TESTOSTERONE IN RETE TESTIS FLUID AND BLOOD OF RAMS AND RATS

1974 ◽  
Vol 62 (3) ◽  
pp. 619-629 ◽  
Author(s):  
T. G. COOPER ◽  
G. M. H. WAITES
Keyword(s):  
Venous Blood ◽  
Rete Testis ◽  
Jugular Veins ◽  
Testosterone Concentration ◽  
Efferent Duct ◽  
Duct Ligation ◽  
Anaesthetized Rats ◽  
Arterial Inflow ◽  
The Mean ◽  
Mean Concentration

SUMMARY Rete testis fluid (RTF) was collected from six conscious Clun Forest rams by cannulation of the efferent ducts, and from anaesthetized rats by cannulation of the rete testis 16–24 h after efferent duct ligation. Testosterone concentration in this fluid was measured by radioimmunoassay and compared with levels in blood collected from the subcapsular testicular artery and veins and spermatic and jugular veins. The testosterone concentration in ram RTF fluctuated from nondetectable (< 100 pg/ml) levels to approximately 20 ng/ml over 1–25 h collection periods. The mean concentration was 8·5 ± 1·2 (s.e.m.). This value was approximately one fifth the mean concentration of testosterone in samples from the testicular veins at the dorsal pole of the testis. Testosterone concentration (ng/ml) in rat RTF collected under sodium pentobarbitone anaesthesia was 26·4 ± 2·7 (18 measurements, 18 rats). A lower value was obtained when ether was the anaesthetic used during efferent duct ligation (ether, 20·3; halothane, 29·9; sodium pentobarbitone, 29·1). The mean concentration of testosterone in the RTF was similar to that in testicular venous blood (29·8 ± 3·9; 27 measurements, 27 rats), although the highest values were obtained after ether anaesthesia (ether, 38·3; halothane, 29·0; sodium pentobarbitone, 21·7). Testosterone concentration in the testicular arterial inflow was similar to that in jugular venous blood in the ram but exceeded carotid arterial levels in the rat. The values reported are used to discuss: the origin and significance of androgens in rete testis fluid, species differences, the effect of anaesthetics and season, and vascular exchange of testosterone in the spermatic cord.

TESTOSTERONE CONCENTRATION IN THE FLUIDS OF SEMINIFEROUS TUBULES, THE INTERSTITIUM AND THE RETE TESTIS OF THE RAT

1976 ◽  
Vol 70 (2) ◽  
pp. 229-235 ◽  
Author(s):  
F. H. COMHAIRE ◽  
A. VERMEULEN
Keyword(s):  
Interstitial Fluid ◽  
Limit Of Detection ◽  
Mean Value ◽  
Rete Testis ◽  
Seminiferous Tubules ◽  
Testosterone Concentration ◽  
Anaesthetized Rats ◽  
The Mean ◽  
The Difference

SUMMARY Testosterone was measured by radioimmunoassay in interstitial fluid, 'free-flow' seminiferous tubular fluid, obtained by micropuncture, and rete testis fluid from intact adult anaesthetized rats. Under non-stimulated conditions the concentration of testosterone in interstitial fluid was below the limit of detection in two rats and achieved a mean level of 150 ± 27 (s.e.m.) ng/ml in the remaining 17 determinations. The testosterone concentration of the seminiferous tubular fluid was below the limit of detection in two rats, and had a mean level in the remaining 15 determinations of 91 ± 14 ng/ml, which is significantly lower (P < 0·02) than that in interstitial fluid. The mean ratio of seminiferous tubular:interstitial fluid testosterone concentration calculated in 14 rats was 0·94 ± 0·24. This ratio was less than unity whenever the interstitial fluid testosterone concentration was more than 50 ng/ml, whereas in all animals with interstitial fluid testosterone of 50 ng/ml, or less, the ratio was greater than or equal to one. The mean testosterone concentration of rete testis fluid in 32 samples was 33 ± 3 ng/ml. After HCG stimulation in 12 rats, testosterone concentration in interstitial fluid increased to a mean value of 660 ± 83 ng/ml, and in seminiferous tubular fluid to 460 ± 44 ng/ml; the difference between the two was significant (P < 0·05). These results are discussed in relation to the presumed dilution of seminiferous tubular fluid in rete testis fluid and the role of androgen-binding proteins in the transport of steroids.

