Ontogeny of gonadotrophin receptors and gonadotrophin-stimulated cyclic AMP production in the neonatal rat ovary

1990 ◽  
Vol 127 (2) ◽  
pp. 297-303 ◽  
Author(s):  
T. Sokka ◽  
I. Huhtaniemi
Keyword(s):  
Cyclic Amp ◽  
Cholera Toxin ◽  
Specific Binding ◽  
The Body ◽  
Neonatal Rat ◽  
Female Rats ◽  
Fetal Life ◽  
Camp Production ◽  
Rat Ovary

ABSTRACT The sequence of appearance of FSH and LH receptors, and response of cyclic AMP (cAMP) production to these hormones and cholera toxin, were studied in the fetal and neonatal rat ovary. Specific binding of radio-labelled human (h)FSH and chorionic gonadotrophin (CG) to ovarian homogenates was first detectable on day 7 of life. The content of FSH receptors per ovary increased tenfold between days 7 and 16, and that of LH receptors 27-fold. A significant response of cAMP production in vitro to FSH appeared on day 4 of life, but no significant effect of hCG on cAMP was achieved until day 7. In contrast, cholera toxin had a marked effect on cAMP production by day 17 of fetal life. Although both FSH and LH receptors were detectable in the neonatal rat ovary by day 7, the present findings indicate that the FSH responsiveness of the ovary appears earlier than that of LH. The post-receptor machinery of cAMP production is already functional in the fetal ovary as shown by the experiments with cholera toxin. The appearance of the receptor may therefore be the last link in the ontogeny of the gonadotrophin signal transduction system in the ovary. To study the hormone dependence of the appearance of gonadotrophin responsiveness, neonatal female rats were treated on days 1–6 or 1–9 of life with a potent gonadotrophin-releasing hormone antagonist, and killed on the following day. In both treatment groups, the pituitary LH and FSH contents were suppressed. The body weights remained unaltered, but ovarian weights decreased significantly during both periods of treatment (days 1–6,26·1%, P < 0·05; days 1–9,54·0%, P <0·001). No difference in basal or FSH-stimulated cAMP production was achieved by antagonist treatment for the first 6 days of life. The basal and hCG-stimulated rates of cAMP production per ovary were reduced in animals treated for 9 days (P <0·01), but the FSH-stimulated cAMP production remained unaffected. Hence, whereas the responsiveness to FSH seems to develop in the absence of normal gonadotrophin secretion, a causal relationship between normal gonadotrophin levels and the appearance of LH/hCG responsiveness is apparent in the neonatal rat ovary. Journal of Endocrinology (1990) 127, 297–303

scholarly journals Effects of dopamine on prolactin secretion and cyclic AMP accumulation in the rat anterior pituitary gland

1981 ◽  
Vol 194 (1) ◽  
pp. 119-128 ◽  
Author(s):  
Keith P. Ray ◽  
Michael Wallis
Keyword(s):  
Cyclic Amp ◽  
Cholera Toxin ◽  
Anterior Pituitary ◽  
Phosphodiesterase Inhibitors ◽  
Prolactin Secretion ◽  
Significant Inhibition ◽  
Female Rats ◽  
Control Value ◽  
Cyclic Amp Accumulation

