Sodium arsenite-induced cardiovascular and renal dysfunction in rat via oxidative stress and protein kinase B (Akt/PKB) signaling pathway

Figures & data

Table 1. Cardiac antioxidant enzyme profile following exposure and withdrawal of sodium arsenite.

Experimental groups		Group I	Group II	Group III	Group IV
SOD	Exposure	34.73 ± 1.21	35.02 ± 0.58	38.31 ± 1.61	35.35 ± 0.61
	Withdrawal	2.81 ± 0.02	2.52 ± 0.07*	2.54 ± 0.02*	2.64 ± 0.03*
GST	Exposure	3.097 ± 0.103	3.127 ± 0.005	3.438 ± 0.129*	3.275 ± 0.004
	Withdrawal	3.246 ± 0.031	2.883 ± 0.086*	2.92 ± 0.023*	3.023 ± 0.030*
GPx	Exposure	196.1 ± 1.39	214.6 ± 1.21*	227.0 ± 1.54*	214.7 ± 2.44*
	Withdrawal	188.7 ± 1.59	174.1 ± 4.85*	170.4 ± 1.33*	175.1 ± 1.11*
CAT	Exposure	623.2 ± 21.06	632.4 ± 10.30	687.1 ± 29.16	652.4 ± 6.93
	Withdrawal	624.9 ± 5.43	561.9 ± 17.20*	560.4 ± 5.81*	579.2 ± 6.41*

Values are presented as mean ± standard deviation (n = 10). Group A (Control), Group B (sodium arsenic (10 mg/kg; p.o.)), Group C (sodium arsenic (20 mg/kg; p.o.)), Group D (sodium arsenic (40 mg/kg; p.o.)). Asterisk (*) indicates significant difference from control at P < 0.05. GPx (glutathione peroxidase; units/mg protein); GST (glutathione-S-transferase; mmole1-chloro-2, 4-dinitrobenzene-GSH complex formed/min/mg protein); SOD (superoxide dismutase; units/mg protein); CAT (catalase; mmole H₂O₂ consumed/min/mg protein).

Table 2. Renal antioxidant enzyme profile following exposure and withdrawal of sodium arsenite.

Experimental groups		Group A	Group B	Group C	Group D
SOD	Exposure	26.27 ± 0.63	25.95 ± 0.66	25.20 ± 0.85	26.55 ± 0.34
	Withdrawal	2.385 ± 0.03	2.357 ± 0.06	2.404 ± 0.02	2.526 ± 0.04*
GST	Exposure	3.203 ± 0.08	3.154 ± 0.08	3.065 ± 0.10	3.237 ± 0.05
	Withdrawal	2.735 ± 0.11	2.805 ± 0.08	2.871 ± 0.01	2.983 ± 0.05*
GPx	Exposure	207.6 ± 4.05	198.2 ± 5.24	192.9 ± 6.62*	200.0 ± 1.68
	Withdrawal	154.6 ± 1.59	156.4 ± 1.87	155.7 ± 1.10	163.0 ± 2.33*
CAT	Exposure	636.5 ± 13.48	621.4 ± 14.90	601.6 ± 19.78	626.5 ± 8.84
	Withdrawal	528.5 ± 23.14	509.6 ± 38.50	547.0 ± 5.11	570.8 ± 9.06

Values are presented as mean ± standard deviation (n = 10). Group A (Control), Group B (sodium arsenic (10 mg/kg; p.o.)), Group C (sodium arsenic (20 mg/kg; p.o.)), Group D (sodium arsenic (40 mg/kg; p.o.)). Asterisk (*) indicates significant difference from control at P < 0.05. GPx (glutathione peroxidase; units/mg protein); GST (glutathione-S-transferase; mmole1-chloro-2, 4-dinitrobenzene-GSH complex formed/min/mg protein, SOD (superoxide dismutase; units/mg protein); CAT (catalase; mmole H₂O₂ consumed/min/mg protein).

Table 3. Cardiac thiols and markers of oxidative stress following exposure and withdrawal of sodium arsenite.

Experimental groups		Group A	Group B	Group C	Group D
Total thiol	Exposure	46.99 ± 1.59	40.55 ± 1.35*	40.44 ± 1.98*	40.56 ± 1.50*
	Withdrawal	38.11 ± 2.40	29.53 ± 2.33*	29.77 ± 1.39*	24.36 ± 0.89*
Non-protein thiol	Exposure	78.07 ± 1.16	77.60 ± 0.38	74.42 ± 2.06	70.96 ± 1.04*
	Withdrawal	24.26 ± 0.85	22.75 ± 1.02	22.77 ± 0.52	23.05 ± 0.31
GSH	Exposure	56.66 ± 1.18	56.95 ± 0.78	55.81 ± 0.20	56.74 ± 0.59
	Withdrawal	51.69 ± 0.89	50.81 ± 0.33	53.33 ± 1.22	51.87 ± 0.41
Nitric oxide	Exposure	0.52 ± 0.04	0.59 ± 0.03	0.62 ± 0.02*	0.77 ± 0.03*
	Withdrawal	0.25 ± 0.01	0.33 ± 0.02*	0.34 ± 0.00*	0.26 ± 0.03
MDA	Exposure	0.51 ± 0.02	0.60 ± 0.01*	0.62 ± 0.03*	0.68 ± 0.03*
	Withdrawal	0.04 ± 0.00	0.04 ± 0.00	0.04 ± 0.00	0.05 ± 0.00*
H2O2 generated	Exposure	12.17 ± 0.23	13.63 ± 0.17*	13.39 ± 0.06*	14.48 ± 0.32*
	Withdrawal	11.73 ± 0.11	11.73 ± 0.38	12.29 ± 0.44	12.98 ± 0.26*

