Stimulation of 3′,5′-cyclic AMP and testosterone production in rat testis in vitro

FEBS Letters ◽  
1972 ◽  
Vol 24 (3) ◽  
pp. 251-254 ◽  
Author(s):  
F.F.G. Rommerts ◽  
B.A. Cooke ◽  
J.W.C.M. van der Kemp ◽  
H.J. van der Molen
Keyword(s):  
Cyclic Amp ◽  
Rat Testis ◽  
Testosterone Production ◽  
Stimulation Of

Stimulation of aromatase activity in the fetal rat testis by cyclic AMP and FSH

1988 ◽  
Vol 118 (3) ◽  
pp. 485-489 ◽  
Author(s):  
J.-P. Weniger ◽  
A. Zeis
Keyword(s):  
Cyclic Amp ◽  
Specific Activity ◽  
Isotopic Dilution ◽  
Aromatase Activity ◽  
Dibutyryl Cyclic Amp ◽  
Rat Testis ◽  
Fetal Rat ◽  
Fetal Rats ◽  
Stimulation Of

ABSTRACT The effect of dibutyryl cyclic AMP and FSH on oestrogen biosynthesis was investigated in testes from 18- to 21-day-old fetal rats cultured in vitro in the presence of tritiated testosterone. Oestrone and oestradiol concentrations were measured by determination of constant specific activity after isotopic dilution. Dibutyryl cyclic AMP and FSH markedly stimulated the conversion of testosterone into both oestrone and oestradiol at all stages studied. Oestradiol synthesis was stimulated by two- to sevenfold, while stimulation of oestrone synthesis was even greater. The results demonstrate that the aromatase enzyme system of the fetal rat testis responds to cyclic AMP and FSH. J. Endocr. (1988) 118, 485–489

scholarly journals Effect of lutropin on phosphorylation of endogenous proteins in testis Leydig cells. Correlation with testosterone production

1977 ◽  
Vol 168 (1) ◽  
pp. 43-48 ◽  
Author(s):  
Brian A. Cooke ◽  
Monica L. Lindh ◽  
Felix H. A. Janszen
Keyword(s):  
Cyclic Amp ◽  
Leydig Cells ◽  
Sodium Dodecyl ◽  
Molecular Weights ◽  
Testosterone Production ◽  
Hypophysectomized Rats ◽  
Endogenous Proteins ◽  
Stimulation Of

The effect of lutropin on phosphorylation of endogenous proteins in testis Leydig cells was investigated, by incubating purified Leydig cells with lutropin and [32P]Pi followed by sodium dodecyl sulphate/polyacrylamide-slab gel electrophoresis of the [32P]phosphoproteins. The radioactivity of the proteins was quantified by densitometry of the radio-autograms obtained. The following results were obtained. 1. Lutropin increased the amount of32 P incorporated into three proteins (A, B and C) with apparent mol.wts. of 14300, 57000 and 77600 respectively. 2. The increase in incorporation of32P into these proteins was detectable within 5min, reaching a maximum in approx. 20min. 3. The32P incorporated into protein B (but not proteins A and C) was significantly increased with 0.1 and 1.0ng of lutropin/ml. Incorporation of32P into all three proteins was significantly increased with 10ng of lutropin/ml, reaching a maximum with 100ng/ml. 4. Testosterone production was significantly increased with 1ng of lutropin/ml, and between 10 and 1000ng/ml the degree of stimulation of testosterone production and incorporation of32P into proteins A, B and C was similar. 5. Cyclic AMP production was significantly increased with 10ng of lutropin/ml and had not reached a maximum with 1000ng/ml. 6. In Leydig cells isolated from hypophysectomized rats 3h after injection of choriogonadotropin in vivo, phosphoproteins with the same molecular weights as proteins A, B and C were found. No further increases in incorporation of32P into these proteins were obtained when lutropin was added to the Leydig cells in vitro. 7. Dibutyryl cyclic AMP (but not follitropin or testosterone) also stimulated the incorporation of32P into proteins A, B and C in Leydig cells.

scholarly journals Interactions between adenylate cyclase and the yeast GTPase-activating protein IRA1.

1991 ◽  
Vol 11 (9) ◽  
pp. 4591-4598 ◽  
Author(s):  
M R Mitts ◽  
J Bradshaw-Rouse ◽  
W Heideman
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Adenylate Cyclase System ◽  
Gtpase Activating Protein ◽  
Yeast Saccharomyces Cerevisiae ◽  
Strong Candidate ◽  
Sepharose 4B ◽  
Stimulation Of ◽  
Cyclic Amp Synthesis

The adenylate cyclase system of the yeast Saccharomyces cerevisiae contains many proteins, including the CYR1 polypeptide, which is responsible for catalyzing the formation of cyclic AMP from ATP, RAS1 and RAS2 polypeptides, which mediate stimulation of cyclic AMP synthesis by guanine nucleotides, and the yeast GTPase-activating protein analog IRA1. We have previously reported that adenylate cyclase is only peripherally bound to the yeast membrane. We have concluded that IRA1 is a strong candidate for a protein involved in anchoring adenylate cyclase to the membrane. We base this conclusion on the following criteria: (i) a disruption of the IRA1 gene produced a mutant with very low membrane-associated levels of adenylate cyclase activity, (ii) membranes made from these mutants were incapable of binding adenylate cyclase in vitro, (iii) IRA1 antibodies inhibit binding of adenylate cyclase to the membrane, and (iv) IRA1 and adenylate cyclase comigrate on Sepharose 4B.

