Effects of ethylene precursor and inhibitors for ethylene biosynthesis and perception on nodulation in Lotus japonicus and Macroptilium atropurpureum.

Inhibitors of ethylene synthesis or its physiological function enhanced nodulation in Lotus japonicus and Macroptilium atropurpureum. In contrast, the application of 1-aminocyclopropane-1-carboxylic acid, a precursor of ethylene biosynthesis, reduced the nodule number in these legumes. These results suggest that an ethylene-mediated signaling pathway is involved in the nodulation process even in the determinate nodulators.

Rhizobitoxine production by Bradyrhizobium elkanii enhances nodulation and competitiveness on Macroptilium atropurpureum.

Application of 1-aminoocyclopropane-1-carboxylic acid, an ethylene precursor, decreased nodulation of Macroptilium atropurpureum by Bradyrhizobium elkanii. B. elkanii produces rhizobitoxine, an ethylene synthesis inhibitor. Elimination of rhizobitoxine production in B. elkanii increased ethylene evolution and decreased nodulation and competitiveness on M. atropurpureum. These results suggest that rhizobitoxine enhances nodulation and competitiveness of B. elkanii on M. atropurpureum.

[Toxicological studies on pepleomycin sulfate (NK 631) II. Subacute toxicity of pepleomycin sulfate in rats (author's transl)].

Studies on subactute toxicity and its recovery of pepleomycin sulfate (NK631) were carried out in both sexes of rats. NK 631 was administered intraperitoneally in dose levels of 0.3, 0.9, 2.7. 8.1 and 24.3 mg/kg/day for 30 days. After finishing administration of NK 631 for 30 days, 5 animals of each group were proceeded to recovery test for 35 days. During the course of the experiment, the body weight gains were suppressed in all dose levels except in 0.3 mg/kg group of male rats. The deaths were found in the animals treated with doses over 24.3 mg/kg during treatment period and in those over 2.7 mg/kg during recovery period. In biochemical and urinary analysis, the increases of serum GPT, BUN, Mg, Ca and urine glucose were moderately recognized in 8.1 mg/kg group. Additionally, in macroscopical and histopathological findings, bone damage was found in the animals treated with doses over 2.7 mg/kg during treatment and recovery periods. From these results, the maximum safety dose of NK 631 in subacute toxicity using rats were estimated to be about 0.3 mg/kg.

[Toxicological studies on pepleomycin sulfate (NK631). III. Subacute toxicity of pepleomycin in dogs (author's transl)].

Subacute toxicity and its recovery of pepleomycin sulfate was studied in both sexes of beagle dogs. At dose levels of 2.4, 1.2 and 0.6 mg/kg, pepleomycin was administered intramuscularly to dogs for 30 successive days. Two dogs of the 1.2 mg/kg dose group were used for recovery test for 35 days. As general symptoms, the decrease of food intake, the loss of body weight, ulceration of foot pad, nail root necrosis and onychoptosic, ulcer of tongue and labia, and alopecia, dermatitis and necrosis at friction sites were observed the more severely in high dose groups, as those in bleomycin were. The death occurred in the 2.4 mg/kg dose group of both sexes. The lesions of liver and kidney were recognized in the 2.4 and 1.2 mg/kg dose groups of both sexes on biochemical, histopathological or urinary findings. Additionally slight fibrous change of lung was observed in all dose groups. Generally subacute toxicity of pepleomycin was revealed approximately in the same as or in a little stronger degree than that of bleomycin, and its recovery was hardly recognized during its period. The maximum safety dose in this studies is estimated to be between 0.3 and 0.6 mg/kg in dogs.

[Toxicological studies on pepleomycin sulfate (NK631), IV. Chronic toxicity of pepleomycin sulfate in rats (author's transl)].

Studies on chronic toxicity and its recovery of pepleomycin sulfate (NK 631) were carried out in both sexes of rats. NK 631 was administered intraperitoneally in dose levels of 0.15, 0.3, 0.6, 1.2 and 2.4 mg/kg/day for 180 days. After finishing administration of NK 631 for 180 days, animals of each group were proceeded for 35 days recovery test. During the course of the experiment, the body weight gains were suppressed in all dose levels except for 0.15 mg/kg group of female. The deaths were found in all dose levels except for 0.15 mg/kg level of male during treatment and recovery periods. In biochemical and urinary findings, the increase of serum BUN, Mg, inorganic P. and urine glucose were slightly recognized in the animals treated with doses over 0.6 mg/kg. Additionally, in macroscopical and histopathological findings, bone damage and renal lesions were found in the animals treated with doses over 0.6 mg/kg during treatment and recovery periods. From these results, the maximum safety dose of NK 631 in chronic toxicity study using rats were estimated to be at less than 0.15 mg/kg.

[Safety evaluation of NK 631. Antigenicity, effect on delated hypersensitivity, irritative effect on eye mucous membrane and mutangenicity of pepleomycin (NK 631) (author's transl)].

1. Whether NK 631 is antigenic to guinea pigs and rabbits was studied by the methods of active and passive anaphylactic shock tests, Schultz-Dale reaction, passive cutaneous anaphylaxis, Ouchterlony, tanned red cell haemagglutination test and test according to the U.S. Appraisal of the Safety of Chemicals in Foods, Drugs and Cosmetics. However, none of the tests proved NK 631 to be antigenic. 2. The immunosuppressive effect of NK 631 was studied by delayed hypersensitivity to picryl chloride in normal and L-1210 tumor bearing mice. Therapeutic dosis of NK 631 was no immunosuppressed but toxic dosis of NK 631 was slightly decreased in ear thickness of delayed hypersensitivity. 3. The acute irritative effect of NK 631 and of bleomycin was studied by single instillation to the rabbit eye mucous membrane with 0.1 ml of either of 10, 33 and 100 mg/ml solution of the drugs in physiological saline. The irritative effect of NK 631 on the eye mucous membrane at each concentration was slightly severe than that of bleomycin at the same concentration. However, the manifestations were only mild to moderate dilatation of the conjunctival and nictating membrane blood vessels and eye mucous, and recovered or were mitigated 48 hours after the instillation. No severe changes such as corneal opacity, corneal desquamation, swelling and deaquamation of the conjunctival and nictating membrane were observed. The histopathological examination revealed no striking changes. 4. Mutagenicity of NK 631 and of bleomycin on Salmonella typhimurium strain TA 100 and TA 98 was studied. It was definitely shown that neither NK 631 nor bleomycin exerted any mutagenic action on either test strains.