Stimulation of rat ovarian ornithine decarboxylase in vitro by hCG, amino acids and bovine serum albumin

1980 ◽  
Vol 94 (4) ◽  
pp. 571-576 ◽  
Author(s):  
Kirsti Käpyaho

Abstract. Rat ovarian ornithine decarboxylase activity could be stimulated in vitro by a variety of factors, which apparently have different modes of action. Ovarian cells prepared from pre-pubertal rats by collagenase dispersion exhibited a low but detectable ornithine decarboxylase activity after a 6-h incubation in a defined medium. The enzyme activity was markedly enhanced in vitro by hCG, which also produced increased accumulation of cyclic AMP and stimulated the secretion of progesterone. In addition to the gonadotrophin, ovarian ornithine decarboxylase activity was strikingly stimulated by some non-essential amino acids, and especially by bovine serum albumin. While markedly enhancing ornithine decarboxylase activity, none of the latter additions increased the accumulation of cyclic AMP or enhanced the secretion of progesterone. Bovine serum albumin enhanced powerfully ornithine decarboxylase activity in vitro at very small concentrations (from 0.75 μm). The half-life of the enzyme remained unchanged (26—28 min) upon stimulation indicating that the stimulation mechanism did not involve any stabilization of the enzyme.

2006 ◽  
Vol 18 (7) ◽  
pp. 789 ◽  
Author(s):  
Chie Suzuki ◽  
Koji Yoshioka

The effects of glutamine, hypotaurine, taurine and premixed solutions of essential amino acids (EAA) and non-essential amino acids (NEAA) on in vitro development of porcine zygotes were evaluated. The effects of refreshing the medium and replacing polyvinyl alcohol (PVA) with bovine serum albumin (BSA) on embryonic development were also investigated. Porcine zygotes produced by in vitro maturation (IVM) and in vitro fertilisation (IVF) were cultured in porcine zygote medium (PZM), as the basal culture medium, for 5 days after IVF. The total number of cells in blastocysts was significantly increased by the addition of 2 mm glutamine to PZM, as was blastocyst yields after supplementation with 0.25 to 4 mm glutamine. Addition of 1.25 to 10 mm hypotaurine to PZM significantly increased blastocyst yields. Addition of 5 mm taurine to PZM significantly increased blastocyst yield, whereas taurine had no effect on blastocyst yield in cultures already containing 5 mm hypotaurine. Adding 1× EAA significantly increased the rate of blastocyst formation compared with no or 2× EAA, whereas 2× NEAA significantly increased the total cell numbers in blastocysts compared with no NEAA. Refreshing the medium at Day 3 had no effect on blastocyst yields, whereas medium change significantly reduced the total cell numbers in blastocysts. Adjusting the amino acid concentrations of a chemically defined medium can improve the developmental competence of porcine embryo.


1981 ◽  
Vol 196 (3) ◽  
pp. 795-801 ◽  
Author(s):  
Johannes D. Veldhuis ◽  
James M. Hammond

We examined the role of Ca2+ in the control of basal and hormone-stimulated ornithine decarboxylase activity in isolated pig granulosa cells maintained under chemically defined conditions in vitro. Omission of Ca2+ from the incubation medium (measured Ca2+ concentration 5μm) decreased basal enzymic activity, and significantly (P<0.01) impaired the response to maximally stimulating doses of either lutropin or follitropin. No significant alteration occurred in the concentration of either gonadotropin required to elicit half-maximal effects. The addition of EGTA (1.27–2.0mm) to chelate residual extracellular Ca2+ further decreased hormone-induced rises in ornithine decarboxylase activity. Despite the presence of 1.27mm concentrations of extracellular Ca2+, the administration of presumptive Ca2+ antagonists, believed to impair trans-membrane Ca2+ influx [verapamil (10–100μm), nifedipine (1–100μm) or CoCl2 (1mm)] suppressed hormone-stimulated ornithine decarboxylase activity. The inhibitory effects of verapamil or of Ca2+ omission from the medium were not overcome by the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (0.25mm), or by cholera toxin, or by an exogenously supplied cyclic AMP analogue, 8-bromo cyclic AMP. Conversely, micromolar concentrations of a putative bivalent-cation ionophore, A23187, increased significantly the stimulation of ornithine decarboxylase activity by saturating concentrations of lutropin or 8-bromo cyclic AMP. Thus the present observations implicate Ca2+ ions in the modulation of hormone action and cellular function in normal ovarian cells.


1969 ◽  
Vol 26 (5) ◽  
pp. 1392-1397 ◽  
Author(s):  
James E. Stewart ◽  
Diane M. Foley

The levels of fluorescent material in the hemolymph of lobsters injected with serum proteins from lobster hemolymph labelled with fluorescein remained relatively constant over a 6-day test period; the levels in lobsters injected with bovine serum albumin labelled with fluorescein declined rapidly. A precipitin-like reaction was observed when lobster hemolymph serum was titrated with bovine serum albumin in vitro.


2006 ◽  
Vol 16 (9) ◽  
pp. 2450-2453 ◽  
Author(s):  
Xiong-Jie Jiang ◽  
Jian-Dong Huang ◽  
Yu-Jiao Zhu ◽  
Fen-Xiang Tang ◽  
Dennis K.P. Ng ◽  
...  

2021 ◽  
Author(s):  
Alessandra Capezzone de Joannon ◽  
Angela Testa ◽  
Natalie Falsetto ◽  
Michela Procaccini ◽  
Lorella Ragni

Aim: Ethanol is highly effective at inactivating enveloped viruses, including SARS-CoV-2. The aim of this study is to evaluate the virucidal activity of Amuchina Gel Xgerm (74% ethanol) against SARS-CoV-2, according to the European Standard EN14476:2013+A2:2019. Materials & methods: Virucidal activity of the study product was evaluated against SARS-CoV-2 strain USAWA1/2020 in suspension, in the presence of 0.3 g/l of bovine serum albumin. Results: The log10 reduction of SARS-CoV-2 in the presence of bovine serum albumin was ≥4.11 ± 0.12 after 30 s of exposure to the study product (80% dilution). Cytotoxicity was observed in the 100 dilution, affecting the detection limit by 1 log10. Conclusion: Virucidal activity against SARS-CoV-2 supports the effectiveness of this alcohol-based formulation as a prevention measure for COVID-19 illness.


2008 ◽  
Vol 2 (1) ◽  
Author(s):  
Md Ashraful Alam ◽  
Md Abdul Awal ◽  
Mahbub Mostofa ◽  
Md Kamrul Islam ◽  
Nusrat Subhan

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