Hepatic acute-phase response, antioxidant biomarkers and DNA fragmentation of two rabbit breeds subjected to acute heat stress

Figures & data

Table 1. Hepatic inflammatory cytokines levels and acute phase protein concentration for New Zealand White and Baladi Black rabbits are exposed to early acute heat stress at weeks 5 and 13 of age.

Parameters	New Zealand White		Baladi Black		SEM	p Value
	NZWC	NZWT	BBC	BBT		HS	Breed	HS × Breed
Week 5^e
TNF-α, pg/ml	112.40^c	152.60^a	86.25^d	128.40^b	1.63	˂.0001	˂.0001	.252
IL-6, pg/ml	53.24^c	93.36^a	41.25^d	69.25^b	2.64	˂.0001	.0003	.016
Cp, ng/ml	7.58^d	12.36^a	8.25^c	11.23^b	0.34	˂.0001	.522	.031
AGP, mg/dl	0.81^c	3.12^a	0.70^d	2.92^b	0.06	˂.0001	.035	.482
Casp-3, ng/ml	1.36^c	2.05^a	1.05^d	1.56^b	0.05	˂.0001	˂.0001	.087
Week 13^f	NZWC2	NZWT2	BBC2	BBT2
TNF-α, pg/ml	121.20^c	179.60^a	92.12^d	139.9^b	1.94	˂.0001	˂.0001	˂.0001
IL-6, pg/ml	59.12^c	103.60^a	49.02^d	82.44^b	2.55	˂.0001	.0003	.062
Cp, ng/ml	8.55^b	10.36^a	9.21^ab	10.02^a	0.44	.019	.728	.294
AGP, mg/dl	1.05^c	3.97^a	0.93^c	3.21^b	0.07	˂.0001	.0002	.001
Casp-3, ng/ml	1.59^b	1.95^a	1.19^c	1.69^b	0.05	˂.0001	˂.0001	.161

HS: early acute heat stress; TNF-α: Tumor necrosis factor α; IL-6: Interleukin 6; Cp: ceruloplasmin; AGP: α-1-acid glycoprotein; Casp-3= caspase-3.

^a,b,c,d Means in rows with different superscript differ significantly (p<.05).

^eAt week 5 of age, the Control groups New Zealand white (NZWC) and Baladi Black (BBC) kept at (28 °C and 40% RH) while HS groups New Zealand white (NZWT) and Baladi Black (BBT) were subjected to acute heat stress (36 °C 62% RH for 6h).

^fAt week 13 of age, all the experimental rabbit groups, both Control exposed (single exposure) (NZWC2 and BBC2) and early heat-stressed groups (Double exposure) New Zealand white (NZWT2) and Baladi Black( BBT2) were subjected to acute heat stress (36 °C 62% RH for 6h).

Table 2. Hepatic lipid peroxidation and antioxidant enzymes levels for New Zealand White and Baladi Black rabbit exposed to acute heat stress at weeks 5 and 13 of age.

Parameters	New Zealand		Baladi Black		SEM	p Value
	NZWC	NZWT	BBC	BBT		HS	Breed	HS × Breed
Week 5^e
MDA, nmol / g	2.13^c	5.27^b	3.33^bc	12.53^a	0.63	˂.0001	.0002	.001
GSH, mg/g	24.33^a	14.40^b	17.77^b	4.67^c	1.28	˂.0001	.0002	.253
CAT, U/g	116.73^a	76.60^b	116.37^a	81.70^b	3.47	˂.0001	.514	.454
SOD, U/g	201.80^b	150.77^c	234.47^a	193.70^b	8.93	.0009	.003	.581
Week 13^f	NZWC2	NZWT2	BBC2	BBT2
MDA, nmol / g	1.57^d	7.30^b	4.00^c	9.10^a	0.37	˂.0001	.0005	.422
GSH, mg/g	13.50^b	4.50^c	21.03^a	14.40^b	1.10	˂.0001	˂.0001	.312
CAT, U/g	185.03^a	108.27^b	188.23^a	117.50^b	3.73	˂.0001	.134	.442
SOD, U/g	117.07^b	73.57^c	142.97^a	75.33^c	4.85	˂.0001	.021	.038

HS: acute heat stress, MDA: lipid peroxidation, GSH: glutathione reduced, CAT: Catalase, SOD: super oxide dismutase.

