THE FORMATION OF OESTROGENS BY THE AUTOTRANSPLANTED OVARY OF THE EWE PERFUSED IN VIVO WITH C19 STEROIDS

1970 ◽  
Vol 65 (2) ◽  
pp. 244-260 ◽  
Author(s):  
Andre Rado ◽  
John A. McCracken ◽  
David T. Baird
Keyword(s):  
Steady State ◽  
Luteinizing Hormone ◽  
Venous Blood ◽  
The Other ◽  
Temporary Increase ◽  
Main Route ◽  
Ovarian Artery ◽  
Constant Rate ◽  
Control Samples

ABSTRACT The autotransplanted ovary of the ewe was perfused in vivo via the ovarian artery with either 14C or 3H labelled C19 steroids. 17β-Oestradiol was the major phenolic steroid isolated in ovarian venous blood from either testosterone or androstenedione. Smaller amounts of oestrone were obtained but there was no 17α-oestradiol, oestriol nor conjugated oestrogens isolated. The yield of oestrogen was approximately ten fold greater from androstenedione than from testosterone suggesting that the main route of oestrogen biosynthesis in the ovine ovary is via the former steroid. The effect of infusing luteinizing hormone (LH) at the rate of 10 μg per hour on the conversion of androstenedione to 17β-oestradiol was measured in 5 experiments. In 2 experiments, when the steady state was not achieved, the increasing rate of conversion was halted. On the other hand LH resulted in a temporary increase followed by a decrease in the rate of conversion in the remaining 3 experiments in which there was a constant rate of conversion in the control samples. These results are compatible with the concept that LH stimulates the aromatisation of androstenedione to oestrogens by the ovary in vivo.

CONVERSION OF LABELLED CHOLESTEROL TO NEUTRAL STEROIDS BY HUMAN OVARIES PERFUSED IN VIVO

1974 ◽  
Vol 75 (2) ◽  
pp. 368-378
Author(s):  
S. Dell'Acqua ◽  
S. Mancuso ◽  
M. G. Catelli ◽  
A. Bompiani
Keyword(s):  
Luteal Phase ◽  
Ovarian Tissue ◽  
Venous Blood ◽  
The Other ◽  
Ovarian Artery ◽  
The Third ◽  
Human Ovaries

ABSTRACT Four human ovaries in mid-luteal phase have been perfused with tritium labelled cholesterol through the cannulated ovarian artery for thirty minutes. Three 15-min samples of ovarian venous blood have been collected, two during the perfusion and the third in the following 15 min. In two cases, 15 min after the beginning of the perfusion, highly purified human urinary LH was rapidly injected into the ovarian artery. The ovarian tissue and the three fractions of venous blood were analysed for phenolic and neutral steroids. In the ovarian tissue only progesterone (4-pregnene-3,20-dione), pregnenolone (3β-hydroxy-5-pregnen-20-one) and 17α-hydroxyprogesterone (17α-hydroxy-4-pregnene-3,20-dione) were isolated. The amount of progesterone isolated from the two ovaries injected with LH was five times higher as compared with the other two ovaries. No steroids were present in the samples of venous blood except in the two cases in which LH was injected, where progesterone was isolated only in the third sample. It is concluded that circulating cholesterol is utilized by the ovary at the mid-luteal phase for the synthesis of C21 steroids and that the presence of LH increases the production and the release of progesterone by the ovary.

STEROIDOGENIC EFFECTS OF LUTEINIZING HORMONE AND PROLACTIN ON THE RAT OVARY IN VIVO

1967 ◽  
Vol 38 (4) ◽  
pp. 423-430 ◽  
Author(s):  
K. YOSHINAGA ◽  
SUSAN A. GRIEVES ◽  
R. V. SHORT
Keyword(s):  
Luteinizing Hormone ◽  
Venous Blood ◽  
The Other ◽  
Progesterone Secretion ◽  
Rat Ovary

