Elimination Pathway of Hematoporphyrin from Normal and Tumor-Bearing Rats

Hematoporphyrin orally administered to rats largely precipitates in the stomach thus reaching the various tissues at a very slow rate. Whatever the administration pathway (oral, i.p., i.V.), hematoporphyrin is eliminated in the feces with no apparent chemical modification; the elimination is slower from rats affected by ascites hepatoma than from normal rats owing to the high affinity of tumor cells for the porphyrin.

Pharmacokinetics of L/105, a New Rifamycin, in Rats and Dogs, after Oral Administration

The absorption and tissue distribution of a new rifamycin, L/105, which chemically is 4-deoxy-4'-methylpyrido [1',2'-1,2]imidazo [5,4 C] rifamycin SV, were studied in rats after oral administration of 100 mg/kg. This study showed that L/105, contrary to what was observed for rifampicin, was practically not absorbed: neither serum nor significant tissue levels were evidenced. Also in dogs, after oral administration of L/105 in a single dose (25 mg/kg) and a multiple dosage (10 mg/kg/day, for 8 days), no traces of the compound were detected in the serum. The elimination was investigated in the rat: the highest recovery of L/105 (more than 50% of the administered dose) was in feces after 72 h, hardly any traces were found in urine.

Disposition in rats of the carbohydrate polymer in Ferastral--an iron-poly (sorbitol-gluconic acid) complex

The disposition and pharmacokinetics in rats of 14C-sorbitol-Ferastral has been studied as an initial step towards elucidating the metabolic fate of the polymeric organic moiety. The period of time studied was 24 h. Following i.v. administration of a dose corresponding to 10 mg/kg of iron approximately 60% of the isotope was found in the urine after this period of time. A further 3% was demonstrated in the faeces whilst the expired air accounted for about 10% in the form of 14CO2. Thus, a relatively large proportion of the radiolabel was promptly excreted via the kidneys whilst the expired air and probably bile constituted secondary excretion routes. The physico-chemical nature of the urinary product was similar to the parent carbohydrate compound. The residual 14C radioactivity was distributed mainly between the liver, which contained approximately 45% of the retained label, carcass with 36% and large intestine with 7%. The plasma disappearance pattern was biphasic. Similar experiments with the 14C-sorbitol polymer starting material were performed for purposes of comparison.

Distribution of the carbohydrate polymer in 14C-labelled iron-poly (sorbitol-gluconic acid) complex after intramuscular administration in normal and anaemic rats

The carbohydrate polymer in an iron-poly (sorbitol-gluconic acid) complex was prepared by using uniformly labelled 14C-sorbitol or 14C-gluconic acid. The distribution of these complexes 7, 14 and 28 days after administration has been followed in non-anaemic and anaemic rats. Most of the 14C from the labelled complexes was found in the expired CO2, faeces and urine. Twenty-eight days after injection of 14C-labelled Ferastral, less than 13% of the given dose of either 14C-sorbitol or 14C-gluconic acid labelled preparation could be found in the body. There was no specific accumulation of 14C in any organ except in the bones, where 3% of the given dose could be seen 28 days after 14C-gluconic acid labelled Ferastral to both non-anaemic and anaemic animals.

Effect of an H2-receptor blocking agent on diarrhoeas after extensive small bowel resection in Crohn's disease

The effect of an H2-receptor blocking agent, cimetidine, on faecal losses of fluid, electrolytes and fat was examined in 10 patients with Crohn's disease, who had diarrhoeas after extensive small bowel resection. A randomized, double-blind and cross-over design was applied, and patients were hospitalized and on a defined diet during the study. Cimetidine, 4 x 400 mg, significantly reduced diarrhoeal volumes by an average of 22% (p less than 0.05) and faecal sodium by 27% (p less than 0.05). Patients with severe diarrhoeas responded better to treatment. No side-effects were recorded. The reported data suggest that cimetidine may be useful in symptomatic treatment of patients with severe diarrhoeas after extensive ileal resection. Due to deficient drug absorption, higher doses may be needed for optimal effect.

Prolonged induction of germfree bile acid pattern in conventional rats by antibiotics

Male conventional rats have been treated for five days with benzylpenicillin, neomycin, kanamycin, erythromycin, bacitracintneomycin, succihylsulfathiazole or metronidazole. Total fecal bile acids were analyzed in samples collected during periods of three days during the pretreatment period and during the eight weeks following drug treatment. Metronidazole or succinylsulfathiazole had no or minor effects on the conventional bile acid pattern and the "bile acid index" (ratio beta-muricholic acid/deoxycholic acid) remained low. Benzylpenicillin, neomycin or kanamycin induced a germfree bile acid pattern, i.e. increased the relative amounts of alpha-and beta-muricholic acid in feces and eliminated deoxycholic acid and hyodeoxycholic acid from feces. The high bile acid index was normalized within three weeks after termination of drug treatment but the excretion of alpha- and beta-muricholic acid was not normalized until a normal flora had been established by giving an enema with intestinal contents from intact, oncentional rats. Treatment with eythromycin or bacitracintineomycin also produced a germfree bile acid pattern. In these cases, the bile acid index was not back to normal until after five to eight weeks and the excretion of the muricholic acids was not normalized until an enema with intestinal bacteria had been given. It is suggested that these long-lasting effects of antibiotics on the metabolism of bile acids in the intestinal tract should be considered after short-term antibiotic therapy in humans.

