[Influence of Laminaria japonica and fucus on hemostasis and sarcoma M-1 growth in Wistar rats].

The study was concerned with the effects of brown seaweeds on hemostasis and sarcoma M-1 growth in rats. Laminaria japonica and focus were shown to exert anticoagulant action to inhibit carcinogenesis. They may be used for adjuvant therapy of tumors.

Refractory hypothalamic alpha-mSH satiety and AGRP feeding systems in rats bearing MCA sarcomas.

In pre-anorectic tumor-bearing (TB: methylcholanthrene-induced sarcoma) rats, injection of alpha-melanocyte stimulating hormone (alpha-MSH) into the perifornical hypothalamus (PFH) had no significant effect on food intake at a dose (5 microg) that reduced feeding in non-TB control rats. Following the development of anorexia, injection of alpha-MSH MC3/MC4 receptor antagonists, SHU9119 (1 microg) or 4 microg agouti-related protein (AGRP), stimulated feeding in non-TB rats, while having no significant effect in TB rats. Concentrations of alpha-MSH were not altered significantly in ventromedial, dorsomedial or lateral hypothalamic areas of TB rats, and proopiomelanocortin (POMC) messenger RNA was not changed in TB rats in these hypothalamic areas. Determination of cytokines by ELISA in non-operated TB and non-TB rats revealed elevated IL-2 in plasma and hypothalamus as well as increased TNF-alpha in the hypothalamus of anorectic TB rats. IL-1B was not detectable in plasma and was not altered significantly in hypothalamus of TB rats. These results suggest that the POMC alpha-MSH satiety system is refractory in TB rats, even prior to the onset of anorexia. This change in MC3/MC4 receptor response does not appear to be secondary to alterations of endogenous alpha-MSH in TB rats. Cytokine involvement in the altered response to MC3/MC4 receptor stimulation and blockade is a possibility, since TNF-alpha and IL-2 were increased in hypothalamus of anorectic TB rats. Therefore, these results suggest major alterations in POMC neuropeptide systems in TB rats as anorexia progresses. Although these changes do not appear to have occurred due to grossly-altered concentrations of alpha-MSH, elevated cytokine activity in the hypothalamus may be an important factor. Due to the complex multi-factorial nature of feeding control, additional factors are likely to be involved in cancer anorexia.

VMN/LHA functional inhibition in tumor-bearing rats suggests hypothalamic involvement in cancer anorexia.

Food intake is mainly controlled in the hypothalamus via a series of functionally related nuclei, including the ventromedial nucleus of hypothalamus (VMN) and the lateral hypothalamic area (LHA). Since food intake is the product of meal number and meal size, we investigated the role of the VMN and LHA in influencing these feeding indices and in mediating cancer anorexia in tumor-bearing (TB) rats, via temporarily inhibiting VMN or LHA. Adult male Fischer-344 rats (n = 23) inoculated with 106 MCA sarcoma cells were studied. When anorexia developed, rats were randomly assigned to stereotaxically located bilateral intra-VMN or intra-LHA microinjections of the neuronal blocker colchicine (CX; n = 6 each group) or saline (n = 6 and n = 5, respectively). Non TB rats (NTB; n = 7) served as controls. Food intake and feeding indices were recorded by a computerized device. At onset of anorexia, a reduction of meal number occurred, leading to reduced food intake. After inhibition of VMN activity by CX, meal number significantly increased, so that food intake increased and almost normalized. In contrast, intra-LHA microinjection of either CX or saline resulted in reduction of meal size, leading to reduced food intake and death. Findings suggest that VMN and LHA influence meal number and meal size, respectively. Since cancer anorexia mainly results from an initial reduction of meal number and the inhibition of VMN led to an increase in meal number, the early effect of tumor growth on VMN activity may be an early step leading to reduced food intake.

Changes in microregional perfusion, oxygenation, ATP and lactate distribution in subcutaneous rat tumours upon water-filtered IR-A hyperthermia.

