Effects of AVP and deoxycorticosterone on Na+ and water transport in the Dahl salt-sensitive rat CCD

Am J Physiol. 1991 Apr;260(4 Pt 2):F471-8. doi: 10.1152/ajprenal.1991.260.4.F471.

Abstract

Cortical collecting ducts (CCD) from inbred Dahl salt-sensitive rats were perfused in vitro to study effects of arginine vasopressin (AVP, present in the bath) and deoxycorticosterone pivalate (DOC) pretreatment on lumen-to-bath and bath-to-lumen fluxes of 22Na+ (J1----b and Jb----1 in pmol.min-1.mm-1, respectively), hydraulic conductivity (Pf, microns/s), and transepithelial voltage (VT, mV). J1----b was 37.1 +/- 5.3 (mean +/- SE) in untreated rats and increased to 83.2 +/- 15.9 with AVP. VT increased from -0.3 +/- 0.6 to -7.0 +/- 2.0. In DOC-pretreated rat CCDs, baseline J1----b was higher (85.1 +/- 7.6) as was VT (-11.3 +/- 1.7); J1b----b and VT were doubled with AVP addition (185.6 +/- 18.6 and -21.7 +/- 2.3, respectively). Thus J1----b in AVP-stimulated CCDs from untreated rats was not significantly different from control (no AVP) J1----b from DOC-pretreated rats; however, AVP produced a greater J1----b increase in the latter CCDs. Neither AVP nor DOC had an effect on Jb----1, which ranged from 25 to 50. Benzamil reduced J1----b to values not significantly different from Jb----1, and VT became zero in CCDs treated with both AVP and DOC, indicating Na+ transport stimulated by both hormones occurs through apical membrane Na+ channels. Pf increased from 59 +/- 80 to 1,072 +/- 176 with AVP addition to untreated rat CCDs and was unaltered by DOC or benzamil. Thus the Dahl rat CCD exhibits a transport response to AVP and DOC that is indistinguishable from that observed in Sprague-Dawley rats, as previously reported by this laboratory.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Absorption
  • Amiloride / analogs & derivatives
  • Amiloride / pharmacology
  • Animals
  • Arginine Vasopressin / pharmacology*
  • Body Water / metabolism*
  • Cell Membrane / metabolism
  • Desoxycorticosterone / pharmacology*
  • Drug Synergism
  • Hypertension / chemically induced*
  • Kidney Tubules, Collecting / drug effects
  • Kidney Tubules, Collecting / metabolism*
  • Kinetics
  • Male
  • Osmolar Concentration
  • Rats
  • Rats, Inbred Strains
  • Sodium / metabolism*
  • Sodium Channels / metabolism
  • Sodium, Dietary / administration & dosage
  • Sodium, Dietary / adverse effects*

Substances

  • Sodium Channels
  • Sodium, Dietary
  • benzamil
  • Arginine Vasopressin
  • Desoxycorticosterone
  • Amiloride
  • Sodium