The effects of dopamine on pituitary prolactin secretion and pituitary cyclic AMP accumulation were studied by using anterior pituitary glands from adult female rats, incubated in vitro. During 2h incubations, significant inhibition of prolactin secretion was achieved at concentrations between 1 and 10nm-dopamine. However, 0.1–1μm-dopamine was required before a significant decrease in pituitary cyclic AMP content was observed. In the presence of 1μm-dopamine, pituitary cyclic AMP content decreased rapidly to reach about 75% of the control value within 20min and there was no further decrease for at least 2h. Incubation with the phosphodiesterase inhibitors theophylline (8mm) or isobutylmethylxanthine (2mm) increased pituitary cyclic AMP concentrations 3- and 6-fold respectively. Dopamine (1μm) had no effect on the cyclic AMP accumulation measured in the presence of theophylline, but inhibited the isobutylmethylxanthine-induced increase by 50%. The dopamine inhibition of prolactin secretion was not affected by either inhibitor. Two derivatives of cyclic AMP (dibutyryl cyclic AMP and 8-bromo cyclic AMP) were unable to block the dopamine (1μm) inhibition of prolactin secretion, although 8-bromo cyclic AMP (2mm) significantly stimulated prolactin secretion and both compounds increased somatotropin (growth hormone) release. Cholera toxin (3μg/ml for 4h) increased pituitary cyclic AMP concentrations 4–5-fold, but had no effect on prolactin secretion. The inhibition of prolactin secretion by dopamine was unaffected by cholera toxin, despite the fact that dopamine had no effect on the raised pituitary cyclic AMP concentration caused by this factor. Dopamine had no significant effect on either basal or stimulated somatotropin secretion under any of the conditions tested. We conclude that the inhibitory effects of dopamine on prolactin secretion are probably not mediated by lowering of cyclic AMP concentration, although modulation of the concentration of this nucleotide in some other circumstances may alter the secretion of the hormone.

Cytochemical Evidence for Presynatic β-Adrenergic Regulation of Secretion in the Developing Rat Submandibular Gland

1977 ◽  
Vol 35 ◽  
pp. 430-431
Author(s):  
L.S. Cutler
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Submandibular Gland ◽  
Neonatal Rat ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Parotid Glands ◽  
Adrenergic Agonist ◽  
Rat Submandibular Gland

Many studies previously have shown that the B-adrenergic agonist isoproterenol and the a-adrenergic agonist norepinephrine will stimulate secretion by the adult rat submandibular (SMG) and parotid glands. Recent data from several laboratories indicates that adrenergic agonists bind to specific receptors on the secretory cell surface and stimulate membrane associated adenylate cyclase activity which generates cyclic AMP. The production of cyclic AMP apparently initiates a cascade of events which culminates in exocytosis. During recent studies in our laboratory it was observed that the adenylate cyclase activity in plasma membrane fractions derived from the prenatal and early neonatal rat submandibular gland was retractile to stimulation by isoproterenol but was stimulated by norepinephrine. In addition, in vitro secretion studies indicated that these prenatal and neonatal glands would not secrete peroxidase in response to isoproterenol but would secrete in response to norepinephrine. In contrast to these in vitro observations, it has been shown that the injection of isoproterenol into the living newborn rat results in secretion of peroxidase by the SMG (1).

Ontogeny of hepatic insulin and glucagon receptors and adenylate cyclase in rabbit

1983 ◽  
Vol 244 (6) ◽  
pp. E624-E631
Author(s):  
S. Ganguli ◽  
M. K. Sinha ◽  
B. Sterman ◽  
P. Harris ◽  
M. A. Sperling
Keyword(s):  
Adenylate Cyclase ◽  
Cholera Toxin ◽  
Plasma Membranes ◽  
Specific Binding ◽  
Regulatory Protein ◽  
Late Gestation ◽  
Camp Production ◽  
Hormonal Activation ◽  
Glucagon Receptors ◽  
Significant Increment

In rabbit liver plasma membranes (LPM), specific binding of 125I-insulin rapidly increased in late gestation and peaked at birth, declining thereafter. In contrast, 125I-glucagon binding was lowest in late gestation, somewhat higher at birth, and increased by 48 h although only to 20-25% of adult. These changes in binding were due to changing numbers of receptors involving predominantly high affinity sites for insulin and low affinity sites for glucagon, with only minor changes in affinity. Despite measurable glucagon receptors by birth, fetal LPM produced no increment above basal in cAMP production with maximal doses of glucagon (10(-6) M), prostaglandin E1 (10(-4) M), or epinephrine (10(-4) M). Near birth only NaF (10 mM) produced a modest but significant increment in cAMP. By 2 h postbirth, all stimuli evoked significant increments in cAMP production that increased progressively but was still only 15-20% of adult at 48 h. Furthermore, although specific binding of cholera toxin was greater in fetal LPM (11 +/- 1 vs. 6 +/- 1%), cholera toxin-stimulated cAMP production increased by only 12-26% above basal in the fetus compared with 220% in adult. Markers of membrane purity including 5'-nucleotidase, phosphodiesterase, and insulin or glucagon degradation were not different in fetus and adult. We conclude that receptors and components of the adenylate cyclase complex mature independently; initial coupling occurs between the G/F regulatory protein and the catalytic unit (NaF but not hormonal activation) followed within hours of birth by coupling to the hormone receptor.

