RESUMO
The role played by sexual hormones and vasoactive substances in the compensatory renal growth (CRG) that follows uninephrectomy (uNx) is still controversial. Intact and gonadectomized adult Wistar rats of both sexes, with and without uNx, performed at 90 days age, were studied at age 150 days. Daily urine volume, electrolyte excretion and kallikrein activity (UKa) were determined. Afterwards, glomerular filtration rate and blood pressure were measured, the kidneys weighed and DNA, protein and RNA studied to determine nuclei content and cell size. When the remnant kidney weight at age 150 days was compared with the weight of the kidney removed at the time of uNx, male uNx rats showed the greatest CRG (50%) while growth in the other uNx groups was 25%, 15% and 19% in orchidectomized, female and ovariectomized rats, respectively. The small CRG observed in the uNx female rats was accompanied by the lowest glomerular filtration value, 0.56 ± 0.02 ml/ min/g kwt compared, with the other uNx groups, p < 0.05. Cell size (protein or RNA/DNA) was similar for all the groups except for uNx orchidectomized rats. In this group the cytoplasmatic protein or RNA content was lower than in the other groups while DNA (nuclei content) was similar. Some degree of hyperplasia was determined by DNA content in the uNx groups. Male sexual hormones positively influenced CRG and its absence modulated cell size. Female sexual hormones, instead, did not appear to stimulate CRG. The kallikrein kinin system may not be involved in CRG.
Assuntos
Adaptação Fisiológica/fisiologia , Hormônios Gonadais/fisiologia , Rim/fisiologia , Animais , Pressão Sanguínea , Tamanho Celular , DNA/análise , Feminino , Taxa de Filtração Glomerular/fisiologia , Hipertrofia/fisiopatologia , Calicreínas/metabolismo , Calicreínas/urina , Rim/crescimento & desenvolvimento , Masculino , Nefrectomia , Orquiectomia , Ovariectomia , Proteínas/análise , RNA/análise , Ratos , Ratos Wistar , Fatores SexuaisRESUMO
The role played by sexual hormones and vasoactive substances in the compensatory renal growth (CRG) that follows uninephrectomy (uNx) is still controversial. Intact and gonadectomized adult Wistar rats of both sexes, with and without uNx, performed at 90 days age, were studied at age 150 days. Daily urine volume, electrolyte excretion and kallikrein activity (UKa) were determined. Afterwards, glomerular filtration rate and blood pressure were measured, the kidneys weighed and DNA, protein and RNA studied to determine nuclei content and cell size. When the remnant kidney weight at age 150 days was compared with the weight of the kidney removed at the time of uNx, male uNx rats showed the greatest CRG (50%) while growth in the other uNx groups was 25%, 15% and 19% in orchidectomized, female and ovariectomized rats, respectively. The small CRG observed in the uNx female rats was accompanied by the lowest glomerular filtration value, 0.56 ± 0.02 ml/min/g kwt compared, with the other uNx groups, p < 0.05. Cell size (protein or RNA/DNA) was similar for all the groups except for uNx orchidectomized rats. In this group the cytoplasmatic protein or RNA content was lower than in the other groups while DNA (nuclei content) was similar. Some degree of hyperplasia was determined by DNA content in the uNx groups. Male sexual hormones positively influenced CRG and its absence modulated cell size. Female sexual hormones, instead, did not appear to stimulate CRG. The kallikrein kinin system may not be involved in CRG.
