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F Varga

Publications and source records attributed to F Varga.

At least 55 records · Page 3Linked to original sources
PubMed1990

Pharmacology of the new H1-receptor antagonist setastine hydrochloride.

Setastine HCl (N-(1-phenyl-1-[4-chlorophenyl])-etoxy-ethylene-perhydroazepine hydrochloride, Loderix; CAS 64294-95-7) is a potent antagonist of histamine H1-receptor mediated responses. The antihistamine activity of the compound is similar to that of clemastine fumarate in the following assays: histamine-induced lethality and bronchospasm in guinea-pigs, plasma extravasation in rats, and contractile action in isolated guinea-pig ileum. Setastine HCl inhibits anaphylactic shock in guinea-pigs sensitized by horse serum. No antiserotonin, anticholinergic and antiadrenergic effect of the compound can be detected. Setastine HCl has a long lasting (up to 16 h) antihistamine effect with a good oral effectiveness. It shows no cardiovascular effects in cats. Setastine HCl shows a much weaker CNS depressant activity than clemestine fumarate measuring inhibition of amphetamine-induced hypermotility, rotarod performance, potentiation of ethanol-narcosis in mice, and prolongation of hexobarbital sleeping time in rats. In displacement studies (3H-mepyramine) setastine HCl had significantly weaker affinity for the central nervous system (CNS) H1-receptors than clemastine fumarate. It is concluded that setastine HCl is a non-sedative highly active H1-antagonist.

Animals↗
PubMed1989

Preferential localisation of red cell vacuoles to pathologically shaped human red blood cells.

The percentage of pitted erythrocytes and Howell-Jolly bodies in peripheral blood samples of 51 individuals following posttraumatic splenectomy and 20 patients splenectomized because of various haematological diseases differed significantly from each other (p less than 0.001) and from that of healthy controls (p less than 0.001). The percentage of pitted erythrocytes was significantly higher in pathologically shaped red blood cells (RBCs) (acanthocytes, schizocytes, elliptocytes) than in normal discoid shaped RBCs (p less than 0.001). As the number of pits per RBC showed great individual variations, a scoring system for the evaluation of pitted RBCs is proposed.

Adult↗
PubMed1985

The role of bile acids in the effect of ethinylestradiol on the biliary excretion of exogenous organic anions.

Ethinylestradiol (EE) has a cholestatic effect and decreases the biliary excretion of xenobiotics. In the present experiments, pretreatment with EE did not influence the biliary excretion of bile acids. On the other hand, the effect of EE on the biliary excretion of exogenous organic anions and on bile production was not influenced by administration of taurocholic acid (TC) or by depletion of bile acids by cholestyramine (CHOL). However, phenobarbital (PB) administered simultaneously with EE prevented the depressive effects of EE on the biliary flow and biliary excretion rate of rose bengal (RB). These results indicate that bile acids do not play an important role in the effects of EE and that changes in the bile salt independent fraction might be responsible for the effects of EE pretreatment on the biliary excretion of exogenous organic anions.

Animals↗
PubMed1985

Substrate and phenobarbital induction of the biliary excretion of exogenous organic anions in rats.

Phenobarbital pretreatment significantly increased the biliary excretion of both non-metabolizable organic anions (rose bengal, eosin and amaranth) and the metabolizable bromsulphthalein (BSP). Phenobarbital stimulated the biliary excretion of BSP due to enhanced conjugation of BSP with glutathione and increased biliary excretion of bromsulphthalein-glutathione conjugate (BSP-GSH). On the other hand, pretreatment with the non-metabolizable substrates (rose bengal, eosin and amaranth) failed to stimulate the biliary excretion rate of these organic anions. Pretreatment with BSP enhanced the biliary excretion of total BSP due to a stimulation of GSH-S-transferase activity which conjugates BSP with glutathione.

Amaranth Dye↗
PubMed1985

The biliary elimination of sulfamerazin in rat and man--a comparison.

Sulfamerazin (S) was given to rats (380 mumol kg-1 body wt, i.v.) and to man (95 mumol kg-1, orally). Bile was collected from the common bile duct in both rats and man (T-tube drain) for 21 and 28 hours, respectively. The calculated amount of S eliminated by bile was seven-times higher in the rat (8.4% of the given dose) than in man. This is the consequence of the higher concentration ratio bile to blood in the rat (0.95) compared with man (0.31) as well as of the differences in bile flow rate of 0.046 and 0.0082 ml min-1 kg-1 in rat and man, respectively.

Adult↗
PubMed1985

Age-development and inducibility of hepatic glutathione S-transferase activities in mice, rats, rabbits and guinea-pigs.