Modulation of the biological activity of thyrotrophin by anti-human thyrotrophin monoclonal antibodies

1990 ◽  
Vol 126 (2) ◽  
pp. 333-340 ◽  
Author(s):  
S. R. Page ◽  
A. H. Taylor ◽  
W. Driscoll ◽  
M. Baines ◽  
R. Thorpe ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Biological Activity ◽  
Monoclonal Antibodies ◽  
Cyclic Amp ◽  
Receptor Activation ◽  
Camp Production ◽  
Dose Dependent ◽  
Bovine Tsh

ABSTRACT The mechanism by which monoclonal antibodies enhance the biological activity of a number of hormones is poorly understood. One such antibody (GC73), which binds to human but not bovine TSH, enhances the bioactivity of human TSH in vivo. We have investigated whether GC73 enhancement of TSH bioactivity involves potentiation of hormone-receptor activation assessed by the cyclic AMP (cAMP) responses of both primary human thyrocyte cultures and a TSH-responsive human thyrocyte cell line (SGHTL-45). GC73 had no effect on basal cAMP production. In contrast to its enhancement of the bioactivity of human TSH in vivo, it markedly inhibited the cAMP response to 1 and 10 mU human TSH/ml in primary thyrocytes. This effect was dose-dependent with neutralization of the bioactivity of TSH occurring at 2 mg GC73/ml. GC73 had no effect on the bioactivity of bovine TSH. In contrast, a second anti-TSH monoclonal antibody (TC12), which binds to both human and bovine TSH, inhibited the bioactivity of both species of TSH. Similar results were obtained using SGHTL-45 cells, although the peak concentrations of cAMP were lower. We conclude that binding of GC73 to human TSH resulted in inhibition rather than enhancement of the in-vitro biological activity of human TSH. We suggest that GC73 enhancement of human TSH bioactivity seen in vivo does not result from a mechanism involving potentiation of receptor activation by human TSH. Journal of Endocrinology (1990) 126, 333–340

THE RESPONSE OF THE IMMATURE RAT OVARY TO GONADOTROPHINS: ACUTE CHANGES IN CYCLIC AMP, PROGESTERONE, TESTOSTERONE, ANDROSTENEDIONE AND OESTRADIOL AFTER TREATMENT WITH PMS OR FSH + LH

1976 ◽  
Vol 82 (2) ◽  
pp. 413-425 ◽  
Author(s):  
T. Sashida ◽  
D. C. Johnson
Keyword(s):  
Cyclic Amp ◽  
Control Level ◽  
Elevated Serum ◽  
Serum Testosterone ◽  
Female Rats ◽  
Serum Testosterone Level ◽  
Base Line ◽  
Serum Progesterone ◽  
Immature Rat ◽  
Rat Ovary

ABSTRACT Radioimmunoassays were used to measure changes in progesterone, testosterone, androstenedione, oestradiol, gonadotrophin and ovarian cyclic AMP in immature female rats during the first 24 h after exposure to slowly (PMS) or rapidly (FSH + LH) disappearing gonadotrophins. Cyclic AMP was increased 30 min after injection of either kind of gonadotrophin but it had returned to control level within 4 h. Serum and ovarian testosterone and androstenedione also increased to a peak at 30 min but decreased to base line by the 4th h. Multiple injections of FSH + LH maintained an elevated serum testosterone level but they had little effect upon the secretion of androstenedione. Serum and ovarian progesterone increased quickly after treatment with gonadotrophin. With PMS the peak in the serum was reached at 8 h, it remained high for 4 h and then fell precipitously between the 12th and 16th h. FSH + LH produced a prompt increase in serum progesterone but the level could be maintained only by repeated doses given every 4 h. Oestradiol was not increased in the serum or the ovary until 20 h after PMS. One or two doses of FSH + LH did not produce an increase in oestrogen but a transient increase was found with 3 doses; 4 doses kept an elevated level of oestradiol for 12 h. These results indicate that the aromatizing system of the immature rat ovary is relatively inactive and that continual stimulation by gonadotrophin for about 10–12 h is necessary to bring about increased function. In contrast, the mechanisms for the synthesis and secretion of progesterone and androgens are very active and can be immediately stimulated by exposure to gonadotrophins.

