation of reactive T cells or by destroying residual effector T cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Inhibition of type I and type II iodothyronine deiodinase activity in rat liver, kidney and brain produced by selenium deficiency.

Abstract: Selenium deficiency for periods of 5 or 6 weeks in rats produced an inhibition of tri-iodothyronine (T3) production from added thyroxine (T4) in brain, liver and kidney homogenate. This inhibition was reflected in plasma T4 and T3 concentrations, which were respectively increased and decreased in selenium-deficient animals. Although plasma T4 levels increased in selenium-deficient animals, this did not produce the normal feedback inhibition on thyrotropin release from the pituitary. Selenium deficiency was confirmed in the animals by decreased selenium-dependent glutathione peroxidase (Se-GSH-Px) activity in all of these tissues. Administration of selenium, as a single intraperitoneal injection of 200 micrograms of selenium (as Na2SeO3)/kg body weight completely reversed the effects of selenium deficiency on thyroid-hormone metabolism and partly restored the activity of Se-GSH-Px. Selenium administration at 10 micrograms/kg body weight had no significant effect on thyroid-hormone metabolism or on Se-GSH-Px activity in any of the tissues studied. The characteristic changes in plasma thyroid-hormone levels that occurred in selenium deficiency appeared not to be due to non-specific stress factors, since food restriction to 75% of normal intake or vitamin E deficiency produced no significant changes in plasma T4 or T3 concentration. These data are consistent with the view that the Type I and Type II iodothyronine deiodinase enzymes are seleno-enzymes or require selenium-containing cofactors for activity.

Acrylamide binding to the DNA and protamine of spermiogenic stages in the mouse and its relationship to genetic damage.

Abstract: Mice received an intraperitoneal injection of 14 C-labeled acrylamide (AA) at an exposure of 125 mg/kg to equal that used in genetic studies carried out by Shelby et al. (1986). Subsequently, spermatozoa were recovered from the reproductive tracts of the animals over a 3-week period and assayed for the amount of bound AA. A strong increase in the level of binding occurred in late-spermatid to early-spermatozoa stages; these same stages are also genetically most sensitive to the action of AA. At all time points, alkylation of DNA within the sperm accounted for a very small fraction (generally

Enhanced growth of tumour cells in healing colonic anastomoses and laparotomy wounds.

Abstract: In the past, it has been noted that experimental tumour cells innoculated into the peritoneal cavity or into the lumen of the bowel will grow at a recently formed colonic anastomosis. However, it has previously been unclear whether the healing process enhances tumour growth or whether the presence of a suture line merely allows the tumour cells to gain access to the tissues. In the present study, using the hooded Lister rat, we have confirmed these findings by showing that growth of the syngeneic MC28 sarcoma and OES5 breast carcinoma occurs preferentially at colonic anastomoses and laparotomy wounds after intraperitoneal injection, and at colonic anastomoses after intraluminal injection. In previous studies using the MC28 sarcoma and the OES5 breast carcinoma injected by the intracardiac route (so that tumour cells reach normal and healing tissues in approximately equal numbers) we have shown that tumour growth is enhanced in healing wounds but not in the surrounding normal tissues when cells reach a healing colonic anastomosis or laparotomy wound within 2 h of its formation. Furthermore, by studying the distribution of radiolabelled tumour cells after intracardiac injection, we have calculated that the probability of a tumour cell leading to a deposit in a healing anastomosis or laparotomy wound is increased 1,000 fold compared to normal tissue. No previous studies have combined the data for intracardiac, intraluminal and intraperitoneal injection of tumour cells using the same animal model. We conclude that the same phenomenon of tumour growth enhancement in colonic anastomoses and laparotomy wounds reported after intracardiac injection of tumour cells may well be enhancing tumour growth after intraperitoneal and intraluminal injection. If these results can be extrapolated to man, then tumour cells spilled at surgery for colorectal cancer (or indeed any other cancer) may well encounter an environment which favours their growth and so the healing process itself may contribute to the genesis of local recurrence of malignant disease.

