Study on effect of low protein feeding on pigment stone formation in guinea pig

The formation rate of pigment stone in the gall bladder was found to be 70%, under he use of low protien feeding in guinea pig by us in 1985, It was thus showed that the bnormality of nutrition metabolism was the major factor to the formation of pigment stone. A urther experimental study was designed on that basis, and 59 guinea pigs were divided into hree groups: 19 animals for the controll group with normal diet; 19 fed with low protien food or 40 days before killed for examination; and 21 initially fed with low protien for 40 days, nd then changed to normal diet for 60 days. The results revealed that the positive tare of tone formation in the second group was 95％ （18/19）, the wall of gall bladder being thikened nd less elastic, the size being reduced, the density of bile being increased and the volume of ile being decreased. However, the positive rate of stone formation in the third group was only 4％ （3/21）, and the appearance of the gall bladder and the bile in it looked normal as the ontroll group （none had stone formation in the first group fed for 100 days）. Two major points f the experiment are: （1） the positive rate of stone is elevated as high as 95％, if the eeding programe designed like us is used; （2） the process of stone formation can be reversed, f the food is changed from initial low protion to final normal one.