Renal function in pregnant rats with two-kidney goldblatt hypertension

This study was carried out in female Wistar-Münich rats with two-kidney, one-clip hypertension, using clipped normotensive rats as controls. Metabolic studies were performed in the first two weeks of pregnancy, consisting of daily measurement of systolic blood pressure (BP) (tail-cuff), body weight (BW), and salt and water balance. At the end of metabolic studies, glomerular dynamics were studied in the unclipped kidney by micropuncture. During pregnancy, urinary output of Na+ and water was greater in hypertensive than normotensive rats. The greater natriuresis accounted for a reduced Na+ retention and a lower increase in maternal BW. Micropuncture studies showed an impaired renal auto-regulation. These results show that hypertension in pregnancy causes a salt-losing tendency, that may be secondary to incomplete renal autoregulation.

Effects of pregnancy on glomerular dynamics: micropuncture study in the rat

Glomerular dynamics were investigated by micropuncture in 15-day pregnant Munich-Wistar rats. Female non-pregnant rats were used as control. In hydropenia, single nephron glomerular filtration rate (SNGFR) averaged 37.2 nl/min/g kidney weight in pregnant rats, and 26.2 nl/min/g kidney weight in controls (P less than 0.0005). During pregnancy, mean glomerular plasma flow (GPF) rose from 63.0 to 104.5 nl/min (P less than 0.0005), and glomerular capillary hydrostatic pressure (PG) from 44.8 to 50.6 mm Hg (P less than 0.0005). This rise in PG accounted for an increase in effective filtration pressure (EFP). Mean EFP at the efferent end of the glomerulus rose from near zero to 9.7 mm Hg, indicating filtration pressure disequilibrium. After extracellular fluid volume expansion with saline, GPF and EFP were still greater during pregnancy. A filtration pressure disequilibrium occurred also in non-pregnant rats, allowing calculation of definite values of the ultrafiltration coefficient (Kf). During pregnancy, mean Kf was reduced from 0.0332 to 0.0285 nl/(sec X mm Hg) (P less than 0.005). SNGFR was moderately, but not significantly, increased. These results show that during pregnancy glomerular dynamics is characterized by a rise in GPF and EFP, and by a reduction in Kf. Following these changes, a plasma-flow dependent rise in SNGFR occurs in hydropenia. After expansion, instead, SNGFR is unmodified because the dependence of ultrafiltration on plasma-flow declines while the influence of Kf increases at high values of GPF.

Muzolimine: a new high-ceiling diuretic suitable for patients with advanced renal disease

Muzolimine was administered by mouth to 24 patients with creatinine clearances ranging from 4 to 28 ml/min to treat oedema or hypertension, or both. In four of these 24 patients muzolimine was given after intravenous high-dose frusemide had been unsuccessful. Muzolimine significantly increased urine volume and excretions of sodium, chloride, and potassium ions. Its diuretic efficacy was further shown by a mean reduction in body-weight of 8% and by the disappearance of oedema in all affected patients, even those refractory to intravenous frusemide. No rebound phenomenon was observed after the drug was stopped. Mean blood pressure was reduced in all hypertensive patients. Blood pressure was restored to normal in five out of seven patients treated with muzolimine alone and 10 out of 11 in whom muzolimine had been added to previously unsatisfactory antihypertensive treatment. Muzolimine was well tolerated by all patients. Muzolimine appears to be the diuretic of choice when treating patients with advanced renal disease.

Echocardiographic detection of cardiac effects of arterio-venous dialysis fistula

The effects of the dialysis fistula were evaluated by echocardiography in 10 patients with terminal renal failure. Echocardiography was performed the day before creation of the fistula (E0) and was then repeated 24 hours after surgery (E1), the day before the first dialysis (E2), the day following the fourth dialysis (E3) and, finally, after 6 months of RDT (E4). Left ventricular internal diameter was measured both in diastole (LVIDd) and in systole (LVIDs), allowing calculation of ventricular diameter percent shortening (LVID%), of ventricular diastolic (EDV) and systolic volume (ESV). In E1 the fistula caused a significant increase in LVIDd, accounting for a rise also in EDV. This ventricular dilation persisted in E2, but was abolished in E3 and in E4. LVIDs, ESV, and LVID% were unmodified throughout the study. these results show that the dialysis fistula causes an immediate rise in cardiac pre-load, which is rapidly reversed by RDT.

Relationship between serum albumin concentration and tubular reabsorption of glucose in renal disease

Micropuncture studies in rats and dogs have provided evidence for a cause-and-effect relationship between peritubular protein concentration and proximal tubular reabsorption (PTR). If this effect is obtained in man, hypoalbuminemia in nephrotic syndrome should lead to a fall in PTR. Sodium excretion, however, is very low in nephrotic patients; but this sodium retention may be due to distal over-reabsorption. Glucose may be used as a marker of PTR. Because of the linkage between glucose and sodium, glucose reabsorption is expected to be suppressed when PTR of sodium is suppressed. Glucose titration studies were performed in 21 patients with chronic glomerulonephritis without renal failure divided in three groups: I (six patients) with serum albumin greater than 3 g/100 ml; II (five patients) with serum albumin of 2 to 3 g/100 ml; and III (10 patients with edema and nephrotic syndrome) with serum albumin less than 2 g/100 ml. The minimum threshold for glucose decreased in nephrotic patients (group III), and its fall was related directly to hypoalbuminemia. The splay of titration curve was markedly increased in group III when compared to the titration curves of patients without nephrotic syndrome (groups I and II). The splay point was 0.78 in group I, 0.52 in group II, and 0.37 in group III. These data provide evidence that glucose reabsorption is decreased in nephrotic syndrome and are consistent with a fall in PTR in nephrotic syndrome.

[Our experience with peripheral vascular contrastography]

The Authors are showing here come of the most significant clinical instances of lumbar aortography and upper & lower limbs arteriography and flebography. As the work comes from the cooperation between a civilian and a Navy medical staff, the Authors hope the'll be allowed by their own respective Authorities to go further on cooperating.