phentolamine

Summary

Summary: A nonselective alpha-adrenergic antagonist. It is used in the treatment of hypertension and hypertensive emergencies, pheochromocytoma, vasospasm of RAYNAUD DISEASE and frostbite, clonidine withdrawal syndrome, impotence, and peripheral vascular disease.

Top Publications

  1. Balayssac S, Gilard V, Zedde C, Martino R, Malet Martino M. Analysis of herbal dietary supplements for sexual performance enhancement: first characterization of propoxyphenyl-thiohydroxyhomosildenafil and identification of sildenafil, thiosildenafil, phentolamine and tetrahydropalmatine as adulterants. J Pharm Biomed Anal. 2012;63:135-50 pubmed publisher
    ..Another formulation was adulterated with phentolamine, a drug that is not approved for boosting male sexual performance when taken orally...
  2. Stevenson P, Dyakonova V, Rillich J, Schildberger K. Octopamine and experience-dependent modulation of aggression in crickets. J Neurosci. 2005;25:1431-41 pubmed
    ..octopamine receptor antagonist epinastine, or with the alpha-adrenoceptor and octopamine receptor antagonist phentolamine, but not with the beta-adrenoceptor antagonist propranolol...
  3. Gontero P, Sriprasad S, Wilkins C, Donaldson N, Muir G, Sidhu P. Phentolamine re-dosing during penile dynamic colour Doppler ultrasound: a practical method to abolish a false diagnosis of venous leakage in patients with erectile dysfunction. Br J Radiol. 2004;77:922-6 pubmed
    ..We evaluated the US parameters and erectile response to the addition of phentolamine to a PGE1 penile Doppler US examination to ascertain whether addition of phentolamine would abolish a ..
  4. Ahn S, Kim S, Kim J, Choi S, Yeum C, Wie H, et al. Phentolamine inhibits the pacemaker activity of mouse interstitial cells of Cajal by activating ATP-sensitive K+ channels. Arch Pharm Res. 2010;33:479-89 pubmed publisher
    The aim of this study was to clarify if phentolamine has proven effects on the pacemaker activities of interstitial cells of Cajal (ICC) from the mouse small intestine involving the ATPsensitive K(+) channels and adrenergic receptor...
  5. Lai H, Yang C, Huang F, Lee Y, Kuo Y, Kuo T. Respiratory-related arterial pressure variability as an indicator of graded blood loss: involvement of the autonomic nervous system. Clin Sci (Lond). 2003;105:491-7 pubmed
    ..b>Phentolamine significantly enhanced baseline %SPV and RAPV, and further enhancement of %SPV and RAPV by graded haemorrhage ..
  6. Yasuda M, Izumi H. Trigeminal nerve-mediated reflex arterial blood pressure decrease and vasodilatation in lower lip of the rabbit. Brain Res. 2003;987:59-66 pubmed
    ..Pretreatment with scopolamine (muscarinic-receptor antagonist, 0.1 mg/kg), phentolamine (alpha-adrenoceptor antagonist, 0.1 mg/kg), or propranolol (beta-adrenoceptor antagonist, 0...
  7. Ruiz Salmerón R, Mora R, Masotti M, Betriu A. Assessment of the efficacy of phentolamine to prevent radial artery spasm during cardiac catheterization procedures: a randomized study comparing phentolamine vs. verapamil. Catheter Cardiovasc Interv. 2005;66:192-8 pubmed
    The objective of this study was to evaluate phentolamine as radial artery spasmolytic in transradial catheterization procedures...
  8. Kim S, Min B, Kim J, Hwang B, Yoo G, Park D, et al. Individual differences in the sensitivity of cold allodynia to phentolamine in neuropathic rats. Eur J Pharmacol. 2005;523:64-6 pubmed
    In neuropathic rats sensitive to phentolamine (alpha-adrenoreceptor antagonist, 2 mg/kg, i.p.), prazosin (alpha1-adrenoreceptor antagonist, 0.5 mg/kg, i.p...
  9. Poulet F, Berardi M, Halliwell W, Hartman B, Auletta C, Bolte H. Development of hibernomas in rats dosed with phentolamine mesylate during the 24-month carcinogenicity study. Toxicol Pathol. 2004;32:558-66 pubmed
    b>Phentolamine is a reversible competitive alpha-adrenergic antagonist with similar affinities for alphal and alpha2 receptors...