SUMMARY Progesterone and 20α-dihydroprogesterone were measured in the ovarian venous blood of rats in early pro-oestrus, late dioestrus, day 5 of pseudopregnancy, and in androgen-treated animals with persistent oestrus. Little progesterone was secreted in early pro-oestrus or persistent oestrus (0·1 μg./hr.), but the secretion rose in dioestrus (2·1 μg./hr.) and in pseudopregnancy (7 μg./hr.). The 20α-dihydroprogesterone secretion was low in the persistent oestrous group; in all the other groups it was 1·5–3 μg./hr. Treatment with luteinizing hormone increased progesterone secretion within 30 min. in pro-oestrus and persistent oestrus, had no significant effect in dioestrus, and depressed it markedly in pseudopregnancy. It appeared to have no significant effect on 20α-dihydroprogesterone secretion except during pseudopregnancy, when it was depressed. Treatment with prolactin produced no effect within 30 min.in pro-oestrous, dioestrous or pseudopregnant animals.

PROGESTERONE SECRETION BY THE SHEEP CORPUS LUTEUM AFTER REPEATED INFUSIONS OF LUTEINIZING HORMONE AND HUMAN CHORIONIC GONADOTROPHIN

1973 ◽  
Vol 57 (2) ◽  
pp. 299-305 ◽  
Author(s):  
D. T. BAIRD ◽  
R. A. COLLETT
Keyword(s):  
Luteinizing Hormone ◽  
Corpus Luteum ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Constant Infusion ◽  
Temporary Increase ◽  
Ovarian Artery ◽  
Progesterone Secretion ◽  
Luteal Tissue

SUMMARY The response of the ovine corpus luteum to repeated infusions of luteinizing hormone (LH) or of human chorionic gonadotrophin (HCG) was tested in four ewes with the left ovary autotransplanted to the neck. Constant infusion for 1 h of either LH (100 or 1000 μg/h) or HCG (200 i.u./h) via the ovarian artery stimulated a temporary increase in secretion of progesterone which fell to control levels by 60 min. Ovarian blood flow increased progressively (P < 0·05) throughout the infusion of gonadotrophin in three of the five experiments. A second infusion of either gonadotrophin after a further control hour failed to stimulate progesterone secretion. These results suggest that ovine luteal tissue rapidly becomes refractory to the steroidogenic effect of LH in vivo.

Identification of the major chemokines that regulate cell influxes in peritoneal dialysis patients.

1996 ◽  
Vol 7 (11) ◽  
pp. 2379-2384 ◽  
Author(s):  
J Tekstra ◽  
C E Visser ◽  
C W Tuk ◽  
J J Brouwer-Steenbergen ◽  
C W Burger ◽  
...  
Keyword(s):  
Peritoneal Dialysis ◽  
Steady State ◽  
Interleukin 8 ◽  
The Other ◽  
Dialysis Patients ◽  
Monocytic Cell ◽  
Bacterial Peritonitis ◽  
Monocyte Migration ◽  
Absolute Correlation

To investigate which members of the recently discovered family of chemotactic cytokines (chemokines) are important in leukocyte recruitment to a bacterial inflammation site, four different chemokines in the effluent of peritoneal dialysis patients suffering from acute bacterial peritonitis were measured. The presence of two neutrophil-attracting chemokines, interleukin-8 and human melanoma growth-stimulating activity (huGRO alpha), and two monocyte-attracting members of the chemokine superfamily, monocyte chemotactic protein-1 (MCP-1) and regulated on activation normal T cell expressed and secreted (RANTES), was investigated in patient effluents just before, during, and after a peritonitis episode. This was studied in seven peritonitis effluents of five patients by using chemokine-specific enzyme-linked immunosorbent assays. Cell populations in the dialysates were differentiated on cytocentrifuge preparations. The contribution of the detected chemokines to neutrophilic and monocytic cell influxes in the inflamed peritoneal cavity was analyzed by correlating concentrations of chemokines to the relevant cell numbers present in the dialysates of these patients. The detection of the neutrophil-attracting chemokine interleukin-8 during peritonitis was in accordance with other studies. Moreover, a second neutrophil chemoattractant, huGRO alpha, was identified in vivo. Both were elevated during inflammation (P < 0.02) and contributed significantly to the neutrophilic cell influx (P < 0.05). One of the monocyte-attracting chemokines, RANTES, could not be detected in any of the effluents, whereas the other, MCP-1, was significantly elevated during peritonitis (P < 0.02). In contrast to the other chemokines measured, MCP-1 concentration was relatively high in steady-state peritoneal dialysates. An absolute correlation between dialysate MCP-1 concentration and the number of macrophages in these effluents was absent. However, in a 48-well chemotaxis assay, monocyte migration toward peritonitis, as well as steady-state patient dialysates, could be blocked with antibodies to MCP-1. It was concluded, therefore, that MCP-1 is the most important monocyte chemoattractant in peritoneal dialysis steady-state and peritonitis patients; whereas, besides interleukin-8, huGRO alpha was identified as a major neutrophil-attracting chemokine in the peritonitis situation.

