Progesterone C21 hydroxylation and steroid carboxylic acid biosynthesis in the rabbit. In vitro studies with endocrine, metabolic, and potential target tissues

1983 ◽  
Vol 61 (7) ◽  
pp. 722-730 ◽  
Author(s):  
I. R. Senciall ◽  
G. Bullock ◽  
S. Rahal
Keyword(s):  
Cytochrome C ◽  
Liver Microsomes ◽  
Acid Synthesis ◽  
Rabbit Kidney ◽  
Liver And Kidney ◽  
Kidney Microsomes ◽  
Intraspecies Variability ◽  
First Time ◽  
Cytochrome P 450

Progesterone C21-hydroxylase activity has been demonstrated with rabbit kidney microsomes for the first time and the formation of 21-hydroxy-4-pregnen-3,20-dione (DOC) by rabbit liver and kidney microsomes has been quantitated. Considerable intraspecies variability in enzyme activity occurred with both tissues. The liver enzyme (Vmax = 1.28–38.0 nmol/mg protein per 30 min of incubation) was significantly more active than the kidney enzyme (Vmax = 0.028–0.28 nmol/mg protein per 30 min of incubation). Apparent KM values were 1.39 and 0.8 μM, respectively. Cytochrome c (10−5 M), potassium ferricyanide (10−3 M), and 2-methyl-1,2-di-3-pyridyl-1-propanone (metyrapone; 10−3 M) were strongly inhibitory with both tissues, whereas the liver microsomal system was less sensitive than the kidney to CO–air (90:10 v/v) inhibition. Metabolism of [14C]DOC to 4-pregnen-3,20-dione-21-oic (pregnenoic) and 4-androsten-3-one-17β-carboxylic (etienic) acids by liver microsomes and adrenal and ovary homogenates was differentially affected by several factors. CO–air (90:10 v/v), cytochrome c (10−5 M), and metyrapone (10−3 M) inhibited pregnenoic acid synthesis to a greater extent than etienic acid. Sodium cyanide had a stimulatory effect on the synthesis of pregnenoic acid by the liver but less consistent effects with other tissues. These results suggest that one or more cytochrome P-450 systems may be involved in the oxidation of progesterone through to pregnenoic acid by rabbit tissues.

scholarly journals Photosynthetic apparatus efficiency, phenolic acid profiling and pattern of chosen phytohormones in pseudometallophyte Alyssum montanum

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ewa Muszyńska ◽  
Krzysztof M. Tokarz ◽  
Michał Dziurka ◽  
Mateusz Labudda ◽  
Kinga Dziurka ◽  
...  
Keyword(s):  
Photosynthetic Apparatus ◽  
Acid Synthesis ◽  
Metabolic Adaptation ◽  
Transport Pathways ◽  
Adverse Conditions ◽  
Benzoic Acid Derivatives ◽  
Tyrosine Ammonia Lyase ◽  
Treated Culture ◽  
First Time

AbstractThe present study investigated the response of non-metallicolous (NM) and metallicolous (M) Alyssum montanum shoots cultured in vitro on a medium supplemented simultaneously with heavy metals (HMs) to identify mechanisms involved in alleviating metal-induced damage. Plant status in respect to photosynthetic apparatus efficiency was determined and linked with changes in biochemical composition of shoots, namely phenolic acids’ and stress-related phytohormones. Results showed the considerable inter-ecotype differences in (1) the photosynthetic pigments’ amount, (2) the functioning of membrane electron transporters as well as (3) the linear and alternative electron transport pathways, whose lower values were reported in NM than in M HM-treated culture. Photosynthetic apparatus protection in M specimens was assured by the activation of cinnamic acid synthesis (by phenylalanine ammonia lyase) and its further transformations to benzoic acid derivatives with high ability to counteract oxidative stress, that was accompanied by the overexpression of jasmonic acid stimulating antioxidant machinery. In turn, detrimental HM effects on NM shoots could result from the diminution of most phenolics’ accumulation, and only the content of coumarate (produced by bifunctional phenylalanine/tyrosine ammonia lyase) and rosmarinic acid increased. All these together with an enhanced concentration of abscisic acid might suggest that NM strategy to cope with HMs is based mostly on a restriction of metal movement with transpiration flow and their limited distribution in leaves. Summarizing, our findings for the first time point out the physiological and metabolic adaptation of pseudometallophyte A. montanum to adverse conditions.

