Formation of releasable γ-aminobutyrate from putrescine by rat adrenal slices in vitro

1989 ◽  
Vol 123 (2) ◽  
pp. 227-232 ◽  
Author(s):  
B. B. Oon ◽  
P. R. Scraggs ◽  
B. Gillham
Keyword(s):  
Catalytic Activity ◽  
Adrenal Gland ◽  
Incubation Medium ◽  
Functional Significance ◽  
Response Curve ◽  
Diamine Oxidase ◽  
Adrenal Glands ◽  
Metabolic Transformation ◽  
Stimulation Of

ABSTRACT Rat adrenal gland slices, when incubated in vitro with [1,4-14C]putrescine, accumulate the radioactive diamine and convert it, in part, to a compound indistinguishable (in four separative systems) from [14C]γ-aminobutyrate (GABA). Adrenal glands taken from animals that had undergone adrenal enucleation 28 days previously, so that the cortex of the tissue had regenerated, likewise formed [14C]GABA from [1,4-14C]putrescine. Putrescine-derived GABA was released from adrenal slices in vitro by 48 mmol K+/l, the release being dependent upon the presence of Ca2+ in the incubation medium. ACTH(1–24) and 8-bromocyclic AMP both provoked a dose-related release of putrescine-derived GABA, although the dose–response curve for the latter differed somewhat from that for the release of corticosterone by this secretogogue. The enzyme believed to be responsible for the first step in the metabolic transformation of putrescine into GABA, diamine oxidase (DAO), is present in extracts of adrenal tissue and its catalytic activity underwent a transient increase followed by a fall below resting levels upon stimulation of adrenal slices with ACTH(1–24). The conclusion that this enzyme initiates the formation of GABA by this pathway is indicated by the observation that adrenal slices pretreated with the DAO inhibitor, aminoguanidine, released significantly less [1,4-14C]putrescine-derived GABA in response to 48 mmol K+/l than did control tissues. The functional significance of these findings remains to be established. Journal of Endocrinology (1989) 123, 227–232

EFFECT OF VARIOUS PREPARATIONS OF PITUITARY AND DIENCEPHALON ON THE IN VITRO SECRETION OF ALDOSTERONE AND CORTICOSTERONE BY THE RAT ADRENAL GLAND

1961 ◽  
Vol 39 (5) ◽  
pp. 901-913 ◽  
Author(s):  
O. J. Lucis ◽  
I. Dyrenfurth ◽  
E. H. Venning
Keyword(s):  
Adrenal Gland ◽  
Linear Relationship ◽  
Dose Response ◽  
Response Curve ◽  
Maximum Effect ◽  
Percentage Increase ◽  
Aldosterone Secretion ◽  
Maximal Stimulation ◽  
Stimulation Of

Purified corticotropin and ACTH peptides increased the secretion of aldosterone, corticosterone, and an unidentified compound RT4in incubated rat adrenal tissue. When the response was expressed as a percentage increase above that of the control tissue, the increases in corticosterone and compound RT4followed a sigmoid log dose – response curve. The maximum effect on aldosterone was obtained at a time when the response curve for corticosterone assumed a linear relationship between the response and the logarithm of the dose of ACTH. This dose level was considerably less than that required for maximal stimulation of corticosterone.The capacity of the ACTH peptides α1+α2and δ′ for stimulating aldosterone secretion could be greatly diminished by allowing solutions of these fractions to stand at 5 °C for 1 week. These solutions still retained their ability to stimulate corticosterone secretion.Saline suspensions and extracts of fresh hog diencephalon contained a factor which selectively stimulated aldosterone secretion.

UTILIZATION OF [26-14C]CHOLESTEROL BY HUMAN FOETAL ADRENAL GLANDS IN VITRO

1978 ◽  
Vol 79 (3) ◽  
pp. 393-394 ◽  
Author(s):  
R. GUNASEGARAM ◽  
K. L. PEH ◽  
P. C. T. CHEW ◽  
S. M. M. KARIM ◽  
S. S. RATNAM
Keyword(s):  
Adrenal Gland ◽  
Steroid Hormones ◽  
Adrenal Glands ◽  
De Novo ◽  
Obstetrics And Gynaecology ◽  
Perfusion Studies

Department of Obstetrics and Gynaecology, University of Singapore, Kandang Kerbau Hospitalfor Women, Singapore 8, Republic of Singapore (Received 3 May 1978) From the previous studies of Bloch & Benirschke (1959, 1962) and Plotz, Kabara, Davis, LeRoy & Gould (1968) it appears that at mid-term, human foetal adrenal glands are capable of synthesizing C21- and C19-steroids de novo from acetate and cholesterol. Villee, Engel, Loring & Villee (1961), however, incubated slices and homogenates of foetal adrenal gland with [2-14C]acetate or [4-14C]cholesterol and could not demonstrate the incorporation of radioactivity into these steroids. Moreover, perfusion studies by three groups of investigators indicated only minute conversions of the same radioactive substrates into neutral steroids in the foetal adrenal glands (Solomon, Bird, Ling, Iwamiya & Young, 1967; Telegdy, Weeks, Archer, Wiqvist & Diczfalusy, 1970a; Telegdy, Weeks, Lerner, Stakemann & Diczfalusy, 1970b). It is widely believed that steroid hormones are normally synthesized from acetate via

scholarly journals Specificity of action of adrenocorticotrophin in vitro on ascorbate transport in rat adrenal glands