The effect of hyperthermia on microcirculatory and metabolic parameters in s.c. DS-sarcomas of different sizes on the hind foot dorsum of SD-rats was investigated. Hyperthermia was carried out using a novel water-filtered, infrared-A radiation technique. Heating was performed at a rate of 0.5 degrees C/min until 44 degrees C was achieved in the tumour centre, which was maintained for 60 min. Using a multichannel laser Doppler flowmeter, red blood cell flux could be assessed continuously and at several sites within the tumour tissue simultaneously. Substantial inter-site variations in laser Doppler flux (LDF) were observed during hyperthermia which were independent of tumour size, site of measurement, and temperature at the site of measurement, indicating that single site measurements of tumour LDF are poor predictors of the mean response of a tumour to hyperthermia. When mean LDF was considered, decreases in red blood cell fluxes occurred that were more pronounced the greater the tumour volume. In no case was vascular stasis observed. Hyperthermia did not affect tumour oxygenation substantially. Microregional and global assessment of lactate and ATP concentrations demonstrated increased lactate and decreased ATP levels following hyperthermia. Tumour glucose levels were increased following hyperthermia, possibly due to an enlarged distribution space resulting from development of interstitial oedema. Changes in lactate and ATP levels and the lack of changes in tumour oxygenation suggest a modification of energy metabolism following hyperthermia in the form of increased ATP hydrolysis, intensified glycolysis and impaired oxidative phosphorylation.

Observations of thermal gradients in perfused tissues during water bath heating.

Actual thermal gradients in perfused tissues are difficult to observe using thermocouples because of thermal conduction along the probes. We have used fine type-K (chromel-alumel) probes, which have a much lower thermal conductivity than equivalent-sized type-T (copper-constantan) thermocouples, to examine thermal gradients in two mouse tumour systems during water bath heating. The results indicate substantial heterogeneity in temperature distribution even in tumours transplanted in the foot and immersed to a depth of 2 cm in a 44 degrees C water bath for 20 min, i.e. thermal gradients greater than 1 degree C/mm were observed in KHT fibrosarcomas. The temperature heterogeneity for water bath heating is primarily a result of blood flow and appears to be tumour-specific. Temperature measurements using an excised perfused canine kidney demonstrate that increased perfusate volume flow increases the range of tissue temperatures. Consistent with theory, an artifactual improvement in temperature homogeneity resulted when temperature was measured using type-T thermocouples instead of type-K probes. These results emphasize the difficulties in obtaining accurate temperature measurements during experimental and clinical hyperthermia. Even extensive measurements of temperature in tissues may underestimate the true range of heterogeneity unless factors such as thermal smearing are controlled.

Hyperthermia enhances mitoxantrone cytotoxicity on human breast carcinoma and sarcoma xenografts in nude mice.

In this preclinical in vivo study, we measured antitumor response, local side effects and systemic toxicity of locally applied water-bath hyperthermia given alone or simultaneously with mitoxantrone (3 mg/kg b.w. i.v.; LD 10) on a human derived breast carcinoma (MX 1) or a human sarcoma (S 117) transplanted to female athymic (nude) mice. A single hyperthermia treatment at a tumor temperature up to 43 degrees C for 1 hr caused in both tumor lines only minor tumor regressions and transient tumor growth delay. However, the antitumor effect of mitoxantrone was significantly enhanced by local hyperthermia at 42 degrees C and particularly at 43 degrees C. In both tumor lines complete tumor regressions were achieved only if mitoxantrone was combined with hyperthermia. Undesired side effects and drug toxicity were not enhanced by hyperthermia. According to in vitro data and the results of the present in vivo study mitoxantrone seems to be a good candidate for clinical trials in combination with locoregional hyperthermia.

Angiogenesis determines blood flow, metabolism, growth rate, and ATPase kinetics of tumors growing in an irradiated bed: 31P and 2H nuclear magnetic resonance studies.

