Phentolamine Research Articles

Exercise Induced Redistribution of Lymphocytes - Influence of Exercise Intensity and Adrenergic Mechanisms

Exercise induces considerable changes of blood lymphocyte counts. Recently, we observed that at least two different mechanisms are involved. First, after exercise lymphocyte apoptosis is enhanced depending on exercise intensity. Second, exercise is followed by a redistribution of lymphocytes between lymphoid and non-lymphoid organs. These lymphocyte movements are known to be controlled by several hormones, cytokines and receptors including adrenergic mechanisms. PURPOSE: Therefore, the aim of the study was to determine the influence of different exercise intensities on lymphocyte redistribution. In a second approach we tried to find out the importance of adrenergic mechanisms on lymphocyte redistribution during exercise. METHODS: Isolated lymphocytes were labelled with a fluorescent dye (Cell-Tracker Green) and injected intravenously in male Swiss mice. Groups performed acute treadmill exercises either at 60% or 80% VO2max or swimming exercise until exhaustion. Another group exercised after a treatment with either phentolamine (PHE) or nadolol (NAD). A third group received single applications of epinephrine (E) or norepinephrine (NE). After the tests, thymus, bone-marrow, spleen, lung, liver, Peyer's patches and lymph nodes were excised. Lymphocyte distribution was investigated both qualitatively and quantitatively using either fluorescence-microscopy or flow cytometry, respectively. RESULTS: We found a decrease of splenic lymphocyte counts after exercise which was related to exercise intensity. The decrease was blocked by prior applications of both PHE and NAD and could be mimicked by an application of E. The increase in lymphocyte counts in the bone marrow and the lung seemed to be intensity dependent, too. However, both movements relied on adrenergic mechanisms only partially. CONCLUSIONS: Lymphocytes are intensity -dependent mobilised from the spleen via adrenergic mechanisms. Redistribution into the target organs is influenced by exercise intensity and is only partially dependent on adrenergic mechanisms. Instead it seems likely that other mechanisms such as the expression of various homing receptors are involved.

Two cases of accidental epinephrine injection into a finger

Two cases of accidental epinephrine injection into a finger

Intracavernous papaverine/phentolamine-induced priapism can be accurately predicted with color Doppler ultrasonography

Objectives To determine the value of penile duplex ultrasonography in predicting the occurrence of intracavernous drug-induced ischemic priapism directly after the rigid erection phase. Methods We evaluated 250 men with erectile dysfunction by color Doppler ultrasonography after the diagnostic injection of papaverine hydrochloride and phentolamine mesylate. Cavernosal artery waveforms were recorded, and peak systolic velocity (PSV) and end diastolic velocity (EDV) of the recorded waveforms were measured. In cases of priapism, color Doppler ultrasonography findings were evaluated to identify any finding that would predict priapism. Results In all, 41 patients experienced painful rigid erection for more than 1 hour after injection. All patients were divided into two groups. Group I included 16 patients who achieved full erection lasting less than 6 hours. Group II included 25 patients who achieved full erection lasting more than 6 hours. All patients of group I had PSV less than 61 cm/s and EDV of 0 to 2 cm/s. On the other hand, all patients of group II had PSV greater than 66 cm/s and EDV of 0 to 1 cm/s. These findings were accurate predictors of persistent erection requiring intervention in all 25 patients of group II and in none of the group I patients (100% specificity and sensitivity). Conclusions Our results show that during the first hour of penile color Doppler ultrasound study, PSV of 66 cm/s or more together with EDV of 0 cm/s is a reliable predictive factor for priapism. This finding is reliable enough that treatment for priapism should be initiated without further delay.