scholarly journals Studies on the metabolism of 5α-androst-16-en-3-one in boar testis in vivo

1974 ◽  
Vol 144 (2) ◽  
pp. 347-352 ◽  
Author(s):  
Y. A. Saat ◽  
D. B. Gower ◽  
F. A. Harrison ◽  
R. B. Heap
Keyword(s):  
Venous Blood ◽  
Specific Radioactivity ◽  
Testicular Tissue ◽  
Constant Rate ◽  
Sexually Mature ◽  
Venous Plasma

1. [5α-3H]5α-Androst-16-en-3-one (5α-androstenone) was infused at a constant rate for 180min into the spermatic artery of a sexually mature boar. Samples of spermatic-venous blood were collected at 1min intervals for the first 10min of the infusion and thereafter at 15min intervals for the first hour, then at 64, 125, 155 and 172min. After infusion, the testis was removed and immediately cooled to −196°C. 2. From both the testicular tissue and the spermatic-venous plasma, endogenous and3H-labelled androst-16-enes were isolated, characterized and quantitatively determined and their specific radioactivity was calculated. 3. The specific radioactivities of 5α-androstenore, 5α-androst-16-en-3α-ol and 5α-androst-16-en-3β-ol (an-α and an-β) in testicular tissue were different from those in the spermatic-venous plasma, suggesting that these compounds may be present in more than one compartment of the testis and differentially secreted into the spermatic-venous blood. 4. The ratios of the specific radioactivities of an-α and an-β to their respective sulphate conjugates in the testicular tissue were less than the ratios of the same compounds in the spermatic-venous plasma. 5. The patterns of secretion of these labelled compounds in the spermatic-venous blood during the period of infusion were demonstrated. 6. The urine that accumulated during the infusion was analysed and found to contain3H-labelled an-β, conjugated as both glucuronide and sulphate, the specific radioactivities of which were determined. Little or no androst-16-enes occurred as free steroids. 7. The presence of an-β glucuronide in the urine is discussed.

THE EFFECT OF BLOOD-BORNE FACTORS ON ADRENAL STEROID SYNTHESIS IN THE GOLDEN HAMSTER (MESOCRICETUS AURATUS NEHRING)

1967 ◽  
Vol 37 (2) ◽  
pp. 139-146 ◽  
Author(s):  
BARBARA J. WHITEHOUSE ◽  
G. P. VINSON ◽  
P. A. JANSSENS
Keyword(s):  
Enzyme Activity ◽  
Golden Hamster ◽  
Venous Blood ◽  
Ringer Solution ◽  
The Other ◽  
Steroid Synthesis ◽  
Adrenal Steroid ◽  
Adrenal Tissue ◽  
Rapid Conversion

SUMMARY Incubation of hamster adrenal tissue in Krebs bicarbonate Ringer solution gave rapid conversion of added [4-14C]cortisol to cortisone. Moreover, incubation in Ringer solution with [4-14C]progesterone as precursor invariably yielded cortisone in greater amounts than cortisol. On the other hand it has been confirmed that cortisol is the major free ultraviolet absorbing steroid in the adrenal venous blood of the hamster. Incubation of adrenal tissue with [4-14C]progesterone in hamster whole blood gave relatively greater amounts of cortisol which were more in keeping with the findings in vivo. This suggested that the blood contains factors which affect the cortisone-cortisol equilibrium by modifying adrenal enzyme activity. Some reduction of [3H] cortisone to cortisol was also observed during incubation with blood alone.