Experimental tumors growing in irradiated tissue have been used to study the biological differences characteristic of locally recurrent tumors. Since the hypoxic cell fraction of tumors growing in irradiated tissue is increased and growth rate is slowed, these tumors are assumed to be metabolically deprived with hypoperfusion. In this study, we directly measured the effect of tumor bed irradiation on blood flow, growth rate, rate of nucleoside triphosphate (NTP) turnover, and metabolic state using 31P and 2H nuclear magnetic resonance, and an intradermal assay for angiogenesis. (NTP turnover refers to ATP-synthetase mediated NTP turnover that is visible to 31P nuclear magnetic resonance using the technique of saturation transfer.) A decrease in the number of small blood vessels perfusing tumors in a preirradiated bed was found. Most of the decrease was due to a loss of vessels with diameters less than 0.04 mm. When tumors growing in preirradiated tissue reached approximately 100 mm3 in volume, a high frequency of gross and microscopic necrosis and hemorrhage was already observed in most tumors. Consistent with these observations, the phosphocreatine/inorganic phosphate and nucleoside triphosphate/inorganic phosphate ratios were significantly lower in the tumors growing in a preirradiated bed compared with tumors in a nonirradiated bed. The blood flow rate was similar to control for tumors less than 100 mm3 (45.8 versus 40.5 ml/100 g/min, P = not significant), but was significantly lower than control for tumors greater than 100 mm3 (40.4 versus 12.2 ml/100 g/min, P less than 0.01). The NTP turnover rates correlated (P less than 0.005, r = 0.66) with the volume doubling rate (1/tumor volume doubling time), but for tumors approximately 100 mm3 in size neither the volume doubling rate nor the NTP turnover rate of tumors growing in an irradiated bed was statistically lower than control [NTP turnover: 14 +/- 3%/s versus 9 +/- 2%/s; volume doubling rate: 0.47 +/- 0.07/day versus 0.33 +/- 0.04/day (mean +/- SE)]. A large intertumor variability of all metabolic parameters was observed.

Lipid composition of the membranes from cells of two rat tumors and its relationship to tumor thermosensitivity.

A plasma membrane-rich fraction has been separated from liver cells and cells of two solid rat tumors. D23 hepatoma and MC7 sarcoma. On the basis of marker enzyme activity the membranes separating at the 31-41% interface on the discontinuous sucrose gradient were enriched 15- to 19-fold. No significant differences in the phospholipid (PL) composition of the three membrane fractions were observed. The PL fatty acid (FA) composition showed that the percentage of unsaturated FA in all three membranes was between 43 and 48%. However, the oleic acid:PUFA ratio was much greater from tumor membranes. Membrane cholesterol was also significantly lower for cells from both tumors compared with liver cells. The DPH fluorescence polarization of the membrane fractions showed that the membranes from cells of both tumors are significantly less ordered than those of liver at all temperatures measured (4-50 degrees C). The Mg2+ ATPase activity of the plasma membranes is inactivated by hyperthermia treatments. The enzyme from liver cells was more thermostable (LT50 = 53.86 degrees C) than that from cells of either D23 (LT50 = 47.51 degrees C) or MC7 (LT50 = 46.34 degrees C) tumors.

Dose-dependent effects of hydralazine on microcirculatory function and hyperthermic response of murine FSall tumors.

The effects of the vasodilator hydralazine (HYD) on microcirculatory function and hyperthermic response were studied in early generation isotransplants of a spontaneous C3Hf/Sed mouse fibrosarcoma (FSall). Red blood cell flux (RBC flux) in superficial tumor regions was assessed using laser Doppler flowmetry. A differential microcirculatory response was seen between tumor and normal skin after 0.25 micrograms/g i.p. HYD, the tumor showing a transient increase in flow and the skin remaining almost stable. At 1.0 micrograms/g i.p., the differential response continued, this time with a transient fall in tumor blood flow but again no change in skin flow. High dose hydralazine (10.0 micrograms/g i.p.) was associated with a dramatic and prolonged decrease in tumor blood flow but a lesser and only transient decline in skin flow. Identical doses of hydralazine were given 30 min prior to heat treatment (43.5 degrees C for 15, 30, or 60 min). Tumor growth was measured daily and compared to controls (HT without hydralazine). Hydralazine at 0.25 micrograms/g i.p. did not affect heat induced growth delay. At 1.0 micrograms/g i.p., it significantly increased growth delay upon heat exposures of 15 min, but not after 30 or 60 min HT. Hydralazine at 10 micrograms/g i.p. increased growth delay for all heat doses (P less than 0.05). Hydralazine alone had no influence on growth delay of sham-heated tumors. The results obtained clearly indicate that tumor and normal tissues have microcirculatory differences in the time-course, degree and/or direction of response after hydralazine, and that hydralazine has potential for increasing the response of tumor to HT.