Microvascular Exchange Response To Local Norepinephrine Administration Is Increased After 7-days Of Exercise Training In Elderly Men

Aging is associated with elevated muscle sympathetic nerve activity and reduced resting limb blood flow. Exercise trained elderly women have greater muscle sympathetic nerve activity compared to their sedentary counterparts; however, exercise trained elderly men have similar muscle sympathetic nerve activity compared to sedentary elderly men. PURPOSE We hypothesized that local skeletal muscle ?-adrenergic vasoconstrictor activity is elevated in aged individuals, and that 7-d of exercise training can alter the microvascular exchange response to the ?-adrenergic agonist norepinephrine and the α-adrenergic receptor blocker phentolamine. METHODS Before and after 7-d of cycle ergometry exercise training (75% VO2max; ∼1-h/d) the microdialysis ethanol technique was utilized to determine resting microvascular exchange in the vastus lateralis of sedentary, young (25 ± 4y; n = 8) and elderly (65 ± 2.3y; n = 8) men. The microdialysis ethanol technique yields an ethanol outflow/inflow (o/i) ratio which is inversely related to microvascular exchange. Norepinephrine (NE) and phentolamine (PA) were administered in an effort to assess sympathetic vasomotor responsiveness through subsequent changes in microvascular exchange. RESULTS Resting ethanol o/i ratios were not significantly different between the young and elderly men and were not altered as a result of exercise training. Prior to exercise training, increases in o/i ratio in response to NE appeared attenuated in elderly men compared to the young (p = 0.1). A main effect for exercise training (p <0.05) was discovered with NE administration. This increase in ethanol o/i ratio (reduction in microvascular exchange) for the young (1.92-fold) and elderly (32-fold) indicate a further reduction in microvascular exchange beyond that which was found prior to exercise training. With PA administration, there was a trend (p = 0.1) for an increased ethanol o/i ratio with 7-d of exercise training. CONCLUSIONS Collectively, these data demonstrate that 7-d of moderate intensity cycle ergometry exercise training increase vasomotor sensitivity to the sympathetic agonist norepinephrine in young and elderly males. Furthermore, we suggest that any potential deficiency in microvascular exchange responsiveness to sympathetic stimuli in sedentary elderly males is normalized after 7-d of exercise training. Supported by NIHAG-19209(R.H.) and NIAAG-21891 (T.G.).

Microvascular Exchange Response To Local Norepinephrine Administration Is Increased After 7-days Of Exercise Training In Elderly Men

Aging is associated with elevated muscle sympathetic nerve activity and reduced resting limb blood flow. Exercise trained elderly women have greater muscle sympathetic nerve activity compared to their sedentary counterparts; however, exercise trained elderly men have similar muscle sympathetic nerve activity compared to sedentary elderly men. PURPOSE We hypothesized that local skeletal muscle ?-adrenergic vasoconstrictor activity is elevated in aged individuals, and that 7-d of exercise training can alter the microvascular exchange response to the ?-adrenergic agonist norepinephrine and the α-adrenergic receptor blocker phentolamine. METHODS Before and after 7-d of cycle ergometry exercise training (75% VO2max; ∼1-h/d) the microdialysis ethanol technique was utilized to determine resting microvascular exchange in the vastus lateralis of sedentary, young (25 ± 4y; n = 8) and elderly (65 ± 2.3y; n = 8) men. The microdialysis ethanol technique yields an ethanol outflow/inflow (o/i) ratio which is inversely related to microvascular exchange. Norepinephrine (NE) and phentolamine (PA) were administered in an effort to assess sympathetic vasomotor responsiveness through subsequent changes in microvascular exchange. RESULTS Resting ethanol o/i ratios were not significantly different between the young and elderly men and were not altered as a result of exercise training. Prior to exercise training, increases in o/i ratio in response to NE appeared attenuated in elderly men compared to the young (p = 0.1). A main effect for exercise training (p <0.05) was discovered with NE administration. This increase in ethanol o/i ratio (reduction in microvascular exchange) for the young (1.92-fold) and elderly (32-fold) indicate a further reduction in microvascular exchange beyond that which was found prior to exercise training. With PA administration, there was a trend (p = 0.1) for an increased ethanol o/i ratio with 7-d of exercise training. CONCLUSIONS Collectively, these data demonstrate that 7-d of moderate intensity cycle ergometry exercise training increase vasomotor sensitivity to the sympathetic agonist norepinephrine in young and elderly males. Furthermore, we suggest that any potential deficiency in microvascular exchange responsiveness to sympathetic stimuli in sedentary elderly males is normalized after 7-d of exercise training. Supported by NIHAG-19209(R.H.) and NIAAG-21891 (T.G.).