Values are presented as mean ± standard deviation (n = 10). Group A (Control), Group B (sodium arsenic (10 mg/kg; p.o.)), Group C (sodium arsenic (20 mg/kg; p.o.)) and Group D (sodium arsenic (40 mg/kg; p.o.)). Asterisk (*) indicates significant difference from control at P < 0.05. Total thiol (µmol/L), non-protein thiol (µmol/L), H₂O₂ (hydrogen peroxide generation; µmol/mg protein), MDA (malondialdehyde; µmol of MDA formed/mg protein), nitric oxide (µmol/mg protein); GSH (reduced glutathione; µmol/mg protein).

Table 4. Renal thiols and markers of oxidative stress following exposure and withdrawal of sodium arsenite.

Experimental groups		Group A	Group B	Group C	Group D
Total thiol	Exposure	52.57 ± 4.14	40.78 ± 2.59*	32.07 ± 2.51*	28.02 ± 1.03*
	Withdrawal	50.76 ± 2.10	42.16 ± 1.61*	48.56 ± 1.73	48.47 ± 0.95
Non-protein thiol	Exposure	52.29 ± 0.97	49.68 ± 0.97*	44.64 ± 0.15*	44.91 ± 1.38*
	Withdrawal	19.71 ± 1.43	20.21 ± 0.69	20.59 ± 1.56	20.36 ± 0.72
GSH	Exposure	57.43 ± 0.57	56.47 ± 0.63	56.55 ± 0.49	56.34 ± 0.33
	Withdrawal	51.59 ± 0.54	49.84 ± 1.07	51.63 ± 0.30	50.30 ± 0.62
Nitric oxide	Exposure	0.95 ± 0.05	1.01 ± 0.03	1.02 ± 0.03	0.95 ± 0.05
	Withdrawal	1.70 ± 0.06	1.37 ± 0.06*	1.53 ± 0.09	1.23 ± 0.04*
MDA	Exposure	0.314 ± 0.029	0.402 ± 0.008*	0.496 ± 0.009*	0.472 ± 0.018*
	Withdrawal	0.034 ± 0.002	0.037 ± 0.002	0.043 ± 0.004	0.042 ± 0.002*
H2O2 generated	Exposure	13.64 ± 0.76	14.14 ± 0.28	14.67 ± 0.57	14.56 ± 0.06
	Withdrawal	19.85 ± 0.65	18.26 ± 0.36*	19.70 ± 0.54	18.58 ± 0.49

Values are presented as mean ± standard deviation (n = 10). Group A (Control), Group B (sodium arsenic (10 mg/kg; p.o.)), Group C (sodium arsenic (20 mg/kg; p.o.)) and Group D (sodium arsenic (40 mg/kg; p.o.)). Asterisk (*) indicates significant difference from control at P < 0.05. Total thiol (µmol/L), non-protein thiol (µmol/L), H₂O₂ (hydrogen peroxide generation; µmol/mg protein), MDA (malondialdehyde; µmol of MDA formed/mg protein), Nitric oxide (µmol/mg protein); GSH (reduced glutathione; µmol/mg protein).

Table 5. Plasma creatinine and urea profile following exposure and withdrawal of sodium arsenite.

Experimental groups		Group A	Group B	Group C	Group D
Creatinine	Exposure	21.88 ± 1.26	27.85 ± 2.52*	20.55 ± 0.46	21.88 ± 1.99
	Withdrawal	2.564 ± 0.07	2.319 ± 0.05*	2.285 ± 0.05*	2.508 ± 0.13
Urea	Exposure	2.008 ± 0.22	1.631 ± 0.20	1.268 ± 0.18*	1.645 ± 0.37
	Withdrawal	1.623 ± 0.31	1.782 ± 0.24	2.322 ± 0.18*	1.837 ± 0.17

Values are presented as mean ± standard deviation (n = 10). Group A (Control), Group B (sodium arsenic (10 mg/kg; p.o.)), Group C (sodium arsenic (20 mg/kg; p.o.)), Group D (sodium arsenic (40 mg/kg; p.o.). Asterisk (*) indicates significant difference from control at p < 0.05. Creatinine (µmol/L); urea (µmol/L).

