Testicular Microcirculation Research Articles

Effects of oestradiol-17 beta on testicular microcirculation in rats.

The effect of oestradiol-17 beta on testicular microcirculation in intact and hypophysectomized rats was studied before and after treatment with human chorionic gonadotrophin (hCG). Treatment of intact rats with oestradiol-17 beta for 5 days did not influence vasomotion but decreased testicular interstitial fluid volume (IFV). Treatment of intact rats with 50 IU hCG 8 h before the experiment began induced an increase in testicular IFV, abolished vasomotion and increased the accumulation of polymorphonuclear leucocytes in the testicular venules and interstitium. These changes were unaffected by pretreatment with oestradiol-17 beta, despite the decreased testosterone production. However, pretreatment with oestradiol-17 beta potentiated the hCG-induced migration of polymorphonuclear leucocytes to the interstitium. The interstitial fluid volume and number of polymorphonuclear leucocytes in blood vessels were decreased in hypophysectomized rats, and vasomotion was abolished. Daily treatment with 5 IU hCG increased the IFV and the number of polymorphonuclear leucocytes in blood vessels, and preserved vasomotion. Treatment of hypophysectomized rats with oestradiol-17 beta decreased testosterone production but did not influence basal IFV, vasomotion or the changes in IFV and vasomotion induced by 5 IU hCG. The present study shows that the regulation of testicular vascular permeability and vasomotion may not be directly related to testicular steroidogenesis, and that oestrogens are probably not involved as a mediator of the hCG-induced changes in testicular microcirculation.

Effect of an LHRH-agonist on testicular microcirculation in hypophysectomized rats.

The effect of an LHRH-agonist on testicular vasomotion was studied in adult hypophysectomized rats. At 0.5 and 1 h after injection of 1 microgram LHRH-agonist, no effect on vasomotion was observed, but after 2 h the pulsatile blood flow pattern had changed to continuous flow in 50% of the rats. At 4 h after treatment with LHRH-agonist, vasomotion was not detected in the testis of any rat. In addition, at the latter time an increased number of polymorphonuclear leucocytes (PMNs) were observed in testicular microvessels, and some PMNs had migrated into the interstitial space. These findings are discussed in relation to the well-known stimulatory effect of LHRH-agonists on testicular interstitial fluid volume.

Testicular Blood Flow and Microcirculation in Rats After Treatment with Ethane Dimethyl Sulfonate1

The effects of ethane dimethyl sulfonate (EDS) on total testicular blood flow, microcirculation, and the testicular interstitial fluid volume (IFV) in rats were studied. In agreement with previous studies, treatment of control rats with human chorionic gonadotropin (hCG) induced an increase in IFV and total testicular blood flow as measured with radioactive microspheres. These effects of hCG were completely abolished in rats pretreated with EDS; in EDS-treated rats not receiving any hCG, there were decreases in IFV when compared with untreated control rats. Furthermore, the pulsatile pattern of testicular microcirculation registered with laser-Doppler flowmetry was abolished after EDS treatment, and this effect was not influenced by hCG treatment. The hCG-induced increase in IFV is associated with an increased accumulation of polymorphonuclear leukocytes locally in the testis, but this accumulation of leukocytes was not observed in rats pretreated with EDS. It was concluded from the present study that hCG-induced changes in total testicular blood flow and testicular microcirculation require functionally intact Leydig cells.

Treatment of rats with hCG induces inflammation-like changes in the testicular microcirculation.

Adult rats were injected subcutaneously with 50 i.u. hCG and vascular permeability was compared to that in saline-treated control rats by two independent methods. At 4 h after hCG treatment the rats were injected intra-arterially (i.a.) with FITC-labelled macromolecular dextran (Mr 150,000) and the testicular microcirculation was studied in vivo by using a fluorescence microscope. Other rats were injected i.a. with a suspension of colloidal carbon and the location of leaking blood vessels was recorded in sections from the testes by light and electron microscopy. In hCG-treated animals leucocytes were found adhering to the endothelium in post-capillary venules and in these venular segments dextran was leaking into the interstitium. Carbon particles were deposited in the walls of post-capillary venules and leucocytes migrated through open interendothelial cell gaps in hCG-treated animals. In control animals leucocyte adhesion and migration were not observed, the injected dextran remained in the circulation and the blood vessels were not labelled by carbon. It is suggested that the hCG-induced increase in testicular interstitial fluid volume, like the tissue oedema in inflammation, is caused by a leucocyte-mediated increase in venular permeability.

