Effect of a lathyrogen (aminoacetonitrile hydrochloride) on aortic physiosclerosis and skeletal mineralization in growing rats of different age.

In one experiment, four groups of six-week-old-male PVG rats were, respectively, given tap water ('control group'), 0.00125M, 0.0025M, and 0.005M lathyrogen (aminoacetonitrile hydrochloride: AAN) solutions ad libitum for a period of 20 weeks. In a second experiment, 12-week-old male rats were similarly treated. It was found that the younger rats were far more susceptible to lathyrogenic influences than the older rats. For example, the rate of aortic physiosclerosis was significantly retarded in the six-week-old rats at dosages of 0.00125M and 0.0025M (the six-week-old rats exposed to 0.005M AAN were eliminated from the experiment before its completion), whilst physiosclerosis was unaffected even in those 12-week-old rats exposed to 0.005M AAN. The degree of mineralization of the femur (as reflected by its ash, Ca, Mg, Na, and K content) was retarded in approximately dose-dependent fashion in the rats of both ages, the effect being somewhat more pronounced in the younger animals. These results were discussed in the context of the known effects of lathyrogenic compounds on the biochemical maturation of connective tissue components, and also in the context of previous attempts to modify the lifespan of laboratory animals by lathyrogen administration.