Institut for Biomedicin

Birgitte Mønster Christensen

Decreased aquaporin-2 expression and apical plasma membrane delivery in kidney collecting ducts of polyuric hypercalcemic rats

Publikation: Bidrag til tidsskrift/Konferencebidrag i tidsskrift /Bidrag til avisTidsskriftartikelForskningpeer review

Standard

Decreased aquaporin-2 expression and apical plasma membrane delivery in kidney collecting ducts of polyuric hypercalcemic rats. / Earm, J H; Christensen, Birgitte Mønster; Frøkiaer, J; Marples, D; Han, J S; Knepper, M A; Nielsen, Søren.

I: Journal of the American Society of Nephrology, Bind 9, Nr. 12, 1998, s. 2181-93.

Publikation: Bidrag til tidsskrift/Konferencebidrag i tidsskrift /Bidrag til avisTidsskriftartikelForskningpeer review

Harvard

Earm, JH, Christensen, BM, Frøkiaer, J, Marples, D, Han, JS, Knepper, MA & Nielsen, S 1998, 'Decreased aquaporin-2 expression and apical plasma membrane delivery in kidney collecting ducts of polyuric hypercalcemic rats', Journal of the American Society of Nephrology, bind 9, nr. 12, s. 2181-93.

APA

Earm, J. H., Christensen, B. M., Frøkiaer, J., Marples, D., Han, J. S., Knepper, M. A., & Nielsen, S. (1998). Decreased aquaporin-2 expression and apical plasma membrane delivery in kidney collecting ducts of polyuric hypercalcemic rats. Journal of the American Society of Nephrology, 9(12), 2181-93.

CBE

Earm JH, Christensen BM, Frøkiaer J, Marples D, Han JS, Knepper MA, Nielsen S. 1998. Decreased aquaporin-2 expression and apical plasma membrane delivery in kidney collecting ducts of polyuric hypercalcemic rats. Journal of the American Society of Nephrology. 9(12):2181-93.

MLA

Earm, J H o.a.. "Decreased aquaporin-2 expression and apical plasma membrane delivery in kidney collecting ducts of polyuric hypercalcemic rats". Journal of the American Society of Nephrology. 1998, 9(12). 2181-93.

Vancouver

Earm JH, Christensen BM, Frøkiaer J, Marples D, Han JS, Knepper MA o.a. Decreased aquaporin-2 expression and apical plasma membrane delivery in kidney collecting ducts of polyuric hypercalcemic rats. Journal of the American Society of Nephrology. 1998;9(12):2181-93.

Author

Earm, J H ; Christensen, Birgitte Mønster ; Frøkiaer, J ; Marples, D ; Han, J S ; Knepper, M A ; Nielsen, Søren. / Decreased aquaporin-2 expression and apical plasma membrane delivery in kidney collecting ducts of polyuric hypercalcemic rats. I: Journal of the American Society of Nephrology. 1998 ; Bind 9, Nr. 12. s. 2181-93.

Bibtex

@article{500f8d3a114d4a88afb9656d4f85a864,
title = "Decreased aquaporin-2 expression and apical plasma membrane delivery in kidney collecting ducts of polyuric hypercalcemic rats",
abstract = "Hypercalcemia is frequently associated with a urinary concentrating defect and overt polyuria. The molecular mechanisms underlying this defect are poorly understood. Dysregulation of aquaporin-2 (AQP2), the predominant vasopressin-regulated water channel, is known to be associated with a range of congenital and acquired water balance disorders including nephrogenic diabetes insipidus and states of water retention. This study examines the effect of hypercalcemia on the expression of AQP2 in rat kidney. Rats were treated orally for 7 d with dihydrotachysterol, which produced significant hypercalcemia with a 15 +/- 2% increase in plasma calcium concentration. Immunoblotting and densitometry of membrane fractions revealed a significant decrease in AQP2 expression in kidney inner medulla of hypercalcemic rats to 45.7 +/- 6.8% (n = 11) of control levels (100 +/- 12%, n = 9). A similar reduction in AQP2 expression was seen in cortex (36.9 +/- 4.2% of control levels, n = 6). Urine production increased in parallel, from 11.3 +/- 1.4 to a maximum of 25.3 +/- 1.9 ml/d (P <0.01), whereas urine osmolality decreased from 2007 +/- 186 mosmol/kg x H2O to 925 +/- 103 mosmol/kg x H2O (P <0.01). Immunocytochemistry confirmed a decrease in total AQP2 labeling of collecting duct principal cells from kidneys of hypercalcemic rats, and reduced apical labeling. Immunoelectron microscopy demonstrated a significant reduction in AQP2 labeling of the apical plasma membrane, consistent with the development of polyuria. In summary, the results strongly suggest that AQP2 downregulation and reduced apical plasma membrane delivery of AQP2 play important roles in the development of polyuria in association with hypercalcemia.",
keywords = "Animals, Aquaporin 2, Aquaporin 6, Aquaporins, Body Water, Cell Polarity, Dihydrotachysterol, Diuresis, Hypercalcemia, Immunoenzyme Techniques, Kidney Cortex, Kidney Medulla, Kidney Tubules, Collecting, Male, Microscopy, Immunoelectron, Osmolar Concentration, Polyuria, RNA, Messenger, Rats, Rats, Wistar, Subcellular Fractions, Urine",
author = "Earm, {J H} and Christensen, {Birgitte M{\o}nster} and J Fr{\o}kiaer and D Marples and Han, {J S} and Knepper, {M A} and S{\o}ren Nielsen",
year = "1998",
language = "English",
volume = "9",
pages = "2181--93",
journal = "Journal of the American Society of Nephrology",
issn = "1046-6673",
publisher = "The American Society of Nephrology",
number = "12",