scholarly journals The irreversible loss of alanine and of glycine in fetal and sucking lambs

1984 ◽  
Vol 52 (3) ◽  
pp. 529-543 ◽  
Author(s):  
G. M. Hatfield ◽  
Jenny Joyce ◽  
Marjorie K. Jeacock ◽  
D. A. L. Shepherd
Keyword(s):  
Specific Activity ◽  
Single Injection ◽  
Venous Blood ◽  
Injection Technique ◽  
Irreversible Loss ◽  
Fetal Tissues ◽  
Arterial Blood ◽  
Pool Model ◽  
The Mean ◽  
Mean Concentration

1. Estimates have been made of the irreversible loss of alanine and of glycine in chronically catheterized fetal lambs and in sucking lambs using [U-14C]-labelled radioisotopes. The experiments in the fetal lambs were carried out at least 5 d after implantation of catheters.2. The mean concentration of glycine in fetal femoral arterial blood between 102 and 129 d conceptual age was 755 μmol/l and this was not significantly different from that in maternal venous blood. The mean concentration of alanine in fetal femoral arterial blood during the same period of gestation was 229μmol/l and this was significantly greater than that in maternal venous blood.3. Assuming a catenary model, the mean irreversible loss of glycine, determined using the single-injection technique, in three fetal lambs of 107, 111 and 127 d conceptual age was 17 μmol/min per kg, whereas in two fetal lambs aged 106 and 109 d into which the isotope was infused continuously the mean irreversible loss, calculated from the specific activity of glycine 5 h after the start of infusion of the tracer ('pseudo plateau'), was 12 μmol/min per kg. In a sucking lamb, 9 d after birth, the irreversible loss of glycine was 11 μmol/min per kg. The mean irreversible loss of alanine, determined by the single-injection technique assuming a catenary model in five fetuses between 112 and 121 d conceptual age was 14μmol/min per kg, and in two sucking lambs, 9 and 11 d after birth, it was 5.1 μmol/min per kg.4. When a two-pool model was assumed in which entry of metabolite was not directly into the sampling pool but was by way of the second pool, then the mean irreversible loss of glycine in the three fetuses was 23 μmol/min per kg and of alanine in the five fetuses was 32 μmol/min per kg. Calculations based on the alternative two-pool model did not alter appreciably the rates of irreversible loss of either alanine or glycine in the sucking lambs.5. From a comparison of the specific activities of the amino acids and of carbon dioxide in blood during the course of the experiments, it was found that in the fetuses 0.96% of the CO2 present in blood was derived from alanine and only 0.12% was derived from glycine. It was calculated that not more than 1.6 μmol lanine/min per kg and 0.29 μmol glycine/min per kg could have been converted to CO2 in the fetal lambs.6. It is concluded that since glycine in fetal blood originates from fetal tissues and not from direct transfer across the placenta the upper value for the irreversible loss describes metabolism best. In the case of alanine, which is derived from both the maternal circulation and from metabolism in fetal tissues, the true rate of irreversible loss must lie between the values predicted by the two models.

scholarly journals Collection of Rete Testis Fluid from Rats Without Previous Efferent Duct Ligation

1979 ◽  
Vol 20 (2) ◽  
pp. 269-278 ◽  
Author(s):  
Michael J. Free ◽  
Richard A. Jaffe
Keyword(s):  
Rete Testis ◽  
Efferent Duct ◽  
Duct Ligation

scholarly journals Early Effects of Efferent Duct Ligation on the Rat Rete Testis

1978 ◽  
Vol 1 (1-6) ◽  
pp. 225-234 ◽  
Author(s):  
Matti Nykänen ◽  
Martti Kormano
Keyword(s):  
Rete Testis ◽  
Efferent Duct ◽  
Duct Ligation ◽  
Early Effects

TESTOSTERONE AND OESTRADIOL IN DOGS WITH TESTICULAR TUMOURS

1974 ◽  
Vol 77 (2) ◽  
pp. 408-416 ◽  
Author(s):  
F. Comhaire ◽  
D. Mattheeuws ◽  
A. Vermeulen
Keyword(s):  
Plasma Concentration ◽  
Sertoli Cell ◽  
Sex Steroids ◽  
Venous Blood ◽  
Plasma Testosterone ◽  
Testosterone Concentration ◽  
Peripheral Plasma ◽  
Normal Mass ◽  
The Mean ◽  
Sertoli Cell Tumours