La importancia que pueden tener las hormonas sexuales y sustancias vasoactivas sobre el crecimiento renal compensador (CRC) que sigue a la uninefrectomía es aún materia de debate. Se estudiaron ratas Wistar de ambos sexos, a los 150 días de vida, intactas y gonadectomizadas con y sin uNx, realizada a los 90 días de vida. Se midió volumen urinario diario y excreción de electrolitos y actividad de kalikreína urinaria. Se midió filtrado glomerular y presión arterial media extrayéndose luego los riñones que fueron pesados y preparados para estudios histológicos y determinación de ADN, ARN y proteínas para estimar contenido nuclear y tamaño celular. El CRC fue calculado comparando el peso del riñón al momento de las uNx (90 dias de vida) con aquel obtenido a los 150 días de vida. En las ratas macho uNx se observó el mayor CRC (50%) mientras que, en los otros grupos uNx solo alcanzó un 25%, 15% y 19%. El filtrado glomerular acompañó los cambios morfológicos observándose el menor filtrado en las ratas hembras uNx respecto al resto de los grupos 0.56 ± 0.02, p < 0.05. El tamaño celular (proteína o ARN/ ADN) fue similar para todos los grupos excepto para los orquidectomizados uNx, cuyo contenido citoplasmático fue menor. El contenido nuclear (ADN) fue semejante en todos los grupos. Se observó que el CRC está influenciado positivamente por las hormonas sexuales masculinas y su ausencia modula el tamaño celular. La falta de hormonas sexuales femeninas, en cambio, afecta negativamente el CRC. El sistema kalikreína kinina no parecería estar involucrado en el CRC.
Assuntos
Animais , Feminino , Masculino , Ratos , Adaptação Fisiológica/fisiologia , Hormônios Gonadais/fisiologia , Rim/fisiologia , Pressão Sanguínea , Tamanho Celular , DNA , Taxa de Filtração Glomerular/fisiologia , Hipertrofia/fisiopatologia , Calicreínas/metabolismo , Calicreínas/urina , Rim/crescimento & desenvolvimento , Nefrectomia , Orquiectomia , Ovariectomia , Proteínas/análise , Ratos Wistar , RNA , Fatores SexuaisRESUMO
The role played by sexual hormones and vasoactive substances in the compensatory renal growth (CRG) that follows uninephrectomy (uNx) is still controversial. Intact and gonadectomized adult Wistar rats of both sexes, with and without uNx, performed at 90 days age, were studied at age 150 days. Daily urine volume, electrolyte excretion and kallikrein activity (UKa) were determined. Afterwards, glomerular filtration rate and blood pressure were measured, the kidneys weighed and DNA, protein and RNA studied to determine nuclei content and cell size. When the remnant kidney weight at age 150 days was compared with the weight of the kidney removed at the time of uNx, male uNx rats showed the greatest CRG (50%) while growth in the other uNx groups was 25%, 15% and 19% in orchidectomized, female and ovariectomized rats, respectively. The small CRG observed in the uNx female rats was accompanied by the lowest glomerular filtration value, 0.56 ± 0.02 ml/min/g kwt compared, with the other uNx groups, p < 0.05. Cell size (protein or RNA/DNA) was similar for all the groups except for uNx orchidectomized rats. In this group the cytoplasmatic protein or RNA content was lower than in the other groups while DNA (nuclei content) was similar. Some degree of hyperplasia was determined by DNA content in the uNx groups. Male sexual hormones positively influenced CRG and its absence modulated cell size. Female sexual hormones, instead, did not appear to stimulate CRG. The kallikrein kinin system may not be involved in CRG.(AU)
La importancia que pueden tener las hormonas sexuales y sustancias vasoactivas sobre el crecimiento renal compensador (CRC) que sigue a la uninefrectomía es aún materia de debate. Se estudiaron ratas Wistar de ambos sexos, a los 150 días de vida, intactas y gonadectomizadas con y sin uNx, realizada a los 90 días de vida. Se midió volumen urinario diario y excreción de electrolitos y actividad de kalikreína urinaria. Se midió filtrado glomerular y presión arterial media extrayéndose luego los riñones que fueron pesados y preparados para estudios histológicos y determinación de ADN, ARN y proteínas para estimar contenido nuclear y tamaño celular. El CRC fue calculado comparando el peso del riñón al momento de las uNx (90 dias de vida) con aquel obtenido a los 150 días de vida. En las ratas macho uNx se observó el mayor CRC (50%) mientras que, en los otros grupos uNx solo alcanzó