ANF inhibits vasopressin-induced Ca/sup 2 +/ mobilization and contraction in glomerular mesangial cells

Journal Article · Sat Oct 01 00:00:00 EDT 1988 · Am. J. Physiol.; (United States)

OSTI ID:6603075

Meyer-Lehnert, H; Tsai, P; Caramelo, C; Schrier, R W

It has been suggested that atrial natriuretic factor (ANF) may increase glomerular filtration rate (GFR) via alteration of the glomerular ultrafiltration area, which is at least in part regulated by the contractile state of mesangial cells. The present study therefore investigated the effect of ANF (atriopeptin III) on arginine vasopressin (AVP)-induced Ca2+ mobilization and contraction in cultured rat mesangial cells. AVP (10(-8) M) increased intracellular Ca2+ (( Ca2+)i) as measured by the quin2 method (142.1 +/- 3.7 vs. 297.9 +/- 8.9 nM, P less than 0.001). This effect, however, was diminished by 10(-8) M ANF (297.9 +/- 8.9 vs. 233.1 +/- 9.3 nM, P less than 0.0025). ANF alone did not affect basal (Ca2+)i. AVP-stimulated 45Ca2+ efflux (cpm.mg prot-1.30 s-1) from mesangial cells within 30 s (1,432 +/- 70 basal vs. 2,751 +/- 287 AVP at 30 s, P less than 0.001). This effect of AVP on 45Ca2+ efflux was also inhibited by ANF (1,403 +/- 62 basal vs. 1,584 +/- 87 AVP and ANF, NS); ANF alone had no effect on spontaneous 45Ca2+ efflux. Furthermore, ANF inhibited AVP-induced 45Ca2+ uptake, which is purportedly one of the major determinants of the sustained phase of cell contraction. Cell contraction was assessed by digital imaging analysis. AVP (10(-7) M) caused contraction of 33.8 +/- 2.0% of the cells, but the contractile response decreased to 20.7 +/- 2.3% in the presence of 10(-9) M ANF and was virtually abolished in the presence of 10(-8) M ANF. Guanosine 3',5'-cyclic monophosphate (cGMP) has been proposed as the second messenger for ANF. ANF (10(-7) M) stimulated cGMP production significantly (0.54 +/- 0.12 vs. 22.30 +/- 5.91 pmol.mg prot-1.10 min-1, P less than 0.01), but it had no effect on cGMP at concentrations of 10(-8) M and below. 8-Bromo-cGMP (8-BrcGMP) attenuated the stimulatory effect of AVP on (Ca2+)i, 45Ca2+ efflux, and 45Ca2+ uptake.

• Research Organization: Univ. of Colorado School of Medicine, Denver (USA)
• OSTI ID: 6603075
• Journal Information: Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States) Vol. 255; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METALS
ANIMAL CELLS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
CALCIUM
CALCIUM 45
CALCIUM ISOTOPES
CELL CULTURES
CONTRACTION
DAYS LIVING RADIOISOTOPES
DOSE-RESPONSE RELATIONSHIPS
ELEMENTS
EVEN-ODD NUCLEI
HORMONES
INHIBITION
INTERMEDIATE MASS NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MAMMALS
MEMBRANE TRANSPORT
METALS
NUCLEI
ORGANIC COMPOUNDS
PEPTIDE HORMONES
PEPTIDES
PITUITARY HORMONES
PROTEINS
RADIOISOTOPES
RATS
REACTION KINETICS
RODENTS
TRACER TECHNIQUES
VASOPRESSIN
VERTEBRATES