ABSTRACT The mean peripheral plasma concentration of oestradiol was found to be increased in 3 dogs with Sertoli cell tumours and in 3 dogs with seminomas, whereas the plasma testosterone showed no difference as compared to a group of dogs without testicular neoplasia. In two thirds of the cases the concentration of oestradiol in the spermatic venous blood draining the neoplastic testes was clearly higher than in the normal dogs. The testosterone concentration in the spermatic venous blood from the tumour bearing testes was lower than in the spermatic venous blood of the contralateral partner testes in the same dogs, though not different from the spermatic venous concentration in the control dogs. There was no correlation between the presence or absence of signs of feminization and the peripheral or spermatic venous concentration of sex steroids. It is concluded that not only Sertoli cell tumours, but also seminomas can secrete increased amounts of oestrogens. This is possibly due to the presence of a larger than normal mass of tissue capable of converting testosterone, or its precursors, to oestradiol.

SECRETION OF ALDOSTERONE IN THE MONOTREME MAMMAL, TACHYGLOSSUS ACULEATUS

1981 ◽  
Vol 90 (2) ◽  
pp. 267-273
Author(s):  
CONRAD SERNIA ◽  
I. R. McDONALD
Keyword(s):  
Angiotensin Ii ◽  
Venous Blood ◽  
Metabolic Clearance ◽  
Control Mechanisms ◽  
Constant Rate ◽  
Response To Stress ◽  
The Mean ◽  
Layer Chromatography ◽  
Mean Concentration ◽  
Rate Infusion

The secretion of aldosterone and its regulation by ACTH and angiotensin II were investigated in conscious, unrestrained echidnas with chronically implanted jugular catheters. Aldosterone was measured by radioimmunoassay after extraction and isolation by silica gel thin-layer chromatography. The mean concentration of aldosterone in blood plasma of five male and three female echidnas was only 5·4 ± 1·3 (s.e.m.) pg/ml. During stress (surgery and anaesthesia) the mean concentration increased to 17·6 ± 3·8 pg/ml. Infusion of β1–24 ACTH at a rate of 5 units/kg per h increased the plasma concentration of aldosterone to 53·8± 9·8 pg/ml. Infusion of angiotensin II at rates of 100 and 500 ng/kg per h also increased aldosterone concentration, to 24·1 ± 8·6 and 35·1 ± 10·9 pg/ml respectively. Production and metabolic clearance rates were measured by the constant-rate infusion of [3H]aldosterone and found to be 5·0 ± 2·2 ng/kg per h and 14·3 ±1·3 ml/kg per min respectively in the unstimulated state. Production rate was increased approximately sevenfold by the infusion of ACTH at 5 units/kg per h and fourfold and sixfold by infusion of angiotensin II at 100 and 500 ng/kg per h respectively. Metabolic clearance decreased following the infusion of ACTH or angiotensin II. Direct measurement of secretion rate by the collection of adrenal venous blood from three anaesthetized, laparotomized echidnas gave values of 9·4, 15·6 and 8·8 mg/kg per h. It is concluded that the adrenal secretion of aldosterone in the echidna is extremely low compared with that in other mammals but the response to stress, ACTH and angiotensin II indicates the presence of typical mammalian control mechanisms for its secretion.

scholarly journals Limitations Imposed by Testicular Blood Flow on the Function of Leydig Cells in Rats in vivo

1983 ◽  
Vol 36 (3) ◽  
pp. 285 ◽  
Author(s):  
BP Setchell ◽  
KAA Galil
Keyword(s):  
Blood Flow ◽  
Leydig Cells ◽  
Venous Blood ◽  
Testis Weight ◽  
Single Exposure ◽  
Efferent Duct ◽  
Efferent Ducts ◽  
Duct Ligation ◽  
Testicular Blood Flow

Testis blood flow per testis closely follows testis weight in rats made aspermatogenic by a single exposure of the testis to 43�C for 30 min or 500 rad (5 Gy) of irradiation from a caesium source, or following ligation of the efferent ducts. Aspermatogenesis following these treatments was associated with only minor changes in the concentrations of testosterone in peripheral blood before stimulation with human chorionic gonadotrophin (hCG), and a reduced responsiveness to hCG when testis weight had fallen after heating. The concentrations of testosterone in testicular venous blood was normal or above normal during aspermatogenesis resulting from heat or irradiation, and only slightly reduced following efferent duct ligation.