Phosphodiesterase-5 inhibition enhances sympathetically mediated vascular tone

Background Phosphodiesterase type-5 (PDE-5) inhibition causes vasodilation and sympathetic activation. The contribution of each of these on resting vascular tone has not been studied. We tested the hypothesis that PDE5 inhibition contributes to increased sympathetically mediated vascular tone. Methods We studied 9 healthy males (44±2 years), randomized in a double-blind, crossover fashion to sildenafil 100 mg or placebo. Blood pressure and forearm vascular resistance (FVR) were determined at rest, after study drug administration and during intra-brachial infusion of norepinephrine (NE) 480 pmol/minute (to test alpha-receptors), adenosine (ADEN) 300 μg/minute (control), isoproterenol (ISO) 250 ng/minute (to test beta receptors) and phentolamine (PHEN) 120 μg/minute (to test sympathetically-mediated vascular tone). Norepinephrine was measured at baseline and 1 hour after study drug administration. Results Mean arterial blood pressure increased slightly after placebo (p=0.06) but was unchanged after sildenafil. FVR responses to NE, ADEN, ISO were similar (see Table; p=NS for all). FVR was reduced during PHEN following sildenafil compared to placebo(* p=0.002). Plasma norepinephrine increased by 84±31% and 30±12% following sildenafil and placebo (p=0.05). Conclusions PDE-5 inhibition significantly increased sympathetically mediated vascular tone compared to placebo in healthy, middle-aged men: this vasoconstriction offsets the vasodilatory effects of PDE-5 inhibition. Clinical Pharmacology & Therapeutics (2005) 77, P10–P10; doi: 10.1016/j.clpt.2004.11.042 Study Drug NE (% ΔFVR) ADEN (% ΔFVR) ISO (% ΔFVR) PHEN (% ΔFVR) Sildenafil 64 ± 15 −80 ± 2 −77 ± 3 −73 ± 3* Placebo 56 ± 14 −78 ± 2 −72 ± 3 −63 ± 3

Hypertensive Krisen endokriner Ursache am Beispiel des Ph�ochromozytoms

Die Kenntnis des Spektrums der Symptomatologie des Phaochromozytoms und der Phaochromozytomkrise sind unabdingbare Voraussetzungen fur das Erkennen der Erkrankung, der Vermeidung einer kontraindizierten und deletaren Betablocker-Applikation ohne initiale Alpha-Blockade sowie der Bahnung der richtigen Diagnostik. Die biochemische Sicherung der Verdachtsdiagnose erfolgt heute unkompliziert uber die Bestimmung der Katecholamine und der Metanephrine im 24h-Sammelurin. Nach erfolgter Lokalisationsdiagnostik ist die praoperative pharmakologische Therapie entscheidend fur die Vermeidung von Komplikationen und Endorganschaden. Fur die praoperative Therapie wird eine initiale Alpha-Blockade mittels des nicht-spezifischen, nicht-kompetitiven, irreversiblen α-Rezeptorantagonisten Phenoxybenzamin dringend empfohlen. Nach einer maximal moglichen Auftitrierung bis zur Normotonie und bis zum Auftreten orthostatischer Beschwerden folgt die Applikation eines nicht-kardioselektiven Beta-Blockers, z. B. Propranolol. Durch konsequente Befolgung dieser Richtlinien sowie durch verbessertes Monitoring und Fortschritte in der Anasthesie konnten die perioperativen Komplikationen deutlich gesenkt werden. Hinsichtlich der Notfalltherapie der hypertensiven Krise beim Phaochromozytom ware Phentolamin prinzipiell das Mittel der Wahl. Aufgrund schwieriger Verfugbarkeit (importierbar uber die Auslands-Apotheke) ist hier Urapidil eine gute Alternative. Beim Gebrauch von Nitroprussid-Natrium sind komplexere pharmakologische und toxikologische Effekte zu beachten.

