Search results for "Adrenocorticotropic hormone"
showing 10 items of 55 documents
Hormonal responsiveness in the Trier Social Stress Test and the dexamethasone‐corticotropin releasing hormone test in healthy individuals
2021
A number of different laboratory procedures investigate the hormonal response in a standardized pharmacological challenge test (dexamethasone-corticotropin releasing hormone; DEX-CRH) or in a psychosocial stress induction on the hypothalamic-pituitary-adrenocortical axis by the Trier Social Stress Test (TSST). However, the magnitude of the response related to the different stressors and the interaction of the responsiveness between the two tests is still unclear. Fifty-two participants underwent both the DEX-CRH test and the TSST on two separate days. The cortisol and the plasma adrenocorticotropic hormone (ACTH) release were assessed before and after the stress tests. For a specification o…
Pharmacological Characterization of Melanocortin Receptors in Fish Suggests an Important Role for ACTH
2005
The melanocortin (MC) receptor subtypes have distinctive characteristic binding profiles. We found that the trout and Fugu MC4 receptors have similar affinity for alpha-MSH and beta-MSH and a much higher affinity for ACTH than does the human MC4 receptor. The Fugu MC1 and the trout and Fugu MC5 receptors also have higher affinity for ACTH-derived peptides than alpha-, beta-, or gamma-MSH. It is tempting to speculate that ACTH-derived peptides may have played an important role as "original" ligands at the MC receptors, while the specificity of the different subtypes for the alpha-, beta-, and gamma-MSH peptides may have appeared at later stages during vertebrate evolution.
Hypothalamic-Pituitary-Adrenal Dysfunction in the Polycystic Ovary Syndrome
2007
Between 20 and 30% of patients with polycystic ovary syndrome (PCOS) demonstrate adrenal androgen (AA) excess, detectable primarily by elevated dehydroepiandrosterone sulfate (DHEAS) levels. Generalized adrenocortical hyperresponsivity to adrenocorticotropic hormone (ACTH) stimulation is also observed and may be the principal mechanism determining AA excess in PCOS. The causes of this abnormality are unclear, but increased peripheral metabolism of cortisol, altered factors regulating glucose-mediated glucose disposal, and perhaps ovarian sex steroids may in different ways contribute to the AA excess in PCOS. Additionally, DHEAS levels and the response of AAs to ACTH are relatively constant …
65 ASSOCIATION BETWEEN ALDOSTERONE AND CORTISOL LEVELS DURING THE OVULATORY PERIOD IN SPANISH PUREBRED MARES
2014
Preovulatory increased aldosterone (ALD) has been described as one of the physiological events that characterise the oestrous cycle in relation to the dynamics of the renin angiotensin aldosterone system. Within the mechanisms associated with this response are the stimulating effect of oestrogen on the synthesis of angiotensinogen, haemodynamic variations of renal blood flow, changes in sodium concentration, changes in the local sympathetic activity, and the effect of cortisol (CORT). In fact, CORT via adrenocorticotropic hormone contributes primarily to preovulatory ALD, and it is the primary regulator factor synthesis ALD (Chidambaram et al. 2002; Pechère-Bertschi et al. 2002; Szmuilowic…
ACTH-Eosinopenie nach Splenektomie und Blockade des RES
1955
Es wird uber ACTH-Versuche an Meerschweinchen bei verschiedenem Funktionszustand des RES berichtet. Splenektomierte, splenektomiert und zusatzlich mit 6 cm3 sowie mit 18 cm3 Trypanblau blockierte Tiere zeigten jedesmal ein deutliches Absinken der Eosinophilen im peripheren Blut nach Injektion von 10 mg ACTH. Eine Aufhebung oder Abschwachung des eosinopenischen Effektes durch die Funktionseinschrankung des RES wurde nicht beobachtet.
Tagesprofile von Plasmaaldosteron,-Cortisol, -Renin, -Angiotensinogen und -Angiotensinasen bei Normalpersonen
1976
Plasma cortisol and renin were estimated in 1 h intervals, plasma aldosterone, angiotensinogen and angiotensinases in 3 h intervals over periods of 24 h in six normal volunteers (age 20-26) under control conditions and subsequently under suppression of ACTH release by dexamethasone. Highest cortisol levels were found around 7 a.m., minimum levels between 9 p.m. and 1 a.m. Dexamethasone reduced cortisol to constantly low concentrations. Aldosterone was highest around 4 a.m. under control conditions and under dexamethasone, and showed lowest concentrations between 4 and 10 p.m. There were no significant differences between mean aldosterone concentrations at corresponding time points of the co…
Aldosterone biosynthesis induced by ACTH and angiotensin II in newborn rat adrenocortical cells transfected by c-EJ-Ha-ras oncogene
1991
Abstract Adrenocortical cells were obtained by fractionated trypsination of newborn rat adrenal glands and transfected with a plasmid containing the EJ T24 -Ha-ras oncogene. Isolation of adhesive cells led to a proliferative cell line with an overexpression of 21 kDa ras protein. These cells incubated with corticosterone or deoxycorticosterone as the precursor produced a high level of 18-hydroxycorticosterone and aldosterone as identified by gas chromatography- mass spectrometry. ACTH and angiotensin II increased the basal production of aldosterone nineteen-fold and six-fold respectively. Under ACTH stimulation the ratio between aldosterone and 18-hydroxycorticosterone production was 1:3. T…
Cardiovascular and Endocrine Properties of L-Tryptophan in Combination with Various Diets
1991
Brain serotonin neurons are intimately involved in a number of relevant physiological functions such as cardiovascular regulation, neuroendocrine output from the anterior pituitary (e.g. ACTH, prolactin), regulation of behavior (e.g. agression, sleep, locomotor and sexual behavior), mood or appetite control (Fernstrom, 1983; Lehnert et al., 1987; Spring et al., 1987; Wurtman, 1987). The synthesis of brain serotonin is dependent on the availability of the large neutral amino acid L-tryptophan that is hydroxylated to 5-L-hydroxytryptophan and subsequently decarboxylated to yield serotonin. The rate-limiting enzyme tryptophan hydroxylase has a Michaelis constant of approximately 2–3 x 10−5 M w…
18-hydroxylation in the Y-1 adrenal cell line: response to ACTH and to culture conditions.
1992
The 18-hydroxylation of deoxycorticosterone in the Y-1 adrenal cell line was studied under various incubation and cell culture conditions and compared to 11 beta-hydroxylation. Repeated incubation of the substrate increased both 18- and 11 beta-hydroxylation in the Y-1 cells. Furthermore, both 18- and 11 beta-hydroxylation were increased with increased serum concentration and prolonged incubation time. While the increase in 11 beta-hydroxylation seemed to be independent of the type of serum, 18-hydroxylation was much more important in cells cultured in fetal or newborn calf serum supplemented medium than in those cultured in horse serum supplemented medium. As expected, ACTH treatment incre…
Cloning of two melanocortin (MC) receptors in spiny dogfish
2004
We report the cloning and characterization of two melanocortin receptors (MCRs) from the spiny dogfish (Squalus acanthias) (Sac). Phylogenetic analysis shows that these shark receptors are orthologues of the MC3R and MC5R subtypes, sharing 65% and 70% overall amino acid identity with the human counterparts, respectively. The SacMC3R was expressed and pharmacologically characterized in HEK293 cells. The radioligand binding results show that this receptor has high affinity for adrenocorticotropic hormone (ACTH)-derived peptides while it has comparable affinity for alpha- and beta-melanocyte stimulating hormone (MSH), and slightly lower affinity for gamma-MSH when compared with the human ortho…