TY - JOUR

T1 - Connexin abundance in resistance vessels from the renal microcirculation in normo- and hypertensive rats

AU - Braunstein, Thomas Hartig

AU - Sørensen, Charlotte Mehlin

AU - Holstein-Rathlou, Niels-Henrik

N1 - Keywords: Animals; Arterioles; Blood Pressure; Body Weight; Connexins; Hypertension; Immunohistochemistry; Kidney; Male; Microscopy, Confocal; Protein Isoforms; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Rats, Sprague-Dawley; Statistics, Nonparametric

PY - 2009

Y1 - 2009

N2 - The expression of connexins in renal arterioles is believed to have a profound impact on conducted responses, regulation of arteriolar tonus and renal blood flow. We have previously shown that in renal preglomerular arterioles, conducted vasomotor responses are 40% greater in spontaneously hypertensive rats (SHR) than in normotensive Sprague-Dawley (SD) rats. Because conducted vasomotor responses depend on the cell-cell communication mediated through gap junctions, we hypothesized that the increased magnitude of conducted vasomotor response in SHR is associated with an increased amount of connexins in renal arterioles. To test this hypothesis, the amount of connexin 37 (Cx37), Cx40 and Cx43 was assessed in renal arterioles from normo- and hypertensive rats using quantitative immunofluorescence laser confocal microscopy. To account for differences in genetic background, we included both normotensive Wistar-Kyoto (WKY) and SD rats in the study. In all three strains of rats, and for all three isoforms, the expression of connexins was predominantly confined to the endothelial cells. We found a significantly increased abundance (240 +/- 17.6%, p<0.05) of Cx37 in arterioles from WKY compared with SD and SHR. This high abundance of Cx37 was not related to blood pressure because normotensive SD demonstrated a level of Cx37 similar to that of SHR. Additionally, we found no evidence for an increased abundance of Cx40 and Cx43 in renal arterioles of SHR when compared with normotensive counterparts.

AB - The expression of connexins in renal arterioles is believed to have a profound impact on conducted responses, regulation of arteriolar tonus and renal blood flow. We have previously shown that in renal preglomerular arterioles, conducted vasomotor responses are 40% greater in spontaneously hypertensive rats (SHR) than in normotensive Sprague-Dawley (SD) rats. Because conducted vasomotor responses depend on the cell-cell communication mediated through gap junctions, we hypothesized that the increased magnitude of conducted vasomotor response in SHR is associated with an increased amount of connexins in renal arterioles. To test this hypothesis, the amount of connexin 37 (Cx37), Cx40 and Cx43 was assessed in renal arterioles from normo- and hypertensive rats using quantitative immunofluorescence laser confocal microscopy. To account for differences in genetic background, we included both normotensive Wistar-Kyoto (WKY) and SD rats in the study. In all three strains of rats, and for all three isoforms, the expression of connexins was predominantly confined to the endothelial cells. We found a significantly increased abundance (240 +/- 17.6%, p<0.05) of Cx37 in arterioles from WKY compared with SD and SHR. This high abundance of Cx37 was not related to blood pressure because normotensive SD demonstrated a level of Cx37 similar to that of SHR. Additionally, we found no evidence for an increased abundance of Cx40 and Cx43 in renal arterioles of SHR when compared with normotensive counterparts.

U2 - 10.1111/j.1600-0463.2009.02432.x

DO - 10.1111/j.1600-0463.2009.02432.x

M3 - Journal article

C2 - 19338515

VL - 117

SP - 268

EP - 276

JO - A P M I S. Acta Pathologica, Microbiologica et Immunologica Scandinavica

JF - A P M I S. Acta Pathologica, Microbiologica et Immunologica Scandinavica

SN - 0903-4641

IS - 4

ER -