Comparative study of the cardiotoxicity of the anthracycline antibiotics, carminomycin and adriamycin, in white mice]

The cardiotoxic effect of karminomycin and adriamycin administered intravenously for 5 times in equitoxic doses constituting equal portions of LD50 of the respective antibiotic on its single intravenous administration was studied on albino mice. Histological examination of the heart showed that almost identical damages of the myocardium occured after administration of karminomycin and adriamycin in doses of 0.45 of LD50 (1.5 mg/kg) and 0.3 of LD50 (6.3 mg/kg) respectively. The character of the damages due to the antibiotics was close, the most significant changes were observed when the animals were sacrificed 1 month after the last administration of the drug. The histological method is of value in estimation of the cardiotoxic effect of the drugs, using mice as the model suitable for the investigation. Adriamycin had more pronounced cumulative properties as compared to karminomycin: suppression of the weight gain in the mice and their death rate were higher with the use of adriamycin.     

Antitumor activity of carminomycin antibiotic used orally]

Antitumor activity of karminomycin used perorally was studied with respect to 3 strains of mouse transplantable tumors, i. e. one ascitic strain of lymphadenosis NK/LI and two solid strains of lymphosarcoma L10-1 and sarcoma 180. Karminomycin was shown to have a high antitumor activity against the above tumors on its oral administration. In the experiments with lymphadenosis NK/LI the efficiency of karminomycin was higher when it was used perorally as compared to its intravenous administration. It was found that karminomycin had practically the same inhibitory effect on growth of lymphosarcoma L10-1 and sarcoma 180 on its peroral and intravenous administration in doses equivalent by their toxicity.     

Obtaining 14-oxycarminomycin and a study of its antitumor activity

The authors obtained 14-oxykarminomycin by alkaline hydrolysis of 14-bromokarminomycin. On two-fold intravenous administration to mice with lymphosarcoma, strain L10-1, 14-oxycarminomycin showed the same toxicity as karminomycin. The preparation had the same selective antitumor activity as karminomycin.     

Systemic activation of macrophages by liposome-entrapped muramyl tripeptide in mice pretreated with the chemotherapeutic agent adriamycin

Summary The purpose of these studies was to determine whether macrophages of mice pretreated with the chemotherapeutic agent adriamycin (ADR) could be systemically activated by IV injection of liposomes containing muramyl tripeptide phosphatidylethanolamine (MTP-PE), a lipophilic derivative of muramyl dipeptide. Lower than normal levels of alveolar macrophages or peritoneal exudate macrophages were found in mice following IV injection of ADR. This decrease was dose-dependent and, in mice given <10 mg ADR/kg, it was transient (14 days). Peritoneal macrophages surviving the administration of 15 mg ADR/kg were tumoricidal.At various times after single or repeated administration of ADR, mice were given IV or IP injections of liposomes containing MTP-PE. One day thereafter, the cytotoxic activity of the in situ-activated macrophages (alveolar or peritoneal exudate) was assessed in culture against syngeneic melanoma cells. Our data demonstrate that under defined conditions the systemic administration of ADR does not interfere with the in situ activation of tumoricidal properties of murine macrophages after IV injection of liposomes containing a macrophage-activating agent.     

Production and antitumor properties of carminazone

Karminazon (13-benzoylhydrazon) was prepared by condensation of karminomycin with benzoylhydrazine. In its intravenous use in the treatment of mice with lymphosarcoma L10-1 karminazon was less toxic and had lower antitumor activity than karminomycin. Karminazon had a lower selective antitumor activity with respect to lymphosarcoma than karminomycin.     

Effects of X-irradiation and adriamycin on quiescent and proliferating cells of the seminal vesicle in the castrated mouse.

The sensitivity of resting and proliferating cells of the seminal vesicle to X-irradiation and adriamycin has been investigated. Stimulation with testosterone propionate (250 micrograms/day) was started 11 days after castration in BALB/c mice. X-rays (2.5-7.5 Gy total body irradiation) and intraperitoneal injections of adriamycin (4-16 mg/kg body weight) were administered at various times before or after induction of proliferation by testosterone injection. The DNA contents and the weights of the seminal vesicles were determined at 4 days after the start of stimulation. A Do for X-rays of about 10 Gy was found for the seminal vesicle epithelium. For both X-irradiation and adriamycin no significant differences in sensitivity were observed between quiescent (Go) and proliferating (G1; S) seminal vesicle cells.     

