Heterogeneity of rabbit hepatocytes for bile secretion after acinar zone 3 damage induced by bromobenzene. Effect of bilirubin and bile salt infusions

Anaesthetized rabbits were used to study the effect of bromobenzene-induced hepatic damage to the acinar zone 3 on bile flow, bile salt, sodium secretion as well as bilirubin transport in basal conditions or with infusion of sodium glycodeoxycholate. The bromobenzene-pretreated animals exhibited in basal conditions a lower bile flow (44%) than that of the controls, with a smaller decrease in bile salt output (27%) and sodium output (29%), whereas no modification in endogenous bilirubin excretion was observed. The bile salt independent fraction of secretion (BSIF) was reduced significantly after the toxic lesion both in terms of absolute and relative values. The hepatocytes of the periportal zone were capable of excreting the totality of bilirubin presented to the liver, regardless of the extent of bile flow or the input of bile salts. The infusion of bilirubin at 1.0 mumole/kg/min led to a fall in bile flow which was attributed to the interference of the pigment with the BSIF. The maximal bilirubin excretion was significantly smaller in bromobenzene-pretreated animals than in the controls, which could be due to the incapacity of the intoxicated rabbits to recruit quiescent hepatocytes. When glycodeoxycholate was administered under conditions of maximal bilirubin transport, bile flow increased as did bile salt secretion in both controls and animals with damaged livers. However, clear differences persisted between the two, which could be attributed not only to the volume fraction of necrosis but also to an interference by bilirubin with the hepatic handling of bile salts. Maximal bilirubin excretion increased in a similar way in both groups after glycodeoxycholate administration. It is proposed that glycodeoxycholate infusion facilitates the hepatic depletion of bilirubin, probably by stimulating transport processes.

Choleretic response to hydrocortisone in the rabbit

The influence of i.v. infusion of hydrocortisone sodium succinate on basal biliary secretion and maximal hepatic excretion of bilirubin was investigated in pentobarbitone anesthetized rabbits. Hydrocortisone caused an increase in bile flow and electrolyte secretion in basal conditions. When it was infused after a maximal load of bilirubin, its choleretic effect disappeared and the maximal excretion of bilirubin was not modified. Our data suggest that the effect of hydrocortisone on bile flow and composition takes place at canalicular level and is not directly related to the secretion of bile salts.

A comparison of the effect of bile salts on maximal hepatic excretion of certain organic anions in the rabbit under urethane and pentobarbitone

The influence of two different anaesthetics, sodium pentobarbitone and ethyl urethane, on the enhancement of maximal bilirubin and bromosulphthalein (BSP) excretion induced by bile salts was investigated in rabbits. Two micelle-forming (glycodeoxycholate and taurocholate) and one non-micelle-forming (dehydrocholate) bile salts were used. Under urethane anaesthesia the bile flow was lower than with pentobarbitone, and this could be attributed to a smaller bile salt non-dependent fraction of secretion. The effect of bile salts on the maximal excretion of the two organic anions appeared more clearly related to some kind of micelle interaction in rabbits anaesthetized with urethane than in pentobarbitone-anaesthetized animals. Thus, under urethane, infusions of glycodeoxycholate substantially increased the maximal excretion of bilirubin and BSP, taurocholate exerted an intermediate and dehydrocholate only a small effect. Under pentobarbitone, however, the augmenting action of all three bile salts was similar. The influence of bile salts on the endogenous excretion of bile pigments in experiments in which the test anion was BSP showed corresponding differences dependent upon the anaesthetic used. Possible explanations for those results are discussed.

Enhancement of maximal bilirubin excretion by bile salts in the anaesthetized rabbit

The influence of glycodeoxycholate, taurocholate and dehydrocholate on the maximal hepatic excretion of bilirubin was investigated in rabbits anaesthetized with sodium pentobarbitone. Biliary secretion of dehydrocholate was much less than that of the other two bile salts, which could be explained by its metabolism in the hepatocytes. Glycodeoxycholate and dehydrocholate had a greater choleretic effect than taurocholate. Only glycodeoxycholate and taurocholate increased the secretion of biliary lipids, suggesting that dehydrocholate or its metabolites were unable to form micelles. All three bile salts, however, increased maximal bilirubin excretion to a similar extent. These results indicate that the action of bile salts on the excretion of bilirubin cannot be fully explained in terms of binding to mixed micelles.

