ANP impairs the dose-dependent stimulatory effect of ANG II or AVP on H+-ATPase subcellular vesicle trafficking


Autoria(s): Oliveira-Souza, M.; Morethson, P.; Malnic, Gerhard; Aires, Margarida de Mello
Contribuinte(s)

UNIVERSIDADE DE SÃO PAULO

Data(s)

14/03/2014

14/03/2014

01/08/2013

Resumo

The effect of angiotensin II (ANG II) or arginine vasopressin (AVP) alone or plus atrial natriuretic peptide (ANP) on H+-ATPase subcellular vesicle trafficking was investigated in MDCK cells following intracellular pH (pHi) acidification by exposure to20 mMNH4Cl for 2 min in a Na+-free solution containing Schering 28080, conditions under which H+-AT-Pase is the only cell mechanism for pHi recovery. Using the acridine orange fluorescent probe (5mM) and confocal microscopy, the vesicle movement was quantified by determining, for each experimental group, the mean slope of the line indicating the changes in apical/basolateral fluorescence density ratio over time during the first 5.30 min of the pHi recovery period. Under the control conditions, the mean slope was 0.079 ± 0.0033 min-1 (14) and it increased significantly with ANG II [10-12 and 10-7 M, respectively to 0.322 ± 0.038 min-1 (13) and 0.578 ± 0.061 min-1 (12)] or AVP [10-12 and 10-6 M, respectively to 0.301 ± 0.018 min-1 (12) and 0.687 ± 0.049 min-1 (11)]. However, in presence of ANP (10-6 M, decreases cytosolic free calcium), dimethyl-BAPTA/AM (5 × 10-5 M, chelates intracellular calcium) or colchicine (10-5 M, 2-h preincubation; inhibits microtubule-dependent vesicular trafficking) alone or plus ANG II or AVP the mean slopes were similar to the control values, indicating that such agents blocked the stimulatory effect of ANG II or AVP on vesicle trafficking. The results suggest that the pathway responsible for the increase in cytosolic free calcium and the microtu-bule-dependent vesicular trafficking are involved in this hormonal stimulating effect. Whether cytosolic free calcium reduction represents an important direct mechanism for ANP impairs the dose-dependent stimulatory effect of ANG II or AVP on H+-ATPase subcellular vesicle trafficking, or is a side effect of other signaling pathways which will require additional studies.

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Conselho Nacional de Pesquisas (CNPq)

Identificador

Open Journal of Molecular and Integrative Physiology, Delaware, v.3, n.3, p.95-103, 2013

http://www.producao.usp.br/handle/BDPI/44131

10.4236/ojmip.2013.33015

http://dx.doi.org/10.4236/ojmip.2013.33015

Idioma(s)

eng

Publicador

Scientific Research

Delaware

Relação

Open Journal of Molecular and Integrative Physiology

Direitos

openAccess

http://creativecommons.org/licenses/by-sa/3.0/br/

M. Oliveira-Souza et al.

SciRes.

Palavras-Chave #H+-ATPase Vesicle Trafficking #ANP #ANG II #AVP #Angiotensina II
Tipo

article

original article

publishedVersion