The effects of bisphenol A in in vitro neonatal rat ovary

2014 ◽  
Author(s):  
Korhan Altunbas ◽  
Artay Yagci ◽  
Sefa Celik ◽  
Ozlem Ozden Akkaya ◽  
Berrin Zik
Keyword(s):  
Bisphenol A ◽  
Neonatal Rat ◽  
Rat Ovary

STEROID HORMONE FORMATION BY THE RAT OVARY.

1966 ◽  
Vol 51 (1) ◽  
pp. 131-139 ◽  
Author(s):  
Bernard F. Rice ◽  
Albert Segaloff
Keyword(s):  
Steroid Hormone ◽  
Ovarian Tissue ◽  
Female Rats ◽  
Male Rats ◽  
Corpora Lutea ◽  
Castrate Male ◽  
Rat Ovary ◽  
17 Hydroxyprogesterone ◽  
Hormone Formation

ABSTRACT Ovaries were transplanted to the spleens of castrate male rats. After 120 days, slices of ovarian tissue, composed predominantly of corpora lutea, were incubated in Krebs-Ringer bicarbonate medium containing 50 μc acetate-1-14C. Radioactive steroid formation was assessed quantitatively by reverse isotope dilution. The formation of radioactive progesterone and 20α-hydroxy-pregn-4-en-3-one was established. The formation of radioactive 3β-hydroxy-pregn-5-en-20-one, androst-4-ene-3,17-dione, 17-hydroxyprogesterone, testosterone, oestrone and 17β-oestradiol could not be established. It appears that the corpus luteum of the rat, induced by endogenous gonadotrophins, forms only progestins from acetate-1-14C. Contrary to results previously obtained with ovarian tissue transplanted to female rats, radioactive steroid formation in vitro appeared to be augmented by luteinizing hormone (NIH-LH-S1) added to the incubation flasks. Administration of human chorionic gonadotrophin (200 IU/day) for 5 days prior to autopsy did not enhance acetate-1-14C incorporation in vitro.

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 INFLUENCE OF THE LECTIN LACTOBACILLUS DELBRUECKII ssp. BULGARICUS ON ACTIVITY OF THE PROCESS OF PHAGOCYTOSIS

2018 ◽  
Vol 8 (3) ◽  
pp. 377-382
Author(s):  
A. S. Dolmashkina ◽  
E. A. Gorelnikova ◽  
L. V. Karpunina
Keyword(s):  
Phagocytic Activity ◽  
Specific Binding ◽  
Specific Interaction ◽  
The Body ◽  
Lactobacillus Delbrueckii ◽  
Bacterial Cells ◽  
Short Term ◽  
Adhesive Ability ◽  
Small Activity

