Table 1.

Classification of gpt mutations from the lungs of control and particle multiply (0.2 mg × 4) treated mice^a)

	Control		C60		CB		Kaolin
Type of mutation in gpt	No.	%	No.	%	No.	%	No.	%
Base substitutions
Transitions	10	40	35	41	18	45	37	50
A:T->G:C	2	8	11	13	2	5	5	7
G:C->A:T	8	32	24	28	16	40	32	43
Transversions	10	40	35	40	17	43	30	41
A:T->T:A	0	0	2	2	1	3	0	0
A:T->C:G	2	8	3	3	4	10	5	7
G:C->T:A	8	32	25	29	8	20	17	23
G:C->C:G	0	0	5	6	4	10	8	11
Deletions	4	16	12	14	4	10	6	8
Insertions	1	4	3	4	0	0	1	1
Others	0	0	1b)	1	1C)	3	0	0
Total	25	100	86	100	40	101	74	100

^a)Independent mutations were isolated no more than once from any individual mouse.

^b)Multiple mutation (Four base substitutions)

^C)Tandem mutation (GG->TT)