DIFFERENCES IN ACTION OF LH AND FSH ON THE FORMATION OF CYCLIC AMP IN THE PREPUBERTAL RAT OVARY

1976 ◽  
Vol 81 (1) ◽  
pp. 150-164 ◽  
Author(s):  
Gunnar Selstam ◽  
Sten Rosberg ◽  
Jan Liljekvist ◽  
Lena Grönquist ◽  
Torsten Perklev ◽  
...  
Keyword(s):  
Cyclic Amp ◽  
Incubation Medium ◽  
Time Course ◽  
Tissue Levels ◽  
Rat Ovary ◽  
Camp System ◽  
High Concentrations ◽  
Camp Levels

ABSTRACT The actions of LH (NIH-LH-B8) and FSH (NIH-FSH-S9) on the cyclic AMP (cAMP) system in ovaries of 23–24 day old rats have been analyzed. An intravenous injection of LH increased ovarian cAMP levels in vivo after only 20 seconds. Maximal cAMP levels were seen after 15 min. Addition of LH or FSH in vitro to the isolated ovaries produced dose dependent increases of cAMP in the tissue as well as in the incubation medium. Low concentrations of LH caused a release of cAMP into the incubation medium without any detectable change in the tissue levels. The levels of cAMP in the incubation media for all concentrations of FSH were lower than the tissue levels, whereas for LH the opposite was found. In time-course experiments where the concentrations of LH (10 μg/ml) and FSH (100 μg/ml) were chosen to give similar tissue levels of cAMP, the release of the cyclic nucleotide into the incubation medium was approximately 2–3 times greater for LH than for FSH at the time periods studied (5–240 min). When LH and FSH were tested together in high concentrations, their effects were additive. When the ovaries were first incubated with FSH for 120 min followed by an incubation with LH, the stimulatory effect of LH was considerably reduced. When the order of the incubations was reversed, however, LH did not change the response to FSH. The results show that both LH and FSH have intrinsic effects on the cAMP system in the prepubertal rat ovary, but that the effects of the two gonadotrophins are not identical.

STIMULATORY EFFECT OF FSH IN VITRO ON THE EXTRACELLULARLY ACTIVE CYCLIC AMP PHOSPHODIESTERASE IN THE PREPUBERTAL RAT OVARY

1976 ◽  
Vol 81 (2) ◽  
pp. 563-573 ◽  
Author(s):  
Gunnar Selstam ◽  
Sten Rosberg
Keyword(s):  
Cyclic Amp ◽  
Incubation Medium ◽  
Inorganic Phosphate ◽  
Kinetic Studies ◽  
Bicarbonate Buffer ◽  
Low Concentrations ◽  
Rat Ovary ◽  
Camp System ◽  
Burk Plot

ABSTRACT Intact prepubertal rat ovaries were incubated with radioactively labelled adenosine 3,′5′-cyclic monophosphate (cAMP) in Krebs bicarbonate buffer containing glucose. The rate of degradation of cAMP was determined by measuring the radioactivity in the medium after precipitation with Ba(OH)2 and ZnSO4. The fate of the nucleotide was followed by measuring the products in the incubation medium. Paper chromatography was used for the separation and identification of these products. It was found that cAMP was degraded to AMP, which in turn was degraded to inorganic phosphate (Pi) and adenosine. An uptake of labelled products was also observed. NIH-FSH-S9 (10 and 100 μg/ml), but not NIH-LH-B8 (0.1–100 μg/ml), increased the degradation of cAMP. Concomitantly, an increased accumulation of labelled adenosine and Pi as well as an increased uptake of labelled products were seen. Kinetic studies with low concentrations of cAMP (0.125–0.025 μmol/l) revealed an apparent Km value of 0.12 μmol/l for the phosphodiesterase (PDE) activity. FSH significantly changed the slope of the curve in the Lineweaver-Burk plot by increasing the PDE activity. The increased PDE activity in the presence of FSH is discussed in relation to earlier findings of differences in action between LH and FSH on the cAMP system in the prepubertal rat ovary.

