EFFECT OF INJECTED HUMAN CHORIONIC GONADOTROPHIN ON CAPILLARY PERMEABILITY, EXTRACELLULAR FLUID VOLUME AND THE FLOW OF LYMPH AND BLOOD IN THE TESTES OF RATS

1981 ◽  
Vol 91 (2) ◽  
pp. 245-254 ◽  
Author(s):  
B. P. SETCHELL ◽  
R. M. SHARPE
Keyword(s):  
Blood Flow ◽  
Capillary Permeability ◽  
Venous Blood ◽  
Extracellular Fluid ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Lymph Flow ◽  
Male Rats ◽  
Testicular Cells ◽  
Testicular Blood Flow

The subcutaneous injection of human chorionic gonadotrophin (HCG) into adult male rats caused appreciable rises in capillary permeability and lymph flow in the testis, accompanied by smaller rises in the volume of extratubular, extracellular fluid. Most of these changes were already apparent 8 h after injection, but became progressively greater during the next 12 h. Testicular blood flow was unchanged at 12 h but increased slightly between 12 and 16 h after injection. The primary effect is probably the increase in capillary permeability. The timing of these changes suggests that HCG does not affect the capillaries directly, but it would seem that the changes are due to some substances secreted by the testis in response to the HCG. It is clear that these changes will have important influences both on the access to the testicular cells of peptide hormones in the blood and also on the passage into the venous blood of hormones secreted by the testis.

Reduction of testicular blood flow and focal degeneration of tissue in the rat after administration of human chorionic gonadotrophin

1988 ◽  
Vol 117 (1) ◽  
pp. 51-NP ◽  
Author(s):  
J. van Vliet ◽  
F. F. G. Rommerts ◽  
D. G. de Rooij ◽  
G. Buwalda ◽  
C. J. G. Wensing
Keyword(s):  
Blood Flow ◽  
Leydig Cells ◽  
Cell Damage ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Male Rats ◽  
Seminiferous Tubules ◽  
Prostaglandin E ◽  
Cell Degeneration ◽  
Testicular Blood Flow

ABSTRACT The effect of 100IU human chorionic gonadotrophin (hCG) on testicular capillary blood flow was studied in adult male rats using a 133Xe clearance method and a radioactive microsphere technique. To investigate the role of Leydig cells in regulation of testicular blood flow after treatment with hCG, rats were pre-treated with ethane dimethylsulphonate (EDS) which selectively destroys mature Leydig cells. Six hours after treatment with hCG, testicular blood flow decreased in control and hypophysectomized rats to 25–50% of normal values, but not in EDS-pretreated animals. Prostaglandin E2 levels were also determined 6 h after an injection of hCG. A 300-fold increase in the concentration of prostaglandin E2 occurred in normal testis tissue. This rise was markedly inhibited if EDS was given 3 days before administration of hCG. Furthermore, 6 h after administration of hCG, the filling of the testicular capillary bed with methylacrylate was decreased, while in control rats and rats treated with EDS and hCG, complete filling of the capillaries was seen. Cell degeneration in some subcapsular seminiferous tubules was observed 6–10 days after treatment with hCG. The results suggest that the hCG-induced precapillary vasoconstriction, probably mediated (in part) by prostaglandins, causes reduction in testicular blood flow 6 h after administration of hCG, and may result in cell damage. J. Endocr. (1988) 117, 51–57

Changes in testicular blood flow and testosterone production during aspermatogenesis after irradiation

1983 ◽  
Vol 98 (1) ◽  
pp. 35-46 ◽  
Author(s):  
J. Wang ◽  
K. A. A. Galil ◽  
B. P. Setchell
Keyword(s):  
Blood Flow ◽  
Leydig Cells ◽  
Capillary Permeability ◽  
Extracellular Fluid ◽  
Testis Weight ◽  
Γ Irradiation ◽  
Adult Rats ◽  
Efferent Duct ◽  
Duct Ligation ◽  
Testicular Blood Flow

