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Assandri A, Perazzi A, Bellasio E, Ciabatti R, Tarzia G, Ferrari P, Ripamonti A, Tuan G, Zerilli LF. Metabolic pathways of the anti-hypertensive agent, N-(2,5-dimethyl-1H-pyrrol-1-yl)-6-(4-morpholinyl)-3-pyridazinamine hydrochloride. II: Studies in the dog. Xenobiotica 1985; 15:1089-102. [PMID: 4090528 DOI: 10.3109/00498258509049103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The metabolic fate of a new anti-hypertensive, 1-pyrrolyl-pyridazinamine, was studied in male Beagle dogs given both p.o. and i.v. doses of the 14C-labelled drug (1 mg/kg). The compound given as a single i.v. injection disappeared from the central compartment with a half-life of about 0.9 h. Plasma levels of total 14C were represented mostly by metabolites. Eight urinary metabolites designated as metabolites I, II and XI-XVI were purified and their structures assigned by means of u.v., i.r., n.m.r. and mass spectrometry. Quantitatively the primary metabolic attack involved the morpholine moiety of the molecule which undergoes oxidative opening. A minor pathway afforded the cleavage of the pyrrole followed by chemical rearrangements to form six-membered sidnone-like products or a triazole derivative. The major (XIII) and three minor metabolites were studied for their antihypertensive activity in rats and were shown to be inactive.
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Assandri A, Perazzi A, Baldoli E, Ferrari P, Ripamonti A, Bellasio E, Tuan G, Zerilli F, Tarzia G. Metabolic pathways of the anti-hypertensive agent, N-(2,5-dimethyl-1H-pyrrol-1-yl)-6-(4-morpholinyl)-3-pyridazinamine+ ++ hydrochloride. I. Studies in the rat. Xenobiotica 1985; 15:1069-87. [PMID: 4090527 DOI: 10.3109/00498258509049102] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The metabolic fate of a new anti-hypertensive, 1-pyrrolyl pyridazinamine, was studied in male Wistar rats after both p.o. and i.v. administration (1 mg/kg). The compound undergoes rapid metabolism, disappearing from the central compartment with a half-life of about 0.5 h. Plasma concn. of the parent drug and its major metabolite I following i.v. and p.o. administration suggest a route-dependent first-pass metabolism. Ten metabolites were isolated from the urine and identified by u.v., i.r., mass and 1H-n.m.r. spectroscopy. The structure of some was confirmed by 13C-n.m.r. and chemical synthesis. All biotransformations are restricted to the pyrrole ring which undergoes oxidative cleavage followed by a series of chemical rearrangements. A minor pathway leads to the formation of methyl sulphinyl and methyl sulphonyl pyrroles. It is suggested that, as with natural indoles, the pyrrole might be oxidized by a 2,3-dioxygenase. The three major metabolites, I, II and IX, along with two minor ones, VI and VII, were inactive when tested i.v. for antihypertensive activity.
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Ascenzi A, Bigi A, Koch MH, Ripamonti A, Roveri N. A low-angle X-ray diffraction analysis of osteonic inorganic phase using synchrotron radiation. Calcif Tissue Int 1985; 37:659-64. [PMID: 3937592 DOI: 10.1007/bf02554926] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Using synchrotron radiation the low-angle X-ray diffraction method has been applied to single osteon samples to yield new data on the texture of the inorganic bone fraction. Two sample types--cylindrically shaped osteonic samples and osteonic radial hemisections--were prepared from longitudinal and alternate osteons at both the initial and final stages of calcification. The results indicate that the diffraction pattern is due to the inorganic phase, which reveals the same axial periodicity as native collagen fibrils and fits into the main band. No change is appreciable as osteons pass from the initial to the final stage of calcification. This means that when crystallites covering much more than a collagen axial period are observed under the electron microscope, they do not appreciably affect the calcified banding of collagen fibrils. The osteonic axis corresponds to the main direction of collagen orientation both in longitudinal and alternate osteons. The degree of orientation, however, is lower in alternate osteons than in longitudinal ones, where only few thin, incomplete transversal lamellae are found.