Hepatic glutathione S-transferase (GST) activities towards 1-chloro-3,4-dinitrobenzene (DNCB), 3,4-dichloronitrobenzene (DCNB), sulfobromophthalein (BSP), p-nitrobenzyl chloride (NBC), ethacrynic acid (EA), trans-4-phenyl-3-buten-2-one (TPBO) and 1,2-epoxy-3-(p-nitrophenoxy)propane (ENPP) were determined in mice, rats, rabbits and guinea-pigs during ageing and after pretreatment with enzyme inducers. Variations were observed in the developmental patterns and in the phenobarbital-, benzo(a)pyrene-, pregnenolone-16 alpha-carbonitrile-, butylated hydroxyanisole-, trans-stilbene oxide-inducibility of hepatic GST activities in the same species towards different substrates. For example, in rats GST activities for EA, DCNB and TPBO increased respectively, 2.3-, 4.8- and 25-fold during age-development, and after treatment with TSO 1.2-, 3.6- and 1.3-fold. Species differences were found in the maturation and in the inducibility of GST activities. For instance, GST activity toward EA at birth is mature in guinea pigs but not in the other species; phenobarbital treatment increased GST activities in mice and rats but not in rabbits and guinea-pigs; treatment with trans-stilbene oxide enhanced GST activity for TPBO 4.5-fold in mice but not at all in rats. It is concluded that hepatic glutathione conjugation exhibits functional heterogeneity which may be due to species dependent variations in the responsiveness of GST isoenzymes to endogenous and exogenous influences.

Aging↗
PubMed1985

Role of glutathione and hepatic glutathione S-transferase in the biliary excretion of methyl mercury, cadmium and zinc: a study with enzyme inducers and glutathione depletors.

The effect of hepatic glutathione (GSH) depletion and enzyme induction on hepatic glutathione S-transferase (GST) activity, biliary excretion of GSH, methyl mercury, cadmium and zinc was studied in rats. The GSH depletors, methyl iodide and diethyl maleate, did not influence hepatic GST activity but, depending on the substrate used, benzo(a)pyrene, phenobarbital, pregnenolone-16 alpha-carbonitrile (PCN) and trans-stilbene oxide (TSO) increased it by 16-33, 44-89, 53-97 and 208-279%, respectively. GSH depletors decreased (-88%), benzo(a)pyrene and TSO did not affect, phenobarbital and PCN increased (+113 and +149%) the transport of GSH into bile. The biliary excretion of methyl mercury, cadmium and zinc was reduced by GSH depletors (-97, -74 and -93%), and enhanced by phenobarbital (+139, +280 and +220%) and PCN (+150, +121 and +160%). Treatment with benzo(a)pyrene and TSO did not affect the excretion of methyl mercury and zinc into bile, but decreased that of cadmium. These results do not provide evidence for the role of hepatic GST but strongly support the importance of biliary GSH excretion in the hepatobiliary transport of methyl mercury, cadmium and zinc. It is assumed that phenobarbital and PCN enhance the biliary excretion of these metals by increasing the transport of GSH, the carrier molecule, from liver to bile.

Animals↗
PubMed1984

Effect of taurocholate pretreatment on the biliary excretion of exogenous organic anions in rats.

The effect of pretreatment with taurocholate (1.12 mmol/kg per os twice daily for two days) on the biliary excretion of exogenous organic anions (rose bengal, bromcresol green, unconjugated and conjugated bromsulphthalein, eosine and amaranth) has been investigated in rats. Bromsulphthalein was excreted at a higher rate into the bile when its conjugation with glutathione was prevented by diethyl maleate (0.7 ml/kg i.p.). On the other hand, when conjugated bromsulphthalein was given intravenously, the taurocholate pretreatment failed to significantly enhance its biliary excretion rate. The changes found after taurocholate pretreatment in the biliary excretion of rose bengal and bromcresol green were similar to those observed during the excretion of unconjugated bromsulphthalein. However, in the biliary excretion of eosine and amaranth no increase was found following taurocholate pretreatment. The results indicate that taurocholate pretreatment does not exert a uniform stimulatory effect on the biliary excretion of exogenous organic anions.

Animals↗
PubMed1983

Thyrotropin and prolactin response to thyrotropin-releasing hormone in healthy and asphyxiated full-term neonates.

To evaluate the effect of perinatal asphyxia on the pituitary response to thyrotropin-releasing hormone (TRH) in full-term newborn infants, serum thyrotropin (TSH) and prolactin (PRL) levels were measured before and 30 and 180 min after i.v. administration of 40 micrograms TRH. Birth weight, gestational and postnatal age were similar in the healthy (group NA) and in the asphyxiated (group A) babies. Hormone levels were determined by radioimmunoassay using commercial kits. It was demonstrated that the basal TSH level was slightly higher and the basal PRL level significantly (p less than 0.05) higher in group A than in group NA. In response to TRH administration in group A a marked increase in PRL occurred from 6781 +/- 887 to 11 072 +/- 1318 and 9636 +/- 1024 mU/l at 0, 30 and 180 min, respectively. A similar response was seen in group NA; the values, however, remained significantly lower during the TRH-test. The respective PRL values at 0, 30 and 180 min were 4672 +/- 411, 7945 +/- 343 (p less than 0.05) and 5963 +/- 372 mU/l (p less than 0.05). TRH administration also resulted in a significant elevation of the serum TSH level from 6.20 +/- 1.30 to 49.02 +/- 7.25 (p less than 0.01) and 18.72 +/- 6.35 mU/l (p less than 0.05) in group A, and from 3.90 +/- 0.57 to 24.01 +/- 3.81 (p less than 0.01) mU/l in group NA, but in group NA the 180 min TSH value of 6.07 +/- 1.25 mU/l did not differ statistically from the basal level (p greater than 0.1). It is concluded that the pituitary PRL and TSH reserves are maintained in full-term newborn infants recovering from perinatal asphyxia whose biochemical findings are indicative of subclinical hypothyroidism.

