Abstract
Nitric oxide (NO) has been suggested as a non-adrenergic non-cholinergic neurotransmitter in the urogenital tract and has previously been shown to have a smooth muscle relaxing effect in the urogenital organs both in various animals and in humans. It has been shown that NO is a mediator of the erection and the dilatation of the bladder neck and urethra. The aim of the study was to analyse nitric oxide synthase (NOS) activity in the human urogenital tract. NOS activity was measured by the conversion of l-[U-14C] arginine to l-[U-14C] citrulline. In the upper urinary tract there was Ca2+-dependent NOS activity in the renal pelvis, but no significant NOS activity could be found in the ureter. In the lower urinary tract we found high Ca2+-dependent NOS activity in the urethra, intermediate activity in the bladder neck and comparatively low activity in the detrusor muscle. In the male genital tract the testis and epididymis had no significant NOS activity. The vas deferens, prostate, seminal vesicle and corpus cavernosum were found to have high levels of Ca2+-dependent NOS activity. Ca2+-independent NOS activity was not obtained in the urogenital tract. Our results correspond well with previous functional studies indicating NO to be an important nerve-induced mediator of erection and in the micturition reflex, but also suggest that NO may be involved in several other functions in the human urogenital tract.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Andersson K-E, Garcia-Pascual A, Forman A, Tottrup A (1991) Non-adrenergic non-cholinergic nerve-mediated relaxation of rabbit urethra is caused by nitric oxide. Acta Physiol Scand 141:133
Andersson K-E, Garcia-Pascual A, Persson K, Forman A, Tottrup A (1992) Electrically-induced nerve-mediated relaxation of rabbit urethra involves nitric oxide. J Urol 147:253
Burnett AL, Lowenstein CJ, Bredt DS, Chang TSK, Snyder SH (1992) Nitric oxide: A physiologic mediator of penile erection. Science 257:401
Burnett AL, Tillman SL, Chang TSK, Epstein JI, Lowenstein CJ, Bredt DS, Synder SH, Walsh PC (1993) Immunohistochemical localisation of nitric oxide synthase in the autonomic innervation of the human penis. J Urol 150:73
Caine M, Raz S, Zeigler M (1975) Adrenergic and cholinergic receptors in the human prostate, prostatic capsule and bladder neck. Br J Urol 47:193
Chapple CR, Aubry ML, James S, Greengrass PM, Burnstock G, Turner-Warwick RT, Milroy EJG, Davey MJ (1989) Characterisation of human prostatic adrenoreceptors using pharmacology receptor binding and localisation. Br J Urol 63:487
Ehrén I, Iversen H, Jansson O, Adolfsson J, Wiklund NP (1994) Localisation of nitric oxide synthase activity in the human lower urinary tract and its correlation with neuroeffector responses. Urology 44:683
Garcia-Pascual A, Costa G, Garcia-Sacristan A, Andersson K-E (1991) Relaxation of sheep urethral muscles induced by electrical stimulation of nerves: involvement of nitric oxide. Acta Physiol Scand 141:531
Holmqvist F, Hedlund H, Andersson K-E (1992) Characterisation of inhibitory neurotransmission in the isolated corpus cavernosum from rabbit and man. J Physiol 449:295
Ignarro LJ, Bush PA, Buga GM, Wood KS, Fukuto JM, Rajfer J (1990) Nitric oxide and cyclic GMP formation upon electrical field stimulation cause relaxation of corpus cavernosum smooth muscle. Biochem Biophys Res Commun 170:843
Reference deleted
Kim N, Azadzoi KM, Goldstein I, Saenz De Tejada I (1991) A nitric oxide-like factors mediates non-adrenergic non-cholinergic neurogenic relaxation of penile corpus cavernosum smooth muscle. J Clin Invest 88:112
Knowles RG, Moncada S (1994) Nitric oxide synthases in mammals. Biochem J 298:249
Leone AM, Wiklund NP, Hökfelt T, Brundin L, Moncada S (1994) Release of nitric oxide by nerve stimulation in the human urogenital tract. Neuroreport 5:733
Moncada S (1992) The l-arginine: nitric oxide pathway. The 1991 Ulf von Euler lecture. Acta Physiol Scand 145:201
Persson K, Andersson K-E (1992) Nitric oxide and relaxation of pig lower urinary tract. Br J Pharmacol 106:416
Persson K, Alm P, Johansson K, Larsson B, Andersson K-E (1993) Nitric oxide synthase in pig lower urinary tract: immunohistochemistry, NADPH diaphorase histochemistry and functional effects. Br J Pharmacol 110:521
Rajfer J, Aronson WJ, Bush PA, Dorey FJ, Ignarro LJ (1992) Nitric oxide as a mediator of relaxation of the corpus cavernosum in response to nonadrenergic, noncholinergic neurotransmission. N Engl J Med 326:90
Sneddon P, Machaly M (1992) Regional variation in purinergic and adrenergic responses in isolated vas deferens of rat, rabbit and guinea pig. J Auton Pharmacol 12:421
Tainio H, Kylmälä T, Heikkinen A (1992) Peptidergic innervation of the normal and obstructed human pyeloureteral junctions. Urol Int 48:31
Tanagho E (1992) Anatomy of the lower urinary tract. In: Walsh PC, Retik AB, Stamey TA, Vaughan DE, Jr (eds) Campbell's urology. WB Saunders, p 63
Thornbury KD, Hollywood MA, McHale NG (1992) Mediation by nitric oxide of neurogenic relaxation of the urinary bladder neck muscle in sheep. J Physiol 451:133
Vaalasti A, Tainio H, Pelto-Huikko M, Hervonen A (1986) Light and electron microscope demonstration of VIP- and enkephalin-immunoreactive nerves in the human male genitourinary tract. Anat Rec 215:21
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Ehrén, I., Adolfsson, J. & Wiklund, N.P. Nitric oxide synthase activity in the human urogenital tract. Urol. Res. 22, 287–290 (1994). https://doi.org/10.1007/BF00297196
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00297196