THE EFFECTS OF SYNTHETIC GONADOTROPHIN RELEASING FACTOR ON THE RELEASE OF LUTEINIZING HORMONE AND FOLLICLE-STIMULATING HORMONE FROM OVINE PITUITARY TISSUE IN VITRO

1973 ◽  
Vol 58 (3) ◽  
pp. 387-391 ◽  
Author(s):  
D. B. CRIGHTON
Keyword(s):  
Luteinizing Hormone ◽  
Incubation Medium ◽  
Synthetic Peptides ◽  
Follicle Stimulating Hormone ◽  
The Other ◽  
Pituitary Tissue ◽  
Incubation System ◽  
Stimulating Hormone

SUMMARY A synthetic decapeptide gonadotrophin releasing factor was tested for effects on the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) using an ovine pituitary incubation system. The effects of other synthetic peptides used at similar doses were studied. The synthetic decapeptide consistently provoked significant increases in the LH content of the incubation medium at doses equal to or in excess of 0·5 ng/flask (0·2 ng/ml medium). Significant increases in the FSH content of the incubation medium at doses equal to or in excess of 0·25 ng/flask (0·1 ng/ml medium) were observed. The other synthetic peptides failed to influence LH or FSH release in vitro even at a dose 20–40 times greater. The results demonstrate that the decapeptide releases both LH and FSH from sheep pituitary tissue, suggesting that it may play a role in the release of both hormones in vivo in the sheep.

PRODUCTION AND SECRETION OF 5α-DIHYDROTESTOSTERONE BY THE CANINE PROSTATE

1972 ◽  
Vol 69 (2) ◽  
pp. 394-402 ◽  
Author(s):  
Gary C. Haltmeyer ◽  
Kristen B. Eik-Nes
Keyword(s):  
Venous Blood ◽  
Steroid Secretion ◽  
Metabolic Chamber ◽  
Arterial Blood ◽  
Constant Rate ◽  
Animal Preparation ◽  
Storage Pools

ABSTRACT An animal preparation has been developed which permits investigation of steroid secretion by the prostate of the dog. In this preparation the prostate is removed from the dog, placed in a metabolic chamber and infused with the animal's arterial blood via the prostatic arteries at a constant rate. This animal preparation secretes 5α-dihydrotestosterone into the prostatic venous blood. While testosterone is the most probable precursor for secreted 5α-dihydrotestosterone, data from experiments indicate that other steroids may serve as precursors for 5α-dihydrotestosterone in this animal preparation in vivo. The presence of »storage pools« and »secretory pools« for steroids in the infused canine prostate has been discussed.

Control of steady-state pH in rabbit proximal straight tubules

1987 ◽  
Vol 253 (2) ◽  
pp. F282-F289
Author(s):  
J. L. Atkins ◽  
M. B. Burg
Keyword(s):  
Steady State ◽  
Proximal Tubule ◽  
The Other ◽  
Slow Flow ◽  
Bicarbonate Concentration ◽  
Flow Rates ◽  
Other Hand ◽  
Straight Tubules

Steady-state pH (defined as the limiting pH reached at slow flow rates) was measured in isolated perfused rabbit proximal straight tubules (S2). With normal bath conditions (pH 7.4, bicarbonate 25 mM) the luminal steady-state pH was 6.85. Steady-state pH was directly related to bath pH and bicarbonate, but not to bath PCO2. Lowering of bath pH or bicarbonate consistently decreased luminal steady-state pH, and raising either caused steady-state pH to increase. When bath PCO2 was increased, on the other hand, steady-state pH either increased or decreased, depending on the concomitant changes in bicarbonate and pH. The changes in steady-state pH observed in the present studies following alterations in bath pH and bicarbonate concentration should, when extrapolated to the in vivo kidney, result in decreased delivery of bicarbonate from the proximal tubule in acidosis and increased delivery in alkalosis. The effects of potassium and chloride were also determined. Removal of potassium from the bath increased the steady-state pH, but removal of chloride from both the perfusate and bath had no significant effect.

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