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.

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.

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.

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

Abstract Context Experimental 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. Objective To analyze the testicular microcirculation in KS by contrast-enhanced ultrasonography (CEUS) and correlate vascular parameters with endocrine function. Design and Setting Prospective study. University Setting. Patients 68 testicular scans, 34 testes from 19 T-naïve subjects with KS and 34 testes from age-matched eugonadal men (CNT) who underwent CEUS for incidental nonpalpable testicular lesions. Main Outcomes. CEUS kinetic parameters. Results CEUS revealed slower testicular perfusion kinetics in subjects with KS than in age-matched CNT. Specifically, the wash-in time (Tin, p = 0.018), mean transit time (MTT, p = 0.035), time to peak (TTP, p &lt; 0.001), and washout time (Tout 50%, p = 0.004) 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. Conclusions Testicular venous blood flow is altered in KS and independently predicts T peripheral release.

TESTICULAR BLOOD FLOW AND TESTOSTERONE CONCENTRATIONS IN THE SPERMATIC VENOUS BLOOD IN RATS WITH EXPERIMENTAL CRYPTORCHIDISM

1978 ◽  
Vol 88 (3) ◽  
pp. 611-618 ◽  
Author(s):  
Jan-Erik Damber ◽  
Anders Bergh ◽  
Per Olof Janson
Keyword(s):  
Blood Flow ◽  
Leydig Cells ◽  
Venous Blood ◽  
Relative Increase ◽  
Morphological Data ◽  
Interstitial Tissue ◽  
Testicular Blood Flow ◽  
Cryptorchid Testis ◽  
Abdominal Testis ◽  
Main Factor

ABSTRACT Testicular blood flow and testosterone concentrations in the spermatic venous plasma were measured on unilaterally cryptorchid rats. Blood flow to the cryptorchid testis was 31.4 ± 11.7 (sd) ml/100 g x min which was significantly higher than that of the scrotal testis (17.7 ± 4.4 ml/100 gx. min) Stereological analysis showed a relative increase of blood vessel containing interstitial tissue in the cryptorchid testis, which was probably the main factor responsible for the relative increase of blood flow to the cryptorchid testis. The increase of interstitial tissue was greater than the increase of blood vessels and thus, the interstitium in the cryptorchid testis contained a number of vessels which was smaller than that of the interstitium in the scrotally located testis. The concentration of testosterone in the spermatic vein of the abdominal testis was 18.0 ± 5.5 (sd) ng/ml and the corresponding value for the scrotal testis was 41.2 ± 7.0 ng/ml. Calculations based on functional and morphological data indicate that the function of the Leydig cells in the abdominal testis was impaired. It was concluded that the outflow of testosterone from the cryptorchid testis was highly reduced.

A comparison of the effects of bilateral efferent duct ligation and of partial epididymectomy on the testes of rats

1990 ◽  
Vol 2 (4) ◽  
pp. 321 ◽  
Author(s):  
C Soler ◽  
C Blazquez ◽  
J Pertusa ◽  
M Nunez ◽  
J Nunez ◽  
...  
Keyword(s):  
Body Weight ◽  
Cross Sections ◽  
Seminiferous Tubules ◽  
Testis Weight ◽  
Efferent Duct ◽  
Efferent Ducts ◽  
Linear Decrease ◽  
Endocrine Effect ◽  
Duct Ligation ◽  
Exponential Decrease

Testis weight as a percentage of body weight did not change following bilateral ligation of the efferent ducts (EDL) close to the epididymis, whereas following removal of part of the epididymis between the site of ligation and a point close to the junction between the caput and corpus (PCE), testis weight first rose linearly until Day 4 and then showed an exponential decrease between Days 4 and 28. After EDL, the perimeter of the seminiferous tubules rose for the first 7 days and then remained elevated, whereas after PCE, there was a linear decrease between Days 4 and 28. Following EDL, the percentage of altered and degenerated tubular cross-sections rose to about 30% and 10%, respectively, during the first 7 days after operation and then remained constant; after PCE, the percentage of altered tubules reached a maximum of 54% by 4 days and then fell, whereas the percentage of degenerated tubules continued to rise to 95% by 28 days. It would appear that all the effects of removal of a portion of the epididymis cannot be explained by blockage of the excurrent ducts, and a specific endocrine effect of the epididymis on the testis is proposed.