Asphyxia Neonatorum↗
PubMed1983

Renal aspects of neonatal sodium homeostasis.

Current knowledge on renal sodium handling during the neonatal period is reviewed with particular reference to its clinical implications. It has been demonstrated that fractional sodium excretion is inversely proportional to the maturity of the neonate. The high rate of urinary sodium excretion in the low-birth-weight premature infants results in sodium depletion, hyponatraemia and hypoosmolality; evidence has been provided to indicate that it may contribute to the development of late metabolic acidosis, failure to gain weight and impaired function of the central nervous system. When challenged by salt loading, a significantly more marked natriuretic response could be seen in preterm than in full-term neonates. Acute sodium overdose may cause iatrogenic hypernatraemia and neonatal intracranial haemorrhage. Long-term high sodium intake may induce salt and water retention, peripheral oedema, increased intracranial pressure, congestive heart failure, reopening of the ductus arteriosus and hypertension in adult life. Alterations in salt balance even in the very low-birth weight premature infant result in adaptive changes in the function of the renin-angiotensin-aldosterone system, renal prostaglandin E and F2a production and plasma prolactin level. When drug therapy known to affect renal sodium handling such as indomethacin, furosemide, dopamine, aminophylline and glucocorticoid is prescribed in the perinatal period, neonatal salt and water balance should carefully be monitored.

Humans↗
PubMed1983

Effect of pretreatment with exogenous organic anions on biliary excretion in rats.

The effect of pretreatment with exogenous organic anions (rose bengal, amaranth, eosine, bromsulphthalein) on biliary excretion has been investigated in rats. Pretreatment with exogenous nonmetabolized organic anions (rose bengal, amaranth, eosine) had no significant influence on the biliary excretion of rose bengal, amaranth, eosine, bromsulphthalein and bromsulphthalein-glutathione conjugate. Pretreatment with bromsulphthalein, which is metabolized in the liver, significantly enhanced the biliary excretion of total bromsulphthalein due to stimulation of the conjugation of BSP with glutathione. Both the activity of glutathione S-transferase and the glutathione content in the liver were increased following BSP pretreatment. Pretreatment with rose bengal and eosine influenced neither the conjugation of bromsulphthalein with glutathione, nor the biliary excretion of total bromsulphthalein. These results indicate that the biliary excretion rate of exogenous organic anions cannot be increased by pretreatment with substrates of the hepatic transport system. The enhanced biliary output of total bromsulphthalein after bromsulphthalein pretreatment can be explained solely by stimulation of its conjugation with glutathione.

Animals↗
PubMed1982

The influence of cadmium on the biliary excretion of eosine and bromsulphthalein and on microsomal monooxygenase activities in the rat.

Cadmium sulfate x 8/3 H2O (0.3, 0.6, 1.5 and 2.0 mg/kg) administered simultaneously with eosine and bromsulphthalein (120 mumol/kg i.v.) did not significantly change the biliary excretion of the dyes. After a 3 days pretreatment with 2.0 mg/kg CdSO4 i.p. a body weight loss and an increase in the relative liver weight when calculated on body weight were observed together with an enhanced bile flow, but the excretion of the dyes was not markedly influenced. Ethylmorphine N-demethylation and ethoxycoumarin O-deethylation activities as well as microsomal cytochrome P-450 concentration were diminished by about 50%. It can be concluded that in male rats the hepatic microsomal monooxygenase system is more sensitive towards cadmium than the hepatic transport system for organic anions.

Animals↗
PubMed1982

Thyrotropin and prolactin response to ambient temperature in newborn infants.

Plasma TSH and PRL level was measured by RIA in 8 full-term newborn infants with mean birth weight of 3420 g (range 3000-4100 g) and mean gestational age of 39.0 weeks (range 38-40 weeks) at postnatal age of 3-4 days. Determinations were performed at neutral thermal environment (32 degrees C) and after 1 h exposure to cold (28 degrees C) and warm (37 degrees C) environment. In response to cold challenge, TSH and PRL increased significantly from 4.17 +/- 0.28 mU/1 and 4625 +/- mU/1 to 4.76 +/- 0.21 mU/1 (p less than 0.01) and 5975 +/- 944 mU/1 (p less than 0.05), respectively. When the newborns were placed in warm environment, both TSH and PRL fell significantly to 3.52 +/- 0.4 mU/1 (p less than 0.05) and 3318 +/- 759 mU/1 (p less than 0.05), respectively. A weakly significant positive correlation was found between TSH and PRL levels suggesting that thermal stress in the newborn results in similar alterations in TSH and PRL, presumably through the same central mechanism.

Birth Weight↗