Use of Inhibitors of γ‐Aminobutyric Acid (GABA) Transaminase for the Estimation of GABA Turnover in Various Brain Regions of Rats: A Reevaluation of Aminooxyacetic Acid

Abstract: The technique of estimating gamma-aminobutyric acid (GABA) turnover by inhibiting its major degrading enzyme GABA-T (4-aminobutyrate:2-oxoglutarate aminotransferase; EC 2.6.1.19) and measuring GABA accumulation has been used repeatedly, but, at least in rats, its usefulness has been limited by several difficulties, including marked differences in the degree of GABA-T inhibition in different brain regions after systemic injection of GABA-T inhibitors. In an attempt to improve this type of approach for measuring GABA turnover, the time course of GABA-T inhibition and accumulation of GABA in 12 regions of rat brain has been studied after systemic administration of aminooxyacetic acid (AOAA), injected at various doses and with different routes of administration. A total and rapidly occurring inhibition of GABA-T in all regions was obtained with intraperitoneal injection of 100 mg/kg AOAA, whereas after lower doses, marked regional differences in the degree of GABA-T inhibition were found, thus leading to underestimation of GABA synthesis rates, e.g., in substantia nigra. The activity of the GABA-synthesizing enzyme GAD (L-glutamate-1-decarboxylase; EC 4.1.1.15) was not reduced significantly at any time after intraperitoneal injection of AOAA, except for a small decrease in olfactory bulbs. Even the highest dose of AOAA tested (100 mg/kg) was not associated with toxicity in rats, but induced motor impairment, which was obviously related to the marked GABA accumulation found with this dose. The increase in GABA concentrations induced with intraperitoneal injection of 100 mg/kg AOAA was rapid in onset, allowing one to estimate GABA turnover rates from the initial rate of GABA accumulation, i.e., during the first 30 min after AOAA injection. GABA turnover rates thus determined were correlated in a highly significant fashion with the GAD activities determined in brain regions, with highest turnover rates measured in substantia nigra, hypothalamus, olfactory bulb, and tectum. Pretreatment of rats with diazepam, 5 mg/kg i.p., 5-30 min prior to AOAA, reduced the AOAA-induced GABA accumulation in all 12 regions examined, most probably as a result of potentiation of postsynaptic GABA function. The data indicate that AOAA is a valuable tool for regional GABA turnover studies in rats, provided the GABA-T inhibitor is administered in sufficiently high doses to obtain complete inhibition of GABA degradation.

Cytogenetic effects of fenvalerate in mammalian in vivo test system

Abstract: A synthetic pyrethroid insecticide, fenvalerate, was tested for its cytogenetic effects in the mouse in vivo test system at 100, 150 and 200 mg/kg. Bone marrow metaphase analysis revealed significant increases in chromosomal aberrations in the groups treated with 150 and 200 mg/kg by intraperitoneal injection. In the micronucleus test the occurrence of PCEs with MN marginally increased with dose. Induction of PCEs with MN was significant over control again with the higher two doses. Incidence of sperm abnormalities slightly increased with dose but a significant increase was noted in all treated series over control.

Mast-cell secretion and angiogenesis, a quantitative study in rats and mice

Abstract: The activation of the autogenous mast cells (MCs) in situ in intact mesenterial windows was elicited by the intraperitoneal injection of the MC secretagogue Compound 48/80 over a period of 1, 3 and 5 days in Sprague-Dawley rats and in C57 BL/6 and CBA/Ca mice. As a probe of MC secretion, the release of histamine was quantified fluorometrically at predetermined intervals during the treatment. Fourteen days after the start of the treatment, the angiogenic response was quantified histologically as the number of vessel profiles per unit length of mesenteric window. Both the MC-activating and the angiogenic effect of the 48/80-treatment was greater in the rats than in the mice. The occurrence of MC-mediated angiogenesis in the mouse is demonstrated here for the first time. In the rat, 48/80-induced MC mediated angiogenesis increased in a distinctly dose-dependent manner. Two daily doses of 48/80 was the most efficient angiogenic protocol tested; a single day's treatment increased the number of vessels almost fivefold. The remarkable potency of the angiogenic reaction following MC secretion supports our previous notion that MC-mediated angiogenesis may have therapeutic implications in poorly vascularized tissues.

Induction of hemopoietic chimerism in the caprine fetus by intraperitoneal injection of fetal liver cells.

Abstract: Intraperitoneal injection of allogeneic liver cells from 43-day-old male fetuses into normal 60-day female goat fetuses resulted in persistent hemopoietic chimerism in surviving recipients without clinical evidence of graft-versus-host disease. Transplantation of normal fetal liver cells into preimmunocompetent goat fetuses affected with β-D-mannosidosis may provide an alternative strategy for evaluating hemopoietic stem cell transplantation in the treatment of human lysosomal storage diseases.

Reversal of haemorrhagic shock in rats by cholinomimetic drugs.

