Effect of a local delivery of triiodothyronine (T3) within neuroregenerative guide on recovery of erectile function in a rat-model of cavernous nerve injury.
BACKGROUND
A promoting effect of thyroid hormones has been established on the maturation of central and peripheral nervous systems. However, effects on autonomic nerves have never been experimentally investigated.


OBJECTIVE
To assess the effect of a local treatment combining silicone guides and local administration of Triiodothyronine (T3) on the erectile function and the histological neuroregeneration of crushed cavernous nerves (CNs) in rats.


METHODS
Forty-five rats were divided into five equal groups: SHAM surgery, guide without crush, crush, crush + guide, crush + guide + T3. All surgical procedures were bilateral. CNs were crushed with microvascular bulldog clamp of 100 g/cm(2). A silicone guide was placed around the nerves. The guides were filled with T3 neuroregenerative solution.


METHODS
Erectile function was assessed 10 weeks post-operatively. Intra-cavernous pressure (ICP) and mean arterial pressure (MAP) were monitored during electrical stimulation of CNs at various frequencies. The main outcome was hardness of erection defined as DeltaICP/MAP. Fluorescent immunohistochemical analysis of CNs was performed to assess regeneration of nerves morphologically.


RESULTS
Electrophysiological data showed increased recovery of erectile function in the group with guide + T3 neuroregenerative solution compared with the empty guide. Immunohistochemical analysis of cavernous nerves demonstrated in morphology that regenerated axons were straighter in nerves with guide and more regular if guides had been filled with T3.


CONCLUSIONS
The use of guides prevented axonal sprouting, facilitated functional neuroregeneration and enabled a local delivery of thyroid hormones. Triiodothyronine improved neuroregeneration and recovery of erectile function after a nerve-sparing-like injury in a rat model.
Bessede
Thomas
T
UPRES EA 4122 University Paris-Sud, Le Kremlin-Bicetre, France. tbessede@yahoo.fr
Alsaid
Bayan
B
Ferretti
Ludovic
L
Pierre
Michel
M
Bernabé
Jacques
J
Giuliano
François
F
Karam
Ibrahim
I
Benoît
Gérard
G
Droupy
Stéphane
S
D000287:Administration, Topical; D000818:Animals; D017776:Autonomic Pathways / Q000187:drug effects* / Q000293:injuries* / Q000473:pathology; D004195:Disease Models, Animal; D008297:Male; D009409:Nerve Crush; D009416:Nerve Regeneration / Q000187:drug effects*; D010410:Penile Erection / Q000187:drug effects*; D010413:Penis / Q000294:innervation*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014284:Triiodothyronine / Q000494:pharmacology*
D014284:Triiodothyronine