Diurnal rhythm of steroid biosynthesis in the testis of terminal phase male of protogynous wrasse, Pseudolabrus sieboldi, a daily spawner

Abstract The effect of intracerebroventricular (lateral ventricle) administration of arginine8-vasopressin (AVP) on the concentration of β-endorphin immunoreactivity in the cerebrospinal fluid obtained from the cisterna magna was studied in rats. A decrease was observed 5 min following injection of 0.9 fmol AVP. No statistically significant changes were found 5 min after intracerebroventricular treatment of rats with 0.09 or 9 fmol. The decrease induced by 0.9 fmol AVP was of short duration and was found 5 min after treatment but not 10 and 20 min. Desglycinamide9-AVP (0.97 fmol), [pGlu4, Cyt6]-AVP-(4–9) (1.44 fmol), Nα-acetyl-AVP (0.88 fmol), lysine8-vasopressin (0.94 fmol) and oxytocin (1 fmol) when intracerebroventricularly injected did not affect the levels of β-endorphin immunoreactivity in the cerebrospinal fluid 5 min later. This suggests that the intact AVP-(1–9) molecule is required for this effect. Intracerebroventricular pretreatment of rats with the vasopressin V1-receptor antagonist d(CH2)5Tyr(Me)AVP (8.63 fmol) completely blocked the effect of AVP (0.9 fmol). In order to investigate further the underlying mechanism, the effect of AVP on the disappearance from the cerebrospinal fluid of exogenously applied β-endorphin was determined. Following intracerebroventricular injection of 1.46 pmol camel β-endorphin-(1–31), the β-endorphin immunoreactivity levels in the cisternal cerebrospinal fluid increased rapidly, and reached peak values at 10 min. The disappearance of β-endorphin immunoreactivity from the cerebrospinal fluid then followed a biphasic pattern with calculated half-lifes of 28 and 131 min for the initial and the terminal phase, respectively. Treatment of rats with AVP (0.9 fmol; icv) during either phase (10, 30, 55 min following intracerebroventricular administration of 1.46 pmol β-endorphin-(1–31)) significantly enhanced the disappearance of β-endorphin immunoreactivity from the cerebrospinal fluid. The data suggest that vasopressin plays a role in the regulation of β-endorphin levels in the cerebrospinal fluid by modulating clearance mechanisms via V1-receptors in the brain.

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Acute changes in steroid biosynthesis in patients following severe trauma: the golden hour study

Endocrine Abstracts ◽

10.1530/endoabs.65.p230 ◽

2019 ◽

Author(s):

Angela Taylor ◽

Conor Bentley ◽

Mark Foster ◽

Janet Lord ◽

Jon Hazeldine ◽

...

Keyword(s):

Severe Trauma ◽

Steroid Biosynthesis ◽

Golden Hour ◽

Acute Changes

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Diurnal Rhythm of Feeding Activity and Estimation of Daily Ration of the Larval Red Spotted Grouper Epinephelus akaara.

NIPPON SUISAN GAKKAISHI ◽

10.2331/suisan.62.399 ◽

1996 ◽

Vol 62 (3) ◽

pp. 399-405 ◽

Cited By ~ 4

Author(s):

Syozo Yamamoto

Keyword(s):

Diurnal Rhythm ◽

Feeding Activity ◽

Daily Ration ◽

Epinephelus Akaara

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Evaluation of the EDSTAC female pubertal assay in CD rats using 17beta- estradiol, steroid biosynthesis inhibitors, and a thyroid inhibitor

Toxicological Sciences ◽

10.1093/toxsci/52.2.269 ◽

1999 ◽

Vol 52 (2) ◽

pp. 269-277 ◽

Cited By ~ 48

Author(s):

M. Marty

Keyword(s):

Steroid Biosynthesis ◽

Biosynthesis Inhibitors

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Pharmacokinetic Appraisal of Carprofen Delivery from Intra-Articular Nanoparticles: A Population Modeling Approach in Rabbits

Proceedings ◽

10.3390/iecp2020-08677 ◽

2020 ◽

Vol 78 (1) ◽

pp. 11

Author(s):

Alexander Parra-Coca ◽

Antonio Boix-Montañés ◽

Ana C. Calpena ◽

Helena Colom

Keyword(s):