EFFECTS OF GONADOTROPHINS AND CYCLIC 3′,5′-AMP ON IN VITRO INCORPORATION OF [3H]URIDINE INTO RNA OF THE PREPUBERTAL RAT OVARY

1973 ◽  
Vol 72 (4) ◽  
pp. 771-785 ◽  
Author(s):  
Jan Jarlstedt ◽  
Lars Nilsson ◽  
Lars Hamberger ◽  
Kurt Ahrén
Keyword(s):  
Cyclic Nucleotide ◽  
Gel Electrophoresis ◽  
Incubation Medium ◽  
Polyacrylamide Gel Electrophoresis ◽  
Labelling Pattern ◽  
Total Rna ◽  
Rat Ovary ◽  
Prepubertal Rats

ABSTRACT In vivo and in vitro effects of FSH and LH on in vitro incorporation of [3H]uridine into RNA of the prepubertal rat ovary have been studied. RNA was fractionated with composite agarose-polyacrylamide gel electrophoresis. When FSH was injected into the prepubertal rats 4 h before incubation of the ovaries, the incorporation of labelled uridine into total RNA was decreased showing relatively more radioactivity concentrated to the RNA fractions lighter than 28S as compared to the controls. These effects were not seen when FSH was added to the incubation medium in vitro. When LH was added in vitro to the isolated ovaries a higher percentage of incorporated radioactivity was concentrated in the RNA fractions heavier than 28S without any change in the incorporation of [3H]uridine into total RNA. LH administered in vivo 30 min before incubation of the ovaries gave the same change in the labelling pattern between the RNA fractions as LH in vitro but in addition showed a decreased incorporation of radioactivity into total RNA. The in vitro effects of cyclic 3′,5′-AMP were also studied. When prepubertal rat ovaries were incubated in 10 mmol/l of this cyclic nucleotide, the incorporation of [3H] uridine into total RNA was decreased without any change in the labelling pattern.

ACUTE INFLUENCE OF LH AND FSH ON CYCLIC AMP FORMATION IN ISOLATED GRANULOSA CELLS OF THE RAT

1978 ◽  
Vol 88 (3) ◽  
pp. 567-579 ◽  
Author(s):  
Lars Hamberger ◽  
Knut Nordenström ◽  
Sten Rosberg ◽  
Anita Sjögren
Keyword(s):  
Cyclic Amp ◽  
Granulosa Cells ◽  
Phosphodiesterase Inhibitor ◽  
Maximal Response ◽  
Adenylate Cyclase System ◽  
Rat Ovary ◽  
Mechanical Isolation ◽  
Ovulatory Follicles ◽  
Camp Levels

ABSTRACT A technique for the mechanical isolation of granulosa cells from the rat ovary is described. Cyclic AMP formation by the isolated granulosa cells of the follicles in various stages of development was studied in response to the administration in vitro of gonadotrophins. In granulosa cells from small to medium-sized follicles FSH but not LH stimulated cAMP formation, while in cells from pre-ovulatory follicles both gonadotrophins had a stimulatory effect. The effects of both gonadotrophins were transient with a maximal response after 15 to 60 min of incubation. In the presence of the phosphodiesterase inhibitor, 3-isobutyl-methylxanthine, the action of FSH was potentiated and prolonged while the response to LH was unaffected. These data indicate that both gonadotrophins activate the adenylate cyclase system of the isolated granulosa cells while FSH in addition stimulates the phosphodiesterase activity. Consecutive determinations of cAMP during and after the pre-ovulatory LH-FSH surge, demonstrated a rise of cAMP levels in granulosa cells from the pre-ovulatory follicles following endogenous gonadotrophin release. cAMP levels remained high or increased until the time of ovulation.