Exposure of the testes of anaesthetized adult rats to 527 rads of γ-irradiation caused testis weight to fall slowly at first and then more rapidly from 21 days afterwards, reaching a minimum at 52 days, when spermatogenesis was severely disrupted. The weights of the accessory organs and the concentrations of testosterone in peripheral blood were slightly reduced; the concentrations in blood from the testicular veins were lower than control at shorter intervals after irradiation, but at later times tended to be similar or greater than control. Testicular blood flow per testis followed testis weight closely, and as a result the production of testosterone by the smaller testes (calculated as the product of plasma flow and the veno–arterial difference in testosterone concentration) was markedly reduced especially when the rats had been stimulated with human chorionic gonadotrophin (hCG). Serum FSH and LH rose appreciably as testis weight fell but there was a proportionately greater rise in FSH than LH, in comparison with surgically castrated animals. Increased amounts of extratubular, extracellular fluid were found in the aspermatogenic testes, but injection of hCG still caused increases in capillary permeability and the amount of fluid in the testis. These results indicate that during aspermatogenesis following irradiation (as with heat and efferent duct ligation) the capacity of the testes to secrete testosterone is severely limited by decreased testicular blood flow, not by the ability of the Leydig cells to release testosterone into their immediate environment.

OVARIAN VENOUS BLOOD FLOW IN NON-PREGNANT AND PREGNANT RATS

1977 ◽  
Vol 72 (2) ◽  
pp. 127-133 ◽  
Author(s):  
N. W. BRUCE ◽  
S. B. DIMMITT
Keyword(s):  
Blood Flow ◽  
Venous Blood ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Venous Blood Flow ◽  
Radioactive Microspheres ◽  
Venous Outflow ◽  
Pregnant Rats ◽  
Flow Through ◽  
The Right

SUMMARY A modified venous outflow technique was used to measure ovarian blood flow in the rat. The rate of flow through the right ovary was 0·198 ± 0·009 (s.e.m.), 0·476 ± 0·076 and 0·958 ± 0·162 ml/min in six Day 0 (dioestrous), five Day 16 and six Day 22 pregnant rats respectively. The intravenous administration of 50 i.u. human chorionic gonadotrophin increased ovarian blood flow by 26 ± 4, 57 ± 19 and 46 ± 9% respectively, from 2 to 8 min after the injection. The present ovarian venous outflow results are substantially higher than those previously reported in the rat but agree with values determined with radioactive microspheres.

Relationship between human chorionic gonadotrophin-induced changes in testicular microcirculation and the formation of testicular interstitial fluid

1986 ◽  
Vol 109 (3) ◽  
pp. 419-425 ◽  
Author(s):  
A. Widmark ◽  
J. E. Damber ◽  
A. Bergh
Keyword(s):  
Blood Flow ◽  
Flow Pattern ◽  
Interstitial Fluid ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Blood Flow Pattern ◽  
Adult Rats ◽  
Doppler Flowmetry ◽  
Testicular Blood Flow ◽  
Induced Changes

ABSTRACT The relationship between testicular vascular permeability and testicular microcirculation as measured by laser Doppler flowmetry was studied in adult rats. In untreated control animals there was an oscillatory testicular blood-flow pattern with a frequency of 10·6 ± 0·8 pulses/min and the amount of testicular interstitial fluid (IF) collected was 61·5 ± 2·2 μl/g testis. Treatment of the rats with 25–200 i.u. human chorionic gonadotrophin (hCG) s.c. 8 h before the experiment resulted in a change in the testicular flow pattern from pulsatile to continuous and an increase in IF volume. Treatment with hCG (50 i.u., s.c.) changed the testicular blood-flow pattern from oscillatory to continuous 4, 8 and 16 h after treatment. The flow pattern returned to being pulsatile 32 h after treatment with hCG. The IF information was increased at those times when the blood-flow pattern was continuous. No effects on blood flow or IF formation were observed with 12·5 i.u. hCG s.c. The present study shows a dose- and time-dependent covariation between the increase in testicular IF volume and the disappearance of the pulsatile flow in testicular microcirculation. It appears that a continuous flow pattern favours the transport of fluid from blood vessels to the interstitium. J. Endocr. (1986) 109, 419–425

Adrenal and gonadal function in hypothyroid adult male rats

1997 ◽  
Vol 152 (1) ◽  
pp. 147-154 ◽  
Author(s):  
A Tohei ◽  
M Akai ◽  
T Tomabechi ◽  
M Mamada ◽  
K Taya
Keyword(s):  
Adult Male ◽  
Functional Relationship ◽  
Plasma Concentrations ◽  
Gonadal Hormones ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Male Rats ◽  
Plasma Acth ◽  
Corticosterone Release ◽  
Acth Release