Erectile Dysfunction: Anatomical Parameters, Etiology, Diagnosis, and Therapy

Functional anatomy of the human penis involves various parameters: cavernous tissue, covering integument, prepuce foreskin, corpora cavernosa, corpus spongiosum, glans, facia, arterial supply, venous drainage, lymph drainage, musculature, and nerve supply. Several factors affect the expression/degree of erectile dysfunction (ED) endocrine profile, aging/senescence, demyelinating diseases, and surgery. Risk factors of ED are: age, vascular factors, metabolic diseases (diabetes mellitus), neurologic diseases, and HIV/AIDS. Several drugs are associated with ED: antiandrogenic, anticholinergic, antidepressants, antihypertensive, major tranquilizers, anxiolytics, and certain medicines/metabolites. The International Index of Erectile Function (IIEF) is a multidimensional scale for assessment of erectile dysfunction. The main structures mediating erection are the corpora cavernosa or "erectile bodies," which are fused distally for approximately three-quarters of their length. They separate proximally to fuse with each ischial tuberosity of the pelvis. On their ventral surface lies the corpus spongiosum, which surrounds the urethra. Coital dysfunction is classified into "erectile dysfunction" (psychosexual and endocrine/neuro-endocrine) and "ejaculatory dysfunction" (psychosexual, and genitourinary surgery). Vasculogenic impotence was evaluated by high-resolution ultrasonography and pulsed Doppler spectrum analysis. Cavernosal, alpha-blockade is a technique used to evaluate and treat ED. Another diagnostic procedure for ED involves color floro and spectural Doppler imaging after papaverine-induced erection in impotent men. Color Doppler and duplex ultrasonography are used to evaluate Peyronie's disease. Sildenafil cilrate (Viagra) is an effective therapy of ED in men. Vardenavil is a highly selective phosphodiesterase 5 (PDE5) inhibitor which improved ED. Prostagland E1, vasoactive intestinal polypeptide (VIP), and phentolamine mesylate (administered by autoinjectors) have been applied to treat ED in patients resistant to other intracavernosal agents. Clinical trials were conducted on self-injection of vasoactive drugs, apomorphine SL, and tadalafil in diabetic men. Medical therapy of ED includes: medicated urethral system for erection (MUSE), intravenous pharmacotherapy, arterial revascularization, vacuum devices, two- and three-component inflatable penile prosthesis, semi-rigid penile prosthesis in situ, and inflatable one-piece penile prosthesis. Surgical therapy include procedures to correct Peyronie's penile deformity and penile deformity, procedures to avoid inevitable shortening accompanying Nesbit's disease, and for penile lengthening.

Effects of social stress on blood leukocyte distribution: the role of α- and β-adrenergic mechanisms

