In vivo inhibition by antioxidants of adriamycin-induced apoptosis in murine peritoneal macrophages.

Adriamycin (ADM) is an oncostatic of the anthracycline family with confirmed experimental and clinical efficiency. This antitumoral drug has been reported to stimulate macrophage activity and is able to induce apoptosis (AP) in some tumour cells. The objective of the present work was to investigate if in vivo administration of ADM to mice induces AP in their peritoneal macrophages (PM). AP was expressed by the apoptotic index (AI) of peritoneal macrophages observed under fluorescence microscope after ethidium bromide and acridine orange staining and confirmed by detection of the ladder pattern on DNA electrophoresis, indicates DNA fragmentation in 80-120 bp characteristic of apoptotic state. 24 hours after i.p. ADM administration, AP was observed in PM. The effect was best visible after the injection of 5 mg/kg ADM. (Al: 76.3+/-8.9 vs untreated control group AI: 2.8+/-1.1). In the ADM treated group a DNA ladder electrophoretic pattern was observed while DNA from normal PM was genomic. Since ADM toxicity has been attributed to reactive oxygen species generation, we investigated its possible participation in AP induction by pretreating mice with antioxidants: (+)-alpha-tocopherol acid succinate (30 IU/mouse per os) for 3 days before ADM administration with E. coli lipopolysacharide (0.15 microg/mouse i.p.) 24 hours before ADM administration or with superoxide dismutase (10,000 IU/mouse i.p.) 1 hour before ADM administration. AI was significantly decreased, with values close to those of the untreated control group (AI: 15+/-5.7, 9.6+/-8.0 and 32.9+/-6.9, respectively). Antioxidants given before ADM treatment significantly increased the live cell index (p < or = 0.001) in PM the groups while inactivated antioxidants no longer protect PM against the ADM AP induction. DNA analysis confirmed the effect: in the untreated control and in the antioxidant protected groups DNA was genomic while in either ADM or inactivated-antioxidants + ADM treated groups, DNA presented the ladder pattern. AP can thus be induced in PM by ADM and inhibited by antioxidants. These observations may have clinical applications.

Enhanced functional capacity of the peritoneal macrophages as antigen presenting cells after aclacinomycin treatment in mice.

Aclacinomycin (ACM) is an oncostatic of the anthracycline family, largely used in patients and experimentally in mice. ACM has been reported to enhance phagocytosis, secretion of free oxygen radicals and of interleukin 1. Its injection is also followed by an increase of the cytotoxic and cytostatic activity of murine peritoneal macrophages. In the present work we investigated whether ACM modifies the antigen-presenting cell capacity of murine peritoneal macrophages. Purified T lymphocytes were cultured with peritoneal macrophages from either normal or ACM treated mice (4 mg/kg day -4) which were previously incubated with phytohemagglutinin. The T cell proliferative response was greater in cultures with normal macrophages, indicating that macrophages from ACM-treated mice had a better antigen presenting activity than normal untreated macrophages.

Proteolytic activity in extracts of invasive cervical carcinoma and precursor lesions.

In this preliminary report, we showed that proteolytic activity of extracts from 85 cervical samples of patients with normal cervix, low and high-grade squamous intra-epithelial lesions and invasive carcinoma, increased according to the natural history of the cervical cancer when measured with three different substrates. Inhibitor assays for four different catalytic classes of endopeptidases indicated that the predominant catalytic class in extracts of all groups was that of metalloproteinases. Substrate gel electrophoresis revealed that invasive carcinoma extracts had two bands with proteolytic activity (with M(r) of 72 and 52 kDa) which were not present in normal tissue or biopsies with precursor lesions. Immunological and molecular characterization of these bands may provide information relevant to cervical cancer biology and clinical applications.

Hepatotoxicity induced by a single ip injection of ruthenium red.

Ruthenium red (RR) has been used as a marker in morphological observations of the glycocalix because it interacts with polyanionic mucopolysaccharides. This fact may explain its agglutinating effect on rat blood red cells following a single 20 mg/kg intraperitoneal injection, which increases with time post-injection. This study was performed to determine whether such an effect was due to a direct effect of the RR on the blood cells, to interference with coagulation, or to the non-specific general toxicity of this dye. Male rats were injected with 20 mg/kg RR ip and the enzymatic and coagulation parameters, plus the liver morphology were examined. Alanine aminotransferase (ALAT) activity was increased at 30, 60 and 120 min, and aspartic aminotransferase (ASAT) activity was increased 60, 120 and 480 min after RR injection. The prothrombin time (PT) and partially activated thromboplastin time (PTT) were significantly decreased, particularly after 60-120 min. The liver had an external granular appearance with clear signs of congestion and oedema, and showed degenerative changes very soon after RR injection. A single administration of RR induces serious functional and structural changes in the liver. Such a toxicity, and these changes must be taken into consideration, particularly with regard to neurological studies.

Increased phagocytic activity of peripheral blood monocytes after intravenous injection of phospholipase A2 to monkeys.

One of the expressions of the activity of phagocytic cells such as monocytes or macrophages is a burst of increased oxidative activity on stimulation. The free oxygen radicals liberated, mainly O2- and H2O2, lead to chemoluminescence, which is thus a measure of activation. Chemoluminescence also depends on arachidonic acid metabolism, and this depends on phospholipase A2 (PLA2). We modified monocyte activity in monkeys by injecting them i.v. with this enzyme and observed that 30 min after injection, the phagocytic activity of peripheral blood monocytes and the chemoluminescence they emitted was greater than that of controls. We suggest that PLA2 may act as an in vivo immunomodulator in mammals.

[Increase of proliferative and cytotoxic responses to alloantigenic stimulation of mouse spleen cells treated with aclacinomycin]. / Incremento a las respuestas proliferativa y citotóxica a la estimulación aloantigénica de células esplénicas de ratones tratados con aclacinomicina.

Aclacinomycin (ACM) is an oncostatic substance on the family of the Anthracyclines, with a proven activity in human and rodents. Splenic cells from C57BL/6 ACM injected mice by intraperitoneal or intravenous route four days before their sacrifice showed a significant increase in the proliferative and cytotoxic response respectively measured by incorporation of 3H-TdR and by the liberation of 51Cr when stimulated in vitro with irradiated mouse DBA/2 splenic cells. This response is doses dependent, and one can clearly observe different effects on the proliferative and cytotoxic responses at high doses. The cultures supernatants of splenic cells from mice treated with ACM during allogeneic stimulation showed a greater activity to induce the proliferation of a line of T cytotoxic cells dependent on Interleukin-2. Finally, the cytotoxic activity of splenic cells induced by the allogeneic stimulation in vitro, of mice treated with ACM, was found in a subpopulation of cells non adherent to plastic, mainly made up of lymphocytes.

Pulmonary toxicity of oxygen.

Prolonged exposure to hyperoxia in order to compensate for inefficient ventilation can lead to progressive pulmonary damage and death. Since pulmonary macrophages control bacterial and viral penetration, we studied the effect of hyperoxia on pulmonary alveolar macrophages from newborn and adult rats, kept in air or in a 95% normobaric oxygen atmosphere. The viability of pulmonary alveolar macrophages in bronchoalveolar lavages of newborn rats after 3 d in oxygen was significantly lower than that of newborn rats after 3 days in air. The functional capacity, as measured by the phagocytosis of Candida was similarly affected and these observations mays explain why infections develop. Adult rat macrophages were not sensitive to hyperoxia.