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Assandri A, Bernareggi A, Ripamonti A, Perazzi A, Toja E. Pharmacokinetics and metabolism of tomoxiprole, a new analgesic antiinflammatory agent, in the rat. Eur J Drug Metab Pharmacokinet 1985; 10:161-70. [PMID: 4043144 DOI: 10.1007/bf03189711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The pharmacokinetics and the metabolic profile of tomoxiprole, a new analgesic antiinflammatory agent belonging to the class of 3-alkyl-2-aryl-3H-naphth (1,2-d)imidazoles, were studied in the rat. After oral administration (5 mg/kg) to male rats, tomoxiprole was rapidly absorbed, mostly by the gut, and reached maximum plasma levels of about 0.5 microgram/ml in 0.25-2 h. A metabolic first pass reduced the extent of oral bioavailability of the parent compound to about half, while absorption (total 14C data) was estimated to be complete. After intravenous injection (2.5 mg/kg), the plasma kinetics of tomoxiprole in male rats showed a bi-exponential profile, and the terminal elimination half-life was 4.2 h. The apparent volume of distribution was high, suggesting a wide distribution of the drug. Increasing the oral dose by ten times (50 mg/kg), resulted in linear kinetics with a proportional increase of the C max and AUC values and the same value of terminal elimination half-life. In females given a 5 mg/kg dose, the plasma levels of 14C, tomoxiprole and AUC values were somewhat higher than in males. The plasma levels of total 14C after iv or po treatments were higher and more sustained than those of tomoxiprole. The kinetic profile after iv administration was described by a three exponential terms equation and the terminal elimination half-life was 38.7 h. Upon iv administration, total 14C was rapidly distributed in highly vascularized tissues while in others, like the bone, fat, gonads, pancreas and skin the equilibrium with the central compartment was attained later. Target organs were the adrenals, liver, lungs, pancreas, thyroid, stomach and above all the fat tissue. Elimination from tissues was almost complete 48 h after the treatment. 14C was eliminated mainly in the feces (80% of dose) as metabolites. In the bile, five polar metabolites were detected; one of them, desmethyl tomoxiprole glucuronide, accounting alone for more than 80% of the total biliary radioactivity; was purified and its structure assigned.
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Bigi A, Koch M, Purslow P, Ripamonti A, Roveri N, Sayers Z. Structural organization of collagen in Metridium senile. Int J Biol Macromol 1985. [DOI: 10.1016/0141-8130(85)90060-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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31
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Assandri A, Perazzi A, Ferrari P, Martinelli E, Ripamonti A, Tarzia G, Tuan G. Metabolic fate of zetidoline, a new neuroleptic agent, in man. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 1985; 328:341-7. [PMID: 2858825 DOI: 10.1007/bf00515564] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Healthy volunteers administered orally a single dose (20 mg) of [2-14C]zetidoline, a new dopamine antagonist, exhibited rapid absorption of radioactivity with peak plasma levels of 250-300 ng/ml achieved in 1 h. The compound underwent intensive metabolic first-pass so that plasma radioactivity was represented mostly by two products, metabolite B endowed with neuroleptic activity, and metabolite D inactive, while unchanged zetidoline was not detected. Disappearance of radioactivity from plasma was rapid with a half-life of 1.78 +/- 0.20 h. The simultaneous assay of plasma prolactin showed increased levels of the hormone (+ 464% at the peak time) up to the 6th h after dosing, with plasma concentration profile which mimic those of metabolite B. The radioactive test-dose was eliminated mainly via the kidneys with an average urinary recovery of 84.7 +/- 1.7% in 4 days (73.4 +/- 1.1% within 8 h). The main urinary metabolite (metabolite G) and two minor ones (metabolites B and D) were purified and their structures assigned by IR, MS and NMR spectroscopy, they are: 1-(3-chloro-4-hydroxyphenyl)-3 [2-(3,3-dimethyl-1-azetidinyl)ethyl]imidazolidin-2-one, metabolite B; 1-[2-(3,3-dimethyl-1-azetidinyl)ethyl]-imidazolidin-2-one, metabolite D and the 4'-O-sulphate ester of metabolite B, metabolite G. The metabolic fate of zetidoline in man follows the same phase I reactions demonstrated in rats and dogs, while the phase II reaction is sulphoconjugation instead of the glucuronidation observed in animals.
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Ripamonti A, Ferrari P, Gallo GG. Structure identification of rifampicin N-oxide. IL FARMACO; EDIZIONE SCIENTIFICA 1984; 39:806-9. [PMID: 6500047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
1H- and 13C-N.M.R. spectra, in addition to previous physicochemical data, confirm the structure of rifampicin N-oxide and indicate that the oxygen atom is bonded to the piperazine N--CH3 group.
