Sex difference of the metabolic disposition of clioquinol in rats

The order of plasma levels of clioquinol and its conjugates in male rats after intraduodenal administration of 32.7 mumol/kg dose of clioquinol was clioquinol sulfate (C-Sul) greater than glucuronide (C-Glu) much greater than clioquinol, whereas that in female rats was C-Glu greater than C-Sul much greater than clioquinol. Total (urine + bile) recovery was almost the same among male and female rats. The percentage of excretion amounts of C-Sul (urine + bile) to the total excretion amounts for 24 h in male rats after intravenous administration of clioquinol was about twice that in female rats, while the percentage of excretion amounts of C-Glu to the total excretion amounts in male rats was smaller than that in female rats. In intravenous administration of 16.4 mumol/kg dose of C-Glu, C-Sul and clioquinol other than C-Glu were found in bile and urine of male and female rats. The percentage of excretion amounts of C-Sul and C-Glu (urine + bile) to the total excretion amounts was similar among male and female rats, respectively. In intravenous administration of 16.4 mumol/kg dose of C-Sul, C-Glu and clioquinol other than C-Sul were found in bile and urine of male and female rats, and the percentage of excretion amounts of C-Sul (urine + bile) to the total excretion amounts in male rats was 1.3 fold that in female rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Determination of ambenonium in biological samples by reversed-phase ion-pair liquid chromatography

A sensitive and selective analytical method for the determination of ambenonium ion in biological samples is described. The procedure involves ion-pair extraction of the drug, followed by reversed-phase ion-pair chromatographic analysis with ultraviolet detection at 217 nm. The detection limits at a signal-to-noise ratio of 5 were 100 pmol/ml using 0.2 ml of plasma and bile, 250 pmol/ml using 0.2 ml of urine and 200 pmol/g using 1 ml of tissue homogenates containing 0.1 g/ml of each tissue. This assay procedure was used to study the pharmacokinetics of ambenonium ion after intravenous administration in rats.

Determination of pemoline in plasma, urine and tissues by reversed-phase high-performance liquid chromatography

A simple and selective high-performance liquid chromatographic method with ultraviolet detection at 215 nm for the determination for pemoline in rat plasma, urine and tissues is described. Pemoline in the samples was extracted with methylene chloride at pH 10 and the organic phase was evaporated after adding 5-methyl-5-phenylhydantoin used as an internal standard. Pemoline and the internal standard were separated on a Kaseisorb LC C8-60-5 reversed-phase column. The limits of determination of pemoline in 0.1-0.2 ml of plasma, urine and tissue homogenates were 2, 100 and 20 ng, respectively. The method should be useful for studies of the pharmacokinetics and distribution of pemoline in small animals.

Changes in lipid peroxide concentrations in plasma and tissues by repeated administration of clioquinol to neonatal rats

The changes in lipid peroxide concentrations in plasma and tissues after subcutaneous administration of clioquinol to clioquinol-sensitive (S-rats) and -resistant neonatal rats (R-rats) were investigated. When a fixed dose of 150 mg/kg/d of clioquinol was given to R-rats for 14 d after birth, no significant difference in lipid peroxide concentrations in plasma, liver, kidney, brain and spinal cord at 5, 10 and 15 d was observed between clioquinol-treated and untreated rats. However, with increasing doses of clioquinol to R-rats every 5 d (150----300----600 mg/kg/d), the lipid peroxide concentrations at 15 d were higher in plasma, brain and spinal cord of clioquinol-treated rats than in those of untreated rats. These results suggested that repeated administrations of large doses of clioquinol to rats increased the lipid peroxides in nerve tissues. With S-rats at 5 d after birth, the lipid peroxide concentrations in liver were approximately twice those in R-rats regardless of the clioquinol administration.