More Information

Publications62

  1. Sawaki D, Otani Y, Sekita G, Kobayakawa N, Fukushima K, Takeuchi H, et al. Pheochromocytoma complicated with refractory paralytic ileus dramatically improved with intravenous administration of alpha-adrenergic receptor antagonist, phentolamine. J Clin Gastroenterol. 2003;37:194 pubmed
  2. Davison D, Chawla L, Selassie L, Tevar R, Junker C, Seneff M. Neurogenic pulmonary edema: successful treatment with IV phentolamine. Chest. 2012;141:793-795 pubmed publisher
    ..We uniquely document a rise and fall of serum catecholamine levels correlating with disease activity and a dramatic clinical response to IV phentolamine.
  3. Yang C, Kuo T. Impact of pulse pressure on the respiratory-related arterial pressure variability and its autonomic control in the rat. Pflugers Arch. 2000;439:772-80 pubmed
    ..However, the influence of lung volume on MP persisted with a near-zero phase lag. Combined administration of phentolamine and atropine facilitated respiratory variability in PP and SP and failed to block the effect of propranolol...
  4. Subhani M, Sridhar S, DeCristofaro J. Phentolamine use in a neonate for the prevention of dermal necrosis caused by dopamine: a case report. J Perinatol. 2001;21:324-6 pubmed
    ..In most cases, these complications are associated with the use of high-dosage dopamine infusion. Subcutaneous phentolamine has been used as a therapeutic agent for these complications...
  5. Shafik A, Shafik A, El Sibai O, Ahmed I. Role of sympathetic innervation in the defecation mechanism: a novel concept of its function. J Spinal Cord Med. 2003;26:150-4 pubmed
    ..The effect of individual administration of alpha- and beta-adrenoceptor blocking agents (3 mg/kg phentolamine mesylate and 1 mg/kg propranolol hydrochloride, respectively) and the effect of thoracolumbar sympathectomy on ..
  6. Shamloul R, Ghanem H, Salem A, Kamel I, Mousa A. The value of penile duplex in the prediction of intracavernous drug-induced priapism. Int J Impot Res. 2004;16:78-9 pubmed
    ..were evaluated before and after diagnostic intracavernous injection of a trimix solution (papaverine+phentolamine+PGE1) using color Doppler sonography...
  7. Kalamidas S, Kotoulas O, Hann A. Studies on glycogen autophagy: effects of phorbol myristate acetate, ionophore A23187, or phentolamine. Microsc Res Tech. 2002;57:507-11 pubmed
    ..of agents that could manipulate the lysosomal calcium such as phorbol myristate acetate, ionophore A23187, and phentolamine on the lysosomal glycogen degradation were studied by electron microscopy, morphometric analysis, and ..
  8. Nazaré Nunes Alves M, Alves M, Dos Santos M, Nobre T, Martinez D, Martinez D, et al. Mechanisms of blunted muscle vasodilation during peripheral chemoreceptor stimulation in heart failure patients. Hypertension. 2012;60:669-76 pubmed publisher
    ..b>Phentolamine increased FBF responses in both groups, but the increase was lower in HF patients...
  9. Gazzolo D, Masetti P, Kornacka M, Abella R, Bruschettini P, Michetti F. Phentolamine administration increases blood S100B protein levels in pediatric open-heart surgery patients. Acta Paediatr. 2003;92:1427-32 pubmed
    b>Phentolamine administration during open-heart surgery shortens the cooling and rewarming phases of cardiopulmonary bypass (CPB) and hastens weaning from mechanical ventilation and extubation...
  10. Romana Souza B, Santos J, Monte Alto Costa A. beta-1 and beta-2, but not alpha-1 and alpha-2, adrenoceptor blockade delays rat cutaneous wound healing. Wound Repair Regen. 2009;17:230-9 pubmed publisher
    ..Male rats were treated with propranolol (beta1- and beta2-antagonist), atenolol (beta1-antagonist), or phentolamine (alpha1- and alpha2-antagonist) dissolved in drinking water...
  11. Onimaru H, Homma I. Optical imaging of respiratory neuron activity from the dorsal view of the lower brainstem. Clin Exp Pharmacol Physiol. 2005;32:297-301 pubmed
    ..The hyperpolarization became almost negligible after treatment with the alpha-adrenergic antagonist, phentolamine. (iii) In the dorsal medulla, the predominantly inspiratory activity was detected at the rostral level of the ..
