mRNA EXPRESSION OF TRANSFORMING GROWTH FACTOR-α AND THE EGF RECEPTOR FOLLOWING NEPHROTOXIC RENAL INJURY

Figures & data

Figure 1A. Solution hybridization assay for in control and mercuric chloride (HgCl₂) EGF injected rats at days 1 and 3. The probe is shown diluted 1:10 and 1:100. Simultaneous hybridization was carried out with 18S shown in the lower panel.

Figure 1B. EGF data corrected for lane background and sample loading using 18S. * p < 0.01.

Table

	HgCl2 (2 mg/kg)		Control
Day	Creatinine (mg/dL)	BUN (mg/dL)	Creatinine (mg/dL)	BUN (mg/dL)
1	2.2 ± 0.26^*	52.8 ± 9.7^* (n = 5)	0.3 ± 0.01^a	12.2 ± 0.7 (n = 5)
3	2.4 ± 0.8^**	112.0 ± 38.2^** (n = 4)	0.6 ± 0.04^b	15.4 ± 0.08 (n = 4)
5	0.8 ± 0.4	38.3 ± 8.9^* (n = 5)	0.6 ± 0.02^b	14.0 ± 1.3 (n = 5)
	HgCl2 (4 mg/kg)		Control
3	4.7 ± 0.32^*	210.1 ± 7.8^* (n = 4)	0.3 ± 0.03^a	19 ± 1.2 (n = 4)

Creatinine and blood urea nitrogen (BUN) values for the various groups. HgCl₂ (mercuric chloride).

^a,bDifferent creatinine standards were used for these groups.

^*p < 0.01

^**p < 0.05, comparisons were made between experimental and control values for that day.

Figure 2. Gel of the probe and protected fragments after solution hybridization for heparin binding EGF at day 3 in controls and mercuric chloride treated rats. 18S is presented in the lower panel.

Figure 3A. Gel of the probes and protected fragments for TGF-α and the EGF receptor 3 days following vehicle injection or HgCl₂ 4 mg/kg. A standard curve was prepared from normal rat kidneys; 18S was hybridized as well in these assays.

Figure 3B. Data normalized for background and sample loading for TGF-α mRNA. Four animals were studied in each group. * p < 0.05.

Figure 3C. Corrected data for EGF receptor mRNA in the various groups of control and mercuric chloride treated rats. Four animals were studied in each group. * p < 0.01.

Figure 4. Immunohistochemistry for TGF-α. (A) Injury section stained with control serum alone. (B) control kidney section stained for TGF-α. (C) Cortical section from a rat treated with HgCl₂ 4 mg/kg at day 3. Staining was confined to distal tubules in control kidneys whereas it was more pronounced following the induction of injury. Similar observations were made in multiple other sections from 5 animals.