Phloretin inhibits Na+ and K+ uptake in cultured alveolar type II cells by reduction of cellular ATP content.

A number of Na+ and K+ transport pathways have been identified in the alveolar epithelium and multiple inhibitors have been used to uncover these mechanisms. However, the effect of phloretin, a small dipolar nonelectrolyte compound which exerts many effects on membrane transport on Na+ and K+ uptake in alveolar epithelial cells, is not known. The purpose of this study was then to determine the impact of phloretin in Na+ and K+ uptake in cultured rat alveolar type II cells. Phloretin at a dose of 250 microM decreased Na+ uptake by 80% and K+ uptake by 90%. This decrease in Na+ and K+ uptake was not associated with a cytotoxic effect of phloretin, but this treatment did decrease ATP levels in the cells to 80% of the control cells value by 5 minutes and to 95% by 10 minutes. Our study demonstrates that phloretin is a nonspecific inhibitor of ions transport in alveolar type II cells. This inhibition is probably mediated by a reduction of intracellular ATP content.

[A luminescent cytological method of the determination of sex gonad hormonal activity in males]. / Liuminestsentno-tsitologicheskii metod opredeleniia gormonal'noi aktivnosti polovykh gonad muzhchin.

A method for assessing gonadal hormonal activity in men is suggested. It consists in fluorescent and cytologic examinations of navicular fossa epithelium making use of a fluorescent marker (acridine orange) and is based on specific sensitivity of navicular fossa epithelium to male sex hormones, because navicular fossa is formed in the course of embryogenesis from the urogenital sinus under the effect of androgen induction. Navicular fossa epithelium reacts to changed androgen/estrogen ratio by restructuring which is characterized by cellular apparatus regression or depression. Parallel with the cytologic reaction, blood androgen levels were measured in patients and normal subjects. The authors have developed a classification singling out four basic and four intermediate epithelial reactions. The suggested method was used in examinations of 327 patients with various andrologic abnormalities and of 96 healthy men. Examinations have demonstrated a high diagnostic value of this method in assessment of the hormonal balance (androgens and estrogens) in men and the possibility of using it as a screening test in andrologic abnormalities.

[The characteristics of histocompatibility antigen distribution in urolithiasis patients with a phosphorus metabolic disorder]. / Osobennosti raspredeleniia antigenov gistosovmestimosti u bol'nykh urolitiazom s narusheniem fosfornogo obmena.

Phosphorus metabolic disturbances play a great role in the occurrence of urolithiasis. This study covered 150 patients with urolithiasis to establish correlations between the frequency of histocompatibility antigens and the increase in blood and urinary phosphorus levels. The HLA antigens were identified by the routine microlymphocytotoxic method involving a histotyping serum panel. The ABO antigens and rhesus were determined by the agglutination method by using reference sera. The study revealed specific distribution of histocompatibility antigens in urolithiasis patients with disturbed phosphorus metabolism. Hyperphosphatemia correlated with the higher frequency of HLA-B35 (chi 2 = 9.89) and E/E system rhesus (chi 2 = 8.63); hyperphosphaturia showed a negative association with the HLA-A28 antigens (chi 2 = 9.7), as well as with E/e (chi 2 = 14.69) and e/e (chi 2 = 39.36) and a positive association with HLA-B13 (chi 2 = 5.98) and B35 (chi 2 = 36.58). The highest relative risk for hyperphosphatemia associated with the B27 and B35 antigens was observed with genetic predisposition, being 3.63 and 7.13, respectively. B12- and B35-positive individuals were at higher risk for hyperphosphaturia up to 11.25. There were significant differences in antigen frequency, and sex, genetic predisposition to urolithiasis, association of phosphorus metabolic disturbances with other metabolic disorders, and their effects of parathyroid lesions, etc. The findings reveal the immunogenetically induced risk for the occurrence and development of urolithiasis with disturbed phosphorus metabolism to make goal-oriented prophylactic measures.

[Characteristics of adenosine triphosphatase activity in carp erythrocytes treated with saponin]. / Osobennosti aktivnosti adenozintrifosfataz v éritrotsitakh karpa, obrabotannykh saponinom.

