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PnTx2‐6 Toxin, From Phoneutria nigriventer Spider Venom, Attenuates The Erectile Dysfunction In Aged Rats
Author(s) -
Nunes Kenia Pedrosa,
Toque Haroldo A.,
Borges Marcia Nascimento,
De Lima Maria Elena,
Webb R. Clinton
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.1049.7
Subject(s) - venom , erectile dysfunction , phenylephrine , medicine , sodium nitroprusside , chemistry , endocrinology , pharmacology , anesthesia , blood pressure , nitric oxide , biochemistry
Erectile dysfunction (ED) is a condition associated with aging. Human accidents involving Phoneutria nigriventer spider venom are characterized by erection. PnTx2‐6, a toxin from this venom, has been implicated in this phenomenon. We investigated the effect of PnTx2‐6 in the erectile function of aged rats. Erectile function was evaluated through changes in intracavernosal pressure/mean arterial pressure ratio (ICP/MAP) during electrical field stimulation (EFS) of the pelvic ganglion of aged and adult rats (70 vs. 14 weeks). In functional studies, corpus cavernosum (CC) strips were contracted by phenylephrine (Phe) and relaxation induced by EFS or nitroprusside with or without PnTx2‐6 (10 −8 M). EFS and Phe‐contractile response were performed. Results showed erectile function decreased with age, but partially restored 15–20 min after s.c. injection of PnTx2‐6. Whereas NPS‐induced relaxation was not effected by PnTx2‐6, EFS‐induced relaxation was enhanced by this toxin as well as PnTx2‐6 plus SNP in both CC. Improved relaxation due to PnTx2‐6 was increased after incubation with Y‐27632 a Rho‐kinase inhibitor, in aging CC, and abolished by ω‐conotoxin GVIA, an N‐type Ca +2 channel in both CC. Increased contractile responses in aging CC was not modified by PnTx2‐6. In conclusion, PnTx2‐6 improves penile relaxation in aged and adult rats, probably via activation of calcium channels in nitrergic nerves.