Social stress in mammals has repeatedly been shown to cause substantial alterations in the distribution pattern of immune cells in the peripheral blood. The studies described here investigated the role of adrenergic mechanisms in mediating stressor-induced changes in blood leukocyte numbers using a social confrontation procedure in the rat. Experimental manipulations were carried out to eliminate the stress-associated release of adrenal hormones or to block the binding of endogenous catecholamines to α- and β-adrenergic receptors. Adrenalectomy completely abolished the stressor-induced decreases in circulating numbers of T helper cells (CD4 +), cytotoxic T cells (CD8 +) and B cells but was ineffective in preventing neutrophil granulocytosis, monocytosis and an increase in natural killer (NK) cells. Treatment with the α-adrenergic antagonist phentolamine (PHE) was highly effective in preventing granulocytosis and partially blocked lymphopenia, but failed to abolish monocytosis and an increase in NK cells. Treatment with the β-adrenergic antagonists propranolol (PROP) or nadolol (NAD) entirely blocked the increases in monocytes and NK cells. In addition, β-adrenergic blockade also significantly reduced neutrophilia, with PROP being more effective than NAD. The results presented here provide evidence that catecholamines play an important role in the redistribution of blood leukocytes during social stress. In particular, the mobilization of cells of the innate immune response seems to be regulated by adrenergic mechanisms.

Alkylation of Diphenylamines with Chloroacetonitrile: A New Entry to Phentolamine Analogues.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Development of Hibernomas in Rats Dosed with Phentolamine Mesylate During the 24-Month Carcinogenicity Study

Phentolamine is a reversible competitive alpha-adrenergic antagonist with similar affinities for alphal and alpha2 receptors. It has a long history of safe clinical use, and was developed as a potential therapy for male erectile dysfunction because of its capacity to increase the arteriolar blood flow to the corpora cavernosa. Phentolamine mesylate was administered to rats by oral gavage at daily doses of 10, 50, and 150 mg/kg for 24 months. A dose-related increase in mortality, ascribed to an exaggerated pharmacologic effect, was seen at high doses. Systemic exposure as measured by plasma drug concentration increased with dose and duration of dosing and slight drug accumulation occurred, particularly in high-dose males. In the treated groups, 10 males and 1 female were diagnosed with hibernomas, neoplasms of brown adipose tissue, which appeared in the thoracic cavity or retroperitoneal area as circumscribed, tan to reddish-brown lobulated masses. Histologically, the masses were well circumscribed with variably sized lobules defined by a rich capillary network and consisted of closely apposed oval to polygonal cells with large amounts of cytoplasm and a centrally located nucleus. The cytoplasm's appearance varied from multivacuolated to univacuolated to granular eosinophilic. In a few cases, neoplastic emboli were observed in capsular vessels. Ultrastructurally, the neoplastic cells contained numerous mitochondria with transverse parallel cristae that occupied over 60% of the cytoplasm and lipid droplets. This study documents the previously unreported development of hibernomas in rats treated with phentolamine mesylate.

Correlation between penile duplex findings and stress electrocardiography in men with erectile dysfunction.

The aim of this work is to assess the association between vasculogenic erectile dysfunction (ED) and coronary artery disease in men above the age of 40 y. The study included 40 patients above 40 y of age with vasculogenic ED of more than 3 months duration. A dynamic duplex study after intracavernosal injection of a bimix solution (60 mg papaverine + 2 mg phentolamine mesylate) was carried out using a color ultrasound machine. The patients underwent a stress ECG test, carried out on a motor-driven treadmill according to the 'Bruce Protocol'. A total of 12 patients were diagnosed with positive ischemic heart disease (IHD). Their mean peak systolic velocity (PSV) was PSV = 19.58 cm/s. In all, patients were diagnosed with negative IHD; their mean PSV was 36.21 cm/s. A statistically significant difference was observed between patients with positive IHD and patients with negative IHD regarding PSV (P = 0.003). The sensitivity of a PSV of less than 35 cm/s in predicting IHD was 50% with a specificity of 100%. Positive predictive value for abnormal stress ECG to predict a PSV of less than 35 cm/s was 100%. In conclusion, the PSV of cavernosal arteries is a reliable measure for predicting IHD in patients with vasculogenic ED. Patients with a PSV of less than 35 cm/s should be referred for cardiologic assessment as they carry a real risk of having silent IHD.