scholarly journals Flow Threshold for Reduction of Cyclic AMP Binding in the Hippocampus CA1 and other Brain Regions during Stroke Development in Gerbils

1996 ◽  
Vol 16 (3) ◽  
pp. 468-473 ◽  
Author(s):  
Kortaro Tanaka ◽  
Shintaro Gomi ◽  
Ban Mihara ◽  
Toshitaka Shirai ◽  
Shigeru Nogawa ◽  
...  
Keyword(s):  
Cyclic Amp ◽  
Time Course ◽  
Brain Regions ◽  
Artery Occlusion ◽  
Carotid Artery Occlusion ◽  
Dependent Protein ◽  
Camp System ◽  
Flow Threshold ◽  
Common Carotid Artery Occlusion

The flow threshold for alterations of the in vitro [3H]cyclic AMP (cAMP) binding, an indicator of the total amount of particulate cAMP-dependent protein kinase, was evaluated in the gerbil brain after 30 min, 2 h, and 6 h of unilateral common carotid artery occlusion, respectively. The autoradiographic method developed in our laboratory enabled us to measure the [3H]cAMP binding and local CBF in each region of the same brain. The ischemic flow thresholds for reduction of the cAMP binding in the hippocampus CA1 were 18, 34, and 49 ml 100 g–1 min–1 after 30-min, 2-h, and 6-h ischemia, respectively. These values were higher than those in other regions such as the hippocampus CA3 and temporal cerebral cortex in each duration of ischemia. These findings indicate that (a) the ischemic flow threshold for perturbation of the cAMP system may be higher in the hippocampus CA1 than in other brain regions, suggesting that the hippocampus CA1 could be especially vulnerable to acute ischemic stress; and (b) the level of the aforementioned threshold may increase progressively during the time course of ischemia in particular regions such as the hippocampus CA1 and CA3, suggesting that the duration of ischemia exerts a definite influence on the viability of the ischemic neuronal cells in these regions.

CYCLIC AMP IN ISOLATED CORPORA LUTEA OF THE RAT: INFLUENCE OF GONADOTROPHINS AND PROSTAGLANDINS

1974 ◽  
Vol 77 (4) ◽  
pp. 737-752 ◽  
Author(s):  
Hans Herlitz ◽  
Lars Hamberger ◽  
Sten Rosberg ◽  
Kurt Ahrén
Keyword(s):  
Corpus Luteum ◽  
Incubation Medium ◽  
Time Course ◽  
First Generation ◽  
Prostaglandin E ◽  
Corpora Lutea ◽  
Bicarbonate Buffer ◽  
Camp Content ◽  
Camp Levels

ABSTRACT Corpora lutea were isolated from 34–39 day-old rats injected with 10 IU PMSG when 30 days old leading to ovulation early in the morning of day 33. Three day-old corpora lutea were incubated in Krebs bicarbonate buffer containing 5.5 mmol/l glucose. Addition of LH to the incubation medium increased accumulation of cyclic 3′, 5′-AMP (cAMP) in a dose-dependent way in the isolated tissue and caused a release of cAMP to the incubation medium. cAMP was determined by the protein binding technique of Gilman (1970). There was a continuous rise in the levels of cAMP in both tissue and medium with increasing incubation time in presence of LH. Neither prolactin nor FSH could influence the cAMP levels in the corpus luteum tissue in vitro. Prostaglandin E2 (PGE2) caused a stimulation with respect to cAMP formation. The time-course of the PGE2 effect was quite different from that of LH: PGE2 gave maximal tissue cAMP content within 5–15 min with decreasing levels thereafter, compared to the continuous rise with LH stimulation for at least 1 h. In experiments performed on corpora lutea of different ages (1–7 day-old), tissue levels of cAMP were determined after incubations with LH or PGE2. There was a dramatic increase of tissue cAMP in the very young corpus luteum and a marked decrease in sensitivity to LH with increasing age of the corpus luteum with a very small but still significant effect on the old corpora lutea. The stimulatory effect of PGE2 on cAMP levels on the other hand showed only a minimal change. A few experiments on the first generation of corpora lutea from mature cycling rats are also reported for comparison.