Influence of a psyllium-based fibre preparation on faecal and serum parameters

A fibre made of psyllium husk was given to 12 elderly patients for 4 months in order to investigate their faecal output and selected serum parameters. The fibre significantly improved bowel function and faecal output confirming its value as a non-irritant, harmless bulk-forming laxative. Serum cholesterol was decreased by 20% while triglycerides remained unchanged. There was a significant reduction in serum calcium after withdrawal of the fibre supplement. There were no significant changes in serum iron, total iron binding capacity, fibrinogen, or in the haematological parameters (ESR, haemoglobin, leucocyte count) attributable to the fibre. The high phytate content of the fibre does not appear to have any clinically significant effect on mineral absorption. It is suggested that dietary fibre (at least psyllium-based fibre preparations) may have significant cholesterol lowering capacity due to the binding of bile-acids in the intestine.

The mechanism of lincomycin-induced diarrhoea

Metabolic studies were performed before and seven days after treating rats orally with lincomycin. Following the treatment the mean faecal weight increased from 302.2 g/72 hr +/- 3.8 (S.D.) to 65.5 +/- 8.2. The faecal fat excretion was unchanged, and the weight increase was mainly due to increased water content. To find whether the watery diarrhoea was due to bile acid malabsorption, the absorption rate of [14C]-taurocholic acid was measured in untreated rats and rats treated with lincomycin using an in vivo perfusion technique. There was no significant difference in bile acid absorption rate measured at three different concentrations of bile acid in the perfusate. Alternative mechanisms of lincomycin-associated diarrhoea are discussed.

The folic acid absorption test compared with other laboratory tests for malabsorption

In 25 patients with malabsorption, the folic acid urinary excretion (TRIFA) test was compared with the degree of steatorrhoea, the Schilling test, and the D-xylose test. No correlation was found between the faecal lipid excretion, the Schilling test, and the TRIFA test, whereas the TRIFA test did correlate fairly well with the D-xylose test. It is concluded that the TRIFA test does not replace estimations of faecal lipid excretions in the diagnosis of intestinal malabsorption. As it mainly supplies information about absorptional capacity in the upper small bowel, it is complementary to the Schilling test, which chiefly measures the absorption in the lower intestine. Finally, the TRIFA test has several advantages over the D-xylose test in practical clinical use.

Distribution of 59Fe-labelled iron-poly(soribitol-gluconic acid) complex in normal and anaemic rats

An iron carbohydrate complex, iron-poly(sorbitol-gluconic acid), Ferastral, was labelled with 59Fe, and its distribution in rats was studied. The animals were intramuscularly treated with a dose of 10 mg of iron/kg. Three groups of animals were used: group A: non-anaemic and group B: anaemic rats, both kept on iron-deficient diet, and group C: non-anaemic rats kept on iron-supplemented diet. Urinary and faecal excretion, distribution in the body and incorporation in blood of the 59Fe was followed up to 28 days. The total excretion after that time was 15%. There was a rapid initial phase followed by a slower continuous one. After 28 days group A had 25, group B 13 and group C 40% of the given dose remaining at the site of injection. The corresponding values in liver after 28 days were 7, 4 and 17% of the given dose, respectively. In blood a continuous increase was observed. At 28 days after administration 26, 43 and 17% of the given dose had been incorporated in the red blood corpuscles of the respective groups. These results show that the iron complex is absorbed from the site of injection and is utilized for haemoglobin synthesis. They also show that the disposition of the complex is influenced by the iron content of the diet.

Hereditary hepatic porphyrias in Finland

The occurrence of hepatic porphyrias--acute intermittent porphyria (AIP) and variegate porphyria (VP)--in Finland has been studied. During a period of 9 years 107 patients with AIP and 45 patients with VP were found. The prevalence of hereditary hepatic porphyrias was calculated to be 3.4 per 100 000 inhabitants. The patients belonged to 42 different families. Eighty-nine patients (59%) had had acute attacks, whereas 63 were symptomless latent cases. Precipitating factors, symptoms and excretion of porphyrins and their precursors did not significantly differ from what has been reported earlier from other parts of the world. A slight fragility of the skin on the back of the hands was noted in some 50% of VP patients. Abnormal sensitivity to sunlight could not be seen in a single case. However, about 50% of patients with VP showed an abnormal reaction when irradiated with artificial ultraviolet light. The difference in the skin symptoms in South African and Finnish VP patients is discussed.