Effect of (+)-catechin on renal and intestinal transport.

The ability of dog renal cortex slices to accumulate beta-methyl-glucoside or glycine is enhanced by the flavonoid (+)-catechin at a concentration of 3.5 mM. This stimulatory effect is apparently due to a decreased rate of efflux of either substrate. On the other hand, the uptake of p-amino-hippuric acid and N1-methyl-nicotinamide is inhibited by (+)-catechin. The drug at the same concentration is without action on amino-acid transport by guinea-pig intestine in vitro.     

3′-O-Methyl-(+)-catechin glucuronide and 3′-O-methyl-(+)-catechin sulphate: new urinary metabolites of (+)-catechin in the rat and the marmoset

Summary The major urinary metabolites of (+)-catechin (cyanidanol-3) in the rat were (+)-catechin glucuronide, 3′-O-methyl-(+)-catechin glucuronide and 3′-O-methyl-(+)-catechin sulphate. The latter conjugate was the major metabolite in marmoset urine. To whom reprint requests should be addressed. Acknowledgment. The authors wish to thank Miss Rosemary Dring and Mr P.B. Wood for skilled technical assistance, Zyma S.A., Nyon, Switzerland, for financial support, and the Medical Research Council for a research studentship (to I.C.S.).     

Collagen treated with (+)-catechin becomes resistant to the action of mammalian collagenase

Treatment of radioactively labeled guinea-pig skin soluble collagen or calf skin collagen with the flavonoid (+)-catechin makes the collagen resistant to the action of mammalian collagenase but not to the action of bacterial collagenase. Complete resistance to the action of the mammalian enzyme may be achieved by incubating 0.6 mg of collagen (dry weight) with 0.1 mM (+)-catechin, followed by dialysis to remove the unbound flavonoid. Since incubation of the mammalian enzyme with (+)-catechin does not inhibit its activity, it is postulated that (+)-catechin binds tightly to collagen and modifies its structure sufficiently to make it resistant to enzyme degradation.     

Collagen treated with (+)-catechin becomes resistant to the action of mammalian collagenase

Summary Treatment of radioactively labeled guinea-pig skin soluble collagen or calf skin collagen with the flavonoid (+)-catechin makes the collagen resistant to the action of mammalian collagenase but not to the action of bacterial collagenase. Complete resistance to the action of the mammalian enzyme may be achieved by incubating 0.6 mg of collagen (dry weight) with 0.1 mM (+)-catechin, followed by dialysis to remove the unbound flavonoid. Since incubation of the mammalian enzyme with (+)-catechin does not inhibit its activity, it is postulated that (+)-catechin binds tightly to collagen and modifies its structure sufficiently to make it resistant to enzyme degradation.Acknowledgments. This work was supported by grants from the Easter Seal Research Foundation of the National Easter Seal Society for Crippled Children and Adults (R-7821), and the National Institutes of Health (HL-20447). (+)-Catechin was a generous gift from Zyma SA, CH-1260 Nyon, Switzerland.     

Effect of anesthetics on the organic acid transport system of renal tubules

Zusammenfassung Die Fähigkeit zur Anreicherung von rotem Chlorphenol wird durch Stickoxydul, Methoxyfluran und Thiopental bei isolierten Fischharnkanälchen herabgesctzt, während Halothan ohne Wirkung blieb. Es wird gefolgert, dass allgemeine Betäubungsmittel den Transport organischer Säuren in benachbarten Nierenkanälchen beeinflussen.

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This work was supported by the Harold C. Strong Anesthesia Research Fund.     

Effect of insulin upon renal amino acid transport in lambs

Zusammenfassung An Nierenrindenschnitten von Lämmern und Schafen wurde untersucht, ob die Anwesenheit von Insulin bzw. Glukagon im Inkubationsmedium die gegen ein Konzentrationsgefälle erfolgende Aufnahme von -Aminoisobuttersäure in Nierenrindenzellen beeinflusst. Insulin stimulierte in diesen Versuchen (Inkubationszeit: 80 min) die Akkumulation von -Aminoisobuttersäure in Nierenrindenzellen bei jungen Lämmern, nicht jedoch bei älteren Lämmern und Schafen. Für Glukagon konnte kein Effekt nachgewiesen werden.