  12. Kawada T, Yamazaki T, Akiyama T, Inagaki M, Shishido T, Zheng C, et al. Vagosympathetic interactions in ischemia-induced myocardial norepinephrine and acetylcholine release. Am J Physiol Heart Circ Physiol. 2001;280:H216-21 pubmed
    ..of atropine (Atro, n = 6); transection of the stellate ganglia (TSG, n = 5); local administration of phentolamine (Phen, n = 6); and combined vagotomy and transection of the stellate ganglia (VX+TSG, n = 5)...
  13. Amour J, Loyer X, Michelet P, Birenbaum A, Riou B, Heymes C. Preservation of the positive lusitropic effect of beta-adrenoceptors stimulation in diabetic cardiomyopathy. Anesth Analg. 2008;107:1130-8 pubmed publisher
    ..The positive lusitropic effect of beta-adrenoceptor stimulation was preserved in diabetic cardiomyopathy. beta3-adrenoceptor over-expression does not seem to affect this process. ..
  14. Kong H, Dong C, Tian Z, Mao N, Wang C, Cheng Y, et al. Altered immunity in crowded Mythimna separata is mediated by octopamine and dopamine. Sci Rep. 2018;8:3215 pubmed publisher
    ..Another octopamine antagonist, phentolamine, inhibited the activity of PO and lysozymes...
  15. Shah S, Allen J, Wood J, Gonzalez N. Dissociation between skeletal muscle microvascular PO2 and hypoxia-induced microvascular inflammation. J Appl Physiol (1985). 2003;94:2323-9 pubmed
    ..9 +/- 0.9 vs. 11.2 +/- 1.1 leukocytes/100 microm, control vs. SHx, P < 0.05). Phentolamine-induced hypotension (MABP of 55 +/- 4 mmHg) in normoxia lowered Pm(O(2)) to 26 +/- 6 Torr but did not increase ..
  16. Woolard J, Bennett T, Dunn W, Heal D, Aspley S, Gardiner S. Acute cardiovascular effects of sibutramine in conscious rats. J Pharmacol Exp Ther. 2004;308:1102-10 pubmed
    ..rats, in the absence and presence of beta- and/or alpha-adrenoceptor antagonism (with propranolol and/or phentolamine, respectively)...
  17. Israilov S, Shmuely J, Niv E, Engelstein D, Livne P, Boniel J. Evaluation of a progressive treatment program for erectile dysfunction in patients with diabetes mellitus. Int J Impot Res. 2005;17:431-6 pubmed
    ..9%) failed the treatment. In conclusion, the progressive treatment program for ED seems to be very effective for diabetic patients, yielded a complete response for short-term and 91.2% rate of success at the end of 2 y follow-up. ..
  18. Carter J, Fretwell L, Woolard J. Effects of 4 multitargeted receptor tyrosine kinase inhibitors on regional hemodynamics in conscious, freely moving rats. FASEB J. 2017;31:1193-1203 pubmed publisher
    ..effects of cediranib were unaffected by losartan (10 mg/kg/h), bosentan (20 mg/kg/h), or a combination of phentolamine and propranolol (each 1 mg/kg/h), suggesting a need for new strategies to overcome them.-Carter, J. J...
  19. Thanapaalasingham K, Pollmann A, Schelew B. Failure of metyrosine therapy for preoperative management of pheochromocytoma: a case report. Can J Anaesth. 2015;62:1303-7 pubmed publisher
    ..Significant hypertension (up to 201/110 mmHg) developed upon tumour manipulation and resolved with phentolamine administration and surgical isolation of the tumour...
  20. Bhatt S, Li D, Flynn D, Wisialowski T, Hemkens M, Steidl Nichols J. Statistical power analysis of cardiovascular safety pharmacology studies in conscious rats. J Pharmacol Toxicol Methods. 2016;81:128-35 pubmed publisher
    ..Additionally, data from a crossover CV study with phentolamine at 4, 20 and 100mg/kg are reported as a representative example of data analysis methods...
  21. Hebi M, Ajebli M, Zeggwagh N, Eddouks M. Pharmacological evidence of ?-adrenergic receptors in the hypotensive effect of Chamaemulum nobile L. Cardiovasc Hematol Agents Med Chem. 2016;: pubmed
    ..001). Specific receptor antagonists (Phentolamine, Terazosin and Atropine) and pharmacological agents (N(omega)-Nitro-L-Arginine Methyl Ester and Captopril) were ..
