Antigenic and allergenic characterization of the enzymes alcalase and savinase by crossed immunoelectrophoresis and crossed radioimmunoelectrophoresis.

Alcalase and savinase, produced by Bacillus species, are proteolytic enzymes that are used in laundry products and are known to cause respiratory allergy. Antigenic and allergenic characteristics of alcalase and savinase and their potential cross-reactivity were evaluated using crossed immunoelectrophoresis and crossed radioimmunoelectrophoresis. Alcalase exhibited two distinct antigens; one electropositive and one electronegative. The electropositive antigen exhibited some retrograde anodic mobility when coupled with antiserum components. Savinase exhibited one electropositive and two electronegative antigens. The antigens of the two enzymes were clearly different from each other, the three savinase antigens exhibiting greater electrophoretic mobility than the two alcalase antigens. In crossed radioimmunoelectrophoresis studies, only the electropositive antigen of alcalase, its retrograde complex, and the electropositive antigen of savinase bound IgE from the sera of individuals who were skin test positive to one or both enzymes. No evidence of cross-reactivity was observed in heterologous and tandem crossed immunoelectrophoresis studies and heterologous microimmunodiffusion reactions.

Light- and electron-microscopic evaluation of renal tubular cell vacuolation induced by administration of nitrilotriacetate or sucrose.

Cytoplasmic vacuolation of renal proximal tubular epithelial cells was studied in rats following administration of nitrilotriacetate (NTA) or sucrose. Sucrose was administered at both a high dose (29.2 mmol/kg) and low dose (7.3 mmol/kg) by ip injection. Both levels of sucrose induced severe vacuolation of the renal proximal tubular epithelium, as observed by light microscopy. However, at the high dose, the vacuolation was widespread, affecting essentially all the proximal tubules, while at the low dose, the lesion was distributed in a multifocal pattern. Nitrilotriacetate administered by gavage at a level of 7.3 mmol/kg also induced severe cytoplasmic vacuolation in the renal proximal tubular epithelium. The distribution of this lesion was multifocal and indistinguishable from that caused by the 7.3-mmol/kg dose of sucrose. Electron-microscopic examination of vacuolated tubule cells demonstrated that, in both the NTA- and sucrose-treated animals, the lesion was due to changes in the endocytotic/lysosomal system. The nuclei, mitochondria, golgi and endoplasmic reticulum and the highly convoluted areas of the basal membrane appeared normal in both the vacuolated and non-vacuolated tubule cells of rats given either NTA or sucrose.

Alterations of renal tissue structure during a 30-day gavage study with nitrilotriacetate.

Nitrilotriacetate (NTA), as the monohydrated trisodium salt, was administered by gavage to male Sprague-Dawley rats at levels of 0, 0.73 or 7.3 mmol/kg body weight/day for periods of up to 30 days. Two animals from each of the groups were killed 24 hr after dosing on day 9, 13, 16, 20, 23, 27 or 30. Cytoplasmic vacuolation and hyperplasia of the proximal convoluted tubules were the most prominent alterations observed by light microscopic examination of kidney tissue from both groups of NTA-treated rats. The number and severity of the lesions was greater in the high-dose group and in this group, erosion and hyperplasia of the pelvic transitional epithelium were also noted. The results of this study suggest that NTA-associated urinary tract lesions develop in a sequential pattern and that the rate and extent of these lesions is dose dependent.

The effects of nitrilotriacetate on cation disposition and urinary tract toxicity.

In this review a summary is presented of the experimental evidence that has led to the development of hypotheses to explain how the chronic ingestion of nitrilotriacetate (NTA), which is a non-mutagenic, non-metabolized and non-accumulating compound, might induce urinary tract toxicity that can lead to neoplasia. The hypotheses attribute the toxic process to alterations in divalent cation (M2+) distribution in the urinary tract during the processing of NTA for excretion in the urine. The hypotheses do not identify a 'carcinogen' per se but rather define conditions that must exist for the initiation and propagation of toxicity that is an essential precursor of and accompanies tumours associated with chronic, high dosage NTA ingestion. The proposed hypotheses are consistent with all available information on NTA toxicity and define ingestion doses that do not alter urinary tract M2+ distributions and do not initiate urinary tract toxicity after chronic exposure. The existence of no-effect doses that must be exceeded for the initiation and propagation of toxicity negates the validity of mathematical extrapolations of possible tumour incidence at doses below the threshold levels from the results obtained in chronic, high dosage experiments. The thresholds determined in the experimental animals are several orders of magnitude greater than human exposure via drinking-water based upon measured NTA concentrations in Canada where NTA has been used in detergents since 1970.

Acute ultrastructural effects of the antitumor antibiotic carminomycin on nucleoli of rat tissues.

Male Sprague-Dawley rats were treated with carminomycin i.v. in doses ranging from 1 to 40 mg/kg. Within 1 hr after the administration of carminomycin, 20 mg/kg, nucleoli of cardiac and skeletal muscle cells were segregated, while nucleoli of liver parenchyma cells were unaffected. Three and one-half hr after drug administration, cardiac muscle nucleoli reverted to normal ultrastructure. However, some skeletal muscle cell nucleoli were still segregated. Following treatment with carminomycin, 10 mg/kg, no significant ultrastructural changes were observed. These results demonstrate that at sufficiently high doses carminomycin induces ultrastructural lesions in nucleoli of both cardiac and muscle cells. The dose of carminomycin required to produce nucleolar segregation in cardiac and skeletal muscle is 6 times greater than the dose of Adriamycin (3.5 mg/kg) required to induce equivalent alterations.

Comparison of adriamycin-induced nucleolar segregation in skeletal muscle, cardiac muscle, and liver cells.

Male Sprague-Dawley rats were treated with either 2.5, 3.5, or 5.0 mg/kg of adriamycin by iv injection. After 1 or 3 hours of treatment, samples of liver, cardiac muscle, and skeletal muscle cells were examined by electron microscopy. The changes in ultrastructure observed in these tissues after the first hour included nucleolar segregation and altered distribution of the perinucleolar chromatin. However, no alterations in the ultrastructure of either the nucleus or cytoplasm were observed in tissues examined 3 hours after a 5-mg/kg dose of adriamycin. The doses at which nucleolar alterations occurred varied between tissues. In skeletal and cardiac muscle cells, marked alterations in nucleolar ultrastructure were observed at doses of 3.5 and 5.0 mg/kg of adriamycin. Liver cell nucleoli, however, exhibited few structural aberrations at these doses. The similarities in response of skeletal and cardiac muscle suggest that ultrastructural analysis of skeletal muscle biopsies may be useful in evaluating adriamycin cardiotoxicity.

Effects of adriamycin on ultrastructure of nucleoli in the heart and liver cells of the rat.

Ultrastructural studies of the effects of adriamycin on liver and cardiac cell nucleoli of the rat showed that nucleolar segregation occurred within 1 hr after an i.v. injection of a 40-mg/kg dose. Between 3 and 27 hr after this single dose, liver cell nucleoli progressively reverted to a normal ultrastructure. Nucleoli of rat myocardial cells did not recover but underwent further fragmentation, segragation, and conversion to ring-shaped structures. The ultrastructural alterations of myocardial cell nucleoli may represent an important aspect of adriamycin toxicity.