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L Hernando

Publications and source records attributed to L Hernando.

120 records · Page 7Linked to original sources
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Mechanisms of the impaired diuretic and natriuretic responses to a sustained and moderate saline infusion in rats with experimental cirrhosis.

Kidney function and tubular handling of water and sodium by superficial nephrons, packed cell volume, total plasma proteins and albumin distribution space were studied in control and cirrhotic rats before and after a moderate and sustained saline infusion (3% body weight per 30 min + reposition of urinary losses). Tubular fluid samples were obtained from late proximal, early distal and late distal convolutions of superficial nephrons using micropuncture. Protein distribution was assessed by intravenous injection of 0.5 muCi of (125I)-albumin. In basal conditions, both groups of rats showed similar glomerular filtration rate and renal plasma flow, but cirrhotic animals had lower sodium excretion (fractional excretion of sodium = 0.04 +/- 0.01% vs. 0.22 +/- 0.02%, p less than 0.05) and urinary volume (4.31 +/- 0.41 vs. 7.57 +/- 0.53 microliter per min; p less than 0.05). After saline infusion, total plasma proteins decreased more in cirrhotic than in control rats (-18.5 +/- 2.7 vs. -12.9 +/- 2.2%, p less than 0.05). The opposite was observed for albumin distribution space (34.5 +/- 6.1 vs. 22.1 +/- 3.5%, p less than 0.05). Fractional sodium excretion increased to 2.98 +/- 0.15% in control rats but only to 0.61 +/- 0.080% in cirrhotic rats. The ratio single nephron glomerular filtration rate/glomerular filtration rate increased from 19.6 +/- 0.7 to 21.2 +/- 1.0 (X10(-6), p less than 0.005) in control animals but did not change in cirrhotic rats. These animals were unable to decrease adequately fractional fluid reabsorption in the proximal tubule and the loop of Henle.(ABSTRACT TRUNCATED AT 250 WORDS)

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PubMedDate not supplied

Effect of volume expansion on hemodynamics, capillary permeability and renal function in conscious, cirrhotic rats.

General and splanchnic hemodynamics (radioactive microspheres), renal function, spontaneous and histamine-mediated vasopermeability and albumin distribution space were studied in conscious control and nonascitic cirrhotic rats, before and after a moderate and sustained saline infusion (3% of body weight per 30 min + repletion of urinary losses). In basal conditions, cirrhotic rats showed lower fractional sodium excretion than did control rats (0.09 +/- 0.01 vs. 0.15 +/- 0.01%, p less than 0.005). In addition, cirrhotic animals showed higher cardiac output (161.4 +/- 12.8 ml per min) and lower total peripheral resistance (0.63 +/- 0.05 mm Hg . min per ml) and mean arterial pressure (102.9 +/- 3.9 mm Hg) than did control rats (cardiac output: 89.0 +/- 7.6; total peripheral resistance: 1.31 +/- 0.11; mean arterial pressure: 117.5 +/- 5.11; p less than 0.005). No differences in portal-systemic shunt rate or vasopermeability between both groups were observed. After saline infusion, fractional sodium excretion increased to 4.31 +/- 0.16% in controls but only 2.11 +/- 0.02% in cirrhotic animals. In this group, cardiac output decreased by 49.6 +/- 5.1% whereas mean arterial pressure and total peripheral resistance increased by 7.1 +/- 0.6 and 112 +/- 10%, respectively. In control rats, no significant hemodynamic changes were observed. Blood gases did not change after expansion in any group. Saline infusion induced an increase in histamine-mediated vasopermeability in cirrhotic rats but not in control rats. Also albumin distribution space increased more in cirrhotic than in control animals. Heart weight was higher in cirrhotic rats.(ABSTRACT TRUNCATED AT 250 WORDS)

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