Influence of gonadotrophins on cAMP formation in theca cells isolated from pre-ovulatory rat follicles

1981 ◽  
Vol 96 (4) ◽  
pp. 534-540 ◽  
Author(s):  
Knut Nordenström ◽  
Lars Hamberger
Keyword(s):  
Theca Cells ◽  
In Vitro Exposure ◽  
Camp System ◽  
Ovulatory Follicles ◽  
Camp Levels ◽  
Camp Formation ◽  
Significant Stimulatory Effect

Abstract. Pre-ovulatory follicles were obtained from immature PMSG treated rats at various times on the day of pro-oestrus. From these follicles the theca capsules were mechanically isolated and subsequently incubated in the presence or absence of LH and/or FSH. The accumulation of cyclic adenosine 3'5'-monophosphate (cAMP) in tissue plus medium was determined. In certain experiments the rats were injected with LH, FSH or saline 2 h prior to sacrifice. When the theca cells were isolated from rats sacrificed before the endogenous gonadotrophin surge, FSH added in vitro did not significantly stimulate cAMP formation, while LH had a small but significant stimulatory effect. When isolated 2–5 h after the endogenous gonadotrophin surge the theca cells responded with a marked increase in cAMP formation when exposed to LH in vitro, whereas FSH in vitro still had no stimulatory effect. Theca cells, isolated before the endogenous gonadotrophin surge, from rats pre-treated with a single ip injection of FSH 2 h prior to sacrifice, responded to a subsequent in vitro exposure to LH with a marked increase in cAMP levels. The results indicate that the FSH component of the endogenous gonadotrophin surge increases the sensitivity of the theca cells to LH - i.e. in vivo exposure to FSH seems to be essential for the development of responsiveness of the cAMP system to LH in the theca cells from pre-ovulatory rat follicles.

In Vitro Effects of Ethanol on Rabbit Platelet Aggregation, Secretion of Granule Contents, and Cyclic AMP Levels in the Presence of Prostacyclin

1989 ◽  
Vol 61 (02) ◽  
pp. 254-258 ◽  
Author(s):  
Margaret L Rand ◽  
Peter L Gross ◽  
Donna M Jakowec ◽  
Marian A Packham ◽  
J Fraser Mustard
Keyword(s):  
Cyclic Amp ◽  
Inhibitory Effect ◽  
Rabbit Platelet ◽  
Inhibitory Effects ◽  
Low Concentrations ◽  
Rabbit Platelets ◽  
High Concentrations ◽  
In Vitro Effects ◽  
Aggregation Of Platelets

SummaryEthanol, at physiologically tolerable concentrations, inhibits platelet responses to low concentrations of collagen or thrombin, but does not inhibit responses of washed rabbit platelets stimulated with high concentrations of ADP, collagen, or thrombin. However, when platelet responses to high concentrations of collagen or thrombin had been partially inhibited by prostacyclin (PGI2), ethanol had additional inhibitory effects on aggregation and secretion. These effects were also observed with aspirin- treated platelets stimulated with thrombin. Ethanol had no further inhibitory effect on aggregation of platelets stimulated with ADP, or the combination of ADP and epinephrine. Thus, the inhibitory effects of ethanol on platelet responses in the presence of PGI2 were very similar to its inhibitory effects in the absence of PGI2, when platelets were stimulated with lower concentrations of collagen or thrombin. Ethanol did not appear to exert its inhibitory effects by increasing cyclic AMP above basal levels and the additional inhibitory effects of ethanol in the presence of PGI2 did not appear to be brought about by further increases in platelet cyclic AMP levels.