The effect of indomethacin on food and water intake, motor activity and survival in tumour-bearing rats.

This investigation has addressed the question whether food and water intake, motor activity and tumour growth are influenced by indomethacin in experimental cancer. Growing rats implanted with a methylcholanthrene-induced sarcoma were studied in metabolic cages connected to a computer. Food intake, water consumption and motor activity were continuously recorded over 30 days following tumour implantation. Treated tumour-bearing animals received indomethacin 1.0 mg/kg per day in drinking water. Food intake declined early in untreated tumour-bearing animals, but water intake was not affected. Motor activity decreased in untreated tumour-bearing animals from days 16-17 onward. Indomethacin treatment prolonged survival and 40% of these tumour-bearers were 'complete responders'. In some animals tumour growth was only marginally affected, but survival was still significantly improved ('partial responders'). Food intake was significantly improved in complete responders. Thus this positive effect seen in complete responders was secondary to less active tumour growth. Motor activity was also significantly higher in responders compared with non-responders.

The influence of pre-treatment temperature on the thermal sensitivity of a mouse tumour.

The response of tumours to hyperthermia was tested by giving graded heat treatments and assessing local control at 90 days. Mice were divided into three groups which were pre-treated for 3 days in ambient temperatures of 4, 21 or 35 degrees C. This enabled the mean tumour resting temperature to be varied by up to 11 degrees C, before subsequent heat treatment. For the heat treatments, the tumours were clamped in order to eliminate blood flow, resulting in uniform temperature distributions and hence more uniform thermal sensitivity. TCD50 values were used to construct Arrhenius plots. For all three pre-treatment temperatures, these plots demonstrated a factor of 1.6 increase in heating time per degree Celsius reduction in heating temperature. However, tumours kept in a 4 degrees C environment before treatment were more thermally sensitive than those kept in 21 degrees C conditions, while those in a 35 degrees C environment were more resistant. Pretreatment at 4 degrees C was equivalent to an increase of either 0.5 degree C in heating temperature or 28 per cent in heating time, compared with pre-treatment at 21 degrees C. Pre-treatment at 35 degrees C was equivalent to a reduction of either 0.6 degree C in heating temperature or 25 per cent in heating time. These data indicate that the pre-treatment tumour temperature is an important parameter, but the effect of heat treatment is more closely related to absolute heating temperature rather than to the increase in temperature above the normal resting level.

[Light optical and electron microscopic studies of the tumor cells in rats exposed to vinblastine against a background of increased activity of the anticoagulating system]. / Svetoopticheskoe i élektronno-mikroskopicheskoe issledovanie opukholevykh kletok krys pri deistvii vinblastina na fone povyshennoi aktivnosti protivosvertyvaiushchei sistemy.

It is shown that the damage of sarcoma 45 cells at different stages of cell life cycle occurs under the effect of vinblastine treatment against a background of higher activity of the blood anticoagulating system. A decrease in the mitotic activity, mitosis accumulation in prophase and especially in the metaphase as well as essential changes in the interphase cell ultrastructure are detected.

[Functional state of the thyroid and its regulatory system in tumor-bearing animals]. / Funktsional'noe sostoianie shchitovidnoi zhelezy i sistem ee reguliatsii u zhivotnykh s opukholiami.