un 25%, 15% y 19%. El filtrado glomerular acompañó los cambios morfológicos observándose el menor filtrado en las ratas hembras uNx respecto al resto de los grupos 0.56 ± 0.02, p < 0.05. El tamaño celular (proteína o ARN/ ADN) fue similar para todos los grupos excepto para los orquidectomizados uNx, cuyo contenido citoplasmático fue menor. El contenido nuclear (ADN) fue semejante en todos los grupos. Se observó que el CRC está influenciado positivamente por las hormonas sexuales masculinas y su ausencia modula el tamaño celular. La falta de hormonas sexuales femeninas, en cambio, afecta negativamente el CRC. El sistema kalikreína kinina no parecería estar involucrado en el CRC.(AU)
Assuntos
Animais , Feminino , Masculino , Ratos , Adaptação Fisiológica/fisiologia , Hormônios Gonadais/fisiologia , Rim/fisiologia , Pressão Sanguínea , Tamanho Celular , DNA/análise , Taxa de Filtração Glomerular/fisiologia , Hipertrofia/fisiopatologia , Calicreínas/metabolismo , Calicreínas/urina , Rim/crescimento & desenvolvimento , Nefrectomia , Orquiectomia , Ovariectomia , Proteínas/análise , RNA/análise , Ratos Wistar , Fatores SexuaisRESUMO
The role played by sexual hormones and vasoactive substances in the compensatory renal growth (CRG) that follows uninephrectomy (uNx) is still controversial. Intact and gonadectomized adult Wistar rats of both sexes, with and without uNx, performed at 90 days age, were studied at age 150 days. Daily urine volume, electrolyte excretion and kallikrein activity (UKa) were determined. Afterwards, glomerular filtration rate and blood pressure were measured, the kidneys weighed and DNA, protein and RNA studied to determine nuclei content and cell size. When the remnant kidney weight at age 150 days was compared with the weight of the kidney removed at the time of uNx, male uNx rats showed the greatest CRG (50
) while growth in the other uNx groups was 25
, 15
and 19
in orchidectomized, female and ovariectomized rats, respectively. The small CRG observed in the uNx female rats was accompanied by the lowest glomerular filtration value, 0.56 ± 0.02 ml/ min/g kwt compared, with the other uNx groups, p < 0.05. Cell size (protein or RNA/DNA) was similar for all the groups except for uNx orchidectomized rats. In this group the cytoplasmatic protein or RNA content was lower than in the other groups while DNA (nuclei content) was similar. Some degree of hyperplasia was determined by DNA content in the uNx groups. Male sexual hormones positively influenced CRG and its absence modulated cell size. Female sexual hormones, instead, did not appear to stimulate CRG. The kallikrein kinin system may not be involved in CRG.
Assuntos
Adaptação Fisiológica/fisiologia , Hormônios Gonadais/fisiologia , Rim/fisiologia , Animais , Pressão Sanguínea , Tamanho Celular , DNA/análise , Feminino , Taxa de Filtração Glomerular/fisiologia , Hipertrofia/fisiopatologia , Calicreínas/metabolismo , Calicreínas/urina , Rim/crescimento & desenvolvimento , Masculino , Nefrectomia , Orquiectomia , Ovariectomia , Proteínas/análise , RNA/análise , Ratos , Ratos Wistar , Fatores SexuaisRESUMO
The kallikrein-kinin system (KKS) appears to be involved in blood pressure regulation. We showed that ovariectomy (oVx) stimulates urinary kallikrein activity (UKa). So, we test whether gonadectomy (Gx) would affect blood pressure through an increase in KKS activity and which mechanism(s) were involved. We studied adult Wistar rats of either sex, with and without Gx. At baseline all groups were normotensive although the oVx mean arterial pressure (MAP) was lower than female MAP (p < 0.05). KKS blockade by aprotinin increased MAP (p < 0.05) exclusively in the oVx group. The probably mechanism(s) involved in KKS regulation (synthesis, renal content and UKa) were also studied. Previous Gx, kallikrein content (nkat/g kidney weight) and UKa (nkat/g kidney weight/day) were higher in female than in male rats: 12 +/- 1.1 versus 6 +/- 0.7 and 40 +/- 6.8 versus 26 +/- 3.4, respectively. After Gx, kallikrein content increased significantly in both orchiectomized (oRx) and oVx rats, and UKa showed a similar tendency (NS). Kallikrein synthesis did not show gender difference in non-Gx rats, but an increase after oVx was observed. KKS was found to be involved in blood pressure regulation in oVx animals. oVx may trigger the increase in kallikrein synthesis and content and UKa to act upon blood pressure.