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Acknowledgment. The investigation was supported by the Deutsche Forschungsgemeinschaft (SFB 147 Jungtierkunde).     

Effect of substrate pretreatment on renal organic ion transport in the adult rat

Summary The ability of renal cortical slices to accumulate PAH and NMN was not significantly affected by pretreatment of adult rats with large doses of PAH. Pretreatment of adult rats with THAM significantly increased PAH accumulation but had no effect on NMN. Inulin and PAH clearance and filtration fraction were significantly decreased by PAH pretreatment but unaffected by THAM pretreatment. The effects of pretreatment on transport are probably due to non-specific toxicity.Supported in part by U. S. Public Health Service Grant No. AM10913.Supported in part by a predoctoral fellowship from the Upjohn Company.Acknowledgments. The technical assistance of Mr.Grant Moore and Ms.Peggy Wagner is gratefully acknowledged.     

Effect of substrate pretreatment on renal organic ion transport in the adult rat.

The ability of renal cortical slices to accumulate PAH and NMN was not significantly affected by pretreatment of adult rats with large doses of PAH. Pretreatment of adult rats with THAM significantly increased PAH accumulation but had no effect on NMN. Inulin and PAH clearance and filtration fraction were significantly decreased by PAH pretreatment but unaffected by THAM pretreatment. The effects of pretreatment on transport are probably due to non-specific toxicity.     

The influence of sodium transport on glucose transport by anin vitro intestinal preparation

Riassunto Vengono riportati i dati ottenuti sul trasporto di sodio e di glucosio attraverso l'intestino isolato di ratto, perfuso con soluzioni isotoniche a diverso contenuto di sodio. Da questi dati appare che non solo il trasporto di sodio dipende dalla concentrazione di sodio nel liquido mucosale, ma anche il transporto di glucosio. Si prospetta l'ipotesi, inoltre, che il passaggio di sodio dalla mucosa alla sierosa sia necessario sopratutto per il trasferimento del glucosio dalle cellule al liquido serosale.     

Adaptation of intestinal amino acid transport

Zusammenfassung An evertierten Dünndarmsäcken (proximales Jejunum) erwachsener Ratten, die zwei Wochen lang eine proteinarme (13% Kasein) oder proteinreiche (88% Kasein) Diät erhalten hatten, wurde der aktive intestinale Transport vonl-Leuzin undd-Galaktose untersucht. Proteinreiche Ernährung führte zu einer Stimulierung desl-Leuzin-Transports, während derd-Galaktose-Transport dadurch unbeeinflusst blieb. Diese Befunde sprechen für eine spezifische Adaptation des intestinalen Aminosäurentransports an den Proteingehalt der Nahrung.     

Phosphorylation and uphill intestinal transport of thiamine,in vitro

Riassunto L'impiego di tiamina-¹⁴C, con la tecnica dei sacchetti rovesciati di intestino di ratto, ha permesso di dimostrare che, durante il trasporto contro gradiente in vitro, la tiamina viene fosforilata dal tessuto intestinale. Gli inibitori metabolici e gli analoghi strutturali della tiamina che ne inibiscono la fosforilazione del pari ne riducono il trasporto netto. Ciò dimostra che il trasporto intestinale della tiamina è strettamente connesso con la sua fosforilazione.     

Net transport of water and solutes by anin vitro rat intestinal preparation

Riassunto Vengono riportati i dati ottenuti sul passaggio netto di acqua e di soluti attraverso l'intestino isolato di ratto, perfuso con soluzione isotonica o ipertonica per aggiunta di solfato di sodio. È stato determinato anche il crioscopico dei liquidi raccolti e delle soluzioni di perfusione. Da questi dati appare che il passaggio di acqua dipende dall'istituirsi di un gradiente di concentrazione per il trasporto attivo di soluti nello stesso senso.Il solfato di sodio eserciterebbe sui tessuti intestinali una azione impermeabilizzante, riducendo così il trasporto netto totale di soluti.     