The effect of Lactobacillus delbrueckii ssp. bulgaricus on the activity of macrophages — peritoneal (PMP) and alveolar (AMP), isolated from the body of white mice at 1, 3, 5, 7 days after the introduction of lectin, in the process of phagocytosis of bacteria Staphylococcus aureus 209-P. In the course of the studies, it was shown that by 6 hours the activity of PMP and AMP isolated within 24 hours after lectin administration had increased by 3.4 and 2.9 times. The PMP and AMP, isolated from the mice for 3 days, showed the greatest activity after 6 hours of incubation with bacterial cells in 1.6 and 2 times in comparison with the control. On day 5, PMP and AMP showed the greatest activity by 6 hours in the process of phagocytosis compared with the control, respectively, in 2.2 and 2.4 times. At day 7, only AMP had the highest activity after 30 minutes of incubation with bacteria 1.5 times in comparison with the control in the process of phagocytosis in vitro by S. aureus 209-P. With respect to PMP, no changes were observed compared to the control. The analysis of the obtained data showed that the activity of macrophages isolated from the organism of mice injected with lectin on days 1, 3, 5 significantly differed from the control values at the final stages of the phagocytosis process of S. aureus 209-P. It can be assumed that the lectin interacting with the surface structures of PMP and AMP on the 1st, 3rd, 5th day of the experiment promotes a more short-term process of adhesion of bacterial cells in phagocytosis. To evaluate the specificity of lectin interaction with receptor structures of macrophages, experiments were conducted with a protein that did not have lectin properties-bovine serum albumin-BSA and lectin blocked by specific carbohydrates. It was shown that the phagocytic activity of macrophages in the presence of BSA was similar to control and did not differ significantly from it. BSA did not influence the completion of bacterial phagocytosis by macrophages. When studying the interaction of lectin blocked by specific carbohydrates on the phagocytic activity of macrophages, there was a slight increase in phagocytic activity against PMP, after 6 hours of phagocytosis and a slight decrease after 0.5 hours, 1 hour and 24 hours of phagocytosis. For AMP, the lectin blocked by a mixture of carbohydrates was similar to the control values. The results obtained made it possible to speak of the specific binding of lectin L. delbrueckii ssp. bulgaricus with surface AMP receptors. However, with respect to PMP, a small activity of macrophages in the process of phagocytosis was observed, which indicates the specific and non-specific binding of lectin L. delbrueckii ssp. bulgaricus with surface TMF receptors. It can be assumed that, at the molecular level, L. delbrueckii ssp. bulgaricus, in addition to a specific interaction with the receptor structures of PMP, can participate in a variety of nonspecific reactions. Thus, the lectin L. delbrueckii ssp. bulgaricus increased the adhesive ability of macrophages of mice, significantly influenced the completeness of the phagocytosis process of bacterial cells. A specific interaction of L. delbrueckii ssp bulgaricus with surface AMP receptors, both specific and non-specific interactions were observed with respect to PMP.

scholarly journals Exogenous Cyclic AMP, Cholera Toxin, and Endotoxin Induce Expression of the Lipopolysaccharide Receptor CD14 in Murine Bone Marrow Cells: Role of Purinoreceptors

1999 ◽  
Vol 6 (6) ◽  
pp. 885-890 ◽  
Author(s):  
Thierry Pedron ◽  
Robert Girard ◽  
Richard Chaby
Keyword(s):  
Bone Marrow ◽  
Cyclic Amp ◽  
Cholera Toxin ◽  
Bone Marrow Cells ◽  
Specific Binding ◽  
Cell Surface Receptor ◽  
Intracellular Camp ◽  
Purine Derivatives ◽  
Murine Bone Marrow ◽  
Surface Receptor

ABSTRACT Little is known about the mechanisms of lipopolysaccharide (LPS) signaling in immature cells that do not express the LPS receptor CD14 yet. Bone marrow granulocytes do not constitutively express CD14 but can be stimulated by low doses of LPS in the absence of serum and then express an inducible form of LPS receptor (iLpsR). We show that in addition to LPS, cholera toxin (CT) and various cyclic AMP (cAMP) analogs can also induce the expression of iLpsR, which was identified as CD14. Induction was independent of intracellular cAMP. The hypothesis that cAMP analogs act via a cell surface receptor was suggested by the unresponsiveness of trypsin-treated cells to these inducers and by the specific binding of [3H]cAMP to the cells. This binding was not inhibited by LPS or CT but was inhibited by various purine derivatives. However, the receptor involved is not a conventional purinoreceptor since both an agonist and an antagonist of such receptors were able to induce iLpsR expression. The results suggest that cAMP analogs and other purine derivatives induce iLpsR after interaction with an unconventional, trypsin-sensitive, purinoreceptor distinct from LPS and CT receptors.

Sign in / Sign up

Export Citation Format

Share Document