scholarly journals Precocious development of glucuronidating and hydroxylating enzymes in chick embryos treated with pituitary grafts

1975 ◽  
Vol 152 (2) ◽  
pp. 325-331 ◽  
Author(s):  
Graham J. Wishart ◽  
Geoffrey J. Dutton
Keyword(s):  
Chorioallantoic Membrane ◽  
Pars Distalis ◽  
Liver And Kidney ◽  
Embryo Liver ◽  
First Time ◽  
Cytochrome P 450 ◽  
Isolated Liver ◽  
Precocious Development ◽  
Nadph Cytochrome C Reductase

1. Initiation of precocious development of UDP-glucuronyltransferase by an endogenous factor is reported for the first time. 2. This development occurs in chick embryo liver and kidney after grafting of the cephalic lobe of chicken pars-distalis pituitary tissue on to the chorioallantoic membrane, and in liver results in a rise in the enzyme activity from virtually zero to ‘adult’ values. Aniline hydroxylase also precociously develops in the liver of grafted embryos, its activity rising from one-third to the full adult value. Specific activities of glucose 6-phosphatase, cytochrome P-450 and NADPH–cytochrome c reductase did not significantly change. 3. The response of the transferase does not require the presence of host pituitary gland nor, apart from 1 day's necessary initiation, the presence of the graft itself. 4. The host becomes competent to respond on the 14th day of incubation; response continues for at least 3 days after removal of the graft, and for 2 days in the isolated liver. Grafting of embryonic pars distalis younger than 17 days does not evoke a response in the host liver. 5. Secretion of the pituitary factor increases suddenly some 24–48h before the naturally developing surge in liver UDP-glucuronyltransferase activity and may be responsible for initiating this rise in vivo. 6. The factor is probably not a growth or luteinizing hormone; its nature and the likelihood of a secondary hormone acting directly on the liver are discussed.

scholarly journals Contribution of cytochrome P-450 4A1 and 4A2 to vascular 20-hydroxyeicosatetraenoic acid synthesis in rat kidneys

1999 ◽  
Vol 276 (2) ◽  
pp. F246-F253 ◽  
Author(s):  
Mong-Heng Wang ◽  
Hui Guan ◽  
Xuandai Nguyen ◽  
Barbara A. Zand ◽  
Alberto Nasjletti ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Rat Kidney ◽  
Acid Synthesis ◽  
Biologically Active ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Antisense Odns ◽  
Cytochrome P 450

20-Hydroxyeicosatetraenoic acids (20-HETE), a biologically active cytochrome P-450 (CYP) metabolite of arachidonic acid in the rat kidney, can be catalyzed by CYP4A isoforms including CYP4A1, CYP4A2, and CYP4A3. To determine the contribution of CYP4A isoforms to renal 20-HETE synthesis, specific antisense oligonucleotides (ODNs) were developed, and their specificity was examined in vitro in Sf9 cells expressing CYP4A isoforms and in vivo in Sprague-Dawley rats. Administration of CYP4A2 antisense ODNs (167 nmol ⋅ kg body wt−1 ⋅ day−1iv for 5 days) decreased vascular 20-HETE synthesis by 48% with no effect on tubular synthesis, whereas administration of CYP4A1 antisense ODNs inhibited vascular and tubular 20-HETE synthesis by 52 and 40%, respectively. RT-PCR of microdissected renal microvessel RNA indicated the presence of CYP4A1, CYP4A2, and CYP4A3 mRNAs, and a CYP4A1-immunoreactive protein was detected by Western analysis of microvessel homogenates. Blood pressure measurements revealed a reduction of 17 ± 6 and 16 ± 4 mmHg in groups receiving CYP4A1 and CYP4A2 antisense ODNs, respectively. These studies implicate CYP4A1 as a major 20-HETE synthesizing activity in the rat kidney and further document the feasibility of using antisense ODNs to specifically inhibit 20-HETE synthesis and thereby investigate its role in the regulation of renal function and blood pressure.

