Various Tissues Of Guinea Pigs Research Articles

Fluctuation of Zinc, Copper, Magnesium and Calcium Concentrations in Guinea Pig Tissues after Administration of Captopril (SQ 14225)

The effect of the administration of captopril on Zn (zinc), Cu (copper), Ca (calcium) and Mg (magnesium) concentrations in guinea pig tissues was studied. For nine weeks 2 mg captopril per kg b.w. were administered daily to adult male guinea pigs intraperitoneally. The concentrations of the studied metals were determined in several tissues. Captopril significantly decreased Zn concentration in liver, Cu concentration in liver, adrenals, jejunum, urine and hair and Mg concentrations in blood and urine. A significant increase was observed in testicular and epididymal Zn, in heart, epididymal and fecal Cu, in Mg concentration of lung, kidney, adrenals, jejunum, epididymis and hair and in Ca concentrations in brain, heart, lung, kidney, spleen and stomach. No significant changes were observed in the colon and the thigh bone concentrations of the various elements tested. In conclusion Captopril treatment can produce translocation and/or elimination of Zn, Cu, Mg and Ca ions in various tissues of guinea pigs.

A positive correlation between catalase activity and ascorbate uptake in the tissues of guinea pigs and cultured cells of mammals.

We recently reported that the concentration of supplemental ascorbate which inhibits cell growth is positively related to intracellular catalase activity. It is assumed that the cells with high catalase activity are resistant to high concentrations of ascorbate since catalase can decompose hydrogen peroxide (H2O2) induced by the auto-oxidation of ascorbate in cultured medium. In this study, we investigated whether intracellular catalase activity affects the uptake of ascorbate into animal tissue and cultured cells. Ascorbate concentrations in the tissues of guinea pigs and various cultured cells, with and without supplementation of ascorbate, were determined to evaluate the efficiency of ascorbate uptake. We found a positive correlation between the efficiency of ascorbate uptake and catalase activity in various tissues of guinea pigs (r = 0.767, p < 0.05). Furthermore, a positive correlation between the two was also found in various species of cultured cells. This study indicates that tissues and cells with higher efficiency of ascorbate uptake are required for higher catalase activity, presumably for the decomposition of H2O2 from ascorbate.

Effects of acute and short-term repeated application of fullerene C 60 on agonist-induced responses in various tissues of guinea pig and rat

1. 1. Effects of fullerene C 60 in trachea, right atria, ileum and stomach (fundus) of guinea pig and vas deferens and uterus of rat were studied pharmacologically. 2. 2. C 60 (4 μM) had no direct effect in all tissues. In guinea pig trachea and heart, relaxation and positive inotropic and chronotropic actions of isoprenaline and in isolated rat vas deferens and uterus the responses on norepinephrine and oxytocin were not affected by the short-term repeated application of C 60 30 mg/kg i.p. for 4 wk. 3. 3. The pD 2 values (potencies) of acetylcholine in ileum and its longitudinal muscle from guinea pig after the short-term repeated application of C 60 were significantly smaller than those obtained without the application. The value of 5-hydroxytryptamine in rat stomach (fundus) also tended to be smaller than obtained without the application. 4. 4. Atropine inhibited competitively the contractions for acetylcholine in the longitudinal muscles prepared from C 60-treated and non-treated guinea pigs, and the pA, values for atropine were not significantly different with each other. 5. 5. These results suggest that C 60 has no direct effects or antagonistic properties toward drug receptors, but sub-chronic exposure of C 60 decreased responsiveness. This may be due to a change in post-receptor processes.

Blood content in guinea-pig tissues: Correction for the study of drug tissue distribution

The blood content in different organs or tissues of guinea-pigs was determined by means of [ 125I]bovine serum albumin. The blood distribution expressed as percentage of total body blood for various organs or tissues ranged from 0.35 (adipose) to 17.5 (muscle) %. The blood content in tissue preparations expressed as the blood background correction factor, F (ml blood/g wet tissue) depended on the extent of bleeding during experiment; that factor can cause a considerable difference in the results of a tissue distribution study of a drug. Blood content was high in the lung (0.36 ml/g). heart, liver, kidney and spleen, but low in adipose and brain tissues (0.021 ml/g). The distribution of valproic acid in various tissues of guinea-pigs after intravenous injection was determined from the homogenates of isolated organs. The results showed that blood contamination can greatly alter the data of tissue distribution of a drug to as much as 25%. This study proposed a maximum (non-bled) and a minimum (extreme-bled) blood background correction factor for respective tissues of guinea-pigs, as well as equations for correcting the blood contamination in tissue during the drug distribution study. The results suggest that to obtain an exact analysis of drug concentrations in specific tissues, a correction for the blood of that specific tissue is necessary.

The distribution of mercury in various tissues of guinea-pigs after application of dental amalgam fillings (a pilot study)

Mercury accumulation in brain, kidney, liver and heart following insertion of amalgam in the teeth of guinea-pigs has been studied. During the accelerated wear of the amalgam in these gnawing animals, a significant mercury accumulation in the above tissues was demonstrated. Finely diffused and abraded amalgam must not be ignored as a source of absorbable mercury.