Abstract The functional relationship between thyroid, adrenal and gonadal hormones was investigated using adult male rats. Hypothyroidism was produced by the administration of 4-methyl-2-thiouracil (thiouracil) in the drinking water for 2 weeks. Plasma concentrations of TSH dramatically increased, whereas plasma concentrations of tri-iodothyronine and thyroxine decreased in thiouracil-treated rats as compared with euthyroid rats. Hypothyroidism increased basal levels of plasma ACTH and pituitary content of ACTH. The pituitary responsiveness to CRH for ACTH release markedly increased, whereas the adrenal responsiveness to ACTH for corticosterone release decreased. These results indicated that hypothyroidism causes adrenal dysfunction in adult male rats. Pituitary contents of LH and prolactin decreased in hypothyroid rats as compared with euthyroid rats. In addition, hypothyroidism lowered pituitary LH responsiveness to LHRH. Testicular responsiveness to human chorionic gonadotrophin for testosterone release, however, was not different between euthyroid and hypothyroid animals. These results indicated that hypothyroidism causes adrenal dysfunction and results in hypersecretion of ACTH from the pituitary gland. Adrenal dysfunction may contribute to the inhibition of LHRH secretion from the hypothalamus, possibly mediated by excess CRH. Journal of Endocrinology (1997) 152, 147–154

scholarly journals Testicular microvascular flow is altered in Klinefelter syndrome and predicts circulating testosterone

2021 ◽  
Author(s):  
Francesco Carlomagno ◽  
Carlotta Pozza ◽  
Marta Tenuta ◽  
Riccardo Pofi ◽  
Luigi Tarani ◽  
...  
Keyword(s):  
Blood Flow ◽  
Klinefelter Syndrome ◽  
Mean Transit Time ◽  
Venous Blood ◽  
Experimental Studies ◽  
Principal Component ◽  
Endocrine Function ◽  
Venous Blood Flow ◽  
Testicular Blood Flow

ABSTRACTContextExperimental studies on Klinefelter syndrome (KS) reported increased intratesticular testosterone (T) levels coexisting with reduced circulating levels. Abnormalities in testicular microcirculation have been claimed; however, no studies investigated in vivo testicular blood flow dynamics in humans with KS.ObjectiveTo analyze the testicular microcirculation in KS by contrast-enhanced ultrasonography (CEUS) and correlate vascular parameters with endocrine function.Design and SettingProspective study. University Settings.Patients51 testicular scans, 17 testes from 10 T-naïve subjects with KS and 34 testes from age-matched eugonadal men (CNT) who underwent CEUS for incidental nonpalpable testicular lesions.Main OutcomesCEUS kinetic parameters.ResultsCEUS revealed slower testicular perfusion kinetics in subjects with KS than in age-matched CNT. Specifically, the wash-in time (Tin, p = 0.008), mean transit time (MTT, p = 0.008), time to peak (TTP, p < 0.001), and washout time (Tout 50%, p = 0.008) were all prolonged. Faster testicular blood flow was associated with higher total T levels. Principal component analysis and multiple linear regression analyses confirmed the findings, and supported a role for reduced venous blood flow as independent predictor of total T levels.ConclusionsTesticular venous blood flow is altered in KS and independently predicts T peripheral release.

SHORT-TERM EFFECTS OF COPULATION, HUMAN CHORIONIC GONADOTROPHIN INJECTION AND NON-TACTILE ASSOCIATION WITH A FEMALE ON TESTOSTERONE LEVELS IN THE MALE RAT

1974 ◽  
Vol 60 (3) ◽  
pp. 429-439 ◽  
Author(s):  
K. PURVIS ◽  
N. B. HAYNES
Keyword(s):  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Physical Contact ◽  
Male Rats ◽  
Male Rat ◽  
Plasma Testosterone ◽  
Short Term ◽  
Testosterone Levels ◽  
Peripheral Plasma ◽  
First Contact

SUMMARY Peripheral plasma testosterone levels in the male rat were increased above control levels 5 min after the first intromission with an oestrous female, or 8–10 min after first contact with the female. The levels remained raised for at least 30 min if copulation was allowed to continue. Intravenous injection of human chorionic gonadotrophin resulted in an increased peripheral concentration of plasma testosterone after 10–15 min and an increase of testosterone content of the testis 5–10 min after injection, indicating that the rat testis has a potential to respond rapidly to gonadotrophin. The results suggested that if the testosterone surge during copulation was gonadotrophin-dependent, it was initiated before the first intromission. Indeed, plasma testosterone levels were raised in male rats 5 min after being placed in the proximity of oestrous females but not allowed physical contact.

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