The activities of Ca-ATPase and Na,K-ATPase in saponin-treated erythrocytes of man, rat and carp were compared. It was shown that at free calcium concentrations lower than 1 microM the activity of Ca-ATPase in carp erythrocytes was by one order of magnitude lower than in rat erythrocytes and 3-4 times lower than in human red blood cells. At [Ca2+] = 0.4 microM the activities of Na,K-ATPase in all species under study were essentially the same. The increase in Ca2+ concentration up to 1 microM resulted in a 2-5-fold activation of Na,K-ATPase in rat and carp erythrocytes, respectively. In all cases studied a further elevation of free calcium concentration was accompanied by a decline of the Na,K-ATPase activity. It was shown that the Pi content in carp erythrocytes is 5-6 times as high as that in mammalian cells. This circumstance is a considerable obstacle to a detailed analysis of mechanisms of ATPase activity regulation in carp erythrocytes by methods used for determination of inorganic phosphate production.

[Purification and properties of two enzymes of meta-cleaving the aromatic ring controlled by the biphenyl biodegradation plasmid pBS 241 from Pseudomonas putida]. / Ochistka i svoistva dvukh fermentov meta-rasshchepleniia aromaticheskogo kol'tsa, kontroliruemykh plazmidoi biodegradatsii bifenila pBS 241, iz bakterii Pseudomonas putida]

It was shown that two metapyrocatechases (EC 1.13.11.2) function in Pseudomonas putida BS893. Biphenyl degradative plasmid pBS241 carries the genes of these enzymes. The basic properties of the both enzymes, i. e., MPC1 and MPC2, were investigated. It was found that MPC1 is an enzyme with a molecular mass of 135 kD and has a heterotetrameric subunit structure (alpha 2 beta 2), being made up of two non-identical polypeptides with Mr of 34 and 22.5 kD; pI is 5.15, the pH optimum is at 8.0, a temperature optimum is at 54 degrees C. MPC2 has a molecular mass of 154 kD and possesses a homotetrameric subunit structure (alpha 4); it consists of identical polypeptides with Mr of 41 kD and has a pI of 4.95, a pH optimum at 7.5 and a temperature optimum at 60 degrees C. The substrate specificity of the enzymes was studied, and the Km and Vmax values for substituted catechols were determined. MPC1 shows a high affinity for 2.3-dihydroxybiphenyl and hydrolyzes 3-methylcatechol and catechol (but not 4-methylcatechol) at a low rate. MPC2 has a moderate affinity for catechol, 3- and 4-methylcatechols, but is incapable of cleaving 2.3-dihydroxybiphenyl. Both enzymes share in common some typical properties of metapyrocatechases. The different role of MPC1 and MPC2 in biphenyl catabolism is discussed.

[Plasmid participation in the degradation of alpha-methylstyrene]. / Uchastie plazmid v degradatsii al'fa-metilstirola.

Pseudomonas acidovorans 9 transforming alpha-methylstyrene into acetophenone contains four types of plasmid DNA with molecular masses of 130, 110, 36 and 54 MD. The loss of the "growth on alpha-methylstyrene" property by this strain correlates with the absence of plasmids with the molecular masses of 130 and 110 MD from the cells. All the types of plasmid DNA are found in transconjugants growing on alpha-methylstyrene and produced by crossing the parent P. acidovorans strain with the plasmidless variant of this strain incapable of alpha-methylstyrene transformation. Apparently, plasmids with the molecular masses of 130 and 110 MD participate in the genetic control of alpha-methylstyrene transformation into acetophenone by P. acidovorans 9.

[A strain of Pseudomonas aeruginosa growing on petroleum hydrocarbons]. / Shtamm Pseudomonas aeruginosa, rastushchii na uglevodorodakh nefti.

The strain Pseudomonas aeruginosa BS313 was used to isolate mutants that are capable to utilize octane as the sole carbon source. By means of conjugation plasmids of camphor (CAM) and naphthalene (pBS2) biodegradation were inserted into one of the mutant strains P. aeruginosa BS316. The resultant strain P. aeruginosa BS315 shows the capacity to degrade aliphatic, aromatic and cyclic oil hydrocarbons.