Assuntos
Pressão Sanguínea/fisiologia , Sistema Calicreína-Cinina/fisiologia , Orquiectomia , Ovariectomia , Animais , Aprotinina/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Feminino , Taxa de Filtração Glomerular/efeitos dos fármacos , Taxa de Filtração Glomerular/fisiologia , Hemostáticos/farmacologia , Sistema Calicreína-Cinina/efeitos dos fármacos , Calicreínas/metabolismo , Rim/metabolismo , Cininas/metabolismo , Masculino , Modelos Animais , Ratos , Ratos WistarRESUMO
BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) shows an increase in both urine monocyte chemoattractant protein-1 (MCP-1) and carotid intima-media thickness (CIMT) before changes in serum creatinine concentration. Although microalbuminuria is an index of disease progression, data on whether renal alterations and vascular remodelling are already present at normal or minimally increased levels of urine albumin excretion in early stages of the disease are lacking. METHODS: Forty-eight ADPKD patients (24.8 +/- 0.8 years) with normal renal function (MDRD 108.1 +/- 3.1 ml/min) and 21 age-matched controls were studied in a cross-sectional study. The urine albumin/creatinine ratio (UACR) above the upper range of controls (6.8 mg/g) was taken as the predictor of renal alterations and vascular remodelling. Urine MCP-1, MCP-1 fractional excretion (FE(MCP-1)), endothelial-dependent vascular relaxation (EDVR), aortic pulse-wave velocity (Ao-PWV) and CIMT were chosen as biological markers. RESULTS: No differences between ADPKD with UACR Assuntos
Albuminúria/metabolismo
, Artéria Braquial/fisiopatologia
, Rim/metabolismo
, Rim Policístico Autossômico Dominante/urina
, Vasodilatação
, Adulto
, Quimiocina CCL2/sangue
, Creatinina/sangue
, Creatinina/urina
, Estudos Transversais
, Feminino
, Humanos
, Masculino
, Rim Policístico Autossômico Dominante/sangue
, Pulso Arterial
RESUMO
AIMS: To test whether blood pressure is affected by potassium supplementation which modifies urinary kallikrein (UK) in SHR of either sex, and to elucidate the mechanisms involved. DESIGN: In SHR and WKY blood pressure, renal function and hormonal profile were studied after 1% oral potassium supplementation starting at 4 weeks of age and throughout until 12 weeks of age. Results were compared with those of untreated SHR and WKY of either sex. RESULTS: Systolic blood pressure (mm Hg) started to rise in SHR and was significantly different at 6-8 weeks of age: 153.5 +/- 7.9 versus 100 +/- 5.6 in female and 157 +/- 7.7 versus 98.4 +/- 6.8 in male rats (p < 0.01). Systolic blood pressure increased progressively in female and male rats reaching 164.5 +/- 4.8 and 204.5 +/- 7.6, respectively, at 12 weeks of age. At this time systolic blood pressure was higher in male than in female SHR (p < 0.01) and UK activity (UKa; nkat/day/100 g body weight) was slightly lower in male SHR. After 1% oral potassium supplementation administered from 4 to 12 weeks of age, a decrease in systolic blood pressure was seen in male SHR: 204.5 +/- 7.6 versus 173.5 +/- 7.9 (p < 0.05); and 164.5 +/- 4.8 versus 156.8 +/- 5.5 in female rats (NS) at 12 weeks of age, concomitant with an increase in UKa, particularly in male rats (29.35 +/- 1.92 versus 36.54 +/- 2.61, p < 0.05). As expected, plasma aldosterone (pg/ml), increased markedly after potassium treatment from 129 +/- 31.4 in untreated female and male SHR and WKY to 528 +/- 180.7 in SHR and 473 +/- 88.4 in WKY (p < 0.05 in both cases). After potassium supplementation, potassium excretion was significantly correlated with both aldosterone levels and UKa (p < 0.001 in both cases). No significantly concurrent changes in plasma renin activity were observed, but instead a significant decrease was seen in SHR (p < 0.01). The potassium blood pressure-lowering effect was blunted by aldosterone receptor antagonist treatment that also decreased UKa from 36.5 +/- 2.61 to 19.5 +/- 1.9, particularly in male SHR. No attempt was made in this experimental setting to block kallikrein or kinin receptors. CONCLUSIONS: UKa increases as a consequence of aldosterone stimulation by potassium load since an aldosterone receptor blockade abolishes UKa increment and blood pressure fall. These results further support the hypothesis that the kallikrein kinin system plays a role in blood pressure regulation and they also show a gender different response to potassium load in relation to UKa and blood pressure.