Reference Values of Umbilical Cord and Third-Day Cystatin C Levels for Determining Glomerular Filtration Rates in Newborns

2003 ◽  
Vol 31 (3) ◽  
pp. 231-235 ◽  
Author(s):  
A Bahar ◽  
Y Yilmaz ◽  
S Unver ◽  
I Gocmen ◽  
F Karademir
Keyword(s):  
Umbilical Cord ◽  
Cystatin C ◽  
Reference Values ◽  
Venous Blood ◽  
Serum Cystatin C ◽  
Serum Cystatin ◽  
Peripheral Venous Blood ◽  
The Mean ◽  
Mean Concentration ◽  
Duration Of Gestation

The aim of this study was to determine reference values for serum cystatin C at, and 3 days after, birth, and to determine if the concentration was influenced by gender, gestational age or bilirubin level. Umbilical cord and peripheral venous blood was taken, and serum cystatin C, creatinine, and total and direct bilirubin levels were measured. The mean concentration of cystatin C was not significantly different between cord blood and blood taken on day 3 (1.36 ± 0.35 mg/l and 1.35 ± 0.33mg/l, respectively). Comparison of subgroups, divided by gender, duration of gestation and bilirubin levels, using the Mann-Whitney U-test and Wilcoxon analysis, showed no effect of these parameters on cystatin C levels.

Instant 99mTc-Labelled Glucoheptonate Kit for Kidney Imaging

1983 ◽  
Vol 22 (05) ◽  
pp. 246-250 ◽  
Author(s):  
M. Al-Hilli ◽  
H. M. A. Karim ◽  
M. H. S. Al-Hissoni ◽  
M. N. Jassim ◽  
N. H. Agha
Keyword(s):  
Sodium Hydroxide Solution ◽  
Normal Subjects ◽  
Organ Distribution ◽  
Stable Complex ◽  
Scintillation Camera ◽  
Ph Adjustment ◽  
The Mean ◽  
The Stability ◽  
Kidney Imaging ◽  
Mean Concentration

Gelchromatography column scanning has been used to study the fractions of reduced hydrolyzed 99mTc, 99mTc-pertechnetate and 99mTc-chelate in a 99mTc-glucoheptonate (GH) preparation. A stable high labelling yield of 99mTc-GH complex in the radiopharmaceutical has been obtained with a concentration of 40-50 mg of glucoheptonic acid-calcium salt and not less than 0.45 mg of SnCl2 2 H2O at an optimal pH between 6.5 and 7.0. The stability of the complex has been found significantly affected when sodium hydroxide solution was used for the pH adjustment. However, an alternative procedure for final pH adjustment of the preparation has been investigated providing a stable complex for the usual period of time prior to the injection. The organ distribution and the blood clearance data of 99mTc-GH in rabbits were relatively similar to those reported earlier. The mean concentration of the radiopharmaceutical in both kidneys has been studied in normal subjects for one hour with a scintillation camera and the results were satisfactory.

PROGESTERONE IN THE HUMAN PERIPHERAL BLOOD IN THE PREOVULATORY PERIOD OF THE MENSTRUAL CYCLE

1967 ◽  
Vol 55 (1) ◽  
pp. 91-96 ◽  
Author(s):  
Benno Runnebaum ◽  
Josef Zander
Keyword(s):  
Menstrual Cycle ◽  
Corpus Luteum ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Progesterone Concentration ◽  
Plasma Progesterone ◽  
Progesterone Secretion ◽  
Graafian Follicle ◽  
The Mean ◽  
Mean Concentration

ABSTRACT Progesterone was determined and identified in human peripheral blood during the preovulatory period of the menstrual cycle, by combined isotope derivative and recrystallization analysis. The mean concentration of progesterone in 1.095 ml of plasma obtained 9 days before ovulation was 0.084 μg/100 ml. However, the mean concentration of progesterone in 1.122 ml of plasma obtained 4 days before ovulation was 0.279 μg/100 ml. These data demonstrate a source of progesterone secretion other than the corpus luteum. The higher plasma-progesterone concentration 4 days before ovulation may indicate progesterone secretion of the ripening Graafian follicle of the ovary.

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