Figure 1. Immunohistochemistry of protein kinase B (PKB) in the heart of rats exposed to sodium arsenite for 4 weeks. (A) Control: shows positive and high expression of PKB; (B) 10 mg/kg NaAsO₂: shows lower expression of PKB than control: (C) 20 mg/kg NaAsO₂ shows lower expression of PKB than control; (D) 40 mg/kg NaAsO₂: shows no expression of PKB. The result is indicative that exposure of rats to NaAsO₂ reduced the expressions of survival protein (Akt/PKB). Scale bar (for A, B, C and D) = 5.04 × 3.87 mm. The slides were counterstained with high definition hematoxylin and viewed ×400 objectives.

Figure 2. Immunohistochemistry of protein kinase B (PKB) in the kidneys of rats exposed to sodium arsenite for 4 weeks. (A) Control: shows positive expression of PKB; (B) 10 mg/kg NaAsO₂ shows lower expression of PKB than control; (C) 20 mg/kg NaAsO₂ shows no expression PKB; (D) 40 mg/kg NaAsO₂: shows no expression PKB. The result is indicative that exposure of rats to NaAsO₂ reduced the expressions of survival protein (Akt/PKB). Scale bar (for A, B, C, and D) = 5.04 × 3.87 mm. The slides were counterstained with high definition hematoxylin and viewed ×400 objectives.

Figure 3. Immunohistochemistry of protein kinase B (PKB) in the heart of rats after withdrawal of sodium arsenite exposure for 4 weeks. (A) Control: shows positive and high expression of PKB; (B) 10 mg/kg NaAsO₂: shows lower expression of PKB than control; (C) 20 mg/kg NaAsO₂ shows lower expression of PKB than control; (D) 40 mg/kg NaAsO₂: shows lower expression of PKB than control. The result shows that following withdrawal of NaAsO₂, the expressions of the survival protein (Akt/PKB) are still lower than the control. Scale bar (for A, B, C, and D) = 5.04 × 3.87 mm. The slides were counterstained with high definition hematoxylin and viewed ×400 objectives.

Figure 4. Immunohistochemistry of protein kinase B (PKB) in the kidneys of rats after withdrawal of sodium arsenite exposure for 4 weeks. (A) Control: shows positive and high expression of PKB; (B) 10 mg/kg NaAsO₂ shows lower expression of PKB than control; (C) 20 mg/kg NaAsO₂: shows no expression of PKB; (D) 40 mg/kg NaAsO₂: shows no expression of PKB. The result shows that following withdrawal of NaAsO₂, the expressions of the survival protein (Akt/PKB) are still lower than the control. Scale bar (for A, B, C, and D) = 5.04 × 3.87 mm. The slides were counterstained with high definition hematoxylin and viewed ×400 objectives.

Figure 5. Photomicrograph showing heart of rats exposed to sodium arsenite orally for 4 weeks. (A) Control shows no significant lesion; (B) 10 mg/kg NaAsO₃ mild pyknosis and necrotic cells (black arrows); (C) 20 mg/kg NaAsO₃ reveals loss of striations and pyknotic cells (black arrows) and (D) 40 mg/kg NaAsO₃ with loss of structural architecture, severe pyknosis and necrosis of cells (black arrows). Scale bar (for A, B, C and D) = 2.15 × 2.79 mm Plates are stained with H and E stains and viewed with ×100 objectives.

Figure 6. Photomicrograph showing heart of rats post withdrawal of sodium arsenite for 4 weeks. (A) Control; (B) 10 mg/kg NaAsO₃ mild myocardial damage with pyknotic cells (black arrows); (C) 20 mg/kg NaAsO₃ moderate myocardial damage with pyknotic cells (black arrows) and (D) 40 mg/kg NaAsO₃ severe myocardial damage with pyknotic cells (black arrows). Scale bar (for A, B, C and D) = 2.15 × 2.79 mm. Plates are stained with H and E stained and viewed with ×100 objectives.

Figure 7. Photomicrograph showing kidney of rats exposed to sodium arsenite orally for 4 weeks. (A) Control shows focal hemorrhagic lesion (blue arrow); (B) 10 mg/kg NaAsO₂ with peritubular infiltration by inflammatory cells (black arrow) and mild tubular necrosis (green arrow); (C) 20 mg/kg NaAsO₂ showing congestion of vessel (blue arrow) and (D) 40 mg/kg NaAsO₂ showing congestion of vessels (blue arrow) and peritubular infiltration by inflammatory cells (black arrow). Scale bar (for A, B, C and D) = 2.15 × 2.79 mm. Plates are stained with H and E stains and viewed with 100 objectives.

Figure 8. Photomicrograph showing kidneys of rats post withdrawal of sodium arsenite for 4 weeks. (A) Control with mild congestion of blood vessel (blue arrow); (B) 10 mg/kg NaAsO₂ shows congestion of vessel (blue arrow); (C) 20 mg/kg NaAsO₂ with marked disseminated congestion of blood vessel (blue arrow) and (D) 40 mg/kg NaAsO₂ shows focal area of peritubular inflammation (black arrow). Scale bar (A, B, C and D) = 2.15 × 2.79 mm. Plates are stained with H and E stains and viewed with ×100 objectives.