Effect of brain serotonin on the arterial pressure and plasma renin in normal and hypertensive rats]

The effects of changes in brain serotonin content after injections of p-chlorophenylalanine (p-CPA), L-5-hydroxytryptophan (L-5HTP) and 5-6-dihydroxytryptamine (5-6DHT) on the mean arterial pressure (MAP), plasma renin activity (PRA) and peripheral levels of atrial natriuretic peptide (ANP) have been studied in normal and hypertensive (2K:1C model) male Wistar rats. The p-CPA (250 mg/kg) and L-5HTP (200 mg/kg) were injected i.p., while 5-6 DHT (15 micrograms/animal in 10 mu/animal vehicle) was injected into lateral brain ventricles. The effects were studied 24 h after the p-CPA injection, 2 h after L-5HTP and 10 or 20 days after 5-6DHT administration. The fall in brain serotonin produced by p-CPA and 5-6DHT did not modify the MAP values in the normal and hypertensive rat model, whereas the increase induced after L-5HTP injection only caused a slight decrease in arterial pressure in normotensive animals. The ARP experimented remarkable rises in the normal and hypertensive rats, these values increasing after L-5HTP and falling after p-CPA and 5-6 DHT injections. Similar changes are detected in the normal group after administration of these substances related to serotoninergic brain activity. The ANP levels rose after renal artery constriction, and they are not affected by the above mentioned substances. Only p-CPA and 5-6DHT reduced a low decrease in the ANP levels 10 days after their administration.(ABSTRACT TRUNCATED AT 250 WORDS)     

Morphological changes in the digestive organs on the administration of the antineoplastic antibiotics, rubomycin and carminomycin

The effect of antitumour antibiotics, such as rubomycin and karminomycin on the digestive tract as one of the most vulnerable systems during chemotherapy was studied. Investigation of the tongue, oesophagus, stomach, small and large intestine of mice with the current morphological and some histochemical methods showed that the most pronounced changes in the above organs occurred during the first 10 days after the drug administration. The damages were of the same type, i.e. dystrophic changes in the tegmental and granular epithelium with edema and infiltration of the mucosa and tunica submucosa. The drugs induced a decrease in the levels of the nucleic acids, protein and hydrolytic enzymes and impairement of the distribution pattern of these substances in the cells. Karminomycin had a more pronounced effect and its damaging effect was more stable as compared to rubomycin.     

Myeloinhibitory effect of the action of some antitumor antibiotics and its comparative assessment]

General toxic and myeloinhibitory effects of some antitumor antibiotics, such as rubomycin, olivomycin, bruneomycin and karminomycin administered intraperitoneally in a single LD50 to mice were studied. It was found that the general toxicity of bruneomycin and karminomycin was almost the same and 5 to 8 times higher than that of rubomycin and olivomycin. The use of the above antibiotics resulted in definite shifts in the blood systems of healthy mice. The most significant suppression of hemopoesis accompanied by a pronounced depression of the number of the myelocariocytes was observed after the use of olivomycin. The effect of karminomycin was characterized by suppression of erythro-, myelo- and lymphopoesis and depression of the number of the granulocytes and lymphocytes of the blood. Bruneomycin and rubomycin had a short-time myeloinhibitory effect. The erythroid cords of the bone marrow proved to be most sensitive to the inhibitory effect of the antibiotics. However, inhibition of the erythropoesis accompanied by deep reticulocytopenia did not induce the respective depression of the erythrocyte number. The lymphoid cords was in the 2nd place by its sensitivity to the antibiotics and the myeloid and megocariocytal cords were in the 3rd and the 4th places respectively. Complete reduction of hemopoesis in the animals was observed by the 10th day of the drugs use.     