  22. Wu S, Jv X, Li J, Xu G, Cai X, Gao C. Pharmacological characterisation and functional roles for egg-laying of a β-adrenergic-like octopamine receptor in the brown planthopper Nilaparvata lugens. Insect Biochem Mol Biol. 2017;87:55-64 pubmed publisher
    ..The activated effect of octopamine is abolished by co-incubation with epinastine, mianserin, phentolamine, methiothepin, butaclamol or methysergide...
  23. Janssen R, Roeleveld Versteegh A, Wessels Basten S, Hendriks T. [Auto-injection with epinephrine in the finger of a 5-year-old child]. Ned Tijdschr Geneeskd. 2008;152:1005-8 pubmed
    ..Treatment consisted of phentolamine (0.15 mg in 0...
  24. Yosten G, Pate A, Samson W. Neuronostatin acts in brain to biphasically increase mean arterial pressure through sympatho-activation followed by vasopressin secretion: the role of melanocortin receptors. Am J Physiol Regul Integr Comp Physiol. 2011;300:R1194-9 pubmed publisher
    ..the first phase of neuronostatin-induced increase in mean arterial pressure was reversed by pretreatment with phentolamine, indicating that phase 1 was, indeed, due to an increase in sympathetic activity...
  25. Xu F, Xu G, Su L, Feng E. Stability and compatibility of doxofylline with phentolamine mesilate in 0.9% sodium chloride or 5% dextrose injection for intravenous infusion. J Clin Pharm Ther. 2011;36:99-102 pubmed publisher
    ..The objective was to assess the physical compatibility and the chemical stability of doxofylline with phentolamine mesilate in 0.9% sodium chloride or 5% dextrose injection for intravenous infusion...
  26. Fields A, Richards T, Ibrahim I, Kaye A. Ephedrine in the cat lung vasculature. Acta Anaesthesiol Scand. 2003;47:979-85 pubmed
    ..The effects of phentolamine, a non-selective alpha-receptor blocker, and prazosin, an alpha1-selective antagonist, were investigated on ..
  27. Salem H, Mostafa T. Rehabilitation of the cavernous smooth muscle in patients with organic erectile dysfunction. Andrologia. 2012;44:125-9 pubmed publisher
    ..9%, 9.1% and 3.7% respectively). It is concluded that repeated regular use of ICI, sildenafil or VCD by patients with organic erectile dysfunction has a positive impact on their cavernous blood flow and erectile activity. ..
  28. Hoover J, Kaye A, Ibrahim I, Fields A. Ma huang and alpha subtype adrenoceptors in the cat pulmonary vascular bed. J Diet Suppl. 2008;5:164-75 pubmed publisher
    ..To test the hypothesis that ma huang induces a pressor response in the pulmonary vascular bed of the cat and identify the alpha (1)-adrenoceptor subtype pathway(s) involved in the mediation or modulation of these effects...
  29. Halang P, Toulouse C, Geißel B, Michel B, Flauger B, Müller M, et al. Response of Vibrio cholerae to the Catecholamine Hormones Epinephrine and Norepinephrine. J Bacteriol. 2015;197:3769-78 pubmed publisher
    ..b>Phentolamine blocks the response of E. coli QseC to E or NE. A V...
  30. Jian H, Hao J. [Comparing effect in the management of erectile dysfunction by using 2 sets of drugs of intracavernosal injection]. Zhonghua Nan Ke Xue. 2003;9:200-1 pubmed
    ..Fifty-six ED patients were randomly classified into 2 groups and received phentolamine along with papaverine (for group 1) or phentolamine, papaverine and ligustrazin hydrochloride(for group 2)...
  31. Swart J, Tate K, Crossley D. Development of adrenergic and cholinergic receptor cardiovascular regulatory capacity in the Canada goose (Branta canadensis) and domestic goose (Anser anser domesticus). Comp Biochem Physiol A Mol Integr Physiol. 2014;167:59-67 pubmed publisher
  32. Oda Y, Funao T, Tanaka K, Asada A. Vasodilation increases the threshold for bupivacaine-induced convulsions in rats. Anesth Analg. 2004;98:677-82, table of contents pubmed
    ..Male Sprague-Dawley rats were randomly divided into control (C), nicardipine (N), and phentolamine (P) groups (n = 12 in each group)...