Alkylation of Diphenylamines with Chloroacetonitrile: A New Entry to Phentolamine Analogues

The alkylation of diphenylamines with chloroacetonitrile followed by annulation with ethylenediamine gave 2-imidazoline analogues of phentolamine.

A Review of the Physiology and Pharmacology of Peripheral (Vaginal and Clitoral) Female Genital Arousal in the Animal Model

We review contemporary scientific data concerning the physiology and pharmacology of peripheral female genital arousal responses in the animal (rabbit and rat) model. We reviewed the contemporary literature and our research studies concerning physiology and pharmacology of peripheral genital arousal from 3 experimental animal models, including genital smooth muscle cell culture, genital strip organ bath and in vivo animal model studies. Nitric oxide (NO) appears to be a key pathway mediating clitoral smooth muscle relaxation. In the vagina NO appeared to have a more controversial role in mediating vaginal muscularis smooth muscle relaxation. Vasoactive intestinal polypeptide induced vaginal smooth muscle relaxation. Functional alpha-adrenergic receptors were expressed in the clitoris and vagina, and mediated norepinephrine induced genital smooth muscle contraction. Androgens and estrogens modulated distinct physiological responses in vagina, and androgens facilitated vaginal smooth muscle relaxation. Papaverine hydrochloride, a smooth muscle relaxant, and phentolamine mesylate, an alpha-blocker, administered into the vaginal spongy muscularis layer increased vaginal wall pressure and vaginal blood flow. Sildenafil caused significant increases in genital (clitoral and vaginal) blood flow and vaginal lubrication in intact and ovariectomized animals. This response was more pronounced in animals treated with estradiol, suggesting that the NO cyclic guanosine monophosphate pathway is involved in the physiological mechanism of female genital arousal and that sildenafil facilitates this response in an in vivo animal model. To achieve improved understanding of the biological aspects of female sexual function, further research is needed in the physiology and pharmacology of peripheral (clitoral and vaginal) genital arousal in the animal model.

The effects of GnRH and adrenergic agents on PRL and ß-endorphin secretion by porcine pituitary cells in vitro

The direct effects of alpha- and beta-adrenergic agents on PRL and beta-endorphin (beta-END) secretion in vitro by porcine pituitary cells have been investigated. Pituitary glands were obtained from mature gilts, which were ovariectomised (OVX) one month before slaughter. Ovariectomised gilts, assigned to four groups, were primed with: (1) vehicle (OVX); (2) and (3) oestradiol benzoate (EB; 2.5 mg/100 kg b.w.) at 30-36 h (OVX+EB I) and 60-66 h (OVX+EB II) before slaughter, respectively; and (4) progesterone (P4; 120 mg/100 kg b.w.) for 5 consecutive days before slaughter (OVX+P4). Isolated anterior pituitary cells were submitted to 3.5 h incubation in the presence of GnRH, alpha- and beta-adrenergic agonists [phenylephrine (PHEN) and isoproterenol (ISOP), respectively], or alpha- and beta-adrenergic blockers [phentolamine (PHENT) and propranolol (PROP), respectively]. The culture media were assayed for PRL (exp. I) and beta-endorphin-like immunoreactivity (beta-END-LI) (experiment II). In experiment I, GnRH did not influence PRL release by pituitary cells in all experimental groups. Some of tested doses of adrenergic agonists, PHEN and ISOP, increased PRL release from pituitary cells of OVX gilts, but not from those of OVX+EB I animals. In the OVX+EB II group, PHEN alone, but ISOP with PROP, potentiated PRL secretion by the cells. In OVX+P4 animals, PHEN alone or in combination with PHENT and also ISOP alone or with PROP enhanced PRL output from the cells. In experiment II, addition of GnRH increased beta-END-LI release from pituitary cells only in the OVX+EB II group. PHEN and PHENT potentiated beta-END-LI secretion by pituitary cells in OVX+EB II and OVX+P4 groups, while ISOP and PROP increased beta-END-LI secretion by the cells of OVX and OVX+EB II animals. In turn, in the OVX+EB I group, effect of PHENT and PROP on PRL secretion by pituitary cells was inhibitory. In conclusion, our results suggest that adrenergic agents can modulate PRL and beta-END secretion by porcine pituitary cells in a manner dependent on the hormonal status of gilts.