Abstract: 1. In an experimental model of haemorrhagic shock resulting in the death of all rats within 20-30 min, the intravenous (i.v.) injection of the tertiary amine cholinesterase inhibitor physostigmine (17-70 micrograms kg-1) induced a prompt, sustained and dose-dependent improvement of cardiovascular and respiratory function, with marked increase in the volume of circulating blood and survival of all treated animals, at least for the 2 h of observation. 2. Similar results were obtained with the i.v. injection of the cholinoceptor agonist oxotremorine (5-25 micrograms kg-1), while neostigmine (54 or 70 micrograms kg-1), a quaternary cholinesterase inhibitor which cannot cross the blood-brain barrier, had negligible effects. 3. The anti-shock activities of oxotremorine and physostigmine were blocked by the intracerebroventricular injection of either of the combined nicotinic and M2-muscarinic receptor antagonists gallamine and pancuronium, or of the nicotinic antagonist mecamylamine. They were also blocked by intraperitoneal injection of the adrenergic neurone blocking agent guanethidine, but they were not antagonized by either the combined M1- and M2-muscarinic receptor antagonist atropine, the M1-muscarinic receptor antagonist pirenzepine, or the M2-muscarinic receptor 4-diphenylacetoxy-N-methylpiperidine methobromide. 4. It is concluded that cholinomimetic drugs can reverse hypovolaemic shock through central activation (seemingly mediated by nicotinic receptors) of sympathetic tone, with mobilization and redistribution of the residual blood.

Stimulatory effect of caffeine on the hypothalamo-pituitary-adrenocortical axis in the rat.

Abstract: Intraperitoneal injection of caffeine (12.5-100 mg/kg) into rats caused a significant, dose-related increase in plasma corticosterone 2 h later, when the greatest response was measured. The corticosterone response to laparotomy stress or i.v. injection of ACTH(1-24) was unaffected by prior injection of caffeine. The response to stress or caffeine was unaffected by adrenal enucleation 28 days previously. In vitro, 10 mmol caffeine/l stimulated basal release of corticosterone from adrenal quarters and potentiated the response to a sub-maximal stimulatory concentration of cyclic AMP (cAMP). The drug had no effect on release stimulated by a sub-maximal concentration of ACTH(1-24). Release of ACTH from pituitary fragments incubated in vitro was stimulated in a dose-related manner by caffeine (0.01-10 mmol/l), and the responses to hypothalamic extract and sub-maximal concentrations of corticotrophin-releasing factor (CRF-41) or arginine vasopressin (AVP), but not cAMP, were significantly enhanced by 10 mmol caffeine/l. Release of immunoreactive CRF-41 (but not AVP) was significantly increased by caffeine (0.01-10 mmol/l) added to hypothalami incubated in vitro. The response to injection of caffeine in vivo was completely prevented by pharmacological blockade of endogenous CRF release. Taken together, these results show that caffeine at high concentrations can stimulate directly the release of the hormones of the hypothalamo-pituitary-adrenocortical axis in vitro, but the fact that these concentrations are unlikely to be reached after administration in vivo suggests that the effect of caffeine may be mediated centrally.

Effect of interleukin-1 on adrenocortical activity in intact and hypothalamic deafferentated male rats.

Abstract: The present study was designed to elucidate the site of action of interleukin 1 (IL-1) modulation of the hypothalamic-hypophyseal-adrenal (HHA) axis. An intraperitoneal injection of recombinant human IL-1β (160 U/rat) significantly elevated serum levels of ACTH and corticosterone (CS). In rats with complete mediobasal hypothalamic deafferentation, the HHA response to IL-1 was inhibited. An intracerebroventricular injection of rIL-1 (2 U/ rat) caused a marked increase in serum ACTH and CS. These results suggest that IL-1 activates the HHA axis by a direct effect upon the brain, and that intact neural connections between the mediobasal hypothalamus and extrahypothalamic brain regions are essential for IL-1-induced HHA responses.

Endotoxin-induced lung injury in rats: role of eicosanoids.

Abstract: We studied lung vascular injury and quantitated lung eicosanoids in rats after intraperitoneal injection of Salmonella enteritidis endotoxin. Within 40 min after endotoxin injection (20 mg/kg), lung tissue thromboxane B2 doubled, although 6-ketoprostaglandin F1 alpha (6-keto-PGF1 alpha) increased by 8- to 10-fold. Lung 5-hydroxyeicosatetraenoic acid and leukotriene C4 were variably increased by endotoxin. The levels of all eicosanoids returned to base line 6 h after endotoxin challenge. Lung vascular injury, as assessed by the extravascular accumulation of 125I-albumin and water in isolated perfused lungs, was observed 90 min after endotoxin injection (0.02-20 mg/kg) in vivo. Inhibition of the cyclooxygenase pathway with indomethacin and the lipoxygenase pathway with diethylcarbamazine and 2-(12-hydroxydodeca-5,10-dinyl)-3,5,6-trimethyl-1,4-benzoqui none failed to attenuate endotoxin-induced lung injury. In addition, essential fatty acid deficiency, which markedly reduced lung tissue levels of 6-keto-PGF1 alpha, thromboxane B2, and leukotriene C4, did not protect against endotoxin injury. We conclude that although lung eicosanoids are activated during endotoxemia, they do not play a crucial role in the development of acute lung vascular injury in rats.

