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Microsoft word - 3-dr pazoki-ok

Received: 27.10.2009 Accepted:
Original Article The Effects of Finasteride and Azelaic Acid on Skin Flap Viability in Rats
Marjan Ajami1, Mohamad Ali Nilforoushzadeh2, Shahab Babakoohi3, Rouhollah Habibey4, Fatemeh Banimostafa Arab3, Niloofar Pazoki-Toroudi3, Mehdi Rashighi-Firoozabadi3, Alireza Firooz3, Yahya Dowlati3, Hamidreza Pazoki-Toroudi5 Abstract
Background: Skin flaps still play a crucial role in reconstructive surgery but they are frequently at the risk of ischemia lead-
ing to distal necrosis. The aim of this study was to assess the effects of pre-treatment with azelaic acid and finasteride on
skin flap viability and impact of L-NAME on the function of these two drugs.
Methods: Five treatment groups and one control group of 200-250 gram male rats were used. In 3 treatment groups, finas-
teride (1 mg/flap, subcutaneous), azelaic acid (100 mg/flap, topical) and L-NAME (20 mg/kg, intraperitoneal) were admin-
istered, respectively, before random skin flap elevation. In two other treatment groups, L-NAME was administered half an
hour before application of finasteride and azelaic acid, respectively. Flap samples were used for measurement of necrotic
area.
Results: Skin flap necrotic area decreased from 48.17% ± 2.22% in control group to 35.0% ± 1.59% and 35.0% ± 02.55% in
finasteride and azelaic acid treated groups, respectively (P < 0.05). L-NAME abolished the effects of finasteride and azelaic
acid on flap survival (P < 0.001 and P < 0.01, respectively).
Conclusion: In conclusion, finasteride and azelaic acid increased the survival of skin flaps via nitric oxide dependent path-
way that was hampered by L-NAME.
Key words: Azelaic acid, Finasteride, Nitric oxide, L-NAME, Skin flap.
Skin & Leishmaniasis 2010; 1(1): 12-17 ntil the dream of skin reproduction by tions and morbidity.3 Previous studies have tissue engineering of skin grafts as a demonstrated that application of specific phar- U routine clinical practice comes true1, macologic agents or physical conditions can skin flap transposition is considered the main- protect tissue against ischemic injury.4,5 Mean- stay in many reconstructive surgeries for deep while, using pharmacological treatments to skin and soft tissue injuries.2 In spite of all mod- survive skin flaps has largely been an issue of ern surgical techniques, using skin flaps to interest in literature.4 A myriad of substances obtain appropriate tissue coverage has a pivotal have been under study for their effects on role, because these flaps are frequently at the ischemia reperfusion injury including inducible risk of ischemia which leads to major complica- nitric oxide synthase (iNOS) and L-Arginine6, 1 Department of Nutrition, Iran University of Medical Sciences, Tehran, Iran. 2 Skin Diseases & Leishmaniasis Research Center, Isfahan University of Medical Sciences, Isfahan and Center for Research and Training in Skin Diseases and Leprosy, Medical Sciences/University of Tehran, Tehran and Skin Diseases & Stem Cell Research Center, Tehran, Iran. 3 Center for Research and Training in Skin Diseases and Leprosy, Tehran University of Medical Sciences, Tehran, Iran. 4 Department of Physiology, Iran University of Medical Sciences, Tehran, Iran. 5 Center for Research and Training in Skin Diseases and Leprosy and Nano Vichar Pharmaceutical Ltd, Tehran University of Medical
Sciences, Tehran, Iran.
Correspondence to: Hamidreza Pazoki-Toroudi, Tehran University of Medical Sciences, Tehran, Iran.