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Assandri A, Perazzi A, Fontanella L, Ferrari P, Ripamonti A, Tarzia G, Tuan G, Martinelli E. Metabolism of the neuroleptic agent zetidoline in the rat and the dog. Drug Metab Dispos 1984; 12:635-40. [PMID: 6149917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The metabolism of zetidoline, a new neuroleptic, in the rat and the dog has been studied. From the urine of rats and dogs given 5 mg/kg of [2-14C] zetidoline orally, unchanged drug and five metabolites were isolated and the structures of four of them assigned by physicochemical analysis. They are: metabolite B, 4'-hydroxy-3'-chlorophenyl zetidoline; metabolite D, zetidoline without the aryl group; metabolite E, the 6'-hydroxy-4'-beta-D-glucuronide of metabolite B, and metabolite F, the 4'-beta-D-glucuronide of metabolite B. The plasma levels of zetidoline and its metabolites after iv administration show that the drug is rapidly excreted and/or metabolized in both animal species. The plasma radioactivity in the dog consists mainly of the pharmacologically active (neuroleptic) metabolite B, whereas in the rat it consists of the more polar metabolites. After oral administration, elimination in both species occurs mostly via the kidneys. In the dog, within a 24-hr period, 6.2 +/- 0.4% of the dose is accounted for as unchanged zetidoline, 7.6 +/- 0.5% as metabolite B, 10.1 +/- 0.7% as the unidentified metabolite C, and 21.4 +/- 1.1% as metabolite F. In the rat, over the same period, zetidoline is present in traces, metabolite B accounts for 6.9 +/- 0.3% of the dose, metabolite D for 6.6 +/- 0.9%, metabolite E for 15.2 +/- 1.4%, and metabolite F for 31.7 +/- 2.2%.
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34
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Ascenzi A, Bigi A, Koch MHJ, Ripamonti A, Roveri N. Small-angle scattering on single osteons using synchrotron radiation. Acta Crystallogr A 1984. [DOI: 10.1107/s0108767384088267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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35
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Assandri A, Perazzi A, Ferrari P, Omodei-Salé A, Ripamonti A, Tuan G, Galliani G, Zerilli LF. Metabolic pathways of the contragestational agent, 3-(2-ethylphenyl)-5-(3-methoxyphenyl)-1H-1,2,4-triazole (DL 111-IT), in the rat. Xenobiotica 1984; 14:429-43. [PMID: 6475103 DOI: 10.3109/00498258409151431] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The metabolic pathways of the non-hormonal anti-fertility agent 3-(2-ethylphenyl)-5-(3-methoxyphenyl)-1H-1,2,4-triazole (DL 111-IT) were studied in rats given the 14C-labelled compound intramuscularly. The diaryltriazole, once absorbed, was metabolized rapidly by three phase I reactions: (a) hydroxylation at the C-4 of the methoxyphenyl ring, (b) hydroxylation at the alpha-C of the ethyl chain, and (c) demethylation of the methoxyl function. Seven free metabolites and three conjugates have been isolated and characterized by u.v., i.r., n.m.r. and mass spectroscopy. The products of the first step of metabolism of the diaryltriazole were tested for their pregnancy-terminating activity in the rat. They were only 5-9% as effective as the parent compound, indicating that the unchanged drug is the active molecule.
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Assandri A, Barone D, Ferrari P, Perazzi A, Ripamonti A, Tuan G, Zerilli LF. Metabolic fate of premazepam, a new anti-anxiety drug, in the rat and the dog. Drug Metab Dispos 1984; 12:257-63. [PMID: 6144494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
A study of the disposition and metabolism of premazepam, 3,7-dihydro-5-phenyl-6,7-dimethyl-pyrrole[3,4-e][1,4]diazepin-2-(1 H) -one, a new anti-anxiety agent, was carried out in rats and dogs given the 14C-labeled compound iv and po. In both species, after oral administration, both total radioactivity and the unchanged drug are rapidly absorbed and peak plasma levels are reached within 0.5-1 hr in rats and 2 hr in dogs. Unchanged premazepam is cleared faster in rats than in dogs, with half-lives about 1.7 and 2.7 hr, respectively. Following oral dosage, two-thirds of the dose is eliminated in urine. From the urine of the two species, eight metabolites and unchanged premazepam were identified. N-7-Desmethyl premazepam (l) is the major metabolite in rat urine (18% of the dose) but is not present in dog urine, while 6-hydroxymethyl premazepam is the most abundant metabolite in dog urine (25% of the dose) but is absent in rat urine. Metabolites III and IV from rat and dog urine are stable derivatives of the intermediate formed by the cleavage of the imine bond of the diazepine ring. A successive hydrolysis of the amidic bond of the same intermediate originates metabolites V-VIII, which are quantitatively minor ones.