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

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 microliter/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.

Treatment of male fertility disturbances. Current concepts.

Medical therapy of male infertility aims to improve or normalise the fertility status of a subfertile patient. However, this can be a frustrating task due to limited knowledge about the pathophysiology of male reproductive functions, and the fact that pharmacological therapy is mainly empirical and less often specific. Nevertheless, the spectrum of treatment approaches has increased within the last decade and comprises hormonal and non-hormonal compounds. Hormonal therapy is performed with antioestrogens (clomiphene, tamoxifen), gonadotrophin-releasing hormone (GnRH), prolactin inhibitors (bromocriptine), gonadotrophins (hMG, hCG), androgens (testosterone, mesterolone), and testosterone aromatase inhibitors (testolactone). Tissue hormone-releasing proteases (kallikrein) can also be applied, liberating kinins as mediator substances with different effects at the cellular level. Non-hormonal therapy includes improvement of testicular microcirculation by oxpentifylline, antimicrobial and anti-inflammatory agents, drugs to improve or allow emission and ejaculation, and psychotropic and antispasmodic drugs to diminish functional disturbances induced by emotional stress. Treatment schedules are either specifically or empirically based. If treatment is based on a pathophysiological concept which implies strong patient selection, success of treatment is excellent. In contrast, despite an increased number of compounds, empirically based therapies remain unpredictable and the results are moderate and often not reproducible. However, when different drugs are compared with a placebo group in selected, well-controlled patients with idiopathic normogonadotrophic oligozoospermia, pregnancy rates will be in the range of 30 to 40% within an observation period of 1 year, as compared with the spontaneous conception rate of between 10 and 20%.

Rhythmical oscillations in rat testicular microcirculation as recorded by laser Doppler flowmetry.

We have earlier reported that local testicular blood flow, recorded by laser Doppler flowmetry, shows large oscillations with a frequency of 5-10 min-1. In the present study it is proposed that the recorded oscillations represent mainly local microvascular blood flow variations rather than variations in total testicular blood flow or tissue movements. The reasons for this are: (a) Blood flow simultaneously measured at two separate sites showed oscillations with different frequencies. (b) A local subcapsular injection of room-tempered saline under one probe site eradicated oscillations under that probe but not under another adjacent probe. (c) When the testicular capsule was split open, recordings of blood flow continued to show oscillations. (d) The amplitude of the oscillations was rather large (peak to peak value about 50% of mean flow value). No movements of the testicular surface were seen. A 20 min continuous infusion of 0.4 microgram/min noradrenaline did induce a decrease in plasma testosterone concentration, but did not change the mean blood flow. However, the oscillations nearly completely disappeared during the infusion period. The present study also shows that laser Doppler flowmetry is a versatile method and the rat testis provides a suitable organ in the study of the origin and functional importance of these oscillations.

Regional sensitivity of the testicular artery to noradrenaline in ram, rabbit, rat and boar.

Department of Physiology & Biochemistry, University of Reading, Whiteknights, Reading RG6 2AJ (Received 6th February 1975) The testicular artery of mammals with scrotal testes is long and either coiled or with multiple branches. The pampiniform venous plexus closely surrounds the artery forming a counter-current heat exchange system (Harrison & Weiner, 1949; Dahl & Herrick, 1959; Waites & Moule, 1961) and the length of the artery attenuates the pulse pressure (Waites & Moule, 1960; Setchell & Waites, 1969; see also review by Setchell, 1970). Unlike the proximal testicular artery, the distal portion of the artery within the testicular capsule in the ram has a thinner wall with less muscle, collagen and elastin, and a wide-bore, elliptical lumen. The only functional significance yet ascribed to the unusual structure of the capsular testicular artery is the induction of a non-pulsatile blood flow through the testis (Waites & Moule, 1960). The testicular microcirculation responds

Dynamics of circulation in the testis of the conscious rat.