Vitamin A supplementation improves macrophage function and bacterial clearance during experimental salmonella infection.

Abstract: The effects of additional but nontoxic amounts of vitamin A on susceptibility to salmonella infection was studied by comparing rates of bacterial clearance and phagocytosis. Forty-eight male Lewis rats were divided into a treatment group receiving a total of 6000 units of vitamin A palmitate weekly for 5 weeks and a control group was given an equal volume of saline. After completion of the treatment regimen, one-half from each group were infected intraperitoneally with 10(5) Salmonella typhimurium; the other half received intraperitoneal injection of saline. At this time no differences in weight gain were noted and all animals were sacrificed within 2 weeks. At 72 hr after bacterial challenge, all saline-treated control animals displayed bacteremia. Cultures of liver and splenic homogenates were positive in 89 and 100% of infected control animals vs 0 and 44% for treated animals during the first week of infection. Kupffer cell, peritoneal, and splenic macrophages of the vitamin A-treated group had greater phagocytic activity than controls as assessed by the percentage of cells ingesting yeast particles and by the number of particles ingested (phagocytic index). These results suggest that vitamin A in moderate amounts may benefit the host's response to infection by enhancing phagocytic cell function.

Chloroquine containing liposomes in the chemotherapy of murine malaria.

Abstract: In this study, the advantage of the use of chloroquine (CQ) containing liposomes (lipCQ) over free CQ in the chemotherapy of murine malaria (Plasmodium berghei) was demonstrated. The maximum permissible dose per intraperitoneal injection was 0.8 and 10 mg for CQ and lipCQ, respectively. An increase in therapeutic and prophylactic efficacy of lipCQ in comparison with free CQ at a 0.8 mg CQ dose level was found. It was possible to obtain 100% efficacy (injection at day 5 after infection; parasitaemia 4-8%) with one single intraperitoneal injection of 6 mg lipCQ. Moreover, the ability to increase the doses of CQ per injection after liposome encapsulation allowed successful treatment of infections with CQ-resistant Plasmodium berghei which could not be cured by a 7-day course with the maximum tolerable dose of free CQ of 0.8 mg/mouse/day.

Synthesis and antitumor activity of chitosan carrying 5-fluorouracils

Abstract: In order to provide a polymeric drug of 5-fluorouracil (5FU) with reduced side-effects, having affinity for tumor cells and exhibiting high antitumor activity, four kinds of chitosan derivatives were synthesized carrying 5FUs through some kinds of spacers via ether, amide, ester, or carbamoyl bonds. The release behaviors of 5FU and 5FU residues were studied in vitro at 37°C in various aqueous media. The antitumor activity was tested against p-388 lymphocytic leukemia in female CDF1 mice in vivo by intraperitoneal injection of the polymeric drugs followed by intraperitoneal injection of the leukemia cells (i. p./i. p.). Chitosan fixing 5FU at 2-position through a hexamethylene spacer and carbamoyl linkages (9) exhibits a higher effect with respect to prolongation of life than free 5FU. The chitosan-5FU conjugates obtained do not display acute toxicity in the high dose range.

Effect of antioxidants in experimental Escherichia coli septicemia.

Abstract: Free radicals have been implicated in the pathogenesis of gram-negative bacterial sepsis We assessed the effectiveness of antioxidants and chelators to alter oxidative injury in established severe experimental Escherichia coli septicemia One hour after challenge by intraperitoneal injection of bacteria, 36 rabbits were treated with moxalactam and randomized in sets of three to receive either placebo, superoxide dismutase (SOD), or a combination of antioxidants and chelators consisting of SOD, sodium thiosulfate, alpha-tocopherol, deferoxamine, and diethyldithiocarbamate Throughout the course of treatment, levels of bacteremia and endotoxemia were similar among the three experimental groups Neither antioxidant-treated group was significantly different from the control group in mean arterial blood pressure, leukocyte count, platelet count, core temperature, blood lactate, oxygenation or survival Arterial pH and [HCO3-] were significantly lower in the antioxidant combination group compared to the control and SOD groups (P less than 01) In this model, antioxidant and chelator therapy does not substantially ameliorate established septicemia

Plasma concentrations of cholecystokinin octapeptide and food intake in male rats treated with cholecystokinin octapeptide.