Interactions of drugs and radiation in haemopoietic tissue assessed by lethality of mice after whole-body irradiation

Drug-radiation interactions in haemopoietic tissue were assessed as the lethality of mice within 7-28 days after whole-body irradiation. The investigated drugs were adriamycin (ADM), bleomycin (BLM), cyclophosphamide (CTX), 5-fluorouracil (5-FU), methotrexate (MTX), mitomycin C (MM-C) and cis-diamminedichloroplatinum II (cis-DDP). The drugs were administered as single doses 15 min before graded doses of whole-body irradiation or at different intervals from 7 days before to 7 days after fixed radiation doses. ADM, CTX, 5-FU, MM-C and cis-DDP enhanced the radiation response when administered 15 min before irradiation. The dose effect factor (DEF) was 9.11 for 5-FU and in the range 1.25-1.59 for the other drugs. MTX administration 15 min before irradiation had no effect (DEF 1.00). However, MTX increased lethality if given 1-3 days after irradiation (DEF 1.21-1.76) and protected against lethality if given 1-3 days before irradiation (DEF 0.83). A similar time dependence was observed for ADM, CTX, 5-FU, MM-C and cis-DDP. Protection against lethality was not observed but in all these cases the lethality was significantly lower at administration 1-3 days before than 1-3 days after irradiation. A proper investigation of the effect of BLM was not possible as the combination of this drug and whole-body irradiation caused a high rate of gastrointestinal deaths.     

Modification of the adjuvans arthritis by carrageenin, compound 48/80, histamine- and serotonin antagonists, non-steroid antiphlogistics as well as protease inhibitors and their possible relations to inflammation mediators]

1. Injections of carrageenin (1,25 mg/kg i.v.) from the 1st to the 3rd day and then each 2nd or 3rd day inhibited paw swelling in adjuvant arthritis of the rat during the time of treatment. Injections from the 11th to the 15th day were ineffective. The level of plasma kininogen was slightly decreased but the total complement serum level was significantly lowered. 2,5 and 3 mg carrageenin/kg respectively were toxic after repeated injections. After a single administration the levels of plasma kininogen and of total serum complement were decreased by 50% although paw swelling was not affected. 2. Pentosane polysulfoester (25 mg/kg i.v.) did not influence paw swelling despite daily administration from the 1st to the 17th day. Heparin (10 000 IE/kg i.v.) was likewise ineffective. 3. Single or repeated injections of compound 48/80 (0,125-0,5 mg/kg i.v.; 1-5 mg/kg i.p.; 3-6 mg/kg s.c.), reserpine (0,2 mg/kg i.p.), cyproheptadine (5 mg/kg i.v.), bromolysergic acid diethylamide (2 x 2 mg/kg i.v.) or metiamide (10 mg/kg i.v.) were without effect on paw swelling. Neither did compound 48/80 effect the complement serum level. 4. Daily administration of chloropromazine (4-10 mg/kg p.o.) or of promethazine (10-15 mg/kg s.c. or p.o.) inhibited paw swelling in the first phase of adjuvant arthritis but not in the second one. 5. The soybean trypsin inhibitor (15 mg/kg i.v.) inhibited paw swelling significantly up to the 4th day, the Kunitz inhibitor (25 000 E/kg i.v.) was ineffective. 6. The content of prostaglandin E of the inflamed paws was increased threefold in both phases of arthritis. The results are discussed with regard to the putative role of mediators of inflammation (histamine, serotonin, kinins, prostaglandins, lysosomal enzymes, lymphokines, complement).     

Quantitative analysis of 5-fluorouracil and 5,6-dihydrofluorouracil in plasma by gas chromatography mass spectrometry

5-Fluorouracil and 5,6-dihydro-5-fluorouracil were analysed in the plasma of patients by combined gas chromatography mass spectrometry. 5-Bromouracil was the internal standard. After extraction from plasma with an isopropanol-diethyl ether mixture (20/80) the components were pentylated and the derivatives produced extracted into diethyl ether. Electron impact mass spectrometry was used for the simultaneous quantitative determinations of 5-fluorouracil and 5,6-dihydro-5-fluorouracil (detection limit 10 ng ml-1 5-fluorouracil, 80 ng ml-1 5,6-dihydro-5-fluorouracil). Chemical ionization was utilized to measure 5,6-dihydro-5-fluorouracil concentrations less than 80 ng ml-1 (sensitivity 10 ng ml-1). The biological applicability of these two techniques was demonstrated by analysing plasma samples from patients after administration of 5-fluorouracil or 5'-deoxyfluorouridine by intravenous injections and infusions.     