Tissue distribution of leukotriene A 4 hydrolase activity in guinea pig

The distribution of the activity of leukotriene A 4 hydrolase, an enzyme catalyzing hydrolysis of the allylic epoxide leukotriene A 4 to the dihydroxy acid leukotriene B 4, was determined in various tissues of guinea pig by using the supernatant fraction (100,000 × g, 60 min) of the homogenates. The activity was ubiquitously distributed in all tissues examined, and the highest specific activity was found in small intestine, followed by lung, aorta, colon, and spleen, in this order. The specific activity in these tissues was higher than that of leukocytes. The physiological roles of this compound in these organs deserve reexamination in this context.

Action and metabolism of circulating leukotriene C

The microvascular permeability effects of intravenously administered leukotriene C 4 were assessed by fluorometric determinations of extravasated Evans blue dye in various tissues of guinea pigs. The effects were widespread, with intensity differences between different vascular beds, which in part reflected the tissue distribution of tritium-labeled leukotriene C 3 in mice. Local tissue specificity favored permeability effects in the urinary tract, pulmonary airways, esophagus, and distal colon. The permeability effects may contribute to the hypotensive actions of leukotriene C 4 and enhance airway obstruction by edema formation in addition to smooth muscle contraction.

Effect of interaction of manganese and nickel on their contents in various tissues of guinea pigs

Effect of interaction of manganese and nickel on their contents in various tissues of guinea pigs

Relationship between Pharmacological Actions of ATP and Biochemical Parameters in Microsomes from Various Tissues of Guinea-Pig

Relationship between Pharmacological Actions of ATP and Biochemical Parameters in Microsomes from Various Tissues of Guinea-Pig

Characterization of cholinesterases in various tissues of guinea pig with respect to their reactivation by obidoxime after inactivation by diisopropylfluorophosphate.

Studies were made to characterize the cholinesterases from erythrocytes, plasma and homogenates of cardiac ventricular muscle and brain of guinea pigs as specific or non-specific cholinesterases (ChEs). The relative content of both can be estimated using the substrates acetylcholine, acetyl-β-methylcholine and butyrylcholine. The content of non-specific ChE was found to decrease in the sequence: plasma cardiac-ventricular-muscle brain. The inactivation, reactivation and ageing-rate of the various ChEs were determined and yielded the following differences: 1. The specific ChEs from erythrocytes and brain were inhibited to different degrees by obidoxime. 2. The non-specific ChEs from plasma and cardiac ventricular muscle could be clearly differentiated from that of brain by means of their different k2-values upon inactivation with DFP. 3. The specific ChE of brain once inactivated by DFP was found to age more slowly than that of erythrocytes, taking the reactivation by obidoxime as indicator. 4. The reactivation of the phosphorylated non-specific ChEs and the half-life of the ageing processes were found to be dependent on the obidoxime concentration used.

Effect of dihydrostreptomycin on tissue lipid of guinea-pigs.

ANTIBIOTICS are known to have profound effects on nucleic acids and protein biosynthesis. Coniglio and Bell1 reported that when antibiotics are administered orally to rats there is a significant increase in the incorporation of 14C-acetate into hepatic fatty acids. Chatterjee et al.2 observed that dihydrostreptomycin significantly influences the lipid metabolism of intestine and whole body of rats. The neurotoxic effects of dihydrostreptomycin on prolonged use in tuberculosis treatment and other infections are well known3. The present work was undertaken to study the effects of DHS on lipid changes in various tissues of guinea-pigs.

STUDIES ON THE ACCELERATING EFFECT OF CYANIDE ON ASCORBIC ACID OXIDATION BY INTESTINAL HOMOGENATE OF RATS

It has been known since the early works on the respiratory systems of animal tissues (1-5), that cytochrome oxidase operates as the terminal system of respiratory chain and the oxidative activity is completely inhibited by cyanide as well as by azide. Stotz et al. (6) and Smith (7) reported that ascorbic acid is oxidized by cytochrome oxidase system in animal tissues. In the course of the studies on the tissue respiration of rat intestine, it was found that respiration of small intestinal homogenate of rats without substrates was not inhibited by cyanide, and when ascorbic acid or cytochrome c and ascorbic acid were added as substrates, the respiration increased by 20 to 40 per cent in the presence of cyanide (8). This accelerating effect of cyanide on the respiration did not take place in other tissues of rats and various tissues of guinea pigs. Therefore, it can be said that this may be characteristic of rat small intestine. The purpose of the present work is to clarify the cause of this phenomenon.

Some Effects on the Cortex of the Adrenal Glands of Guinea Pigs Deprived of Vitamin C in Their Diet

various tissues of guinea pigs. Observations have been made on adults and on embryos of mothers given a vitamin C-free diet. The purpose of this experiment was to discover whether or not the absence of vitamin C in the diet produced a different histological picture of the cortex of the adrenal gland than was found in guinea pigs that had an ample amount of vitamin C in the diet to maintain health and growth.