Regulation of chloride self exchange by cAMP in cortical collecting tubule

Journal Article · Tue Jul 01 04:00:00 EDT 1986 · Am. J. Physiol.; (United States)

OSTI ID:6613899

Tago, K; Schuster, V L; Stokes, J B

The hormonal control of Cl transport was examined in rabbit cortical collecting tubules using the lumen-to-bath /sup 36/Cl tracer rate coefficient (K/sub Cl/, nm/s). Tracer movement via Sl-HCO/sub 3/ exchange was minimized by using HCO/sub 3/-CO/sub 2/-free solutions. The electrical driving force was minimized by treating with amiloride. Under these conditions, net Cl transport was zero, yet there was a large K/sub Cl/ that fell 88% on removing bath (trans) Cl. These results are consistent with the mechanism of tracer flux being predominantly Cl self exchange. K/sub Cl/ fell spontaneously with time in vitro; after this decline K/sub Cl/ could be stimulated with 8-bromo-cAMP. cAMP present from the onset of perfusion prevented the time-dependent fall in K/sub Cl/. When tracer movement was restricted to diffusion by eliminating Cl self exchange (0 Cl bath), cAMP had no effect on K/sub Cl/. Although both isoproterenol and vasopressin are known to stimulate adenylate cyclase in this epithelium, only isoproterenol mimicked the cAMP effect on K/sub Cl/. The isoproterenol effect was blocked by either propranolol or prostaglandin E/sub 2/. Lumen addition of the disulfonic stilbene DIDS had no effect on K/sub Cl/. Lumen addition of furosemide or trichloromethiazide had minimal or no effect. Taken together, these results indicate that Cl self exchange is regulated by ..beta..-adrenergic agents acting via cAMP. The lack of an effect of vasopressin suggests cellular heterogeneity in this response to cAMP.

• Research Organization: Univ. of Iowa, Iowa City
• OSTI ID: 6613899
• Journal Information: Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States) Vol. 251:1; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMP
BIOCHEMISTRY
BIOLOGICAL PATHWAYS
BODY
CHEMISTRY
CHLORIDES
CHLORINE 35
CHLORINE COMPOUNDS
CHLORINE ISOTOPES
HALIDES
HALOGEN COMPOUNDS
HORMONES
ION EXCHANGE
ISOTOPES
KIDNEYS
LIGHT NUCLEI
MEMBRANE TRANSPORT
NUCLEI
NUCLEOTIDES
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PEPTIDE HORMONES
PITUITARY HORMONES
PROSTAGLANDINS
STABLE ISOTOPES
TUBULES
VASOPRESSIN