Development of self-referencing oxygen microsensor and its application to single pancreatic HIT cells: effects of adenylate cyclase activator forskolin on oxygen consumption

2000 ◽  
Vol 199 (2) ◽  
pp. 197-198 ◽  
Author(s):  
SK Jung ◽  
K Hammar ◽  
PJ Smith
1990 ◽  
Vol 1 (3,4) ◽  
pp. 225-232
Author(s):  
Richard C. Carlsen ◽  
Marino De Leon ◽  
Wolfram Tetzlaff ◽  
Irma M. Parhad ◽  
Mark A. Bisby

2010 ◽  
Vol 22 (9) ◽  
pp. 94
Author(s):  
M. Bertoldo ◽  
T. Sellens ◽  
C. G. Grupen

Asynchronous nuclear and cytoplasmic maturation is thought to contribute to poor embryo production in vitro. Nuclear arrest is mediated by cAMP and can be maintained within the oocyte using non-specific phosphodiesterase inhibitors (3-isobutyl-1-methylxanthine ; IBMX) and the adenylate cyclase activator forskolin (FSK) (1). The aim of this study was to investigate the effect of IBMX and FSK supplementation on porcine oocyte nuclear maturation during COC recovery and IVM using a defined culture system. In all experiments, cAMP modulators were added to Hepes-buffered media held in collection tubes. COCs recovered from 3–5 mm diameter follicles of prepubertal ovaries were cultured in basic maturation media in the absence of FSH. Nuclear maturation was assessed using orcein dye. In Experiment 1, IVM media was supplemented with 0, 50 or 500 µM IBMX. In Experiment 2, IVM media was supplemented with 0, 5, 10, 50 and 100µM FSK. In Experiment 3, IVM medium was supplemented with combinations of IBMX and FSK to give the treatments; control, 50IBMX/50FSK, 50IBMX/100FSK, 500IBMX/50FSK and 500IBMX/100FSK. Nuclear maturation was assessed at 0, 2, 4 and 18 h after the onset of IVM. At 18 h of culture, there were no differences in the proportion of oocytes supplemented with 0, 50 or 500 µM IBMX reaching MII. Incubation with 10, 50 or 100 µM FSK resulted in 8-16% of oocytes at MII at 18 h compared to the other groups (25–29%; P < 0.001). The combinations of IBMX and FSK resulted in greater proportions (86–98%) of oocytes remaining at the GV stage at 18 h compared to the control (16%; P < 0.001). There were no differences in the proportion of oocytes remaining at the GV stage at the earlier time points (P > 0.05). The results demonstrate that these cAMP modulators, in combination, are highly effective in maintaining porcine oocyte meiotic arrest in vitro for an extended period. (1) Albuz FK et al., Proceedings of the 25th Annual Meeting of ESHRE, Amsterdam, The Netherlands, 2009.


2020 ◽  
Vol 32 (11) ◽  
pp. 1012
Author(s):  
Elizabeth S. Metcalf ◽  
Keith R. Masterson ◽  
David Battaglia ◽  
Jeremy G. Thompson ◽  
Robert Foss ◽  
...  

Optimising the developmental potential of immature equine oocytes and invitro-produced (IVP) embryos was explored through modifications of established media and holding temperature. In Experiment 1, delaying spontaneous resumption of meiosis through the process of simulated physiological oocyte maturation with the addition of the adenylate cyclase activator forskolin (50µM) and the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (100µM) to overnight holding medium before maturation improved blastocyst production (P&lt;0.05). In Experiment 2, the blastocyst production rate was increased significantly when cumulin (100ng mL−1) was added to the overnight holding or culture media (P&lt;0.05). In Experiment 3, immature oocytes held overnight at 16°C before maturation had improved developmental competence than those held at 20°C and 5°C (P&lt;0.05). There was no difference between maturation rates, but blastocyst formation per cleaved oocyte was significantly greater in oocytes held overnight at 16°C than at 20°C or 5°C. Furthermore, blastocyst formation per recovered oocyte and per fertilised oocyte was greater when oocytes were held before maturation at 16°C than at 5°C (P&lt;0.05). In Experiment 4, the addition of sodium ascorbate (AC; 50µg mL−1) to the maturation and/or culture media of oocytes and IVP embryos did not improve blastocyst production, but did appear to lower cleavage rates compared with oocytes and embryos cultured without AC.


1996 ◽  
Vol 79 (1) ◽  
pp. 25-35 ◽  
Author(s):  
Yutaka Furukawa ◽  
Akira Matsumori ◽  
Toshiro Hirozane ◽  
Shigeo Matsui ◽  
Yukihito Sato ◽  
...  

1985 ◽  
Vol 223 (1232) ◽  
pp. 389-402 ◽  

The K + current induced by isoprenaline acting on (β-adrenergic receptors in Xenopus laevis has been studied in oocytes still surrounded by their follicular cells and inner ovarian epithelium. Forskolin, an adenylate cyclase activator, induced a similar K + current and when used at subliminal concentration it potentiated the current induced by isoprenaline. Inhibition of phosphodiesterase by methylisobutylxanthine also en­hanced the response to isoprenaline. 8-Br-cAMP, a permeant analogue of cAMP also produced a K + current. Acetylcholine produced a long lasting inhibition of the isoprenaline current. This inhibition was not seen in the presence of atropine. It is concluded that the K + current induced by the activation of β-adrenergic receptors in the oocyte is mediated by an intracellular rise of cAMP.


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