  33. Sharabi F, Daabees T, El Metwally M, Senbel A. Comparative effects of sildenafil, phentolamine, yohimbine and L-arginine on the rabbit corpus cavernosum. Fundam Clin Pharmacol. 2004;18:187-94 pubmed
    ..of sildenafil on smooth muscle of the rabbit corpus cavernosum (RCC) and to compare its effect with those of phentolamine, yohimbine and L-arginine...
  34. Padma Nathan H, Goldstein I, Klimberg I, Coogan C, Auerbach S, Lammers P. Long-term safety and efficacy of oral phentolamine mesylate (Vasomax) in men with mild to moderate erectile dysfunction. Int J Impot Res. 2002;14:266-70 pubmed
    The objectives of this study were to evaluate long-term safety and efficacy of phentolamine mesylate, an orally active, rapid-acting alpha-adrenergic receptor antagonist, for the treatment of men suffering from erectile dysfunction (ED)...
  35. Sosa Z, Palmada M, Fóscolo M, Capani F, Conill A, Cavicchia J. Administration of noradrenaline in the autonomic ganglia modifies the testosterone release from the testis using an ex vivo system. Int J Androl. 2009;32:391-8 pubmed publisher
    ..to evaluate androgen release after the addition of noradrenaline or adrenoreceptor antagonists (propranolol or phentolamine) to the ganglionic compartment...
  36. Yosten G, Samson W. Nesfatin-1 exerts cardiovascular actions in brain: possible interaction with the central melanocortin system. Am J Physiol Regul Integr Comp Physiol. 2009;297:R330-6 pubmed publisher
    ..melanocortin-3/4 receptor antagonist, SHU9119 (intracerebroventricular), or the alpha-adrenergic antagonist, phentolamine (intra-arterial), abrogated the rise in MAP induced by nesfatin-1, indicating that nesfatin-1 may interact with ..
  37. Grossini E, Molinari C, Mary D, Ghigo E, Bona G, Vacca G. Intracoronary ghrelin infusion decreases coronary blood flow in anesthetized pigs. Endocrinology. 2007;148:806-12 pubmed
    ..The ghrelin-induced coronary vasoconstriction was not affected by iv atropine (five pigs) or phentolamine (five pigs)...
  38. Jaswal J, Gandhi M, Finegan B, Dyck J, Clanachan A. Effects of adenosine on myocardial glucose and palmitate metabolism after transient ischemia: role of 5'-AMP-activated protein kinase. Am J Physiol Heart Circ Physiol. 2006;291:H1883-92 pubmed
    ..b>Phentolamine, an alpha-adrenoceptor antagonist, which prevents adenosine-induced activation of glycolysis in stressed hearts,..
  39. Adeyemi O, Aigbe F, Badru O. The antidiarrhoeal activity of the aqueous root extract of Aristolochia ringens (Vahl.) Aristolochiaceae. Nig Q J Hosp Med. 2012;22:29-33 pubmed
    ..This effect was significantly (p < 0.001) inhibited by pilocarpine (10 mg/kg, s.c.), phentolamine and propranolol (1 mg/kg, i.p.) respectively but neither significantly inhibited by yohimbine (1 mg/kg, s.c...
  40. Nonogaki K, Kaji T. ?1-Adrenergic receptor downregulates hepatic FGF21 production and circulating FGF21 levels in mice. Neurosci Lett. 2017;638:35-38 pubmed publisher
    ..Here we show that intraperitoneal injection of phentolamine (an ?-adrenergic receptor antagonist, 5mg/kg) significantly increased plasma FGF21 levels compared with the ..
  41. Yasukawa M, Yasukawa K, Kamiizumi Y, Yokoyama R. Intravenous phentolamine infusion alleviates the pain of abdominal visceral cancer, including pancreatic carcinoma. J Anesth. 2007;21:420-3 pubmed
    ..sigmoid colon cancer, and one with rectal cancer), whose abdominal cancer pain was treated with intravenous phentolamine infusion at 80 mg x day(-1) for 2 days. All but one of the patients had already been treated with opioids...
  42. Becker D, Reed K. Local anesthetics: review of pharmacological considerations. Anesth Prog. 2012;59:90-101; quiz 102-3 pubmed publisher
    ..Technical considerations will be addressed in a subsequent article. ..