Hemodynamic responses of conscious rats following intrathecal injections of prodynorphin-derived opioids: independence of action of intrathecal arginine vasopressin

Experiments were conducted (i) to determine the hemodynamic (blood pressure and heart rate) responses of conscious rats following intrathecal (IT) administration of endogenous prodynorphin-derived opioids into the lower thoracic space, (ii) to identify the receptors involved in mediating their cardiovascular responses, and (iii) to reveal any possible hemodynamic interactions with the neuropeptide arginine vasopressin. Male Sprague-Dawley rats were surgically prepared with femoral arterial and venous catheters as well as a spinal catheter (into lower thoracic region, T9-T12). After recovery, hemodynamic responses were observed in conscious rats for 5-10 min after IT injections of artificial cerebrospinal fluid (CSF) solution, prodynorphin-derived opioids (dynorphin A, dynorphin B, dynorphin A (1-13), dynorphin A (1-10), alpha- and beta-neoendorphin, leucine enkephalin (LE), methionine enkephalin (ME), arginine vasopressin (AVP), or norepinephrine (NE)). IT injections of AVP (10 or 20 pmol), dynorphin A (1-13), or dynorphin A (10-20 nmol) caused pressor effects associated with a prolonged and significant bradycardia. Equimolar (20 nmol) concentrations of LE, ME, alpha- and beta-neoendorphin, and dynorphin A (1-10) caused no significant blood pressure or heart rate changes. Combined IT injections of dynorphin A (1-13) and AVP caused apparent additive pressor effects when compared with the same dose of either peptide given alone. IT infusion of the specific AVP-V1 antagonist d(CH2)5Tyr(Me)AVP before subsequent IT AVP, dynorphin A (1-13), or NE administration inhibited only the subsequent pressor responses to AVP. The kappa-opioid antagonist (Mr2266) infused IT blocked the pressor actions of subsequent dynorphin A administration and not AVP or NE.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of long-term nitrazepam administration on sleep cycles in rats]

Single and chronic administration of a low dose of nitrazepam (1 mg/kg) had no effect on sleep cycles in rats. A single injection of a high dose (10 mg/kg) of nitrazepam resulted in prolongation of the total duration of synchronized sleep with a corresponding shortening of desynchronized (paradoxical) sleep. The number of sleep cycles was reduced. Chronic injections of nitrazepam (for 7-14 days) in a dose of 10 mg/kg evoked a gradual prolongation of the duration of paradoxical sleep and an increase in number of sleep cycles. After discontinuance of a long-term administration of nitrazepam (1 mg/kg or 10 mg/kg) prolongation of desynchronized sleep and an increase in the number of sleep cycles were more pronounced in comparison with the last day of chronic administration of the drug.     

Role of the adrenal glands in the cytostatic action mechanism of antitumor antibiotics

The state of the steroidogenic function of the adrenal glands, lipid spectrum of the adrenal gland tissue and metabolism rate of 11-oxycorticosteroids (11-OCS) in the liver tissue and their levels in the blood plasma were studied on rats after a single administration of karminomycin in a dose of LD50 (1.55 mg/kg). The hormones of the adrenal cortex were shown to play a definite role in the mechanism of the karminomycin damaging effect. Dependence of the changes on the time of the drug effect was noted. The shifts were of a reversible character. No direct toxic damages in the tissue of the adrenal glands were observed. Only an increase in the 11-OCS blood levels and a decrease in the steroid metabolism in the liver tissue were shown. The latter must be due to the direct cytotoxic effect of karminomycin on the tissue of this organ.     

Preparation of dihydrocarminomycin and a comparison of its antitumor activity with the activity of carminomycin]

A dihydro derivative of karminomycin was prepared using chemical reduction with potassium boron hydride. When dihydrokarminomycin was administered intravenously to healthy albino mice in a single dose it practically showed the same toxicity as karminomycin. However, unlike the latter dihydrokarminomycin induced the death of the animals at later periods of time. Studies on mice with transplantable tumours showed high antitumor activity of dihydrokarminomycin against lymphosarcoma L10-1, sarcoma 180, Garding-Passy melanoma, lymphoid leukosis L-1210 and lymphocytal leukosis P-388. In treatment of the mice with leukosis L-1210 and Garding-Passy melanoma dihydrokapminomycin was much inferior by its efficiency than karminomycin.     