Biliary excretion of bromosulfthalein in rabbit

The effect of bromosulfthalein (BSP) infusions at different doses on bile secretion was investigated in anaesthetized rabbits. The patterns of biliary excretion were found to be similar to other mammals, maximal biliary excretion being achieved by an infusion of 0.50 mg X kg-1 body weight X min-1. Bromosulfthalein administered at low doses under the maximum hepatic transport capacity resulted in a clear increase of bile flow which was mainly due to an osmotic mechanism. Supramaximal doses produced no effect on bile flow.

Influence of bile salts on the endogenous excretion of bile pigments

Effect of the infusion of glycodeoxycholate (GDC), taurocholate (TC) and dehydrocholate (DHC) on bile flow and on bile salt, biliary lipid and bile pigment secretion, has been studied in pentobarbital-anesthetized rabbits. GDC increased bile flow the most, while DHC increased it more than TC. The different choleretic actions of these bile salts cannot be explained by means of variations in their capacity to form micelles. Only GDC and TC were able to stimulate biliary lipid secretion, which suggests that both bile salts increase the formation of mixed micelles. GDC and TC to a lesser extent increased bile pigment excretion, DHC being without effect. These results favour the hypothesis that micellar binding could be an important factor responsible for the effect of bile acids on bile pigment excretion and should not be completely ruled out.

Total and cell wall phosphorus content in Bacillus megaterium in phosphate-limited media

A comparative study of the amount of total and cell wall phosphorus in Bacillus megaterium ATCC 33085, grown in media with or without phosphate limitation was carried out. The phosphorus levels were investigated during six successive subcultures. A progressive decrease in total phosphorus was found in cells cultivated in a phosphate-limited medium. A decline in the cell wall phosphorus level was observed starting only from the third subculture in phosphate-limited medium, and no phosphorus was detected in the walls of cells in the fifth subculture.

[Rehabilitation of the diabetic child in Cuba]

The author describes a series of important steps followed in Cuba for the rehabilitation of the diabetic child, like education of the patient and his relatives, active participation of the child in his treatment (self control), hospital attention advisable for a minimal period exclusively in severe cases, attention in office visits as ambulatory patient, participation in vocational, social and psychological orientation activities of the antidiabetic center, areas for sport and recreation, vocational camping for diabetic children, homes, education through press, television and radio of special programs on diabetes.

Therapeutic evaluation of ketoconazole in patients with coccidioidomycosis

Eleven adult patients (seven men and four nonpregnant women) with coccidioidomycosis were treated orally with ketoconazole (R41,400). Two patients presented with disseminated coccidioidomycosis, six with pulmonary coccidioidomycosis, and three with the chronic cutaneous form of the disease. Diagnosis was established by culture of Coccidioides immitis and/or histopathologic identification of the fungus. All patients received 400 mg of ketoconazole per day for the first 10 days; afterwards four of them received 200 mg per day. Evaluation indicated that nine patients improved, one did not, and one could not be assessed. Treatment of coccidioidomycosis with ketoconazole appears to be reasonably effective and produces fewer adverse effects than does amphotericin B; however, further studies of the efficacy of this new drug are needed.

Diabetes mellitus and vasopressin sensitive diabetes insipidus

The rare association of diabetes mellitus and vasopressin sensitive diabetes insipidus found in 5 patients attending the Institute of Endocrinology and Metabolic Diseases in a ten-year period is reported. Suspicious signs and criteria for diagnosis were discussed and a brief review made on the pathogenesis and treatment of this association.

Direct duplication 2p14 to 2p23

A malformed male newborn was first diagnosed as having Smith-Lemli-Opitz syndrome. Extensive cytogenetic studies, including Q, G, C, R and T banding and BudR treatment, were applied, finally leading the authors to conclude that the patient had a partial 2p trisomy caused by direct duplication 2p14 to 2p23. This was a de novo chromosome abnormality, as both parents had normal karyotypes.