A comparative study of labelled thyroxine and iodine accumulation was carried out in the thyroid endocrine complex under endoliquor and intraabdominal introduction of thyrotropic hormone (TTH) and thyrotropin-releasing-factor (TRF) in rats with transplantable and induced tumours as well as in intact animals. A sharp decrease of the system response to TRF in tumour-bearing animals was established. The incorporation of labelled thyroxine introduced into the thyroid gland tissue and posterior region of the hypothalamus is found to be lower under the tumour growth. The character of changes causing the disturbances in the activity of the thyroid gland should be taken into account in an attempt to normalize the gland activity. The normalization should be based on the complex influence directed to all the links of the hypothalamus-pituitary thyroid gland system.

Hyperthermia-induced alteration in erythrocyte velocity in tumors.

The effect of a hyperthermic treatment on the microcirculation of the experimental tumor Rhabdomyosarcoma BA1112 was investigated. The tumor was grown in 'sandwich' chambers in the rat skin. The erythrocyte velocity in selected capillaries was used to assess changes in the microcirculation. For this purpose, a simplified comparative method in which the (adjusted) velocity of a train of light dots indicated the velocity in the capillary was employed. During hyperthermic treatment (n = 16) consisting of an exposure of 180 minutes at 43 degrees C, it was apparent that a slight increase in erythrocyte velocity first occurred. This was followed, however, by a decrease and eventually a complete standstill.

Toxicity of diethylaminoreserpine to a transplantable tumor: the significance of the presence of hypoxic cells.

The survival of clonogenic cells from two transplantable mouse tumors has been measured following i.p. injection of diethylaminoreserpine (DL-152) to the tumor-bearing mouse. Reduction of surviving fraction was seen for both tumors following injection of the drug, minimal numbers of surviving cells being seen from 24 to 48 hr after injection. Greater cell kill was observed for the KHT fibrosarcoma (surviving fraction = 3 x 10(-2) at 48 hr) than for the EMT6 mammary carcinoma (surviving fraction = 2 x 10(-1) at 48 hr). Reduction in surviving fraction of the KHT tumor was already observed at 1 hr after injection of the drug, and survival at that time was reduced if tumor cells were acutely hypoxic prior to excision of the tumor. Results also indicated that chronically hypoxic radioresistant cells were more sensitive to the drug than were aerated cells. Significant reduction in surviving fraction was seen for doses of DL-152 as low as 5 mg/kg. Using KHT tumors growing as lung nodules, it was shown that toxicity of DL-152 was not apparent until 11 to 14 days after initiation of the tumor and that subsequent sensitivity of cells to DL-152 increased with increasing age of the lung tumor. Hypoxic cells were detectable in 10-day-old lung tumors, a time at which the tumors were still resistant to the toxic effects of DL-152. In vitro experiments using KHT cells in suspension showed that a high concentration of DL-152 was toxic to both hypoxic and aerated cells but that hypoxic cells were more sensitive to lower concentrations than were aerated cells.

Isolation and partial identification of eight endogenous G1 inhibitors of JB-1 ascites tumor cell proliferation.

Eight endogenous G1 inhibitors of the proliferation of JB-1 ascites tumor cells have been isolated and characterized. The activity of the inhibitors has been analyzed on synchronized JB-1 (murine plasmacytoma) and L1A2 (murine sarcoma) cells in vitro using flow cytometry. The purified inhibitors have been tested for in vivo activity on partially synchronized JB-1 and L1A2 ascites tumors in situ. Four of the inhibitors exhibited a high degree of cell specificity (chalone-like inhibitors) and were chemically related, whereas the other four showed no cell specificity. In most extractions, the amount of cell-specific activity is more than 50% of the total G1-inhibitory activity. Most of the inhibitors are low-molecular-weight peptides and glycopeptides.

[Hematopoietic indices in rats with sarcoma 45 in the process of treatment with cytostatics and diuretic agents]. / Pokazateli krovetvoreniia u krys s sarkomoi 45 v protsesse lecheniia tsitostatikami i mochegonnymi sredstvami.

Sarcoma 45 growth in rats was noted to be followed by the development of anemia and leucocytosis. Sessional use of 6-mercaptopurine and cyclophosphane resulted in the enhancement of anemia, the development of leucopenia, and suppression of bone marrow hemopoiesis. The suppression of hemopoiesis was much less manifested, if cytostatics were used together with diuretics (diacarbe or furocemid).