Rabbit Model ◽

Drug Uptake ◽

Terminal Phase ◽

Pharmacokinetic Analysis ◽

Rate Process ◽

Absorption Data ◽

Time Curve ◽

Flip Flop ◽

Burst Effect ◽

Healthy Humans

Osteoarthritis is frequently treated in veterinary settings with non-steroidal anti-inflammatory drugs (NSAID) such as carprofen (CP). Its action over the articular cartilage can be enhanced by increasing drug uptake into the cartilage, alongside its site of action, and anticipating its rapid distribution towards the bloodstream. A pharmacokinetic study to evaluate carprofen nanoparticles (NP) after intraarticular administration (IA) in rabbits was performed through a modeling allometric approach. The pharmacokinetic analysis of plasma profiles showed a rapid CP distribution outwards the synovial chamber but mainly remaining in plasma (Vc = 0.14 L/5 Kg), according to its high protein-binding. The absorption data modeling showed the occurrence of two different release–absorption rate processes after nanoparticle administration in the synovial space, i.e., a fast rate process causing a burst effect and involving the 59.5% of the total CP absorbed amount and a slow rate process, involving 40.5%. Interestingly, the CP burst effect inside the joint space enhances its diffusion towards cartilage resulting in CP accumulation in about three times higher concentrations than in plasma. In line with these results, the normalized-by-dose area under the concentration vs. time curve (AUC) values after IA were 80% lower than those observed after the intravenous. Moreover, the slower slope of the concentration–time terminal phase after IA administration vs. intravenous (IV) suggested a flip-flop phenomenon (0.35 h-1 vs. 0.19 h-1). Notably, CP clearances are predictive of the pharmacokinetic (PK) profile of CP in healthy humans (0.14 L/h/5 kg vs. 2.92 L/h/70 kg) although an over-estimation has been detected for cats or dogs (10 times and 4 times, respectively). This fact could probably be attributed to inter-species metabolic differences. In summary, despite the limited number of animals used, this study shows that the rabbit model could be suitable for a predictive evaluation of the release enhancement of CP-NP towards the biophase in arthritic diseases not due to sterical retention of the formulation.

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The formation of a hatching line in the serosal cuticle confers multifaceted adaptive functions on the eggshell of a cicada

Zoological Letters ◽

10.1186/s40851-021-00178-8 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Minoru Moriyama ◽

Kouji Yasuyama ◽

Hideharu Numata

Keyword(s):

Protective Role ◽

Terminal Phase ◽

Embryonic Diapause ◽

Insect Eggs ◽

Ridge Structure ◽

Conflicting Demands ◽

Partial Degradation ◽

Egg Period ◽

Eggshell Structure

AbstractInsect eggshells must meet various demands of developing embryos. These demands sometimes conflict with each other; therefore, there are tradeoffs between eggshell properties, such as robustness and permeability. To meet these conflicting demands, particular eggshell structures have evolved in diverse insect species. Here, we report a rare eggshell structure found in the eggshell of a cicada, Cryptotympana facialis. This species has a prolonged egg period with embryonic diapause and a trait of humidity-inducible hatching, which would impose severe demands on the eggshell. We found that in eggs of this species, unlike many other insect eggs, a dedicated cleavage site, known as a hatching line, was formed not in the chorion but in the serosal cuticle. The hatching line was composed of a fine furrow accompanied by ridges on both sides. This furrow-ridge structure formed in the terminal phase of embryogenesis through the partial degradation of an initially thick and nearly flat cuticle layer. We showed that the permeability of the eggshell was low in the diapause stage, when the cuticle was thick, and increased with degradation of the serosal cuticle. We also demonstrated that the force required to cleave the eggshell was reduced after the formation of the hatching line. These results suggest that the establishment of the hatching line on the serosal cuticle enables flexible modification of eggshell properties during embryogenesis, and we predict that it is an adaptation to maximize the protective role of the shell during the long egg period while reducing the barrier to emerging nymphs at the time of hatching.

