scholarly journals Levels of cyclic-AMP and cyclic-GMP in porcine oocyte-cumulus complexes and cumulus-free oocytes derived from small and middle follicles during the first 24-hour period of in vitro maturation

2017 ◽  
Vol 63 (2) ◽  
pp. 191-197 ◽  
Author(s):  
Yuichi OKUDAIRA ◽  
Takuya WAKAI ◽  
Hiroaki FUNAHASHI
Keyword(s):  
1983 ◽  
Vol 50 (04) ◽  
pp. 804-809 ◽  
Author(s):  
Torstein Lyberg

SummaryHuman monocytes in vitro respond to various agents (immune complexes, lectins, endotoxin, the divalent ionophore A 23187, 12-0-tetradecanoyl-phorbol 13-acetate [TPA], purified protein derivative [PPD] of Bacille Calmette-Guerin) with an increased synthesis of the protein component of thromboplastin. The effect of cyclic AMP and cyclic GMP on this response has been studied. Dibutyryl-cyclic AMP, prostaglandin E1 and the phosphodiesterase inhibitors 3-butyl-1-methyl-xanthine (MIX) and rac -4-(3-butoxy-4-methoxybenzyl)-2-imidazolidinone (Ro 201724), separately and in combination have a pronounced inhibitory effect on the response to immune complexes and PPD, and a moderate effect on the response to endotoxin and lectins. The effect on TPA response and on the response to A 23187 was slight. Dibutyryl-cyclic GMP (1 mM) gave a slight inhibition of the TPA arid IC response, but had essentially no effect on the response to other inducers. The intracellular cAMP level increased when monocytes were incubated with IC, TPA or A 23187 followed by a decrease to basal levels within 1-2 hr, whereas lectin (PHA) and PPD did not induce such changes. The cAMP response to endotoxin varied. Stimulation with IC induced an increase in monocyte cGMP levels, whereas the other stimulants did not cause such changes.


1979 ◽  
Vol 237 (5) ◽  
pp. C200-C204 ◽  
Author(s):  
D. J. Stewart ◽  
J. Sax ◽  
R. Funk ◽  
A. K. Sen

Stimulation of salt galnd secretion in domestic ducks in vivo increased the cyclic GMP concentration of the tissue, but had no effect on cyclic AMP levels. Methacholine, which is known to stimulate sodium transport by the glands both in vivo and in vitro, stimulated ouabain-sensitive respiration in salt gland slices. Cyclic GMP stimulated ouabain-sensitive respiration to the same extent as methacholine. Guanylate cyclase stimulators, hydroxylamine and sodium azide, also stimulated ouabain-sensitive respiration. The stimulation of ouabain-sensitive respiration by methacholine was blocked either by atropine or by removal of calcium from the incubation medium. The stimulation of ouabain-sensitive respiration by cyclic GMP still occurred in the absence of calcium. The above observations seem to indicate that cyclic GMP acts as a tertiary link in the process of stimulus-secretion coupling in the tissue.


1983 ◽  
Vol 97 (1) ◽  
pp. 43-49 ◽  
Author(s):  
U. Zor ◽  
B. Strulovici ◽  
R. Braw ◽  
H. R. Lindner ◽  
A. Tsafriri

The aim of this study was to search for direct biochemical effects of highly purified FSH on isolated ovarian follicular theca in vitro. Granulosa cells (GC; approximately 1 × 105 cells per follicle) were flushed from isolated follicles of pro-oestrous rats. The remaining theca layer and the isolated GC were incubated with highly purified ovine FSH. Prostaglandin E (PGE) accumulation was measured by radioimmunoassay. Follicle-stimulating hormone induced a 15-fold increase in PGE accumulation over the basal level in the follicular theca, the stimulated rate exceeding threefold that observed in the GC fraction derived from the same follicle. Follicle-stimulating hormone caused no significant increase in cyclic AMP level or steroidogenesis in the theca layer, but was active on these parameters in the GC. In contrast, LH increased the accumulation of cyclic AMP, progesterone and testosterone, as well as of PGE, in follicular theca. Exogenous 8-bromo cyclic AMP or cyclic GMP also stimulated PGE production in follicular theca or GC, but FSH was without any effect on the level of endogenous cyclic GMP in GC or follicular theca. Antibodies to FSH prevented the effect of FSH (but not that of LH) on PGE formation by follicular theca and GC, while antibodies to the β-subunit of LH blocked the effect of LH but not of FSH. We conclude that highly purified FSH has a stimulatory effect on PGE formation by the follicular theca.


