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Biomedical subjects

A Dal Canton

Publications and source records attributed to A Dal Canton.

At least 91 records · Page 5Linked to original sources
PubMed1980

[Treatment of arterial hypertension with minoxidil in renal insufficiency].

Minoxidil was administered to 13 patients with arterial hypertension resistant to ordinary antihypertensive drugs and with various degrees of renal failure. Four patients were followed in this way for 50 weeks. Blood pressure values fell from 208 +/- 9.8/124 +/- 4.8 to 153.1 +/- 7.8/86.9 +/- 2.6 at the end of the treatment period. Propanolol and furosemide were used to offset sodium retention and reflex tachycardia. There was no decrease in renal function. In patients examined for the longest period, the minoxidyl dose, after an intermediate reduction stage, reached the 8th week value. Hypertrichosis was the most disturbing side-effect, especially for the female patients. The question of pericarditis is discussed.

Adult↗
PubMed1980

Glomerular hemodynamics before and after release of 24-hour bilateral ureteral obstruction.

Glomerular hemodynamics were studied, by micropuncture, in Munich-Wistar rats submitted to 24-hour bilateral ureteral ligation (BUL). Glomerular capillary pressure (PG), intratubular pressure (PT), and pressure in the first order peritubular capillaries (EAP) were measured with a servonulling device. Single nephron filtration fraction (SNFF) was calculated from arterial and peritubular blood protein concentrations. Single nephron glomerular filtration rate (SNGFR) was both measured by conventional micropuncture techniques and calculated from efferent arteriole blood flow and SNFF. Afferent arteriole blood flow (AABF) and resistance of afferent (Ra) and efferent (Re) arteriole were calculated. Measurements were repeated in the left kidney after releasing the ureter. Sham operated rats were used as control. BUL caused a fall in SNGFR (from 101.8 +/- 9.7 to 40.7 +/- [SEM] 6.0 nl/min/kg body wt), accounted for by a rise in PT (from 14.1 +/- 0.7 to 28.9 +/- 3.1 mm Hg), glomerular hemodynamics (particularly PG and AABF) being unchanged. A marked increase in Ra (from 6.6 +/- 0.7 to 10.8 +/- 1.5 dynes. sec. cm-5) occurred after releasing the ureter, lessening both PG and AABF. Therefore, a low SNGFR was maintained despite the concomitant normalization of PT.

Animals↗
PubMed1979

Effects of 24-hour unilateral ureteral obstruction on glomerular hemodynamics in rat kidney.

Glomerular hemodynamics were studied, by micropuncture, in Munich-Wistar rats submitted to 24-hour unilateral ureteral ligation (UUL). Glomerular capillary pressure (PG), intratubular pressure (PT) and pressure in the first-order peritubular capillaries (EAP) were measured with a servonulling device. Single nephron filtration fraction (SNIFF) was calculated fmom arterial and peritubular blood protein concentration. SNGFR was both measured by conventional micropuncture techniques and calculated from efferent arteriole blood flow (EABF) and SNFF. Afferent arteriole blood flow (AABF) and resistance of afferent (Ra) and efferent (Re) arterioles were calculated. Measurements were repeated 1 to 2 hours after the release of the ureter. Sham-operated rats were used as control. UUL caused a marked increase in Ra (from 4.9 +/- [SD] 2.4 to 12.7 +/- 5.1 dynes/sec/cm-5). The fall in SNGFR (from 111.9 +/- [SD] 23.9 to 34.4 +/- 23.1 nl/min/kg body wt) was secondary to a decrease in both PG and AABF. A further increase in Ra (16.0 +/- 6.7 dynes.sec.cm-5) occurred after releasing the ureter. SNGFR, however, was unaltered (33.7 +/- 16.6 nl/min/kg body wt) since PG decreased parallel to PT, but AABF did not significantly change. Conclusion. Ureteral obstruction determines, in 24 hours, a marked cortical ischemia that is not promptly reversed by ureteral release.

Animals↗
PubMed1977

Effects of acute ureteral obstruction on glomerular hemodynamics in rat kidney.

In order to study the effects of acute ureteral obstruction on glomerular hemodynamics, glomerular hydrostatic capillary pressure (PG), pressure in the first-order peritubular capillaries (EAP), and intratubular pressure (PT) were directly measured in superficial nephrons on Munich-Wistar rats by micropuncture with a servo-nulling device, in control conditions and one to two hours after ureteral ligation. Single nephron filtration fraction (SNFF) was calculated from arterial and peritubular blood protein concentration. SNGFR was measured by conventional micropuncture techniques in control conditions and was calculated from efferent arteriole blood flow (EABF) and SNFF during ureteral obstruction. EABF was obtained by timed complete collection of blood from superficial efferent arterioles. Afferent arteriole blood flow (AABF) and resistance of afferent (Ra) and efferent arterioles (Re) were calculated from conventional equations. Ureteral obstruction markedly increased PT from 12.9 +/- 1.4 to 36.8 +/- 6.1 (SD) mm Hg. The fall in SNGFR (from 23.3 +/- 6.4 to 17.9 +/- 5.2 [SD] nl/min) was blunted by the rise in PG (from 45.5 +/- 3.6 to 59.3 +/- 4.0 [SD] mm Hg) and AABF (from 130.0 +/- 59.1 to 144.2 +/- 69.0 [SD] nl/min), secondary to a fall in Ra. These results demonstrate that SNGFR is maintained early after complete ureteral obstruction because of afferent arteriole dilatation.

Acute Disease↗
PubMed1976

Role of the efferent arteriole in glomerular hemodynamics of superficial nephrons.

Hemodynamic pressure in glomerular capillaries (GCP) and in first order peritubular capillaries (EAP) in superficial nephrons of mutant Wistar rats with surface glomeruli was measured by micropuncture with a servo-nulling device in the following conditions: 1) control;2) norepinephrine infusion (NE); 3) epinephrine infusion (E): 4) dopamine infusion (D); 5) hemorrhagic hypotension (HH); 6) HH + NE; 7) HH + E; 8) HH + D; 9) acute hypertension secondary to bilateral cervical vagotomy and occlusion of both common carotid arteries. BP was also recorded. Both GCP/BP and EAP/GCP ratios averaged 0.40 in control conditions, but only the EAP/GCP ratio remained constant in all conditions under study, indicating that approximately 60% of the hydrostatic pressure in glomerular capillaries is constantly dissipated by the efferent arteriole. When all values of EAP were plotted against the respective values of GCP, a liner relationship was detected (r=0.843). These results indicate that changes of pressure in the first order peritubular capillaries of superficial nephrons are merely secondary to changes in glomerular capillary pressure.

Acute Disease↗
PubMed1976

Efferent arterioles in glomerular haemodynamics.

In haemorrhagic rats norepinephrine normalises BP but maintains renal cortical pressures at low levels. Dopamine, however, can normalise both BP and renal cortical pressures. Dopamine is therefore useful in treating haemorrhagic hypotension in addition to or while awaiting blood transfusion. The efferent arteriole in superficial nephrons is a passive resistance in glomerular haemodynamics.

Animals↗