Technical aspects of harvesting the radial artery with the harmonic scalpel.

Harvesting the radial artery (RA) with ultrasonic dissection with the Harmonic Scalpel reduces spasm induced by surgical handling. Topical exposure to phentolamine methanesulphonate (Regitine) exerts an additional effect of vasodilatation. Between January and December 2002, the RA was harvested as a pediculated vessel with the Harmonic Scalpel in 145 consecutive patients undergoing myocardial revascularization. A fasciotomy of the pedicle was performed after harvest ing. A composite graft with the reverse free RA on the in situ left internal thoracic artery (ITA) was prepared before the construction of distal coronary anastomoses. The RA was then placed in a syringe filled with Regitine (0.07 microg/mL) for 10 minutes. \par The mean number of grafts/patient was 3.0. The mean number of RA anastomoses was 2.0/patient. Left ITA free flow was 105 +/- 34 mL/min. Regitine increased the RA free flow from 60 +/- 35 mL/min to 82 +/- 30 mL/min (P <.05). Fourteen patients underwent postoperative coronary angiography. All RA anastomoses were patent. The compound effect of RA harvesting with the Harmonic Scalpel and topical treatment with the alpha- blocking agent Regitine increases the RA free flow and significantly decreases intraoperative spasticity.

Role Of Sympathetic Innervation In The Defecation Mechanism: A Novel Concept Of Its Function

Background/Objective: Because the role of sympathetic innervation in the defecation mechanism is still vague and unidentified, this study was performed to investigate this issue.Methods: The effect of individual administration of α- and β-adrenoceptor blocking agents (3 mg/kg phentolamine mesylate and 1 mg/kg propranolol hydrochloride, respectively) and the effect of thoracolumbar sympathectomy on anal and rectal pressures was studied in 1 3 mongrel dogs. Pressures were measured by a 2-channel microtip catheter. Bilateral thoracolumbar sympathectomy was performed by excising the sympathetic ganglia from T11 to L2. Incremental rectal filling using a rectal balloon with simultaneous anal and rectal pressure measurements was continued until balloon expulsion was achieved.Results: Rectal balloon distension with 3 0 to 40 ml of saline affected rectal pressure increase (P < 0.001 ), anal pressure decrease (P < 0.01 ), and balloon expulsion. Following administration of either phentolamine or propranolol or after thoracolumbar sympathectomy, rectal pressure declined (P < 0.05), but anal pressure showed no change (P > 0.05). At a rectal balloon volume of 50 to 60 ml of saline, rectal pressure increased (P < 0.001 ), anal pressure decreased (P < 0.01 ), and the balloon was expelled.Conclusion: Sympathetic rectal innervation may have a role during both the filling and evacuation phases of the defecation mechanism. During rectal filling, it most likely maintains rectal compliance. During evacuation in cases of rectal sympathetic block or denervation, a larger volume than usual of rectal distension is needed to induce rectal contraction and evacuation.

A New Assistive Device For Intermittent Self-Catheterization In Men With Tetraplegia