1970 ◽  
Vol 118 (2) ◽  
pp. 283-289 ◽  
Author(s):  
M. Clayman ◽  
D. Tsang ◽  
A. F. De Nicola ◽  
R. M. Johnstone
Keyword(s):  
Adrenal Gland ◽  
Transport System ◽  
Adrenal Glands ◽  
Ascorbate Transport

The inhibition of ascorbate transport by rat adrenal quarters in response to steroidogenesis in vitro was shown to be highly specific with respect to tissue, substrate and steroidogenic agent. The transport system in vitro is capable of net accumulation of ascorbate. The evidence is consistent with the conclusion that ascorbate `depletion' in the adrenal gland is due to a specific block by corticoids of the uptake of ascorbate.

FORMATION OF STEROID HORMONES IN THE ADRENAL ADENOMA AND ADJACENT ADRENAL TISSUE OF A PATIENT WITH PRIMARY ALDOSTERONISM

1963 ◽  
Vol 41 (1) ◽  
pp. 1955-1959
Author(s):  
Elizabeth MacArthur ◽  
V. J. O'Donnell
Keyword(s):  
Adrenal Gland ◽  
Steroid Hormones ◽  
Primary Aldosteronism ◽  
Incubation Medium ◽  
Adrenal Adenoma ◽  
Adrenal Vein ◽  
Adrenal Tissue

The in vitro steroidogenic capacity of an adrenal adenoma and adjacent adrenal tissue of a patient with primary aldosteronism was studied. The adenoma slices elaborated into the incubation medium 7.07 μg/g tissue of cortisol (78.2%), corticosterone (7.6%), and aldosterone (14.2%), while the slices of adjacent adrenal gland released 19.88 μg/g tissue of cortisol (79.1%), corticosterone (14.9%), 11β-hydroxyandrostenedione (3.9%), androstenedione (2.1%), and a trace of aldosterone. The steroid content of the adenoma and the adrenal slices after incubation was 4.22 and 3.19 μg/g tissue respectively. From the former, cortisol (51.1%), corticosterone (36.6%), and progesterone (12.4%) were isolated and from the latter cortisol (13.2%), corticosterone (56.1%), progesterone (17.2%), and androstenedione (13.5%). A sample of adrenal vein blood obtained prior to adrenalectomy exhibited a cortisol/corticosterone ratio of 2.45.

EFFECTS OF HYDROXYSTEROID DEHYDROGENASE INHIBITORS ON IN-VITRO AND IN-VIVO STEROIDOGENESIS IN THE OVINE ADRENAL GLAND

1982 ◽  
Vol 92 (2) ◽  
pp. 205-212 ◽  
Author(s):  
P. SINGH-ASA ◽  
G. JENKIN ◽  
G. D. THORBURN
Keyword(s):  
Adrenal Gland ◽  
Incubation Medium ◽  
Bovine Serum ◽  
Hydroxysteroid Dehydrogenase ◽  
Inhibitory Effect ◽  
Bovine Serum Albu ◽  
Stimulatory Action ◽  
Adrenal Steroidogenesis

The effectiveness of trilostane and azastene as inhibitors of adrenal steroidogenesis was compared by in-vitro and in-vivo methods. A radioimmunoassay was developed for the measurement of cortisol in ovine plasma, incubation medium and tissue extract using a specific antiserum raised against cortisol 21-acetate,3-carboxymethyloxime : bovine serum albu Trilostane (20 μmol/l) decreased cortisol synthesis and release both in unstimulated and in ACTH-stimulated adrenal tissues in vitro. The same concentration of azastene had a lesser effect on unstimulated adrenals and was completely ineffective in blocking the stimulatory action of ACTH. In vivo, trilostane suppressed adrenal steroidogenesis in pregnant and cyclic ewes but the suppression in pregnant ewes was over a longer period, and after lower doses. It is concluded that trilostane had an inhibitory effect on ovine adrenal steroidogenesis both in vitro and in vivo.

