Variability of cell proliferation in the proximal and distal colon of normal rats and rats with dimethylhydrazine induced carcinogenesis

Table 1 Multivariate linear regression analyses with 2 design variables against 7 measured parameters

Response variable	Covariate	Coefficient	P-value
CPC	DMH	12.386	< 0.05
	POSITION	5.004	< 0.05
TOTLI	DMH	4.433	< 0.05
	POSITION	-1.528	< 0.05
INDLI 1	DMH	3.915	< 0.05
	POSITION	-9.006	< 0.05
INDLI 2	DMH	4.504	< 0.05
	POSITION	-2.159	0.14
INDLI 3	DMH	10.425	< 0.05
	POSITION	3.343	< 0.05
PZONE	DMH	18.169	< 0.05
	POSITION	-4.454	< 0.05
PZONELI	DMH	-18.312	< 0.05
	POSITION	1.725	0.43

CPC, cell per hemicrypt; TOTLI, total hemicrypt labelling index; INDLI 1, individual LI in compartment 1; INDLI 2 individual LI in compartment 2; INDL 3, individual LI in compartment 3; PZONE, proliferative zone; PZONELI, labelling index of proliferative zone.

Table 2 Comparison of cell proliferation in proximal and distal hemicrypts of normal and DMH rat colon

Parameters	Normal control		DMH
	Proximal	Distal	Proximal	Distal
Cells/hemi-crypt	34.45 ± 0.39	31.45 ± 0.2a	49.09 ± 0.65b	42.68 ± 0.53ac
Labelled cells	2.49 ± 0.16	2.74 ± 0.11	5.7 ± 0.24b	5.67 ± 0.23c
Total LI	7.2 ± 0.45	8.65 ± 0.34a	11.55 ± 0.45b	13.13 ± 0.46ac
Proliferative zone	16.75 ± 1.45	21.74 ± 1.07a	35.52 ± 1.58b	39.6 ± 1.32ac
LI of proliferative zone	59.43 ± 3.39	56.55 ± 2.13	39.84 ± 1.77b	38.89 ± 1.5c

Values expressed as mean ± SEM.

^aP < 0.05 when distal is compared to proximal in the same group,

^bP < 0.05 when DMH proximal is compared to normal proximal,

^cP < 0.05 when DMH distal compared to normal distal.