TESTOSTERONE SECRETION BY FOETAL RAT TESTES IN VITRO

1976 ◽  
Vol 71 (2) ◽  
pp. 231-238 ◽  
Author(s):  
RÉGINE PICON
Keyword(s):  
Cyclic Amp ◽  
Synthetic Medium ◽  
Functional Differentiation ◽  
Dibutyryl Cyclic Amp ◽  
Testosterone Secretion ◽  
Testosterone Production ◽  
Foetal Rat

SUMMARY Testosterone secretion by foetal rat testes (13½–21½ days of gestation) explanted for 3 days in a synthetic medium was measured every 24 h by radioimmunoassay. During the first day of explantation, the foetal testis produced, respectively, 1013 ± 132, 8734 ± 1118, 9179 ± 2185 and 3886 ± 309 (s.e.m.) pg/testis when explanted at 14½, 16½, 18½ and 21½ days respectively. Testosterone production by 13½-day-old testes was not detectable on the first day of culture, but appeared on subsequent days. Daily testosterone secretion increased on the 2nd and 3rd days of culture in 14½-day-old testes and decreased in older stages. These results suggest that the functional differentiation of the testis is independent of stimulatory factors like gonadotrophins. Dibutyryl cyclic AMP was found to stimulate testosterone production significantly from 14½ days of gestation onwards.

Possible role of cyclic GMP in stimulus-secretion coupling by salt gland of the duck

1979 ◽  
Vol 237 (5) ◽  
pp. C200-C204 ◽  
Author(s):  
D. J. Stewart ◽  
J. Sax ◽  
R. Funk ◽  
A. K. Sen
Keyword(s):  
Cyclic Amp ◽  
Guanylate Cyclase ◽  
Cyclic Gmp ◽  
Salt Gland ◽  
Domestic Ducks ◽  
Stimulus Secretion Coupling ◽  
Stimulation Of

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.

Tokishakuyakusan Stimulates Progesterone and Estradiol-17 β Production by Rat Granulosa Cells and Progesterone, Testosterone and Estradiol-17 β by the Residual Portion of the Follicle in Vitro

1991 ◽  
Vol 19 (02) ◽  
pp. 155-161 ◽  
Author(s):  
Satoshi Usuki
Keyword(s):  
Granulosa Cells ◽  
Cell Level ◽  
Testosterone Production ◽  
Progesterone Production ◽  
Preovulatory Follicles ◽  
Immature Rats ◽  
Serum Gonadotropin ◽  
Tissue Compartments ◽  
Stimulation Of

To examine the possible effects of Tokishakuyakusan (TS) on steroidogenesis by preovulatory follicles at the cell level, the expressed granulosa cells and remaining portion of follicles from pregnant mare's serum gonadotropin (PMS)-treated immature rats were incubated in vitro with increasing concentrations of TS for 3 h. TS significantly stimulated progesterone and estradiol-17 b production, with a predominant stimulation of progesterone, by the expressed granulosa cells, while testosterone production was not stimulated. In the remaining portion of the follicle, TS also significantly stimulated progesterone, testosterone and estradiol-17 b production. Similar to the effect produced by granulosa cells, the stimulatory effect of TS was stronger on progesterone than on testosterone and estradiol-17 b production. These results suggest that TS has a potent, direct stimulatory effect on steroidogenesis, especially progesterone production, by constituent tissue compartments of rat preovulatory follicles in vitro.

scholarly journals Alteration of Platelet Cyclic AMP (cAMP) by Ethanol

1977 ◽  
Author(s):  
D.H. Cowan ◽  
M. Kikta ◽  
D. Baunach
Keyword(s):  
Cyclic Amp ◽  
Platelet Function ◽  
Inhibitory Effect ◽  
Human Platelets ◽  
Platelet Dysfunction ◽  
Camp Metabolism ◽  
Subnormal Level ◽  
Camp Levels ◽  
Stimulation Of

Studies of cAMP in human platelets exposed to ethanol were done to assess one possible mechanism for ethanol-related platelet dysfunction. Ingestion of ethanol by 3 subjects produced blood ethanol levels from 65-76 mM. Thrombocytopenia occurred in 1 subject and impaired platelet function occurred in all. Platelet cAMP decreased 36,51, and 59% below control levels. Infusion of ethanol to 2 normals produced blood ethanol levels of 43 mM and decreased platelet cAMP by 15% and 22%. Incubation of normal platelets with 86 mM ethanol in vitro decreased cAMP from 13.8 ± 2.9 (1 SD) to 9.4 ± 3.5 (p<0.02). By contrast, ethanol did not impair the increase in cAMP that occurred with 1.3 μM PGE1. Further, ethanol enhanced the increase in cAMP produced by 2.0 mM papaverine (Pap) by 160-220% and that produced by Pap + PGE1 by 58%. Dopamine, 0.1 mM, caused a 23% decrease in the basal level of cAMP, a 31% decrease below the subnormal level of cAMP seen with ethanol alone, and a 41% reduction in the increased level of cAMP produced by Pap + ethanol. The effect of ethanol on platelet cAMP metabolism is complex. Ethanol reduces basal levels of cAMP, does not decrease elevated levels that result from PGE1 stimulation of adenylate cyclase, and augments the inhibitory effect of Pap on platelet phosphodiesterase (PDE). Despite causing a decrease in basal cAMP levels, ethanol may impair platelet function by potentiating the effect of agents or other conditions which increase cAMP. The effect of ethanol on Pap-stimulated PDE activity may be blocked by dopamine, a neuropharmacologic agent that is actively accumulated by platelets.

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