EFFECTS OF CALCIUM ON THE POTASSIUM AND SODIUM CONTENT OF RAT ADRENAL GLANDS, ON THE STIMULATION OF STEROID PRODUCTION BY ADENOSINE 3′,5′-MONOPHOSPHATE, AND ON THE RESPONSE OF THE ADRENAL TO SHORT CONTACT WITH ACTH

1960 ◽  
Vol 38 (10) ◽  
pp. 1077-1085 ◽  
Author(s):  
Marion K. Birmingham ◽  
Erika Kurlents ◽  
R. Lane ◽  
B. Muhlstock ◽  
H. Traikov
Keyword(s):  
Incubation Medium ◽  
Adrenal Glands ◽  
Sodium Content ◽  
Potassium Content ◽  
Steroid Production ◽  
Short Contact ◽  
Calcium Addition ◽  
Adrenal Tissue ◽  
Stimulation Of

The potassium content of incubated rat adrenal tissue is significantly higher when calcium is present in the incubation medium than when it is absent. The effect of calcium on the sodium content of the adrenal depends upon the presence of ACTH; increased values are obtained with calcium in the presence of ACTH, decreased values in its absence. There is no correlation between the potassium or sodium content of the tissue and its ability to respond to ACTH. Adenosine 3′,5′-monophosphate triples the steroid output of incubated adrenal glands in the absence of both glucose and calcium. Addition of calcium further doubles this response while glucose has only a small effect. The stimulation of steroid production following short contact with ACTH does not depend upon the presence of calcium or glucose in the medium during the time the glands are exposed to the hormone. The results suggest that some step between contact of the tissue with ACTH and the elaboration of adenosine 3′,5′-monophosphate requires the presence of glucose and not necessarily calcium and that a reaction in the sequence between elaboration of the nucleotide and steroid production requires the presence of calcium, but not of glucose.

AN IN-VITRO BIOASSAY FOR PROLACTIN BASED ON STIMULATION OF CASEIN SYNTHESIS BY A DISPERSED CELL PREPARATION FROM MOUSE MAMMARY GLAND

1974 ◽  
Vol 62 (3) ◽  
pp. 463-472 ◽  
Author(s):  
W. A. BULLOUGH ◽  
M. WALLIS
Keyword(s):  
Mammary Gland ◽  
Response Curve ◽  
Mouse Mammary Gland ◽  
Placental Lactogen ◽  
Cell Preparation ◽  
In Vitro Bioassay ◽  
Mammary Gland Cells ◽  
Casein Synthesis ◽  
Stimulation Of

SUMMARY An in-vitro bioassay for prolactin has been devised, based on the stimulation of casein synthesis in a mouse mammary gland preparation. Dispersed mammary gland cells were superior to intact explants for this purpose. Casein synthesis by dispersed cells was stimulated by added prolactin, and a linear log dose—response curve was established (for the range 5–20 μg prolactin/ml). The precision of the assay was high (λ = 0·10–0·15). Sensitivity was rather low, but could be improved by increasing the concentration of amino acids in the medium. The response to prolactin was not influenced by thyroxine, adrenocorticotrophin or oestradiol, but thyrotrophin appeared to inhibit it slightly. Both human placental lactogen and bovine growth hormone showed lactogenic activity in the assay.

ÉTUDE DE L'ACTIVITÉ BIOLOGIQUE IN VITRO DES HORMONES GONADOTROPES

1963 ◽  
Vol 42 (4) ◽  
pp. 509-513 ◽  
Author(s):  
D. Gospodarowicz ◽  
J. Legault-Démare
Keyword(s):  
Incubation Medium ◽  
Cholesterol Synthesis ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Corpora Lutea ◽  
Lactogenic Hormone ◽  
Normal Rat ◽  
Stimulation Of

ABSTRACT Human chorionic gonadotrophin (HCG) and lactogenic hormone (LTH or prolactin) were found practically inactive on the incorporation of 14Cacetate into cholesterol of normal rat corpus luteum in vitro. On the contrary, when added simultaneously to the incubation medium, they increased by 90% the labeling of cholesterol. When pseudopregnancy corpora lutea were used, HCG alone stimulated to the same amount, but no stimulation was observed with LTH alone. These results show that the stimulation of cholesterol synthesis is produced by a synergic action of LTH and HCG, LTH being introduced either in vivo (pseudopregnancy) or in vitro.

ALDOSTERONE STIMULATION IN VITRO

1967 ◽  
Vol 54 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Jürg Müller ◽  
W. Joe Weick
Keyword(s):  
Response Curve ◽  
Gel Filtration ◽  
Monovalent Cations ◽  
Deficient Diet ◽  
Rat Serum ◽  
Assay Procedure ◽  
Serum Fractions ◽  
High Concentrations ◽  
Stimulation Of

ABSTRACT The effect of rat serum and serum fractions on biosynthesis of aldosterone, corticosterone and deoxycorticosterone was investigated by a previously described in vitro assay procedure, using adrenal sections from rats which had been kept on a sodium-deficient diet. Addition of small amounts of serum to the incubation medium significantly stimulated aldosterone and deoxycorticosterone production. An almost linear log-dose/response curve was obtained over a 1:100 concentration range. Stimulation of corticosterone biosynthesis was observed only at high concentrations of serum. Whereas most of the aldosterone- and deoxycorticosterone-stimulating activities were dialysable, most of the corticosterone-stimulating activity remained in the non-dialysable fraction. Ion-exchange and gel filtration chromatography indicated that the unknown dialysable aldosterone-stimulating substance was different from the known aldosterone-stimulating agents, i. e. angiotensin II and monovalent cations.

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