title: Induction of penile erection by intracavernosal and transurethral administration of novel nitric oxide donors in the cat.
abstract: OBJECTIVE
  The effects of novel nitric oxide (NO) donors administered intracavernosally and transurethrally on erectile function in the anesthetized cat were evaluated.
  
  
  METHODS
  In pentobarbital-anesthetized cats, increases in intracavernosal pressure, penile length, and duration of erectile response were determined after intracavernosal and transurethral injections of novel NO donors (MAHMA/NO, PAPA/NO, DEA/NO, PIPERAZI/NO and PROLI/NO). All parameters were measured after administration of NO donors intracavernosally via a 30-gauge needle and urethrally via a Jelco i.v. catheter in a volume of 200 microliters. Systemic arterial pressure was also assessed in these experiments. All NO donors were compared with a triple-drug control combination comprised of papaverine (1.65 mg.), prostaglandin E1 (0.5 microgram.), and phentolamine (25 micrograms.).
  
  
  RESULTS
  MAHMA/NO, PAPA/NO, DEA/NO, PIPERAZI/NO and PROLI/NO induced dose dependent increases in intracavernosal pressure and penile length (p < 0.05) when administered intracavernosally. The increases in cavernosal pressure and penile length were comparable to those observed with the triple-drug control combination. The maximum increase in cavernosal pressure in response to PROLI/NO and PAPA/NO was associated with no significant change in systemic arterial pressure. Transurethral administration of PROLI/NO and PIPERAZI/NO induced dose-dependent increases in cavernosal pressure and penile length (p < 0.05). The response was similar to that of the triple-drug control combination, except that transurethral PROLI/NO and PIPERAZI/NO had no significant effect on systemic blood pressure.
  
  
  CONCLUSIONS
  NO donors caused dose-dependent increases in cavernosal pressure when administered intracavernosally and transurethrally. These data suggest further exploration of the use of NO donors for the treatment of erectile dysfunction.
authors.affiliation: Department of Urology, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA.
authors.forename: H C
authors.initials: HC
authors.lastname: Champion
authors.forename: T J
authors.initials: TJ
authors.lastname: Bivalacqua
authors.forename: R
authors.initials: R
authors.lastname: Wang
authors.forename: P J
authors.initials: PJ
authors.lastname: Kadowitz
authors.forename: L K
authors.initials: LK
authors.lastname: Keefer
authors.forename: J E
authors.initials: JE
authors.lastname: Saavedra
authors.forename: J A
authors.initials: JA
authors.lastname: Hrabie
authors.forename: P C
authors.initials: PC
authors.lastname: Doherty
authors.forename: W J
authors.initials: WJ
authors.lastname: Hellstrom
mesh_terms: D000818:Animals; D002415:Cats; D004305:Dose-Response Relationship, Drug; D008297:Male; D020030:Nitric Oxide Donors / Q000008:administration & dosage*; D010410:Penile Erection / Q000187:drug effects*; D010413:Penis; D014521:Urethra
chemical_list: D020030:Nitric Oxide Donors