Comparison of High Purity Factor IX Concentrates and a Prothrombin Complex Concentrate in a Canine Model of Thrombogenicity

1991 ◽  
Vol 66 (05) ◽  
pp. 609-613 ◽  
Author(s):  
I R MacGregor ◽  
J M Ferguson ◽  
L F McLaughlin ◽  
T Burnouf ◽  
C V Prowse
Keyword(s):  
High Purity ◽  
Time Course ◽  
Prothrombin Complex Concentrate ◽  
Degradation Products ◽  
Canine Model ◽  
Factor Ix ◽  
In Vitro Tests ◽  
Albumin Infusion

SummaryA non-stasis canine model of thrombogenicity has been used to evaluate batches of high purity factor IX concentrates from 4 manufacturers and a conventional prothrombin complex concentrate (PCC). Platelets, activated partial thromboplastin time (APTT), fibrinogen, fibrin(ogen) degradation products and fibrinopeptide A (FPA) were monitored before and after infusion of concentrate. Changes in FPA were found to be the most sensitive and reproducible indicator of thrombogenicity after infusion of batches of the PCC at doses of between 60 and 180 IU/kg, with a dose related delayed increase in FPA occurring. Total FPA generated after 100-120 IU/kg of 3 batches of PCC over the 3 h time course was 9-12 times that generated after albumin infusion. In contrast the amounts of FPA generated after 200 IU/kg of the 4 high purity factor IX products were in all cases similar to albumin infusion. It was noted that some batches of high purity concentrates had short NAPTTs indicating that current in vitro tests for potential thrombogenicity may be misleading in predicting the effects of these concentrates in vivo.

IN VITRO UPTAKE OF TRITIATED OESTRADIOL BY THE ANTERIOR HYPOTHALAMUS AND HYPOPHYSIS OF THE RAT

1970 ◽  
Vol 64 (4) ◽  
pp. 687-695 ◽  
Author(s):  
Junzo Kato
Keyword(s):  
Incubation Medium ◽  
Posterior Hypothalamus ◽  
Anterior Hypothalamus ◽  
Ovariectomized Rats ◽  
Free Medium ◽  
Cortex Cerebri ◽  
Anterior Hypophysis ◽  
In Vitro Uptake

ABSTRACT The anterior, middle, and posterior hypothalamus, the cortex cerebri, the anterior hypophysis as well as the diaphragm of adult ovariectomized rats were incubated in vitro with tritiated 17β-oestradiol. The uptake of tritiated oestradiol was differentially distributed intracerebrally with higher accumulation in the anterior hypothalamus and the hypophysis. Lowering the temperature of the incubation medium caused a reduction in the uptake of radioactivity by the anterior hypothalamus as compared to that found in other brain tissues. Tritiated oestradiol taken up in vitro by the anterior hypothalamus and the hypophysis tended to be retained after further incubation in a steroid-free medium. The addition of non-radioactive 17β-oestradiol to the medium inhibited the uptake of tritiated oestradiol by these tissues. Moreover, pretreatment with non-radioactive 17β-oestradiol in vivo prevented the preferential accumulation of tritiated oestradiol in vitro in the anterior hypothalamus and the hypophysis. These results indicate that oestradiol is preferentially taken up in vitro by the anterior hypothalamus and the hypophysis of the rat.

ÉTUDE DE L'ACTIVITÉ BIOLOGIQUE IN VITRO DES HORMONES GONADOTROPES

1960 ◽  
Vol XXXIII (III) ◽  
pp. 444-450 ◽  
Author(s):  
Maria de la Luz Suarez Soto ◽  
Jean Legault Démare
Keyword(s):  
Paper Chromatography ◽  
Incubation Medium ◽  
Ultraviolet Absorption ◽  
Rat Ovary

ABSTRACT Serum gonadotrophin (PMS) when added to the incubation medium of rat ovary slices increases the amount of Δ4-3-ketosteroids produced. This enhancement is proportional to the logarithm of dose. The ketosteroids were determined by their ultraviolet absorption; paper chromatography has shown that only androst-4-en-3,17-dione is present.

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