^a,b,c,d Means in rows with different superscript differ significantly (p<.05).

^eAt week 5 of age, the Control groups New Zealand white (NZWC) and Baladi Black (BBC) kept at (28 °C and 40% RH) while HS groups New Zealand white (NZWT) and Baladi Black (BBT) were subjected to acute heat stress (36 °C 62% RH for 6h).

^fAt week 13 of age, all the experimental rabbit groups, both Control exposed (single exposure) (NZWC2 and BBC2) and early heat-stressed groups (Double exposure) New Zealand white (NZWT2) and Baladi Black( BBT2) were subjected to acute heat stress (36 °C 62% RH for 6h).

Figure 1. Evaluation of DNA damage in the rabbit's hepatic cells using the comet assay. The photos show the electrophoretic DNA pattern as tailed (T) and untailed (UT) DNA. (A) New Zealand white control at five-week, NZWC (B) NZWT New Zealand white exposed to early acute heat-stress at five-week, (C) Baladi Black control at five-week BBC, (D) BBT Baladi Black exposed to early acute heat-stress at five-week, (E) NZWC2 New Zealand white control exposed to heat stress at 13 weeks (single exposure), (F) NZWT2 New Zealand white exposed for the second time to heat stress at 13 weeks (Double exposure), (G) BBC2 Baladi Black control exposed to heat stress at 13 weeks(single exposure) and (H) BBT2 Baladi Black exposed for the second time to heat stress at 13 weeks (Double exposure). At week 5 of age, only heat stress exposed groups were subjected to acute heat stress (36 °C 62% RH for 6h). At week 13 of age, all the experimental rabbit groups were subjected to acute heat stress (36 °C 62% RH for 6h).

Table 3. DNA damage measured using Comet assay for New Zealand White and Baladi Black rabbit exposed to acute heat stress at weeks 5 and 13 of age.

Parameters	New Zealand		Baladi Black		SEM	p Value
	NZWC	NZWT	BBC	BBT		HS	Breed	HS × Breed
Week 5^e
Tailed DNA %	3.00^d	11.00^a	4.00^c	9.00^b	0.58	˂.0001	1.000	.009
Tail length (µm)	1.75^c	2.36^a	1.52^d	2.01^b	0.04	˂.0001	.0002	.206
Tail DNA %	1.85^c	2.42^a	1.43^d	2.13^b	0.05	˂.0001	˂.0001	.208
Tail moment	3.24^c	5.71^a	2.17^d	4.28^b	0.05	˂.0001	˂.0001	.005
Week 13^f	NZWC2	NZWT2	BBC2	BBT2
Tailed DNA %	6.00^c	13.00^a	6.00^c	8.00^b	0.58	˂.0001	.003	.003
Tail length (µm)	1.82^c	2.52^a	1.69^c	2.16^b	0.05	˂.0001	.002	.066
Tail DNA %	1.93^c	2.59^a	1.66^d	2.23^b	0.06	˂.0001	.001	.481
Tail moment	3.51^c	6.53^a	2.81^d	4.82^b	0.06	˂.0001	˂.0001	˂.0001

HS: acute heat stress.

^a,b,c,d Means in rows with different superscript differ significantly (p<.05).

^eAt week 5 of age, the Control groups New Zealand white (NZWC) and Baladi Black (BBC) kept at (28 °C and 40% RH) while HS groups New Zealand white (NZWT) and Baladi Black (BBT) were subjected to acute heat stress (36 °C 62% RH for 6h).

^fAt week 13 of age, all the experimental rabbit groups, both Control exposed (single exposure) (NZWC2 and BBC2) and early heat-stressed groups (Double exposure) New Zealand white (NZWT2) and Baladi Black (BBT2) were subjected to acute heat stress (36 °C 62% RH for 6h).