}

RIS

TY - JOUR

T1 - Decreased aquaporin-2 expression and apical plasma membrane delivery in kidney collecting ducts of polyuric hypercalcemic rats

AU - Earm, J H

AU - Christensen, Birgitte Mønster

AU - Frøkiaer, J

AU - Marples, D

AU - Han, J S

AU - Knepper, M A

AU - Nielsen, Søren

PY - 1998

Y1 - 1998

N2 - Hypercalcemia is frequently associated with a urinary concentrating defect and overt polyuria. The molecular mechanisms underlying this defect are poorly understood. Dysregulation of aquaporin-2 (AQP2), the predominant vasopressin-regulated water channel, is known to be associated with a range of congenital and acquired water balance disorders including nephrogenic diabetes insipidus and states of water retention. This study examines the effect of hypercalcemia on the expression of AQP2 in rat kidney. Rats were treated orally for 7 d with dihydrotachysterol, which produced significant hypercalcemia with a 15 +/- 2% increase in plasma calcium concentration. Immunoblotting and densitometry of membrane fractions revealed a significant decrease in AQP2 expression in kidney inner medulla of hypercalcemic rats to 45.7 +/- 6.8% (n = 11) of control levels (100 +/- 12%, n = 9). A similar reduction in AQP2 expression was seen in cortex (36.9 +/- 4.2% of control levels, n = 6). Urine production increased in parallel, from 11.3 +/- 1.4 to a maximum of 25.3 +/- 1.9 ml/d (P <0.01), whereas urine osmolality decreased from 2007 +/- 186 mosmol/kg x H2O to 925 +/- 103 mosmol/kg x H2O (P <0.01). Immunocytochemistry confirmed a decrease in total AQP2 labeling of collecting duct principal cells from kidneys of hypercalcemic rats, and reduced apical labeling. Immunoelectron microscopy demonstrated a significant reduction in AQP2 labeling of the apical plasma membrane, consistent with the development of polyuria. In summary, the results strongly suggest that AQP2 downregulation and reduced apical plasma membrane delivery of AQP2 play important roles in the development of polyuria in association with hypercalcemia.

AB - Hypercalcemia is frequently associated with a urinary concentrating defect and overt polyuria. The molecular mechanisms underlying this defect are poorly understood. Dysregulation of aquaporin-2 (AQP2), the predominant vasopressin-regulated water channel, is known to be associated with a range of congenital and acquired water balance disorders including nephrogenic diabetes insipidus and states of water retention. This study examines the effect of hypercalcemia on the expression of AQP2 in rat kidney. Rats were treated orally for 7 d with dihydrotachysterol, which produced significant hypercalcemia with a 15 +/- 2% increase in plasma calcium concentration. Immunoblotting and densitometry of membrane fractions revealed a significant decrease in AQP2 expression in kidney inner medulla of hypercalcemic rats to 45.7 +/- 6.8% (n = 11) of control levels (100 +/- 12%, n = 9). A similar reduction in AQP2 expression was seen in cortex (36.9 +/- 4.2% of control levels, n = 6). Urine production increased in parallel, from 11.3 +/- 1.4 to a maximum of 25.3 +/- 1.9 ml/d (P <0.01), whereas urine osmolality decreased from 2007 +/- 186 mosmol/kg x H2O to 925 +/- 103 mosmol/kg x H2O (P <0.01). Immunocytochemistry confirmed a decrease in total AQP2 labeling of collecting duct principal cells from kidneys of hypercalcemic rats, and reduced apical labeling. Immunoelectron microscopy demonstrated a significant reduction in AQP2 labeling of the apical plasma membrane, consistent with the development of polyuria. In summary, the results strongly suggest that AQP2 downregulation and reduced apical plasma membrane delivery of AQP2 play important roles in the development of polyuria in association with hypercalcemia.

KW - Animals

KW - Aquaporin 2

KW - Aquaporin 6

KW - Aquaporins

KW - Body Water

KW - Cell Polarity

KW - Dihydrotachysterol

KW - Diuresis

KW - Hypercalcemia

KW - Immunoenzyme Techniques

KW - Kidney Cortex

KW - Kidney Medulla

KW - Kidney Tubules, Collecting

KW - Male

KW - Microscopy, Immunoelectron

KW - Osmolar Concentration

KW - Polyuria

KW - RNA, Messenger

KW - Rats

KW - Rats, Wistar

KW - Subcellular Fractions

KW - Urine

M3 - Journal article

C2 - 9848772

VL - 9

SP - 2181

EP - 2193

JO - Journal of the American Society of Nephrology

JF - Journal of the American Society of Nephrology

SN - 1046-6673

IS - 12

ER -