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37
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Purslow P, Bigi A, Ripamonti A, Roveri N. Collagen fibre reorientation around a crack in biaxially stretched aortic media. Int J Biol Macromol 1984. [DOI: 10.1016/0141-8130(84)90042-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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38
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Baravelli S, Bigi A, Ripamonti A, Roveri N, Foresti E. Thermal behavior of bone and synthetic hydroxyapatites submitted to magnesium interaction in aqueous medium. J Inorg Biochem 1984; 20:1-12. [PMID: 6693869 DOI: 10.1016/0162-0134(84)80001-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The thermal behavior of the products obtained from magnesium interaction with powdered femoral bone and carbonate containing synthetic hydroxyapatite under conditions of pH fluctuation in aqueous medium has been investigated. The products, heat treated at different temperatures from 100 to 1300 degrees C, have been characterized by infrared spectroscopy and X-ray diffraction technique. The results show that the interaction with magnesium ion destabilizes the apatitic structure and favours its thermal conversion into beta-tricalcium phosphate (beta-TCP). The replacement of magnesium with calcium in the beta-TCP crystal lattice hinders its subsequent thermal conversion into the alpha form. The influence of magnesium on the thermal stability is much more evident for carbonate-containing synthetic hydroxyapatite than for bone apatite.
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39
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Ascenzi A, Bigi A, Ripamonti A, Roveri N. X-ray diffraction analysis of transversal osteonic lamellae. Calcif Tissue Int 1983; 35:279-83. [PMID: 6871758 DOI: 10.1007/bf02405046] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
When isolated osteon samples are submitted to wide-angle X-ray diffraction, it is not possible to detect any preferential orientation of the hydroxyapatite crystallites of the lamellae with transversally arranged fiber bundles. So a complete and exhaustive X-ray diffraction analysis of an osteon needs adequately prepared osteonic subunits. For the present investigation, 2 types of samples were prepared from longitudinal and alternate osteons: osteonic radial sections and isolated straightened transversal lamellae. An X-ray diffraction microcamera has been used with a rotating anode X-ray generator. In accordance with the data provided by the polarizing microscope, the orientation of crystallites runs parallel to the osteon axis in longitudinally structured osteons, whereas in alternate osteons the orientation changes by about 90 degrees in successive lamellae. Neither crystallites associated with the collagen fibrils that run alongside the osteocyte canaliculi nor those associated with the fibrils that run transversally in longitudinally structured osteons are revealed by X-ray diffraction, because there are so few of them.
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Assandri A, Ferrari P, Perazzi A, Ripamonti A, Tuan G, Zerilli L. Disposition and metabolism of a new steroidal anti-inflammatory agent, deflazacort, in cynomolgus monkeys. Xenobiotica 1983; 13:185-96. [PMID: 6613164 DOI: 10.3109/00498258309052253] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The kinetics and metabolic fate of 2'-14C-deflazacort, a new steroidal antiinflammatory agent, were studied in the cynomolgus monkey after both p.o. and i.v. administration (5 mg/kg). There is no unchanged deflazacort in the plasma or urine after either p.o. or i.v. treatment. As judged from the plasma AUC and urinary elimination values, the oral availability of both total 14C and metabolites seems to be lowered because of a route-dependent first-pass. Both radioactivity and the main metabolite (21-desacetyl deflazacort) are eliminated from the plasma with half-lives of 2--3-5 h. The i.v. administered 14C is eliminated mainly in the urine (52--55% of dose), but biliary excretion is also quantitatively important. Six metabolites were isolated from urine and identified by physico-chemical analysis. Among them desacetylated deflazacort and its 6 beta-hydroxy derivative were shown to be the major radioactive products in plasma and urine, respectively. Minor metabolites were: 21-desacetyl, 6 alpha-hydroxy deflazacort; 21-desacetyl, 5 alpha, 1-eno, deflazacort; 21-desacetyl, 20 beta hydroxy deflazacort; and 21-desacetyl, 11-keto deflazacort.
