The blood level of sulfamonomethoxine (SMM) in the dog and its kinetics were studied. The free form and the acetylated form of SMM were successfully isolated by thin layer chromatography. They were further determined by the method described by Bratton and Marshall with a slight modification. Since various undetermined substances were contained in the urine of dogs positive for Bratton and Marshall's reaction, they were also isolated by thin layer chromatography prior to analysis. When injected intravenously, SMM disappeared from the blood circulation at the rate of 3.6% an hour, and excreted in urine at the rate of 2.5% an hour. The total amount of theoretical excretion of SMM in urine was 65.8%. The theoretical space of distribution of SMM in the body was 448.5 ml/kg. Calculation revealed that 53.8mg/kg of SMM was required to keep a blood level of 5 mg/dl 24 hours after injection. In dogs, the deacetylation of acetyl-SMM was observed. The rate of deacetylation was 10.1%. The rate of disappearance of acetyl-SMM from the venous blood was 20.8%. The space of distribution of acetyl-SMM was 450.6 ml/kg, which was quite similar to that of the free form. SMM administered subcutaneously and orally was also analyzed kinetically. The absorption rate of SMM from subcutaneous tissue was 66.7% an hour. The rate of disappearance from the venous blood wa s 4.8%. The rate of absorption of SMM through the gut varied markedly according to the amount of food in the gut. The rate of absorption of SMM was 54.4% an hour in a dog starred for 24 hours and 31.9% in a dog right after feeding. Mathematically, the onset of absorption was 1.0 ± 0.5 hour after administration in the former dog and 6.8 ± 1.0 hours in the latter. The case of repeated treatment was also analyzed mathematically, but no alteration was obser ved in rate of excretion or accumulation.
The gel diffusion test was carried out using Mycoplasma gallisepticum (MG) antigen extracted by sonication from the organisms grown in PPLO broth (Eiken) with addition of horse serum (contained at 20%), and anti-MG rabbit serum which had been prepared from growth in Hofstad's medium containing 20% chicken serum. The results obtained are as follows. 1) Repeated tests by gel diffusion did not always give similar results with the same lot of antigen and its antiserum. An increase or decrease in the number of precipitation lines was observed, though it aws limited to one line. 2) The protein concentration of antigen and time for bleeding from immunized rabbits greatly affected the number of precipitation lines in the gel diffusion test. Under suitable conditions, however, 5 lines were obtained in this test. 3) With antisera S6 and KP-13, the number of precipitation lines varied from 2 to 5 depending on 27 strains used. At least 2 antigen components were common to these strains. Three strains, S6, KP-13, and PG-31, were employed for the cross tests by gel diffusion under more suitable conditions. At least 3 common antigen components were observed among the three strains. One more common precipitation line was seen between the strains S6 and KP-13, or S6 and PG-31. The additional lines were not serologically related. This indicates that a part of MG antigen was not serologically uniform among the strains. 4) Of 54 serum samples from MG-infected chickens, seventeen produced one or three precipitation lines against the antigens of MG (a total of 26 strains). However, there seemed to be some differences in antigenicity among the strains.