(+)-S-Acetyl-pantetheine and (+)-S-benzoyl-pantetheine

Zusammenfassung Die UV.-Spektren von (+)-S-Acetyl-pantethein, (+)-S-Benzoyl-pantethein und von Pantethein wurden bestimmt und werden mit denjenigen anderer Thiosäureester verglichen. Pantethein und seine beiden S-Acylderivate geben in alkalischer Lösung mit Kupfer-II-Salzen eine violette Färbung. Die biologische Aktivität des stabilen, kristallisierten (+)-S-Benzoyl-pantetheins entspricht seinem Gehalt an Pantethein.     

Possible role of intestinal alkaline phosphatase activity in thiamine transport

Summary Thiamine deficiency caused a marked decrease of intestinal alkaline phosphatase (al-Pase) activity, but had no effect on the Ca⁺⁺-ATPase activity and Ca⁺⁺-absorption in rats. The al-Pase activity was significantly decreased 1 h after oral administration of ethanol at 0.5 and 2.5 g/kg. In contrast, Mg⁺⁺-, Ca⁺⁺- and (Na⁺+K⁺)-ATPase activities did not change after the administration of ethanol. These findings show that the al-Pase activity, unlike the Ca⁺⁺-ATPase activity, is not related to Ca⁺⁺-absorption. A possible role of al-Pase activity in the active transport of thiamine in the intestine was discussed.     

Actinomycin D inhibition of intestinal transport of L-histidine and of vitamin D action

Zusammenfassung Eine grosse Gabe Vitamin D bewirkte bei Kaninchen eine Erhöhung der Histidinabsorption durch den Darm. Vorbehandlung mit Actinomycin D hemmte den Histidintransport und verhinderte die Stimulation desselben durch Vitamin D.     

Effect of lithium on the blood and intestinal serotonin contents of rats

Zusammenfassung Nachweis, dass der Blutspiegel des Serotonins bei Ratten 1h nach oraler Gabe von 5 mEq/kg Lithium anstieg, während der Serotonin-Gehalt im Jejunum und Duodenum abnahm.

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Acknowledgments. The author wishes to thank Taisho Seiyaku Co., Tokyo for supplying lithium carbonate.     

Possible role of intestinal alkaline phosphatase activity in thiamine transport.

Thiamine deficiency caused a marked decrease of intestinal alkaline phosphatase (al-Pase) activity, but had no effect on the Ca++-ATPase activity and Ca++-absorption in rats. The al-Pase activity was significantly decreased 1 h after oral administration of ethanol at 0.5 and 2.5 g/kg. In contrast, Mg++-, Ca++-and (Na+ + K+)-ATPase activities did not change after the administration of ethanol. These findings show that the al-Pase activity, unlike the Ca++-ATPase activity, is not related to Ca++-absorption. A possible role of al-Pase activity in the active transport of thiamine in the intestine was discussed.     

Effect of prenatal and neonatal pantothenic acid deficiency on rat intestinal phosphatases

Summary Alkaline phosphatase activity was increased in the distal part of the small intestine of pantothenic acid deficient neonatal rats, while acid phosphatase activity was slightly increased and protein concentration was decreased throughout the small intestine. The growth and maturation of the distal part of the small intestine were retarded more severely than in the proximal part.     

Effect of prenatal and neonatal pantothenic acid deficiency on rat intestinal phosphatases

Alkaline phosphatase activity was increased in the distal part of the small intestine of pantothenic acid deficient neonatal rats, while acid phosphatase activity was slightly increased and protein concentration was decreased throughout the small intestine. The growth and maturation of the distal part of the small intestine were retarded more severely than in the proximal part.     

Effect of prolactin on human red cell sodium transport

Summary Incubation of red cells with higher concentrations of prolactin in vitro enhanced the cellular sodium level and produced a significant reduction in erythrocyte membrane adenosine triphosphatase activity. This effect was dose and time-dependent. It is the result of an inhibition of the active sodium pump similar to that produced by ouabain, suggesting altered red cell function and electrolyte balance in hyperprolactinemic states.Acknowledgments. Ovine prolactin was generously supplied by Ferring (Malmö, Sweden) and NPA, NIH (Maryland, USA). Thanks are also due to Prof. S. Dutta, Wayne State University, Detroit, for the gift, of ouabain octahydrate and Dr M. Ramachandran and Prof. S. Ramakrishnan, Department of Biochemistry, JIPMER, Pondicherry, for their encouragement and keen interest in this study.