Lipoxygenase-dependent superoxide release in skeletal muscle

2004 ◽  
Vol 97 (2) ◽  
pp. 661-668 ◽  
Author(s):  
Li Zuo ◽  
Fievos L. Christofi ◽  
Valerie P. Wright ◽  
Shengying Bao ◽  
Thomas L. Clanton
Keyword(s):  
Skeletal Muscle ◽  
Arachidonic Acid ◽  
Cytochrome C ◽  
Acid Metabolism ◽  
Arachidonic Acid Metabolism ◽  
Anion Channels ◽  
Cytochrome C Reduction ◽  
First Time ◽  
Cytochrome P 450 ◽  
Different Sources

Superoxide anion radical (O2•−) is released from skeletal muscle at rest and is particularly elevated during conditions of heat stress (42°C). Previous studies have shown that in isolated rat diaphragm O2•− release is not dependent on mitochondrial electron transport, reduced NADP oxidase activity, or the integrity of membrane anion channels. This study hypothesized that O2•− release, as measured by cytochrome c reduction, is linked to metabolism of arachidonic acid. Phospholipase A2 inhibition with manoalide significantly decreased O2•− release. In downstream pathways, neither the blockage of cyclooxygenase with indomethacin nor the inhibition of cytochrome P-450-dependent monooxygenase with SKF-525A decreased O2•− release. However, lipoxygenase (LOX) inhibition with general LOX blockers 5,8,11,14-eicosatetraynoic acid and cinnamyl-3,4-dihydroxy-α-cyanocinnamate greatly attenuated the signal. Furthermore, the specific 5-LOX inhibitor diethylcarbamazine also significantly decreased O2•− release. Immunohistochemistry localized 5- and 12-LOX to the cytosol and sarcolemma of muscle cells. Confocal studies, using the O2•−-sensitive fluorescent indicator hydroethidine, demonstrated that LOX inhibition had no significant influence on intracellular O2•− formation. When compared with the cytochrome c results, this indicates that intra- and extracellular O2•− must arise from different sources. These data show for the first time that arachidonic acid metabolism through LOX activity, is a major source of extracellular O2•− release in skeletal muscle.

scholarly journals Urinary Elimination of Bile Acid Glucuronides under Severe Cholestatic Situations: Contribution of Hepatic and Renal Glucuronidation Reactions

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Martin Perreault ◽  
Ewa Wunsch ◽  
Andrzej Białek ◽  
Jocelyn Trottier ◽  
Mélanie Verreault ◽  
...  
Keyword(s):  
Biliary Obstruction ◽  
Human Liver ◽  
Tandem Mass ◽  
Protein Levels ◽  
Liver And Kidney ◽  
Kidney Microsomes ◽  
Udp Glucuronosyltransferase ◽  
Serum And Urine ◽  
Serum And Urine Samples

Biliary obstruction, a severe cholestatic complication, causes accumulation of toxic bile acids (BAs) in liver cells. Glucuronidation, catalyzed by UDP-glucuronosyltransferase (UGT) enzymes, detoxifies cholestatic BAs. Using liquid chromatography coupled to tandem mass spectrometry, 11 BA glucuronide (-G) species were quantified in prebiliary and postbiliary stenting serum and urine samples from 17 patients with biliary obstruction. Stenting caused glucuronide- and fluid-specific changes in BA-G levels and BA-G/BA metabolic ratios. In vitro glucuronidation assays with human liver and kidney microsomes revealed that even if renal enzymes generally displayed lower KM values, the two tissues shared similar glucuronidation capacities for BAs. By contrast, major differences between the two tissues were observed when four human BA-conjugating UGTs 1A3, 1A4, 2B4, and 2B7 were analyzed for mRNA and protein levels. Notably, the BA-24G producing UGT1A3 enzyme, abundant in the liver, was not detected in kidney microsomes. In conclusion, the circulating and urinary BA-G profiles are hugely impacted under severe cholestasis. The similar BA-glucuronidating abilities of hepatic and renal extracts suggest that both the liver and kidney may contribute to the urine BA-G pool.

IN-VITRO METABOLISM OF 4-ANDROSTENE-3,17-DIONE BY HEPATIC MICROSOMES FROM THE RAINBOW TROUT (SALMO GAIRDNERII): EFFECTS OF HYPOPHYSECTOMY AND OESTRADIOL-17β

1981 ◽  
Vol 90 (1) ◽  
pp. 103-112 ◽  
Author(s):  
TIIU HANSSON ◽  
JAN-ÅKE GUSTAFSSON
Keyword(s):  
Rainbow Trout ◽  
Liver Microsomes ◽  
The Other ◽  
Sham Operation ◽  
Hydroxylase Activity ◽  
Oxidoreductase Activity ◽  
Hepatic Microsomes ◽  
Cytochrome P 450 ◽  
Reductive Metabolism