Assuntos
Aldosterona/sangue , Pressão Sanguínea/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Hipertensão/fisiopatologia , Calicreínas/urina , Potássio na Dieta/administração & dosagem , Potássio na Dieta/metabolismo , Animais , Feminino , Masculino , Ratos , Ratos Endogâmicos SHR , Fatores Sexuais , Resultado do TratamentoRESUMO
The present work was designed to study Na+ K+ ATPase alpha1-subunit phosphorylation in rats with chronic renal failure (CRF) in comparison with normal rats. Na+ K+ ATPase alpha1-subunit phosphorylation degree was measured by binding the McK-1 antibody to dephosphorylated Ser-23 in microdissected medullary thick ascending limb of Henle (mTAL) segments. In addition, the total Na+ K+ ATPase alpha1-subunit expression and activity were also measured in the outer renal medulla homogenates and membranes. CRF rats showed a higher Na+ K+ ATPase activity, as compared with control rats (18.95 +/- 2.4 vs. 11.21 +/- 1.5 micromol Pi/mg prot/h, p < 0.05), accompanied by a higher total Na+ K+ ATPase expression (0.54 +/- 0.04 vs. 0.27 +/- 0.02 normalized arbitrary units (NU), p < 0.05). When McK-1 antibody was used, a higher immunosignal in mTAL of CRF rats was observed, as compared with controls (6.3 +/- 0.35 vs. 4.1 +/- 0.33 NU, p < 0.05). The ratio Na+ K+ ATPase alpha1-subunit phosphorylation/total Na+ K+ ATPase alpha1-subunit expression per microg protein showed a non-significant difference between CRF and control rats in microdissected mTAL segments (2.11 +/- 0.12 vs. 2.26 +/- 0.18 NU, p = NS). The PKC inhibitor RO-318220 10(-6) M increased immunosignal (lower phosphorylation degree) in mTAL of CRF rats to 128.43 +/- 7.08% (p < 0.05) but did not alter McK1 binding in control rats. Both phorbol 12-myristate 13-acetate (PMA) 10(-6) M and dopamine 10(-6) M decreased immunosignal in CRF rats, corresponding to a higher Na+ K+ ATPase alpha1-subunit phosphorylation degree at Ser-23 (55.26 +/- 11.17% and 53.27 +/- 7.12% compared with basal, p < 0.05). In mTAL of CRF rats, the calcineurin inhibitor FK-506 10(-6) M did not modify phosphorylation degree at Ser-23 of Na+ K+ ATPase alpha1-subunit (100.21 +/- 3.00% compared with basal CRF). In control rats, FK 506 10(-6) M decreased the immunosignal, which corresponds to a higher Na+ K+ ATPase alpha1-subunit phosphorylation degree at Ser-23. The data suggest that the regulation of basal Na+ K+ ATPase alpha1-subunit phosphorylation degree at Ser-23 in mTAL segments of CRF rats was primarily dependent on PKC activation rather than calcineurin dependent mechanisms.