摘要:

The effects of a purine precursor, AICAriboside (5-aminoimidazole-4-carboxamide riboside), on postischemic recovery of myocardial function and adenine nucleotides have been studied in the isolated blood-perfused cat heart. The isolated hearts received either AICAriboside or saline prior to 60 min of global ischemia and during 60 min of subsequent reperfusion. After 60 min of global ischemia and reperfusion, left ventricular function of the AICAriboside-treated hearts approached preischemic values, whereas contractile function of the saline-treated hearts remained depressed. At 60 min postischemia, recovery of left ventricular developed pressure (LVDP) was 62 ± 10% for the saline-treated hearts as compared to 93 ± 8% for the AICAriboside-treated hearts. Left ventricular compliance of the saline-treated hearts was decreased slightly at 60 min postischemia. In contrast, left ventricular compliance was increased in the isolated hearts which received AICAriboside. Myocardial ATP concentrations were decreased significantly at 60 min postischemia in both the saline-treated hearts and in the AICAriboside-treated hearts relative to nonischemic hearts. Similarly, total adenine nucleotides (TAN = ATP + ADP + AMP) were decreased significantly in both the saline-treated hearts and AICAriboside-treated hearts relative to nonischemic hearts. The present study demonstrates that AICAriboside protected globally ischemic hearts from the mechanical dysfunction associated with an ischemic insult but did not restore ATP or the total adenine nucleotide pool of the postischemic myocardiu

ISSN:0031-7012    

DOI:10.1159/000138107

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Dietary administration of tyrosine (0.25–2.50%) to rats whose kidneys were bilaterally encapsulated with latex envelopes provided modest protection against the development of hypertension. Elevation of blood pressure was slower (one experiment) and maximal level attained was reduced (two experiments) compared to untreated, renal encapsulated controls. In addition, the polydipsia, polyuria, and reduced renal concentrating ability characteristically accompanying hypertension were attenuated. The mechanism(s) accounting for the partial protection against hypertension reported here is unknown although administration of tyrosine was accompanied by a reduced cardiovascular responsiveness to graded doses of phenylephrin

ISSN:0031-7012    

DOI:10.1159/000138108

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Heparin sodium, dissolved in water, causes plasma clearing activity (PC) and appreciable heparinemia (HE) when directly delivered into the duodenum, the jejunum, the ileum or the large intestine of rats, as well as when administered through an esophageal tube to distal duodenum-ligated animals. However, choledochus occlusion significantly decreases both PC and HE produced by intraesophageal heparin application. It is suggested that, in rats, bile flow participates in intestinal heparin absoption.

ISSN:0031-7012    

DOI:10.1159/000138109

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Phenobarbital pretreatment of male rats induced four microsomal cytochrome P-450 enzymes, at least one of which has previously not been reported. Three of the induced forms of the cytochrome possess identical NH2-terminal amino acid sequence for the first 32 residues (PBRLM5, 6 and 7). This sequence is identical to that shown earlier for PB-4 and PB-5. Apparent values for minimum molecular weight on SDS-PAGE were 52,000 (PBRLM4), 53,000 (PBRLM5), 53,500 (PBRLM6) and 54,000 (PBRLM7). Isomeric metabolite patterns from testosterone and progesterone differed for each enzyme further indicating their unique natures. Studies reveal similarity of PBRLM4 to PB-1, of PBRLM5 to P-450b and PB-4, and PBRLM6 to P-450e and PB-5. PBRLM7, which does not correspond to any reported forms, metabolizes steroids poorly. It preferentially hydroxylates testosterone at the 16β-position. It is the largest and least active of the enzymes shown for all of the substrates tested. This study further provided a cautionary note against assuming that chromatographic pools, like a P-450 PB-B fraction, are homogeneous

ISSN:0031-7012    

DOI:10.1159/000138110

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Sorbinil, an aldose reductase inhibitor, in combination with diet normalization, arrested stage-II galactose cataract and restored lens transparency. During the reversal process, determination of lens dry weight, dulcitol and myo-inositol content as well as individual fiber cell ultrastructure offered a comprehensive index of lens integrity. In this study, young rats received a 50% galactose diet for 10 days to produce a stage-II sugar cataract. Then they were placed on one of the following diets: 50% galactose and Sorbinil (20 mg/kg); 50% galactose; normal diet; normal diet and Sorbinil (20 mg/kg). From each group, equal numbers were sacrificed at 5, 10 and 20 days. Although differences were obtained after 5 and 10 days, the 20-day reversal period provided the most significant findings. Only the combination of Sorbinil and normal diet restored lens transparency, normalized lens myo-inositol content and dry weight and partially restored fiber cell integrity as evidenced by diminished granulation and increased fiber synthesis. Neither Sorbinil treatment during galactose administration nor normal diet alone were sufficient to protect against further cataractogenesis, thus indicating a synergistic effect of Sorbinil in combination with normal diet.

ISSN:0031-7012    

DOI:10.1159/000138111

出版商:S. Karger AG    

年代:1985

数据来源: Karger

ISSN:0031-7012    

DOI:10.1159/000138112

出版商:S. Karger AG    

年代:1985

数据来源: Karger