Hemodynamics and metabolism of the in vivo vascularly isolated canine pancreas.

1979 ◽  
Vol 236 (6) ◽  
pp. E626
Author(s):  
R J Alteveer ◽  
M J Jaffe ◽  
J Van Dam
Keyword(s):  
Blood Flow ◽  
Glucose Uptake ◽  
Venous Blood ◽  
Fatty Acid Uptake ◽  
Acid Uptake ◽  
Anesthetized Dogs ◽  
Metabolic Variables ◽  
The Stability ◽  
First Time

Surgical procedures are detailed that have yielded for the first time an in vivo vascularly isolated, autoperfused preparation of the entire pancreas in anesthetized dogs. Previous studies had isolated only part of the pancreas or had resorted to blood-flow techniques not requiring pooled pancreatic venous blood, necessary for metabolic studies of the organ. Pancreatic blood flow (48 ml/min), O2 uptake (180 mumol/min), glucose uptake (51.0 mumol/min), lactate output (6.6 mumol/min), net free fatty acid uptake (2.23 mumol/min), all per 100 g tissue, and various other measured and calculated hemodynamic and metabolic variables were determined on the preparation during control conditions. The stability of the preparation was verified by serial determinations of these parameters and of blood alpha-amylase and beta-glucuronidase levels from 1 to 2.5 h postsurgery. Metabolic rate and glucose uptake were both found to be much higher than in intestinal tissues and approached values characteristic of liver tissue.

WITHDRAWN: Venous Blood Gases of Varicocele Veins: Correlation With Testicular Blood Flow and Semen Quality in Varicocele Patients

Urology ◽  
2016 ◽  
Author(s):  
Khaleeq ur Rehman ◽  
Hafsa Zaneb ◽  
Ahsan Numan ◽  
Abdul Basit Qureshi ◽  
Imtiaz Rabbani ◽  
...  
Keyword(s):  
Blood Flow ◽  
Semen Quality ◽  
Venous Blood ◽  
Blood Gases ◽  
Testicular Blood Flow

Blood flow in the ovary and adjacent structures of the non-pregnant sheep

1983 ◽  
Vol 103 (2) ◽  
pp. 259-265 ◽  
Author(s):  
P. O. Janson ◽  
D. Williams ◽  
O. M. Petrucco ◽  
F. Amato ◽  
R. F. Seamark ◽  
...  
Keyword(s):  
Blood Flow ◽  
Venous Blood ◽  
Vascular Pedicle ◽  
Venous Flow ◽  
Adjacent Structures ◽  
Pregnant Sheep ◽  
Rapid Changes ◽  
Capillary Bed

Abstract. Blood flow to the ovary, vascular pedicle and oviduct was measured in anaesthetized non-cycling and cycling ewes by timed collection of ovarian venous blood. The degree of arterio-venous shunting across the ovary and pedicle was estimated both in vivo and in vitro by perfusing the tissues with 15 ± 5 μm radioactive microspheres. The mean ovarian blood flow in non-cycling animals was 1.9 ml/min, which was 51% of blood flow in the ovarian vein. In cycling animals ovarian blood flow at midcycle was 2.9 ml/min (66% of ovarian venous flow) in non-luteal ovaries and 4.3 ml/min (79% of venous flow) in luteal ovaries. The degree of arterio-venous shunting was low in all stages of the cycle (1.0–2.6% across ovary + pedicle). The degree of shunting was also found to be very small in vitro (0.007–1.38%) in both non-luteal and luteal ovaries. A considerable number of microspheres was entrapped in the vascular pedicle of the ovary indicating the presence of an extensive capillary bed. There was an inverse relationship between blood flow in the ovary and flow in the vascular pedicle. Alterations in distribution of blood flow between the ovary and adjacent structures supplied by the ovarian artery may be of functional significance in allowing rapid changes in ovarian blood flow. The results of the present study indicate that changes in ovarian blood flow during the oestrous cycle are not caused by an action on arteriovenous shunt vessels.

Sign in / Sign up

Export Citation Format

Share Document