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Icariin protects against cage layer osteoporosis by intervening in steroid biosynthesis and glycerophospholipid metabolism

Animal Diseases ◽

10.1186/s44149-021-00001-z ◽

2021 ◽

Vol 1 (1) ◽

Author(s):

Zhengwang Yu ◽

Jie Huang ◽

Zhongxin Zhou

Keyword(s):

Metabolic Diseases ◽

Chinese Herb ◽

Therapeutic Effects ◽

Mineral Density ◽

Steroid Biosynthesis ◽

Metabolic Pathway Analysis ◽

Effective Prevention ◽

Calcium Diet ◽

Low Calcium Diet ◽

Low Calcium

AbstractCage layer osteoporosis (CLO) is a common bone metabolism disease in the breeding industry of China. However, effective prevention for CLO has not been developed. Icariin (ICA), the main bioactive component of the Chinese herb Epimedium, has been shown to have good therapeutic effects on bone-related diseases. In this study, the effects of ICA were further evaluated in a low-calcium diet-induced CLO, and a serum metabolomics assay was performed to understand the underlying mechanisms. A total of 144 31-wk-old Lohmann pink-shell laying hens were randomly allocated to 4 groups with 6 replicates of 6 hens per replicate. The 4 dietary treatment groups consisted of a basal diet (3.5% calcium), a low-calcium diet (2.0% calcium), and a low-calcium diet supplemented with 0.5 or 2.0 g/kg ICA. The results showed that ICA exerted good osteoprotective effects on low-calcium diet-induced CLO. ICA significantly increased femur bone mineral density, improved bone microstructure, decreased bone metabolic level, and upregulated mRNA expression of bone formation genes in femoral bone tissue. Serum untargeted metabolomics analysis showed that 8 metabolite levels were significantly changed after ICA treatment, including increased contents of 7-dehydrocholesterol, 7-oxocholesterol, desmosterol, PC (18:1(9Z)/18:1(9Z)), PS (18:0/18:1(9Z)), N,N-dimethylaniline and 2-hydroxy-butanoic acid and decreased N2,N2-dimethylguanosine. Metabolic pathway analysis based on the above 8 metabolites indicated that ICA mainly perturbed steroid biosynthesis and glycerophospholipid metabolism. These findings suggest that ICA can effectively prevent bone loss in low-calcium diet-induced CLO by mediating steroid biosynthesis and glycerophospholipid metabolism and provide new information for the regulation of bone metabolic diseases.

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Electrical Aspects of a Diurnal Rhythm in the Eye of Dytiscus fasciventris

Physiological Zoology ◽

10.1086/physzool.16.1.30151673 ◽

1943 ◽

Vol 16 (1) ◽

pp. 101-109 ◽

Cited By ~ 29

Author(s):

Theodore Louis Jahn ◽

Verner John Wulff

Keyword(s):

Diurnal Rhythm

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Preparation and Pharmacokinetic Study of Daidzein Long-Circulating Liposomes

Nanoscale Research Letters ◽

10.1186/s11671-019-3164-y ◽

2019 ◽

Vol 14 (1) ◽

Cited By ~ 4

Author(s):

Qiao Wang ◽

Wenjin Liu ◽

Junjun Wang ◽

Hong Liu ◽

Yong Chen

Keyword(s):

Single Dose ◽

Drug Concentration ◽

Drug Loading ◽

Plasma Drug Concentration ◽

The Body ◽

Molar Ratio ◽

Terminal Phase ◽

Plasma Drug ◽

Ultrasonic Time ◽

Time Required

Abstract In this study, daidzein long-circulating liposomes (DLCL) were prepared using the ultrasonication and lipid film-hydration method. The optimized preparation conditions by the orthogonal design was as follows: 55 to 40 for the molar ratio of soybean phosphatidylcholine (SPC) to cholesterol, 1 to 10 for the mass ratio of daidzein to total lipid (SPC and cholesterol) (w:w), the indicated concentration of 5% DSPE-mPEG2000 (w:w), 50 °C for the hydration temperature, and 24 min for the ultrasonic time. Under these conditions, the encapsulation efficiency and drug loading of DLCL were 85.3 ± 3.6% and 8.2 ± 1.4%, respectively. The complete release times of DLCL in the medium of pH 1.2 and pH 6.9 increased by four- and twofold of that of free drugs, respectively. After rats were orally administered, a single dose of daidzein (30 mg/kg) and DLCL (containing equal dose of daidzein), respectively, and the MRT0−t (mean residence time, which is the time required for the elimination of 63.2% of drug in the body), t1/2 (the elimination half-life, which is the time required to halve the plasma drug concentration of the terminal phase), and AUC0−t (the area under the plasma drug concentration-time curve, which represents the total absorption after a single dose and reflects the drug absorption degree) of daidzein in DLCL group, increased by 1.6-, 1.8- and 2.5-fold as compared with those in the free group daidzein. Our results indicated that DLCL could not only reduce the first-pass effect of daidzein to promote its oral absorption, but also prolong its mean resident time to achieve the slow-release effect.

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