Background/Objective: Because the role of sympathetic innervation in the defecation mechanism is still vague and unidentified, this study was performed to investigate this issue.Methods: The effect of individual administration of α- and β-adrenoceptor blocking agents (3 mg/kg phentolamine mesylate and 1 mg/kg propranolol hydrochloride, respectively) and the effect of thoracolumbar sympathectomy on anal and rectal pressures was studied in 1 3 mongrel dogs. Pressures were measured by a 2-channel microtip catheter. Bilateral thoracolumbar sympathectomy was performed by excising the sympathetic ganglia from T11 to L2. Incremental rectal filling using a rectal balloon with simultaneous anal and rectal pressure measurements was continued until balloon expulsion was achieved.Results: Rectal balloon distension with 3 0 to 40 ml of saline affected rectal pressure increase (P < 0.001 ), anal pressure decrease (P < 0.01 ), and balloon expulsion. Following administration of either phentolamine or propranolol or after thoracolumbar sympathectomy, rectal pressure declined (P < 0.05), but anal pressure showed no change (P > 0.05). At a rectal balloon volume of 50 to 60 ml of saline, rectal pressure increased (P < 0.001 ), anal pressure decreased (P < 0.01 ), and the balloon was expelled.Conclusion: Sympathetic rectal innervation may have a role during both the filling and evacuation phases of the defecation mechanism. During rectal filling, it most likely maintains rectal compliance. During evacuation in cases of rectal sympathetic block or denervation, a larger volume than usual of rectal distension is needed to induce rectal contraction and evacuation.

Simultaneous identification/determination system for phentolamine and sildenafil as adulterants in soft drinks advertising roborant nutrition

An easily available, simultaneous identification/determination procedure for phentolamine (PHE) and sildenafil (SIL) in adulterated dietary supplements was established by using a combination of three different analytical methods; thin-layer chromatography (TLC), liquid chromatography–mass spectrometry (LC/MS) and a high-performance liquid chromatography (HPLC)/photo-diode-array. The sample solution for TLC was applied to silica gel 60 F 254 plates with chloroform/ammonia solution (28)/methanol (70:5:3, lower layer) and chloroform/diethylamine/methanol (15:3:2) as the developing solvent. Spots were located under UV radiation at 254 nm. Mass spectra of PHE and SIL by LC/MS were investigated with electrospray ionization (ESI) interface, under both positive and negative ion mode. The HPLC analysis was performed on a column of Wakosil 5C18 ( 4.6 mm×150 mm, 5 μm) with water/methanol/acetonitrile/triethylamine (580:250:170:1) adjusted with phosphoric acid to pH 3.0 as the mobile phase, and the effluent was monitored with a photo-diode-array detector. Quantitative HPLC analysis of PHE and SIL were detected at 280 nm. When this procedure was applied to commercial soft drinks, PHE and SIL were identified and determined at a concentration of 17 mg PHE and 44 mg SIL per bottle, respectively. The procedure described here is available for the screening of PHE and SIL in adulterated supplements.

Laser oximetry: A novel noninvasive method to determine changes in penile hemodynamics in an anesthetized rabbit model.

This study was designed to determine the utility and validity of laser oximetry in measuring changes in penile hemodynamics. Anesthetized male New Zealand White Rabbits were divided into 2 groups, and penile hemodynamics were assessed by either laser oximetry (oxyhemoglobin, deoxyhemoglobin concentration, and oxygen saturation) or intracavernosal pressure (ICP) monitoring during penile erection induced by pelvic nerve stimulation (PNS) or intracavernosal administration of phentolamine, nitroprusside, papaverine, or sildenafil. PNS caused significant frequency-dependent increases in penile ICP. PNS also caused significant increases in penile tissue oxyhemoglobin concentrations and tissue oxygen saturation in a frequency-dependent manner. The changes in oxyhemoglobin concentrations and oxygen saturation correlated with frequency-dependent increases in ICP. Intracavernosal vasoactive drug administration produced significant increases in ICP, tissue oxyhemoglobin concentration, oxygen saturation, and duration of response as a function of increasing drug concentration. Laser oximetry permits reproducible and valid assessment of changes in penile hemodynamics comparable to conventional ICP measurements. Thus, we consider laser oximetry a reliable technique in evaluating penile hemodynamics. Its sensitivity in detecting small changes in oxyhemoglobin concentration and its noninvasive nature make it advantageous over invasive methods such as ICP monitoring and laser Doppler flowmetry.