Postnatal appearance of glycoconjugate with terminal N-acetylgalactosamine on the surface of selected neurons in mouse brain

Selected neurons in the cortex and other regions of the brain of adult mice stain with Vicia villosa agglutinin (VVA) conjugated to horseradish peroxidase (HRP). This staining demonstrates glycoconjugate with terminal N-acetylgalactosamine (GalNAc) in periodic foci on the neuronal surface. However, brains from mice at 1 week of age lacked neurons with surface reactivity for VVA-HRP but showed neurons with faint cytoplasmic staining. Two weeks postnatally, infrequent cortical neurons located mostly in layer IV disclosed light surface affinity for VVA-HRP. The deep cerebellar nucleus at 2 weeks revealed VVA-positive neurons that were less abundant than in adults but exceeded in number the stained neurons in the cortex of 2-week-old mice. By 3 weeks of age the prevalence of positive neurons in cortical layers II-VI and the deep cerebellar nucleus and the intensity of the surface staining approximated that observed in adult mice. No staining of fiber tracts was observed 1 week postnatally. However, certain tracts exemplified by decussating fibers in the basal pontine region showed strong VVA-HRP reactivity in brains of 2-week-old mice as in adults. Acquisition of VVA surface affinity 3 weeks postnatally coincided with the appearance of cytosolic immunostaining for glutamic acid decarboxylase in a population of GABAergic neurons in the cortex. These findings demonstrate the postnatal development of GalNAc-containing glycoconjugate associated with selected neurons and the variable acquisition of the glycoconjugate among these neurons possibly related to onset of function.

Absorption, distribution and metabolism of clioquinol in clioquinol-sensitive and -resistant neonatal rats

Three types of rats with respect to sensitivity to clioquinol have been identified, the highly sensitive (S-rat), the intermediately sensitive, and the resistant (R-rat). In a toxicity test that lasted for 20 d after birth, the difference in sensitivity to clioquinol between S- and R-rats was confirmed by repeated subcutaneous administration of a clioquinol suspension prepared with polysorbate 80 (clioquinol dose of 150 or 300 mg/kg/d). Plasma and tissue concentrations of clioquinol and the rate of metabolism of the drug in neonatal S- and R-rats were measured. Plasma concentration of clioquinol in 1-d-old S-rats after a single subcutaneous administration was higher than that in the same age R-rats and the area under the mean plasma concentration-time curve for the S-rats was approximately twice that for the R-rats. In addition, clioquinol concentrations in liver, kidney and brain of S-rats at 9 h after the administration were more than twice those of the R-rats. From the experiments on the formation of clioquinol glucuronide and sulfate with 9000 g supernatant fraction of liver, it was suggested that the difference in the plasma concentration after the administration may be responsible for the difference in the metabolizing rate of clioquinol.

Lectin cytochemical evaluation of somatosensory neurons and their peripheral and central processes in rat and man

Paraffin sections of the trigeminal nerve root of the rat, and human spinal nerve root and trigeminal ganglion were stained with a battery of lectin-horseradish peroxidase conjugates to localize and characterize glycoconjugate (GC) in situ. In the rat the myelin sheath of the peripheral segment contained GC with sialic acid most probably linked to the penultinate disaccharide galactose-(beta 1----4)-N-acetylglucosamine (Gal(beta 1----)-GlcNAc), and complex type N-glycosidic side chains. The myelin sheath in the central segment differed in containing little if any of the GC named above and in containing GC with terminal beta-Gal linked to N-acetylgalactosamine (GalNAc), terminal GalNAc and fucose. Schwann cells stained for GC with GlcNAc or mannose whereas oligodendroglia stained for GC with the terminal disaccharide Gal-(beta 1----3)-GalNAc and N-glycosidic side chains, especially in presumed Golgi zones, but also in processes continued as the outer myelin sheath. The human myelin sheath in the central segment differed from that of the rat in not staining with lectins specific for fucose and terminal GalNAc. Sialic acid and terminal beta-Gal were seen in the human central segment but these sugars appeared to bind to astroglial structures rather than to the myelin sheath as in the rat. Astrocytes in both rat and man were stained by two fucose-binding lectins. Several lectins revealed affinity for GC in the neurilemmal sheath, and staining of this structure was stronger in the human specimens. Neurons in the human trigeminal ganglion ranged from unstained to strongly positive for fucoconjugate in cytoplasmic bodies and plasmalemma. Positive ganglion cells gave rise to unmyelinated fibers which also stained for fucoconjugate. Remak fibers and their extensions into the substantia gelatinosa of the human spinal cord stained strongly for content of fucose. The stronger lectin affinity for N-glycosidic core sugars in the peripheral as compared with the central segment suggests that lectins localize Po protein in peripheral myelin. The reactivity for several sugars in the central segment can possibly be attributed to myelin-associated glycoprotein (MAG) of central myelin, but lectin staining for GalNAc shows in addition a biochemically unrecognized GC with O-glycosidic linked oligosaccharides in myelin. The lectin cytochemistry indicates that the 170 K Dalton glycoprotein with PNA affinity obtained from rat sciatic nerves occurs in nodes of Ranvier.

