Effect of lysyl oxidase (LOX) on corpus cavernous ﬁbrosis
caused by ischaemic priapism
a, b, c
, Changjing Wu
, Fudong Fu
, Xuanhe You
, Xue Ma
, Feng Qin
, Tao Li
, Jiuhong Yuan
The Andrology Laboratory, West China Hospital, Sichuan University, Chengdu, Sichuan, China
Department of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
Department of Urology, The Second Afﬁliated Hospital of Chongqing Medical University,
Department of Pediatric Surgery, West China Hospital, Sichuan University, Chengdu,
Department of Urology, University of Texas M.D. Anderson Cancer Center, Houston, TX, USA
Received: August 6, 2017; Accepted: September 4, 2017
Penile ﬁbrosis caused by ischemic priapism (IP) adversely affects patients’ erectile function. We explored the role of lysyl oxidase (LOX) in rat
and human penes after ischemic priapism (IP) to verify the effects of anti-LOX in relieving penile ﬁbrosis and preventing erectile dysfunction
caused by IP in rats. Seventy-two rats were randomly divided into six groups: control group, control + b-aminopropionitrile (BAPN) group,
9 hrs group, 9 hrs + BAPN group, 24 hrs group, and 24 hrs + BAPN group. b-aminopropionitrile (BAPN), a speciﬁc inhibitor of LOX, was
administered in the drinking water. At 1 week and 4 weeks, half of the rats in each group were randomly selected for the experiment. Compared
to the control group, the erectile function of IP rats was signiﬁcantly decreased while the expression of LOX in the corpus cavernosum was sig-
niﬁcantly up-regulated in both 9 and 24 hrs group. Proliferated ﬁbroblasts, decreased corpus cavernosum smooth muscle cells/collagen ratios,
destroyed endothelial continuity, deposited abnormal collagen and disorganized ﬁbers were observed in IP rats. The relative content of collage I
and III was not obviously different among the groups. b-aminopropionitrile (BAPN) could effectively improve the structure and erectile function
of the penis, and enhance recovery. The data in this study suggests that LOX may play an important role in the ﬁbrosis of corpus cavernosum
after IP and anti-LOX may be a novel target for patients suffering with IP.
Priapism is a rare urological emergency, which is deﬁned as abnor-
mally prolonged erection for more than 4 hrs in the absence of or
after sexual stimulation has ended . It can be classiﬁed into sub-
types of non-ischaemic (high-ﬂow), ischaemic (low-ﬂow) and stutter-
ing (recurrent) . The pathophysiology of IP is very complex. At the
beginning, obstruction of the penile venous drainage is triggered by
all kinds of aetiologies, which lead to local congestion and follows
with prolonged erection. If the penis cannot be detumesced in 24 hrs,
necrosis or transformation to ﬁbroblast-like cells of the corpora cav-
ernosum smooth muscle cells (CCSMC) will take place, which will
lead to further penile ﬁbrosis and patients’ erectile dysfunction (ED)
. It has been reported that more than 90% patients are attacked by
permanent ED because of IP lasting more than 24 hrs .
Lysyl oxidase (LOX) is an extracellular and copper-dependent
monoamine oxidase, which has been proven to work through catalys-
ing the crosslink of lysine residues in collagen I and III, promotes
deposition of insoluble elastic ﬁbres and following ﬁbrosis. Our goal
was to explore the effects of LOX on penile ﬁbrosis and ED caused by
IP using a rat model.
*Correspondence to: Jiuhong YUAN, M.D.
ª 2017 The Authors.
Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.
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J. Cell. Mol. Med. Vol 22, No 3, 2018 pp. 2018-2022