Abstract: Intraperitoneal injection of 5 micrograms cholecystokinin octapeptide (CCK-8) into male rats deprived of food for 48 h produced a transient (less than 15 min) increase in plasma levels of CCK-8 but suppressed food intake for an extended period (45 min). Plasma concentrations of CCK-8 after i.p. injection of CCK-8 were raised to levels which were fairly comparable to those after feeding. Intracerebroventricular (i.c.v.) injection of the CCK antagonist proglumide (100 micrograms) reversed the effect of CCK-8 on food intake, while i.p. injection of proglumide (100 micrograms) did not have this effect. Feeding increased the plasma concentrations of somatostatin and gastrin but not of oxytocin, and somatostatin and oxytocin but not gastrin were released in response to i.p. injection of CCK-8. However, neither somatostatin nor oxytocin affected food intake, and their release in response to CCK-8 was unaffected by i.c.v. injection of proglumide. These results support the suggestion that CCK-8 is a physiological 'satiety' peptide, which can affect food intake in rats by mechanisms involving both peripheral and central CCK receptors.

Biodistribution of Indium-111-labeled OC 125 Monoclonal Antibody after Intraperitoneal Injection in Nude Mice Intraperitoneally Grafted with Ovarian Carcinoma

Abstract: The purpose of this work was to study the biodistribution of 111Inlabeled OC 125 monoclonal antibody (MAb) with known affinity for ovarian carcinomas in a nude mouse model grafted i.p. with a human ovarian cancer (NIH:OVCAR-3). Tumor uptake 24 h after i.p. injection was higher with intact 111In-labeled OC 125 MAb (28 ± 7.44%ID/g) than with 111In-nonspecific immunoglobulin (6.86 ± 1.35%ID/g). The kinetics of tumor uptake also differed, showing a plateau followed by a drop at Day 7 with 111In-OC 125 MAb and a decrease beginning at 24 h with 111In-nonspecific immunoglobulin. Tumor-to-normal tissue ratios ranged between 29.91 ± 11.85 and 0.68 ± 0.15 with 111In-OC 125 MAb and between 4.50 ± 1.06 and 0.53 ± 0.04 with 111In-nonspecific immunoglobulin according to the normal tissues and the time points considered. Tumor uptake 2 h after injection was the same for F(ab9)2 fragments as for intact MAb, whereas maximum uptake at 24 h (18.76 ± 4.62%ID/g) was lower and was followed by a decrease at Day 4. Tumor-to-normal tissue ratios were in the same range, except for the tumor to blood ratio which was higher and the tumor to kidney ratio which was lower at 24 and 96 h. Maximum tumor uptake was higher after i.p. (30.77 ± 4.76%ID/g) than i.v. (14.59 ± 2.70%ID/g) injection. Instead of attaining the plateau noted after i.p. injection, tumor uptake after i.v. injection remained low at 2 h (2.11 ± 1.66%ID/g), reaching its peak only after 96 h. 131I-OC 125 injected i.p., which reached maximum tumor uptake at 2 h (13.53 ± 4.25%ID/g), showed tumor-to-tissue ratios ranging between 15.98 ± 2.63 and 0.96 ± 0.86, i.e., not very different from those with 111In. After i.p. injection of a radiolabeled colloid solution, maximum tumor uptake was reached at 96 h (20.22 ± 5.35%ID/g), but with very high nonspecific uptake in liver (31.06 ± 6.22%ID/g) and spleen (55.23 ± 14.11%ID/g). These results indicate high, selective tumor uptake of 111In-OC 125 after i.p. injection and demonstrate the feasibility of i.p. radioimmunotherapy of ovarian carcinomas.

A comparison of serum kinetics and tissue distribution of photofrin ii following intravenous and intraperitoneal injection in the mouse

Abstract: Although hematoporphyrin derivative (HPD) and its ‘purers’ variety Photofrin II are the most widely used tissue sensitizers in both clinical and experimental photodynamic therapy (PDT), quantitative studies of tissue distribution have been few. We have extracted and measured Photofrin II in several organs of the normal mouse including those of relevance to urological practice. In view of the reported heterogeneities in the distribution within tissues of various cytotoxics when administered intraperitoneally. we have compared results for Photofrin II given by this route with those for intravenous injection. Although both routes of administration gave equally consistent results, differences in absolute tissue concentration as a function of time after injection were found for several but not all tissues. Furthermore, the porphyrin accumulated following intravenous administration seemed to contain more of the non-polar photodynamically active component than that accumulated following the intraperitoneal route. We attempt to explain these differences by reference to published data on porphyrin binding to serum proteins.