1. Volume 87, Issue 3, Pages 557-563 (March 2015)
Inducible deletion of connexin 40 in adult mice causes hypertension and disrupts pressure control of renin secretion 
Melanie Gerl, Josef Vöckl, Birgül Kurt, Toon A.B. van Veen, Armin Kurtz, Charlotte Wagner 
Kidney International 
Volume 87, Issue 3, Pages (March 2015)
DOI: /ki
Copyright © 2015 International Society of Nephrology Terms and Conditions

2. Figure 1
Evaluation of Cx40 gene targeting in Cx40flflCreER mice. (a) Cx40 mRNA and Cx40 protein abundance in kidneys of Cx40flfl and Cx40flflCreER mice. In Cx40flflCreER mice, both parameters are reduced to 20 and to 10% of the respective values of Cx40flfl controls. Data are means±s.e.m. of 15–20 animals in each group. Immunolocalization of Cx40 in kidney cortex of Cx40flfl controls (b) and Cx40flflCreER mice (c) after tamoxifen treatment for 2 weeks. (b, left panel) Cx40 immunoreactivity for Cx40 only, which is clearly visible in the glomeruli, juxtaglomerular areas, and afferent arterioles in Cx40flfl controls. (c, left panel) In Cx40flflCreER mice, only very faint Cx40 immunoreactivity can be detected within glomeruli. Right panels show respective colocalizations for Cx40 (red), renin (green), and α-smooth muscle actin (blue) for kidney cortex of Cx40flfl mice (b) or Cx40flflCreER mice (c). aa, afferent arteriole; asterisk, juxtaglomerular region with renin-expressing cells; Cx40, connexin 40; G, glomerulus; GAPDH, glyceraldehyde 3-phosphate dehydrogenase; il, interlobular artery. Bar=20μm.
Kidney International  , DOI: ( /ki )
Copyright © 2015 International Society of Nephrology Terms and Conditions

3. Figure 2
Systolic blood pressure, plasma renin concentration (PRC), and renin mRNA abundance in Cx40flfl and Cx40flflCreER mice after tamoxifen treatment at the age of 12 and 24 weeks. Blood pressure (c) and PRC (b) are elevated in Cx40flflCreER mice at both age groups, whereas renin mRNA (a) is not different between the two genotypes. Data are means±s.e.m. of 15–20 animals in each group. *P<0.05, #P<0.11 versus control mice. Cx40, connexin 40; GAPDH, glyceraldehyde 3-phosphate dehydrogenase.
Kidney International  , DOI: ( /ki )
Copyright © 2015 International Society of Nephrology Terms and Conditions

4. Figure 3
Effects of renal perfusion pressure and extracellular calcium concentration on renin secretion in Cx40flfl and Cx40flflCreER mice. (a) Perfusion pressure–dependent regulation of renin secretion from kidneys of Cx40flflCreER mice (circles) and Cx40flfl mice (black squares) after tamoxifen treatment. Pressure dependency of renin secretion was determined in the presence of 3nmol/l isoproterenol in the perfusate. Renin secretion of Cx40flfl controls is inversely related to perfusion pressure, whereas no pressure dependency on renin secretion was seen in Cx40flflCreER mice. For these experiments, age- and sex-matched littermates were used. *P<0.05 vs. 90mmHg; n=5 in each group. (b) Effects of the β-adrenergic agonist isoproterenol (3nmol/l) or of a reduction of the extracellular calcium concentration by adding 3.1mmol/l EGTA to the perfusate (EGTA) on perfusate renin concentration of isolated perfused kidneys of Cx40flflCreER mice and Cx40flfl mice. Isoproterenol stimulates renin secretion in kidneys of both genotypes. As no matched littermates were used for these experiments, the difference of renin secretion at 90mmHg as seen in a was obscured. Additional lowering of the extracellular calcium concentration strongly stimulates renin secretion in Cx40flfl mice, but it has no effect in Cx40flflCreER mice. *P<0.05 versus control conditions; n=5 in each group. Cx40, connexin 40.
Kidney International  , DOI: ( /ki )
Copyright © 2015 International Society of Nephrology Terms and Conditions

5. Figure 4
Colocalization of renin (green) and of α-smooth muscle actin (blue) in the kidney cortex of Cx40flflCreER mice receiving tamoxifen treatment. (a–c) Different localization patterns of renin-expressing cells that emerged after tamoxifen treatment. Bar=20μm. (a) Renin cells are located outside the walls of afferent arterioles, and they fill the lacis cell field analyzed at the age of 10 weeks (2 weeks after stop of tamoxifen feeding). (b) Renin cells are increased in number in the lacis field analyzed at the age of 24 weeks (14 weeks after stop of tamoxifen feeding). (c) Renin cells are located in the periglomerular interstitium analyzed at the age of 24 weeks (14 weeks after stop of tamoxifen feeding). Cx40, connexin 40.
Kidney International  , DOI: ( /ki )
Copyright © 2015 International Society of Nephrology Terms and Conditions