Aneurysms protruding from the dorsal wall of the internal carotid artery

Saccular aneurysms arising at locations other than at arterial divisions are extremely rare. The authors describe eight such aneurysms that protruded from the dorsal wall of the internal carotid artery (ICA) and were unrelated to any arterial junction. Radical surgery was performed in all eight cases. The aneurysms were saccular with a fragile wide or semifusiform neck. Intraoperative rupture occurred in three cases. From this experience, it is emphasized that these unusual protruding aneurysms of the dorsal ICA should be clipped with the clip blade parallel to the parent artery. In addition to clipping, complete wrapping with fascia or Bemsheet (cellulose fabric) is often advisable to prevent slippage of clips or postoperative rupture of residual aneurysm.

GABAergic neurons of rodent brain correspond partially with those staining for glycoconjugate with terminal N-acetylgalactosamine

Sections of fixed, paraffin-embedded brain from mice and rats were stained with agglutinin from Vicia villosa conjugated to horseradish peroxidase (VVA-HRP) to localize glycoconjugate containing terminal N-acetylgalactosamine (GalNAc). VVA-HRP binding sites were localized in periodic foci at the surface of a selective population of non-pyramidal interneurons in layers II through IV of the rodent cerebral cortex. These multipolar interneurons were shown to utilize gamma-aminobutyric acid (GABA) as a transmitter and thus to be GABAergic by their immunostaining for glutamic acid decarboxylase (GAD) throughout the cytoplasm in serial sections. Pyramidal and other non-pyramidal cortical neurons received GABAergic input as evidenced by punctate immunostaining for GAD on their soma and proximal dendritic arborizations, but these cells failed to show VVA affinity or cytosolic GAD reactivity. Most neurons in the thalamic reticular nucleus stained for the presence of glycoconjugate with terminal GalNAc on their surface and for GAD in the cytosol. In contrast, cerebellar Purkinje cells showed strong cytosolic reactivity with anti-GAD but lacked surface staining with VVA-HRP. These observations show that some but not other populations of GABAergic neurons possess binding capacity for VVA on their surface. The surface of neurons in the deep cerebellar nucleus stained heavily with VVA but failed to show clear cytosolic reactivity for GAD. Some neurons with surface glycoconjugate containing terminal GalNAc are therefore not GABAergic.

The immunocytochemical demonstration of copper-zinc superoxide dismutase in the brain

Copper-zinc superoxide dismutase (CuZn-SOD) has been localized in formalin-fixed, paraffin-embedded sections of both canine and rat brains. Staining with an immunoenzyme bridge sequence revealed CuZn-SOD in all regions of the brains examined. Specific sites of localization included cerebral cortical pyramidal cells, cerebellar Purkinje cells, neurons in 'subcortical nuclei', and oligodendrocytes throughout the brain. Similar sites of CuZn-SOD localization were identified in both species. These results are compared with reports by various investigators of SOD bioactivity in the brain.

Selective cytochemical demonstration of glycoconjugate-containing terminal N-acetylgalactosamine on some brain neurons

Paraffin embedded sections of rat, mouse, dog, and human brain were stained with a battery of lectin-horseradish perioxidase conjugates to localize and characterize glycoconjugates. In the rat and mouse cerebral cortex, a subpopulation of nonpyramidal neurons stained selectively with three lectins with specific affinity for terminal N-acetylgalactosamine (GalNAc). These and only these lectins stained the surface of the cell body, dendritic shafts, and proximal parts of the dendritic arborization. Most reactive, nonpyramidal neurons revealed a multipolar dendritic pattern, but some possibly belonged to the bitufted and bipolar types of neuron. The GalNAc-containing neurons appeared widely distributed in layers II-VI with relatively greater abundance in layers IV and V. In the cortex of rats and mice the stained neurons occurred in moderate numbers in the frontal, frontoparietal, striate, retrosplenial, and entorhinal regions, but were less numerous in the hippocampal gyrus, dentate gyrus, and olfactory area. Other neurons in the basal ganglia and brain stem stained weakly for GalNAc. Examination of the frontal cortex of human and canine brains showed a similar distribution of nonpyramidal neurons with affinity for GalNAc-binding lectins. At high magnification, the surface staining of neurons in the cerebral cortex, deep cerebellar nucleus, and other sites appeared periodic rather than continuous. The periodic character of the neuronal surface staining suggested a location for the reactive glycoconjugate in or between the synapses. The GalNAc-containing glycoconjugate occurred in a selected cell type, failed to bind the other lectin conjugates, and differed from biochemically detected glycoconjugates. It is, therefore, considered a newly recognized entity of possible physiologic significance for a population of cortical neurons.