The metabolism of 4-androstene-3,17-dione by liver microsomes from juvenile rainbow trout, Salmo gairdnerii, was studied in vitro. Hypophysectomy of the fish significantly increased mean hepatic 17-hydroxysteroid oxidoreductase activity when compared with that from sham-operated fish but none of the other enzyme activities investigated were affected. Administration of oestradiol-17β resulted in a significant decrease in mean hepatic 6β-hydroxylase activity and total cytochrome P-450 content but had no effect on the 16-hydroxylation or on the reductive metabolism of androstenedione. The effect of oestradiol-17β on hepatic 6β-hydroxylase activity was as pronounced after hypophysectomy as after sham-operation indicating that these effects of oestradiol-17β are mainly direct and independent of the pituitary gland. The results indicate that hypophysial hormone(s) as well as oestradiol-17β play a role in the regulation of hepatic steroid metabolism in trout.

scholarly journals Phenylhydrazine-mediated induction of haem oxygenase activity in rat liver and kidney and development of hyperbilirubinaemia. Inhibition by zinc-protoporphyrin

1984 ◽  
Vol 217 (2) ◽  
pp. 409-417 ◽  
Author(s):  
M D Maines ◽  
J C Veltman
Keyword(s):  
Rat Liver ◽  
Zinc Protoporphyrin ◽  
Serum Total Bilirubin ◽  
Potent Inducer ◽  
Oxygenase Activity ◽  
Liver And Kidney ◽  
Haem Oxygenase ◽  
Cytochrome P 450

Phenylhydrazine was found to be a potent inducer of microsomal haem oxygenase activity in rat liver and kidney, but not in spleen. The phenylhydrazine-mediated increase in haem oxygenase activity was time-dependent. Maximum activity was attained 12h after treatment in the liver, and 24h after treatment in the kidney. The increases in the activity of haem oxygenase in the liver and the kidney could be inhibited by cycloheximide. Furthermore, the increases could not be elicited by the treatment of microsomal preparations in vitro with phenylhydrazine. In consonance with the increased haem oxygenase activity, a marked increase (16-fold) was observed in the serum total bilirubin concentration in phenylhydrazine-treated rats. The mechanism of haem degradation promoted by phenylhydrazine in vivo appears to differ from that in vitro; only in the former case is bilirubin formed as the end-product of haem degradation. When rats were given zinc-protoporphyrin (40 mumol/kg) 12h before and after phenylhydrazine treatment, the phenylhydrazine-mediated increases in haem oxygenase activity in the liver and the kidney were effectively blocked. Treatment of rats in vivo with the metalloporphyrin also inhibited the activity of splenic haem oxygenase, and promoted a major decrease in the serum bilirubin levels. In phenylhydrazine-treated animals, the microsomal content of cytochrome P-450 was significantly decreased in the absence of a decrease in the microsomal haem concentration. The decrease in cytochrome P-450 content was accompanied by an increased absorption in the 420nm region of the reduced CO-difference spectrum, suggesting the conversion of the cytochrome to an inactive form. The marked depletion of cellular glutathione levels suggests that this conversion may be related to the action of active intermediates and free radicals formed in the course of the interaction of phenylhydrazine with the haem moiety of cytochrome P-450.

scholarly journals Perinatal development of, and effect of chemical pretreatment on, glycine N-acyltransferase activities in liver and kidney of rabbit and rat

1978 ◽  
Vol 172 (2) ◽  
pp. 293-299 ◽  
Author(s):  
M O James ◽  
J R Bend
Keyword(s):  
Zealand White Rabbit ◽  
Rabbit Kidney ◽  
Chemical Pretreatment ◽  
Sprague Dawley ◽  
Adult Rats ◽  
Acyltransferase Activity ◽  
New Zealand White Rabbit ◽  
Ontogenic Development ◽  
Liver And Kidney

The ontogenic development of glycine N-acyltransferase activity was studied in preparations of hepatic and renal mitochondria from the New Zealand White rabbit and the Sprague-Dawley rat. Preparations of hepatic mitochondria from the rat and the rabbit attain adult glycine N-acyltransferase specific activities by birth and 4 weeks of age respectively, whereas mitochondrial preparations from rabbit kidney do not attain adult activity until 4 months of age. Pretreatment of adult rats or immature rabbits with salicylic acid, benzoic acid or phenobarbital had little effect on glycine N-acyltransferase activity in vitro in liver or kidney.

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