  43. Pires O, Ashmawi H, Constantino E, Pelogia N, Posso I. Subarachnoid serotonergic and noradrenergic antagonists increase the pain response in rats. Rev Bras Anestesiol. 2011;61:202-5, 206-10, 108-12 pubmed publisher
    ..objective of the present study was to compare the effects of the subarachnoid administration of methysergide, phentolamine, and phentolamine associated with methysergide on phases I, intermediate, and II of the modified formalin test ..
  44. Vlasova M, Jarvinen K, Herzig K. Cardiovascular effects of ghrelin antagonist in conscious rats. Regul Pept. 2009;156:72-6 pubmed publisher
    ..Sympathetic blockade of alpha-adrenoreceptors with phentolamine (3 mg/kg, s.c.) and simultaneous antagonism of beta(1)-adrenoreceptors with atenolol (10 mg/kg, s.c...
  45. Kombian S, Ananthalakshmi K, Edafiogho I. Norepinephrine and E139 interactions on epileptiform activity in the rat hippocampus in vitro. Med Princ Pract. 2008;17:365-72 pubmed publisher
    ..6 +/- 9.4% and occluded E139 suppression. NE suppression of PS was blocked by phentolamine and yohimbine which also blocked the effect of E139...
  46. Zhao Y, Hao Z, Zhang H, Shi J, Xie Y. [Clinical re-evaluation of effects of different treatments to prevent from phlebitis induced by Chansu injection]. Zhongguo Zhong Yao Za Zhi. 2011;36:2803-6 pubmed
  47. Okada S, Yamaguchi N. Possible role of adrenoceptors in the hypothalamic paraventricular nucleus in corticotropin-releasing factor-induced sympatho-adrenomedullary outflow in rats. Auton Neurosci. 2017;203:74-80 pubmed publisher
    ..Bilateral blockade of adrenoceptors in the PVN revealed that phentolamine significantly suppressed the CRF-induced elevation of plasma adrenaline level, while propranolol significantly ..
  48. Molony D. Adrenaline-induced digital ischaemia reversed with phentolamine. ANZ J Surg. 2006;76:1125-6 pubmed
    ..Accidental misfire into digits can cause prolonged significant ischaemia with serious outcomes. Phentolamine is a readily available treatment, which is easily and safely given in the emergency setting.
  49. Tarhan F, Canguven O, Kuyumcuoglu U. Intracavernous sodium nitroprusside (SNP) versus papaverine/phentolamine in erectile dysfunction: a comparative study of short-term efficacy and side-effects. J Sex Med. 2006;3:377 pubmed
  50. Sanada T, Kohase H, Makino K, Umino M. Effects of alpha-adrenergic agonists on pain modulation in diffuse noxious inhibitory control. J Med Dent Sci. 2009;56:17-24 pubmed
    ..7 +/- 38.9% with continuous administration of PE, and restored to 84.9 +/- 9.7% by intramuscular injection of phentolamine mesylate (PT), an alpha-adrenoceptor antagonist...
  51. Lam M, Mitsui R, Hashitani H. Electrical properties of purinergic transmission in smooth muscle of the guinea-pig prostate. Auton Neurosci. 2016;194:8-16 pubmed publisher
    ..ATP (10 μM) or pyridoxal phosphate-6-azophenyl-2,4-disulfonic acid (PPADS, 10 μM) but not phentolamine (1 μM). Consistently, immunostaining revealed the expression of P2X1 receptors on prostatic smooth muscle...
  52. Wang C, Yu Y, Lai L, Cui Y, Wang X, Wang R. Cardiovascular responses to intrathecal administration of endomorphins in anesthetized rats. Peptides. 2007;28:871-7 pubmed
    ..v.) and alpha-adrenoceptor antagonist phentolamine (1mg/kg, i.v.) significantly reduced the vasodepressor effects of EMs...
  53. Casey D, Madery B, Pike T, Eisenach J, Dietz N, Joyner M, et al. Adenosine receptor antagonist and augmented vasodilation during hypoxic exercise. J Appl Physiol (1985). 2009;107:1128-37 pubmed publisher
    ..In protocol 2 (n = 10), subjects received intra-arterial phentolamine (alpha-adrenoceptor antagonist) and combined phentolamine and aminophylline administration...