ARTICLESDynamics of circulation in the testis of the conscious ratMJ Free, and RA JaffeMJ Free, and RA JaffePublished Online:01 Jul 1972https://doi.org/10.1152/ajplegacy.1972.223.1.241MoreSectionsPDF (3 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Download PDF FiguresReferencesRelatedInformation Cited ByThe VaricoceleUrologic Clinics of North America, Vol. 41, No. 1VaricoceleEffects of Chemical Sympathectomy on Contralateral Testicular Histology and Fertility in Unilateral VasectomyJournal of Korean Medical Science, Vol. 24, No. 5The effects of chemical sympathectomy on testicular injury in varicocele16 July 2009 | BJU International, Vol. 87, No. 3The role of adrenomedullin in varicocele and impotence24 December 2001 | BJU International, Vol. 86, No. 6Acute Spermatic Cord Torsion Alters the Microcirculation of the Contralateral TestisJournal of Urology, Vol. 155, No. 1Acute Spermatic Cord Torsion Alters the Microcirculation of the Contralateral TestisThe Journal of UrologyAlcohol, Opioids, and Testicular FunctionThe preventive role of chemical sympathectomy on contralateral testicular hypoxic parameters encountered during unilateral testicular torsionBritish Journal of Urology, Vol. 74, No. 4Rat testis oedema measured with the impression technique: effects of hyaluronan, albumin, rat plasma and salineMedical & Biological Engineering & Computing, Vol. 32, No. 3The Alterations of Cellular Metabolism in the Contralateral Testis Following Spermatic Cord Torsion in RatsJournal of Urology, Vol. 150, No. 2 Part 2Effects of clonidine-induced hypotension and dopamine-induced hypertension on blood flows in prostatic adenocarcinoma (dunning R3327) and normal tissuesThe Prostate, Vol. 20, No. 3The effect of guanethidine treatment of testicular blood flow and testosterone production in ratsExperientia, Vol. 46, No. 5Cholinergic constriction in the general circulation and its role in coronary artery spasm.Circulation Research, Vol. 65, No. 2Morphologic Changes Induced by Short-term Ischemia in the Rat Testis Are Not Affected by Treatment with Superoxide Dismutase and Catalase2 January 2013 | Journal of Andrology, Vol. 9, No. 1Demonstration of a functional blood-testis barrier to acetaldehydeBiochemical Pharmacology, Vol. 34, No. 5Evaluation and Treatment of the Preadolescent VaricoceleUrologic Clinics of North America, Vol. 12, No. 1Circulation to Male Reproductive Organs1 January 2011Rhythmical oscillations in rat testicular microcirculation as recorded by laser Doppler flowmetryActa Physiologica Scandinavica, Vol. 118, No. 2The effect of norepinephrine, isoprenaline and acetylcholine on the testicular and epididymal circulation in the pigInternational Journal of Andrology, Vol. 6, No. 1Testicular blood flow measured with a laser Doppler flowmeter: acute effects of catecholaminesActa Physiologica Scandinavica, Vol. 115, No. 2Effect of catecholamines on ornithin decarboxylase activity in the testis of immature ratBiochemical and Biophysical Research Communications, Vol. 102, No. 3Varicocele2 January 2013 | Journal of Andrology, Vol. 2, No. 2Reduction in FSH receptors in the rat testis by injection of homologous hormoneMolecular and Cellular Endocrinology, Vol. 12, No. 1Methodological Aspects of Testicular Blood Flow Measurements in RatsActa Physiologica Scandinavica, Vol. 101, No. 3The effects of barbiturate anesthesia and laparotomy on testis and plasma testosterone in ratsJournal of Steroid Biochemistry, Vol. 8, No. 3Blood Supply to the Testis and Its Role in Local Exchange and Transport of HormonesSemen quality from the bull to the freezer: An assessmentTheriogenology, Vol. 3, No. 6[23] The infused testisInteractions Between the Prostaglandins and Steroid HormonesTestosterone Concentrating Mechanism in the Reproductive Organs of the Male RatNature New Biology, Vol. 244, No. 131Effect of prostaglandins on blood flow and pressure in the conscious ratProstaglandins, Vol. 1, No. 6 More from this issue > Volume 223Issue 1July 1972Pages 241-248 Copyright & PermissionsCopyright © 1972 by American Physiological Societyhttps://doi.org/10.1152/ajplegacy.1972.223.1.241PubMed5039068History Published online 1 July 1972 Published in print 1 July 1972 Metrics