In order to study effects of different total parenteral nutritional regimens on the recovery of liver function and on plasma amino acid pattern after major hepatectomy, twelve healthy mongrel dogs were submitted to 70% liver resection and randomly divided into three different groups: group I (control group) received only 10% glucose; group II received 10% glucose plus 8.5% Freamine; group III received 10% glucose plus 100% branched chain amino acid (BCAA) solution. Blood samples were analyzed for determining biochemical parameters, including plasma amino acid levels, before surgery and on 3rd and 7th postoperative day. The 'BCAA group', compared to other groups, showed higher values of plasma proteins (p less than 0.01) and prothrombin activity (p less than 0.05) on the 3rd postoperative day. The total concentration of plasma amino acids decreased after hepatectomy. Gluconeogenetic amino acids alanine and glutamine were markedly decreased in groups II and III, likely due to their increased consumption during gluconeogenesis. Aromatic amino acids were increased in all groups, due to the transient liver insufficiency. BCAA markedly increased in group III on 3rd postoperative day and returned to basal values on 7th postoperative day; possible explanations of such alterations are discussed. Our findings suggest that BCAA may represent a first choice substrate in the early phase after hepatectomy.

Amino Acids↗

PubMedDate not supplied

The effect of verapamil and diltiazem on alveolar type II cells during warm and cold metabolic ischaemia.

The alteration of cytosolic free calcium concentration is an important event during cellular ischaemia. Calcium channel blockers have been shown to be beneficial during experimental ischaemic organ protection. To investigate the mechanisms of this protection, the behaviour of type II pneumocyte cultures, subjected to warm and cold metabolic ischaemia (6 h), was studied. The cells were incubated in electrolytic solutions and treated with high doses of verapamil (10 mg/l) or diltiazem (100 mg/l). Alveolar type II epithelial cells were removed from adult rat lungs using the modified Dobbs' method. Cell viability was determined by analysis of the total protein content, and from the rate of protein synthesis as indicated by the [35S]methionine uptake assay. The results show that verapamil does not have a direct cytoprotective or cytotoxic effect on the incubated cells, but diltiazem seems to be toxic to the cells, especially during cold ischaemia when the toxicity is significant (P < 0.05). Thus, the protection from ischaemia previously attributed to calcium channel blockers is ascribed to action on the blood vessels resulting in vasodilatation, rather than to a direct influence on cytosolic free calcium homeostasis.

Animals↗

PubMedDate not supplied

[Transthoracic electrical impedance variations in the hemodynamic evaluation of patients after open heart surgery].

Adequate assessment of cardiac function in patients who have undergone open intracardiac operations requires determination of cardiac output. Electric impedance technique of determining cardiac output in intensive care unit is presented. Routine measurement of cardiac output in the immediate postoperative period has allowed important innovations in the care of the patients: a) preclinical diagnosis of low cardiac output and prophylactic treatment, b) artificial pacing at optimal rate, c) accurate assessment of the effectiveness of the treatment measures.

Cardiac Output↗

PubMedDate not supplied

[Progression of chronic renal failure in remnant rats: role of arginase inhibition].

BACKGROUND: Oral administration of arginine to remnant (REM) rats (5/6 nx) slows the progression of chronic renal failure through a nitric-oxide(NO)-dependent mechanism. We have recently shown that inhibition of arginase, the main metabolic pathway of arginine, was able to induce similar results on renal dynamics (GIN: 2001, 18:285-290). Aim of the present study was to test whether these changes were mediated by increased availability of arginine-derived NO. Methods. Three Groups of REM rats were studied for 8 weeks after surgery: 1) untreated REM (Group REM); 2) REM rats treated with arginine (1%) in tap water (Group ARG); 3) REM rats administered a Mn++-free diet, to induce partial inhibition of arginase (Group MNF). Normal unmanipulated rats were used as controls (Group NOR). RESULTS: Liver arginase activity was significantly depressed only in MNF-rats (-35% vs. REM, p < 0.01). Blood pressure was significantly lower in Group MNF vs. ARG and REM after 6 weeks (p < 0.05). Proteinuria was significantly decreased in Group ARG (-42%, p < 0.05 vs. REM) and even more in Group MNF (-57%, p < 0.01). ARG plasma levels, decreased in REM rats (-41% vs. Group CON), were normalized in Group ARG (p < 0.01 vs. Group REM); arginase inhibition was able to increase such levels in Group MNF (+38% vs. REM) and this resulted in a proportional rise in urinary nitrite excretion (+33% vs. REM), grossly depressed in REM rats. Renal arginase activity was lower in all the Groups of remnant rats vs. Group NOR, but intrarenal concentrations of ARG were significantly lower only in rats of Group MNF (p < 0.05 vs. all the other Groups). Histological examination showed that MNF-rats had a glomerular sclerosis index lower than in the other Groups (p < 0.05 vs. Group REM and ARG). CONCLUSIONS: In conclusion, inhibition of arginase in remnant rats slows the progression of CRF and preserves renal histology through a direct and/or indirect NO-dependent mechanism.

Animals↗