Reversed-phase liquid chromatographic determination of plasma levels of adriamycin and adriamycinol

A method is given for the determination of adriamycin and its main metabolite, adriamycinol in plasma from cancer patients after administration of adriamycin as the free drug or as a complex with DNA.Adriamycin and adriamycinol are extracted in a column from 1 ml of plasma (pH 8.6) using a mixture of chloroform—1-heptanol (8:2). After re-extraction into phosphate buffer pH 2.2, the separation is performed as reversed-phase liquid chromatography on a LiChrosorb RP-2 (5 μm) column with a mobile phase of acetonitrile—water, acidified with phosphoric acid.The precision by quantitation with photometric detection was better than 5% within the range 50–300 ng/ml. Plasma levels of adriamycin and adriamycinol in a cancer patient are presented in this paper.     

Melatonin Accelerates Reentrainment After Phase Advance of the Light-dark Cycle in Syrian Hamsters: Antagonism by Flumazenil

The objective of this study was to assess whether melatonin injections accelerated reentrainment of locomotor activity and body temperature rhythms of Syrian hamsters after phase-advancing the light-dark (L:D) cycle and to what extent the effect can be modified by the benzodiazepine (BZP) receptor antagonist flumazenil. After a baseline recording of rhythms, a 6-h phase advance of the L:D cycle was made (day D). Groups of hamsters were subjected, on days D -2, D -1, and D, to one of the following treatments: two injections of vehicle 15 min apart; vehicle followed 15 min later by melatonin (1 mg/kg); flumazenil (5 mg/kg) followed 15 min later by vehicle; or flumazenil (5 mg/kg) followed 15 min later by melatonin (1 mg/kg). Injections were given at the expected time of lights off after the phase shift. In vehicle-injected and untreated controls, ～ 1 day per hour of phase advance was needed to resynchronize the rhythms. The administration of melatonin brought about a significant decrease of resynchronization time to 66% of vehicle-injected controls. The effect of melatonin was prevented by first administering flumazenil. Flumazenil, injected alone, did not modify resynchronization after the shift. The results agree with the view that melatonin activity on circadian rhythmicity is sensitive to central-type BZP antagonism.     

Melatonin Accelerates Reentrainment After Phase Advance of the Light-dark Cycle in Syrian Hamsters: Antagonism by Flumazenil

The objective of this study was to assess whether melatonin injections accelerated reentrainment of locomotor activity and body temperature rhythms of Syrian hamsters after phase-advancing the light-dark (L:D) cycle and to what extent the effect can be modified by the benzodiazepine (BZP) receptor antagonist flumazenil. After a baseline recording of rhythms, a 6-h phase advance of the L:D cycle was made (day D). Groups of hamsters were subjected, on days D -2, D -1, and D, to one of the following treatments: two injections of vehicle 15 min apart; vehicle followed 15 min later by melatonin (1 mg/kg); flumazenil (5 mg/kg) followed 15 min later by vehicle; or flumazenil (5 mg/kg) followed 15 min later by melatonin (1 mg/kg). Injections were given at the expected time of lights off after the phase shift. In vehicle-injected and untreated controls, ∼ 1 day per hour of phase advance was needed to resynchronize the rhythms. The administration of melatonin brought about a significant decrease of resynchronization time to 66% of vehicle-injected controls. The effect of melatonin was prevented by first administering flumazenil. Flumazenil, injected alone, did not modify resynchronization after the shift. The results agree with the view that melatonin activity on circadian rhythmicity is sensitive to central-type BZP antagonism.     

Development of a radioimmunoassay for plasma C-peptide in sheep: kinetics of C-peptide and effects of exogenous growth hormone and glucose on insulin and C-peptide

An antiserum to purified bovine C-peptide was used to develop a sensitive radioimmunoassay for C-peptide in sheep. The assay was used to measure kinetics of C-peptide and insulin in non-pregnant and non-lactating sheep. Injected, purified C-peptide was distributed in pools comprising c. 11.4% of liveweight, the half time of C-peptide was estimated as 13.7 min and its clearance rate was c. 5 ml kg-1 min-1. In lactating ewes exogenous recombinant bovine growth hormone (rebGH) increased both plasma insulin and C-peptide as did glucose challenge given before and during administration of rebGH. Estimates of insulin secretion rate in lactating ewes were c. 7 x 10(-3) and 8.5 x 10(-3) nmol kg-1 min-1 before and after glucose challenge prior to injections of rebGH. After 4 days of injection of rebGH, corresponding values were c. 8 x 10(-3) and 10 x 10(-3) nmol min-1 kg-1.