Lectin cytochemistry of cell types in human and canine pituitary

Labeled lectins specific for different sugars were employed to identify different cell types in pituitaries from six human autopsies and seven dogs. To determine the lectins bound by each cell type, fixed-paraffin embedded sections serial to those stained with lectins were immunostained for specific hormones and the serial pairs were examined in a comparison microscope. In human pituitaries corticotrophs stained selectively with lectins having affinity for alpha-L-fucose and the core region of complex type N-glycosyl-proteins. Some corticotrophs also stained for the presence of terminal beta-galactose. Thyrotrophs stained selectively with a periodate oxidation-borohydride reduction-concanavalin A sequence. Some mammotrophs evidenced content of glycoconjugate with terminal beta-galactose. Dendritic cells stained selectively for abundant glycogen with the periodate-reduction-concanavalin A sequence and a lectin from Griffonia simplicifolia. Adenohypophyseal cells of dog pituitary differed in showing absence of terminal beta-galactose in corticotrophs, presence of terminal beta-galactose in thyrotrophs, presence of glycoconjugate with N-glycosidically bound oligosaccharide in thyrotrophs and gonadotrophs and presence of terminal beta-galactose with a different lectin affinity in mammotrophs. The main contributions of lectin histochemistry applied to the pituitary include providing an additional histologic method for identification of some cell types, and localizing glycosylated prohormone or other biochemically unrecognized non-hormone glycoconjugates whose function in pituitary cells remains to be explained.

Biological properties of griseolic acid, a cyclic AMP phosphodiesterase inhibitor with an adenine group

Griseolic acid inhibited cAMP phosphodiesterase (PDE) at low concentrations, the I50 being of the order of 0.01-0.1 microM. Administration of griseolic acid to rats increased the cAMP level in liver and plasma several-fold. It increased glycogen degradation in mouse liver and stimulated lipolysis in isolated rat fat cells. Griseolic acid did not block the adenosine-elicited accumulation of cAMP in guinea pig brain slices. It had no effect on cAMP-dependent protein kinase from rat liver nor on the adenyl cyclase from rat brain.

Glycoconjugate localization with lectin and PA-TCH-SP cytochemistry in rat hypophysis

Glycoconjugates were localized by light microscopy with lectin-peroxidase conjugates and by electron microscopy with the periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) sequence in immunocytochemically or morphologically identified cell types in rat pituitary. Lectin histochemistry demonstrated sialic acid and glycoconjugates with N-glycosidically linked oligosaccharides in gonadotrophs, thyrotrophs, and corticotrophs. Galactose penultimate to sialic acid was observed mostly in gonadotrophs. The terminal galactose-N-acetylgalactosamine disaccharide was detected in a few gonadotrophs and in a moderate number of mammotrophs. Fucose was localized in only corticotrophs with two fucose-binding lectins and in thyrotrophs with another. Several different monosaccharides were seen in glycoconjugates in melanotrophs and in Herring bodies. Melanotrophs displayed heterogeneous staining with fucose-binding lectins. A small number of nonsecretory cells were also visualized in the pars distalis by virtue of their glycogen content. PA-TCH-SP staining revealed complex carbohydrates in secretory granules and some Golgi cisternae in all types of hormone-producing cells in the pars distalis except for the somatotrophs. Melanotrophs of pars intermedia exhibited stained secretory granules and irregular dense bodies containing a stained meshwork. Corticotrophs of the pars distalis lacked the latter bodies, although they form the same glycoprotein precursor hormone as melanotrophs. Lectin conjugates and the PA-TCH-SP sequence stained some groups of secretion granules in Herring bodies, possibly representing vasopressin-containing granules as well as other cell types in the pars nervosa.