1993 ◽  
Vol 10 (6) ◽  
pp. 991-996 ◽  
Author(s):  
Ari Sitaramayya ◽  
Lorraine Lombardi ◽  
Alexander Margulis

AbstractDopamine is a major neurotransmitter and neuromodulator in vertebrate retina. Although its pharmacological and physiological actions are well understood, the biochemical mechanisms of its signal transduction are less clear. Acting via D1 receptors, dopamine was shown to increase cyclic AMP levels in intact retina and to activate adenylate cyclase in retinal homogenates. The action via activation of D2 receptors is controversial: it was reported to decrease cyclic AMP levels in intact retina but inhibition of cyclase could not be demonstrated in retinal homogenates; also it was reported to activate rod outer segment cyclic GMP phosphodiesterase in vitro but did not decrease cyclic GMP levels in aspartate-treated retinas. We made an attempt to fractionate bovine retinal membranes and to investigate the effects of dopamine, via Dl and D2 receptors, on the synthesis and hydrolysis of cyclic AMP and cyclic GMP. Activation of cyclic AMP synthesis was noted in all fractions, but no effects were evident on cyclic nucleotide hydrolysis or cyclic GMP synthesis in any fraction. Also, D2 agonist did not inhibit cyclic AMP synthesis. These observations suggest that D2 receptors may not be directly coupled to cyclic nucleotide metabolizing enzymes in bovine retina.


1978 ◽  
Vol 87 (1) ◽  
pp. 158-163 ◽  
Author(s):  
Anastasia Makris ◽  
Kenneth J. Ryan

ABSTRACT Cyclic AMP and cyclic GMP accumulation in hamster pre-ovulatory follicles was determined after in vitro stimulation by LH and FSH. Combined time course and dose response experiments determined that the acute response of the follicles (0–30 min) to LH and FSH was similar with respect to cyclic AMP accumulation. The pattern of cyclic GMP accumulation was, however, distinctly different in LH and FSH stimulated follicles. LH increased follicular cyclic GMP only at the lowest dose (0.005 IU/ml), while higher doses of LH had no effect. In contrast, FSH at all doses stimulated cyclic GMP accumulation. The different cyclic AMP to cyclic relationships generated in the follicles by LH and FSH may be determinants in specificity of hormone action in pre-ovulatory follicles.


1976 ◽  
Vol 54 (5) ◽  
pp. 692-697 ◽  
Author(s):  
Seymour Heisler

The effects of the α,β-methylene analogue of ATP (Ap(CH2)pp), described as a competitive inhibitor of adenylate cyclase (EC 4.6.1.1), were studied in the rat pancreas in vitro. The analogue did not alter basal cyclic AMP production and basal or carbachol-stimulated efflux of 45Ca from isotope-preloaded glands. On the other hand, Ap(CH2)pp reduced the secretory responses to carbachol, carbachol in the presence of dibutyryl cyclic AMP, pancreozymin (PZ), and the calcium ionophore, A-23187. Release of pancreatic protein in response to dibutyryl cyclic AMP itself was unaffected by the ATP analogue, suggesting that the other secretagogues tested share a common, Ap(CH2)pp-inhibitable pathway in their respective stimulatory actions. Though carbachol, PZ, and A-23187 all stimulated a rapid production (30 s) of pancreatic cyclic GMP, these responses were not affected by Ap(CH2)pp. Additional studies with the analogue indicated that it has a slow onset of action (30–45 min), i.e., its effect on secretion is preceded by secretagogue-induced changes in nucleotide levels and calcium efflux. Nonetheless, the analogue may affect cellular calcium homeostasis, if not during the initial events triggering secretion, then during those events which maintain continued secretory output in the presence of a stimulus.


2003 ◽  
Vol 23 (12) ◽  
pp. 4066-4082 ◽  
Author(s):  
Yongchang Chen ◽  
Shunhui Zhuang ◽  
Stijn Cassenaer ◽  
Darren E. Casteel ◽  
Tanima Gudi ◽  
...  

ABSTRACT Calcium induces transcriptional activation of the fos promoter by activation of the cyclic AMP response element (CRE)-binding protein (CREB), and in some cells its effect is enhanced synergistically by cyclic GMP (cGMP) through an unknown mechanism. We observed calcium-cGMP synergism in neuronal and osteogenic cells which express type II cGMP-dependent protein kinase (G-kinase); the effect on the fos promoter was mediated by the CRE and proportional to G-kinase activity. Dominant negative transcription factors showed involvement of CREB- and C/EBP-related proteins but not of AP-1. Expression of C/EBP-β but not C/EBP-α or -δ enhanced the effects of calcium and cGMP on a CRE-dependent reporter gene. The transactivation potential of full-length CREB fused to the DNA-binding domain of Gal4 was increased synergistically by calcium and cGMP, and overexpression of C/EBP-β enhanced the effect, while a dominant negative C/EBP inhibited it. With a mammalian two-hybrid system, coimmunoprecipitation experiments, and in vitro binding studies, we demonstrated that C/EBP-β and CREB interacted directly; this interaction involved the C terminus of C/EBP-β but occurred independently of CREB's leucine zipper domain. CREB Ser133 phosphorylation was stimulated by calcium but not by cGMP; in cGMP-treated cells, 32PO4 incorporation into C/EBP-β was decreased and C/EBP-β/CRE complexes were increased, suggesting regulation of C/EBP-β functions by G-kinase-dependent dephosphorylation. C/EBP-β and CREB associated with the fos promoter in intact cells, and the amount of promoter-associated C/EBP-β was increased by calcium and cGMP. We conclude that calcium and cGMP transcriptional synergism requires cooperation of CREB and C/EBP-β, with calcium and cGMP modulating the phosphorylation states of CREB and C/EBP-β, respectively.


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