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41
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Assandri A, Omodei-Salè A, Ferrari P, Tuan G, Perazzi A, Ripamonti A, Martinelli E. Species differences in the disposition and metabolism of 1-methyl-3-(3-pyridyl)-5-(2-hydroxy-methylphenyl)-1H-1,2,4-triazole, a potential sedative-hypnotic compound. Xenobiotica 1982; 12:19-30. [PMID: 7090416 DOI: 10.3109/00498258209052451] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
1. Disposition and metabolism of 1-methyl-3-(3-pyridyl)-5-(2-hydroxy-methylphenyl)-1H-1,2,4-triazole, a new sedative-hypnotic, were studied in rats (i.v. and p.o.), cats (i.v.) and human volunteers (p.o.) with 14C-labelled drug. 2. In rat and man, the compound is well absorbed, extensively metabolized, and excreted mostly through the kidney; it has short plasma half-lives, 0.6 h in rat, 0.9 h in man, and 1.9 h in cat. 3. In rat and man metabolism involves N-oxidation of the pyridine ring (Metabolite I), and in cat oxidation of the hydroxymethyl group (Metabolite II). Four other conjugated metabolites (III-VI) isolated from rat urine and bile, and from urine of cats and man, have been characterized. 4. The unchanged compound, but not its metabolites, crosses the blood-brain barrier in rat and cat. 5. The species differences in the disposition and metabolism of the compound are consistent with previous pharmacological data indicating a greater and more prolonged effect in cat.
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Bigi A, Ripamonti A, Roveri N. X-ray investigation of the orientation of collagen fibres in aortic media layer under distending pressure. Int J Biol Macromol 1981. [DOI: 10.1016/0141-8130(81)90044-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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43
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Cricchio R, Antonini P, Ferrari P, Ripamonti A, Tuan G, Martinelli E. Rifamycin Z, a novel ansamycin from a mutant of Nocardia mediterranea. J Antibiot (Tokyo) 1981; 34:1257-60. [PMID: 7309622 DOI: 10.7164/antibiotics.34.1257] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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44
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Ripamonti A, Ettienne EM, Frankel RB. Effect of homogeneous magnetic fields on responses to toxic stimulation in Spirostomum ambiguum. Bioelectromagnetics 1981; 2:187-98. [PMID: 7295365 DOI: 10.1002/bem.2250020209] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Effects of DC magnetic fields, up to 125,000 G, on the survival of the ciliated protozoan Spirostomum ambiguum exposed to the toxic substance 2,2'-dipyridyldisulfide are reported. The magentic field diminishes the ability of the organism to survive the drug, and lengthens the extension phase of the contraction cycle. It is proposed that the magnetic field alters the regulation of intracellular (Ca2+) transients.
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Ripamonti A, Roveri N, Braga D, Hulmes DJ, Miller A, Timmins PA. Effects of pH and ionic strength on the structure of collagen fibrils. Biopolymers 1980; 19:965-75. [PMID: 7378548 DOI: 10.1002/bip.1980.360190503] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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46
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Ascenzi A, Bonucci E, Generali P, Ripamonti A, Roveri N. Orientation of apatite in single osteon samples as studied by pole figures. Calcif Tissue Int 1979; 29:101-5. [PMID: 116749 DOI: 10.1007/bf02408064] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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47
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Martinelli E, Ferrari P, Ripamonti A, Tuan G, Perazzi A, Assandri A. Metabolism of deflazacort in the rat, dog and man. DRUG METABOLISM AND DISPOSITION: THE BIOLOGICAL FATE OF CHEMICALS 1979; 7:335-9. [PMID: 40777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The metabolism of [2'-14C]deflazacort, (11 beta, 16 beta)-21-(acetoxyl)-11-hydroxy-2'-methyl-5'H-pregna-1, 4-dieno[17,16-d]oxazole-3,20-dione, orally given to rats, dogs, and humans, has been studied. From the urine of the three species and from rat bile and liver preparations, five main metabolites I-V have been isolated and their structures investigated by physicochemical analysis: 1,(5 beta,11 beta,16 beta)-11,21-dihydroxy-2'-methyl-5'H-pregn-1-eno[17,16-d]oxazole-3,20-dione; II, (11 beta,16 beta)-11,21-dihydroxy-2'-methyl-5'H-pregna-1,4-dieno[17,16-d]oxazole-3,20-dione; III, (6 beta,11 beta,16 beta)-6,11,21-trihydroxy-2'-methyl-5'H-pregna-1,4-dieno[17,16-d]oxazole-3,20-dione; IV, (3 epsilon,11 beta,16 beta)-3,11,21-trihydroxy-2'-methyl-5'H-pregn-5-eno[17,16-d]oxazol-20-one. Metabolites II and III are quantitatively the most important in the urine of the rat, dog, and man; metabolite V, whose structure is uncertain, has been found in human and rat urine. In the formation of metabolites I-V the fused 2-methyloxazoline ring is unmetabolized, whereas the steroid moiety follows the general metabolic pathways reported for other related corticosteroids.
