11 research outputs found
Endothelin-A receptors mediate renal hemodynamic effects of exogenous Angiotensin II in humans
No full textRenal hemodynamic control by endothelin and nitric oxide under angiotensin II blockade in man
No full textAngiotensin II and Prostaglandin Interactions on Systemic andRenal Effects of L-NAME in Humans
No full textFor investigation of whether interactions between
prostaglandins and angiotensin II modulate renal response to
acute nitric oxide synthesis inhibition in humans, seven young
volunteers who were kept on a 240-mM Na diet underwent
four experiments with 90 min of infusion of 3.0 mg/kg.min21
NG-nitro-L-arginine methyl ester (L-NAME), each preceded by
a 3-d treatment with placebo (PL), 50 mg of losartan (LOS), 75
to 125 mg of indomethacin (IND), or both drugs. Mean arterial
pressure (MAP), GFR, effective renal plasma flow (ERPF),
and Na excretion rate (UNaV) were measured at baseline and
from 0 to 45 min and 45 to 90 min of L-NAME infusion. After
PL, L-NAME reduced GFR by 5% at 45 min (P , 0.05) and by
9% at 90 min (P , 0.001), ERPF by 11 to 17% (P , 0.001),
and UNaV by 28 to 45% (P , 0.001). MAP, unchanged at 45min, rose by 5% (P , 0.001) at 90 min. LOS prevented pressor
but not renal effects of L-NAME. With L-NAME1IND, MAP
rose even at 45 min (15%; P , 0.001 versus baseline) with a
10% rise at 90 min (P , 0.001). Changes in GFR (213 to
220%), ERPF (219 to226%), and UNaV (251 to270%) were
greater than those with L-NAME1PL or L-NAME1LOS (P ,
0.05 to 0.001). With L-NAME1IND1LOS, MAP did not increase,
and GFR, ERPF, and UNaV fell much less than with
L-NAME1IND alone (P , 0.02 to 0.001) with no differences
versus PL or LOS alone. Angiotensin II blockade does not affect
renal changes caused by L-NAME but prevents their potentiation
by prostaglandin inhibition. Thus, endogenous prostaglandins
counteract renal actions of endogenous angiotensin II in Na repleted humans even when nitric oxide synthesis is inhibite
Role of blood pressure in the natriuretic response to acute calcium channel blockade in humans
No full text
O INCONSCIENTE ÓTICO E AS FOTOGRAFIAS DO “OLHAR SOCIOAMBIENTAL”
No full textO trabalho aqui apresentado teve como foco as fotografias produzidas em um projeto de extensão, com adolescentes do ensino médio, na região do litoral do Piauí. Assim, tentou-se dialogar com o autor Walter Benjamin, sobre o inconsciente ótico. Para tanto, escolheu-se o “assunto” do inconsciente ótico, por recentes leituras e por acreditar-se que essa discussão, e essa análise dos objetos empíricos, possam ser feitos através, também, de uma visão do debate com Benjamin e a noção de inconsciente ótico.AbstractThe work presented here focused on the photographs produced in an extension project, with high schoolers, in the coastal region of Piaui. So, we tried to dialogue with the author Walter Benjamin, on the optical unconscious. To this end, picked up the "subject" of the optical unconscious, by recent readings and believe that this discussion, and that analysis of empirical objects, can be made by also a vision of debate with Benjamin and the notion of optical unconscious.Key-words: Photographs; Optical Unconscious; Extension Project; coastal region of Piauí. ResumenEl trabajo que se presenta aquí se centró en las fotografías producidas en un proyecto de extensión, con estudiantes de secundaria, en la región costera de Piauí. Por lo tanto, tratamos de hablar con el autor Walter Benjamin, en el inconsciente óptico. Para ello, recogió el "asunto" del inconsciente óptico, por las lecturas recientes y creo que esta discusión, y que el análisis de los objetos empíricos, se puede hacer también una visión del debate con Benjamin y el concepto de inconsciente óptico.Palabras clave: Fotografías; inconsciente óptico; proyecto de extensión; Costa del Piau
Angiotensin II and Prostaglandin Interactions on Systemic and Renal Effects of L-NAME in Humans
No full textRenal Hemodynamic Control by Endothelin and Nitric Oxide Under Angiotensin II Blockade in Man
No full text
To investigate whether endothelin-A receptors and nitric oxide modulate renal hemodynamics in man under angiotensin II receptor-1 blockade, 6 healthy volunteers, on a 240 mmol Na diet, underwent 4 separate renal hemodynamic measurements, in 3 of which endothelin-A blocker BQ-123 0.2 nmol · kg · min
−1
was infused for 90 minutes after pretreatment with either placebo, telmisartan 1 mg · kg · day
−1
for 3 days, or telmisartan as well, but with co-infusion of both BQ-123 and N
G
-nitro-
l
-arginine methylester 0.5 μg · kg · min
−1
. A fourth infusion was made with N
G
-nitro-
l
-arginine methylester alone. No change followed infusion of either N
G
-nitro-
l
-arginine methylester alone or BQ-123 alone. With BQ-123 after telmisartan, renal blood flow rose from 916±56 mL · min
−1
· 1.73 m
2
to 1047±51.2 (
P
<0.001), and renal vascular resistances fell from 89±7 mm Hg · min · L
−1
to 74±4 (
P
<0.001). These changes were fully abolished by the co-infused N
G
-nitro-
l
-arginine methylester. Infusion of BQ-123, devoid of renal hemodynamic effects at baseline, produces significant renal vasodilation when angiotensin II receptors are blocked, indicating an increasing renal hemodynamic role of endothelin-A–receptor activity. Because such a vasodilation is prevented by nonvasoconstricting microdoses of N
G
-nitro-
l
-arginine methylester, nitric oxide–endothelin balance controls substantially renal hemodynamics under angiotensin II blockade. These findings are consistent with a rationale of the association of endothelin-A blockers with angiotensin II blockers or angiotensin-converting enzyme inhibitors in treating nitric oxide–deficient conditions such as arterial hypertension, heart failure, and chronic renal diseases.
</jats:p
