Studies of the luteinization process in the rat: follicular and luteal adenylate cyclase responsiveness to catecholamines

1987 ◽  
Vol 114 (2) ◽  
pp. 171-177 ◽  
Author(s):  
Gunnar Selstam ◽  
Ensio Norjavaara ◽  
Sten Rosberg ◽  
Knut Nordenström ◽  
Jan-Erik Damber ◽  
...  
Keyword(s):  
Adenylate Cyclase ◽  
Luteal Phase ◽  
Follicular Phase ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Significant Response ◽  
Corpora Lutea ◽  
Preovulatory Follicles ◽  
The Subject ◽  
Catecholamine Responsiveness

Abstract. The subject of the study was the development of follicular and luteal catecholamine responsiveness during the periovulatory period. Follicles and corpora lutea and granulosa cells were obtained from the PMSG ovulatory model and adenylate cyclase activity measured in membrane fractions. In the earlier part of the follicular phase (48 h and 26 h before ovulation) no response to noradrenalin on follicular and granulosa cell adenylate cyclase activity was seen. A small but significant response to noradrenalin was observed from 18 h before until 3 h after ovulation. The response to noradrenalin on luteal adenylate cyclase activity increased markedly with time and reached a maximum 39–57 h after ovulation. After this time the luteal response to noradrenalin decreased with luteal age. The effect of LH was less than that of noradrenalin during the early luteal phase, and in contrast to noradrenalin, increased with luteal age. The combined effects of LH and noradrenalin were not additive. In order to test whether gonadotropins could induce a noradrenalin response, injections of LH and FSH were given to the animals two days before ovulation. LH, but not FSH, induced a small but significant response to noradrenalin 16 h later. The present investigation has shown that ovarian responsiveness to catecholamines appears in preovulatory follicles followed by a marked increase in luteal catecholamine responsiveness. This development could at least partly occur under the influence of LH.

Catecholamine content and adenylate cyclase activity in corpora lutea of different ages of the PMSG-treated immature rat

1987 ◽  
Vol 53 (3) ◽  
pp. 155-160 ◽  
Author(s):  
Gunnar Selstam ◽  
Ensio Norjavaara ◽  
Sten Rosberg ◽  
Iqbal Khan ◽  
Bertil Hamberger ◽  
...  
Keyword(s):  
Adenylate Cyclase ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Corpora Lutea ◽  
Immature Rat ◽  
Catecholamine Content ◽  
Different Ages

Adenylate cyclase activity in rat corpora lutea evidence for a rapid development of the regulatory Ns-protein

1986 ◽  
Vol 112 (4) ◽  
pp. 565-570 ◽  
Author(s):  
Sten Rosberg ◽  
Ensio Norjavaara ◽  
Monica Sender Baum ◽  
Iqbal Khan
Keyword(s):  
Adenylate Cyclase ◽  
Rapid Development ◽  
Close Correlation ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Corpora Lutea ◽  
Constant Amount ◽  
Adrenergic Response ◽  
Catalytic Unit ◽  
Serum Gonadotropin

Abstract. Adenylate cyclase activity was studied in membranes from isolated corpora lutea of defined ages obtained from pregnant mare's serum gonadotropin treated rats and the effects of luteinizing hormone (LH), isoproterenol, guanylylimidodiphosphate (Gpp (NH)p), fluoride and forskolin were compared. The effect of LH on adenylate cyclase activity increased with the luteal age up to nine days of age, while the effect of isoproterenol increased dramatically during the first days, reaching a maximum at 2–3 days of age and then declined. Forskolin potentiated the effects of both LH and isoproterenol without affecting the patterns of age-dependency. The effect of forskolin itself was fairly constant during the luteal phase, indicating a relatively constant amount of the catalytic unit in the corpus luteum. The effects of fluoride and Gpp(NH)p on the other hand increased markedly during the first days and then remained constant for the rest of the period studied. These results suggest that the regulatory Ns-protein develops during the first days of luteal life. It is speculated that the close correlation between the development of β-adrenergic response and the development of Ns-protein are causally related.

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).

Sign in / Sign up

Export Citation Format

Share Document