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48
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Roveri N, Ripamonti A, Bigi A, Volpin D, Giro MG. X-ray diffraction study of bovine lens capsule collagen. BIOCHIMICA ET BIOPHYSICA ACTA 1979; 576:404-8. [PMID: 427197 DOI: 10.1016/0005-2795(79)90415-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The wide angle X-ray diffraction pattern of air-dried lens capsule collagen under tension is the same as the tendon collagen diffraction pattern with regard to the main reflections, and indicates that lens capsule collagen has the characteristic three-stranded helical structure with an axial repeat of 0.29 nm as tendon collagen. The low angle X-ray diffraction pattern shows several weak diffraction maxima corresponding to the meridional reflections of capsule collagen which show orders of 63.0 nm periodicity. This is an evidence of quarter staggered molecular assembly typical of tendon collagen even if less ordered. The results are consistent with the existence in lens capsule collagen of clearly defined molecular units, which can be oriented by stress and are packed in a poor-ordered fibrillar assembly.
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Ascenzi A, Bonucci E, Ripamonti A, Roveri N. X-ray diffraction and electron microscope study of osteons during calcification. CALCIFIED TISSUE RESEARCH 1978; 25:133-43. [PMID: 667661 DOI: 10.1007/bf02010762] [Citation(s) in RCA: 41] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
To obtain information on the changes in the inorganic bone fraction during calcification, low- and wide-angle X-ray diffraction techniques and electron microscopy have been applied to single osteon samples. The samples were cylindrically shaped and their axes corresponded to the axes of the Haversian canals. The selection was made according to the degree of calcification and the orientation of collagen bundles and inorganic particles. Osteons at both the initial and final stages of calcification were chosen. Arrangements of fiber bundles and inorganic particles in successive lamellae characteristic of three types of osteon were selected, that is, longitudinally structured osteons, transversely structured osteons, and alternately structured osteons. The results indicate that in osteonic lamellar bone there are two types of inorganic particles: (1) granules arranged in linear or needle-shapred entities with maximum width 40-45 A, which are regularly distributed at the level of the main band of the collagen fibrils where their maximum length reaches the length of the main band itself; that is , about 400 A; and (2) very long crystallites, with a diameter of 40-45 A, which grow with their crystallographic c-axis parallel to the collagen fibrils and cover much more than a major collagen period.
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Roveri N, Ripamonti A, Garbisa S, Volpin D. Structural organization of collagen fibrils in media aortic wall. Connect Tissue Res 1978; 5:249-53. [PMID: 150965 DOI: 10.3109/03008207809152279] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Small-angle X-ray diffraction patterns of bovine, human and porcine media aortic wall show meridional reflections corresponding to a periodicity which suggest a molecular packing typical of tendon collagen. However the meridional intensity distribution of stretched air dried aortic samples appears different from that of air-dried tendon, probably because of the presence of a large amount of type III collagen with the environment, which are specific for aortic tissue. The stretched wet aortic samples show a marked decrease in intensity, revealing an extensive disorder in the axially-projected structure of the fibrils. When a loading system simulating the effect of blood pressure is applied to a ring of aorta, no evidence of orientation of collagen is seen by X-ray diffraction, as would be expected if collagen fibrils had an isotropic distribution inside the aorta media. Scanning electroni microscopy supports the existence of a network of collagen fibrils surrounding elastic lamellae.
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