Email: [email protected]
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Journal of Skin & Leishmaniasis, Spring / Summer 2010; Vol 1, No 1. Finasteride and Azelaic acid effects on skin flap Ajami
pentoxyfylline,7 hemoglobin vesicles,8 erythro- Dawley male rats (200-250 grams) were chosen poietin9 and enalapril.10 Among all these, the for random pattern cranial based skin flap nitric oxide (NO) has been the target of most elevation. All along the study period, the rats interest and controversy. While some studies were situated in single cages supplied with am- advocate harming effects of nitric oxide on flap ple water and food. survival, many others suggest protective role for it.11-15 NO concentration was increased in Experimental design
rabbit Epigastric Island flaps whereas NO syn- The rats were divided into six equal number thase inhibitors like L-NAME ameliorated the groups (7 rats in each) including one control ischemia induced injury which suggested det- and five treatment groups whose flap survivals rimental effect of NO for flap vitality.11 Con- were evaluated under receiving different single versely, inhibition of NO synthase by L-NAME or combination treatments. Intraperitoneal and aminoguanidine has attenuated oedema administration of a mixture of ketamine and and hyperaemia during one day after flap ele- xylazine (50 and 10 mg/kg, respectively, Pake- vation in rats.12-15 However, plenty of studies do Davis Pharmaceutical Co., Cambridge, UK) was not support the aforementioned ideas about performed for induction of general anesthesia. NO. Nitric oxide plays a role in maintenance of The experimental groups included; 1) control basal blood flow in dorsal flaps of the rats and group that received normal saline by subcuta- its inhibition by L-NAME decreased flap blood neous injection (SC), 2) topical application of flow and survival.13 NO precursor, L-arginine, azelaic acid (100 mg/flap, Merck), 3) SC injec- has shown that promoted angiogenesis and tion of finasteride (1 mg/flap, Reddy, India) at consequently, improved flap microcirculation spots 5.5, 6.5 and 7.5 cm distant from caudal and survival14 by decreased oedema, neutro- margin of flap, 4) intraperitoneal (IP) injection phils infiltration and necrosis.15 of L-NAME (20 mg/kg, Sigma), 5) L-NAME + We focused our study on two substances not azelaic acid [20 mg/kg (IP) and 100 mg/flap tested up to now for their potential effects on skin (topical), respectively] and 6) L-NAME + finas- flap survival, finasteride and azelaic acid. Finasteride teride [20 mg/kg (IP) and 1 mg/flap (SC), is a 5α-reductase inhibitor which decreases dihydro- respectively). In the last two groups, L-NAME testosterone (DHT) and is used in treatment of an- was injected prior to azelaic acid or finasteride drogenic alopecia.16 In a recent study, DHT re- duction by finasteride has stimulated expres- sion of iNOS and as a result, NO production.17 Skin flap surgery and calculation of necrotic
Azelaic acid, an aliphatic dicarboxylic acid is area
used in treatment of acne18, also has inhibitory Half an hour after drug administration, flap effect on 5α-reductase which is compatible with its elevation was performed by making two paral- effect against acne vulgarise, an androgen de- lel caudal to cephalad incisions extending from pendent pathology.19 This similarity in proper- inferior angle of scapulae to superior border of ties of finasteride and azelaic acid encouraged pelvic bones with distance of 3 cm from each us to evaluate their effects on skin flap survival other on the mice backs; so, 8×3 cm flaps were and determine the possible role of NO in this created after final incision connecting distal ends of two parallel cuts and leaving a 3 cm base connected to body for blood supply. After raising the flap and detaching it from underly- This experiment received approval of ethical ing fascia, an impermeable plastic barrier simi- committee of the Center for Research and Train- lar in size to the flap (8×3 cm) was interposi- ing in Skin Disease and Leprosy, Tehran Uni- tioned between the flap and its corresponding versity of Medical Sciences. Forty two Sprauge- bed.20 On the seventh post-operative day, the Journal of Skin & Leishmaniasis, Spring / Summer 2010; Vol 1, No 1. Finasteride and Azelaic acid effects on skin flap Ajami
percentage of skin flap necrosis area was calcu- for data analysis. One way analysis of variance lated using paper template method. The boun- (ANOVA) test was used for comparison of flap dary between viable and necrotic tissue was survival that followed by Tukey test for inter- demarcated considering rosy color, skin soft- group comparisons. P value less than 0.05 was ness, warmth and having hair as markers for considered statistically significant. viability and skin darkening, stiffness, coolness and being devoid of hair as signs of necrosis.21 To calculate the percentage of necrotic area, a As shown in Figure 1, administration of azelaic mould of total flap was drawn and an equal size acid and finasteride kept the random skin flaps transparent paper (representing both viable and from jeopardy. In control group, flap necrotic necrotic skin) was cut and weighed. Then, the area was 48.17% ± 2.22% while for azelaic acid extent of necrosis was outlined on the transpa- and finasteride, the average necrotic areas were rent paper template and was cut and weighed. 32.5% ± 02.55% and 35.0% ± 1.59%, respectively By dividing the weight of paper template of flap (P < 0.05 for both, vs. control group). L-NAME necrosis by that of whole area of flap, the per- treated flaps showed 50% ± 2.75% necrotized centage of necrosis area of flap was obtained. area which was not statistically significant from Immediately after finishing the study, the ani- the control group (P > 0.05). Pre-treatment with mals were killed by intracardiac ketamine injec- L-NAME in azelaic acid treated flaps increased tion (150 mg/kg) and flap tissue samples pre- average necrotic area to 48.0% ± 3.52% (P < 0.01 pared for measurement of necrotic area. vs. azelaic acid) that was not significant com- pared with the control group. Similarly, in the Statistical analysis
case of finasteride, pre-treatment with L-NAME SPSS statistical package (version 14) was used increased necrotic area (P < 0.001 vs. finasteride). Figure 1. Effects of different types of treatments on skin flap survival. Data are shown as mean ±
standard error of mean (SEM) of percent of necrotic area for each group. Azela: azelaic acid, Finas: finasteride. *P < 0.05 vs. control group; #P < 0.01 vs. azelaic acid; and †P < 0.001 vs. finasteride. Journal of Skin & Leishmaniasis, Spring / Summer 2010; Vol 1, No 1. Finasteride and Azelaic acid effects on skin flap Ajami
Discussion
filling molecule between finasteride inhibitory This study for the first time evaluated the effects effects on 5-alpha-reductase28-29 and protection of finasteride or azelaic acid 20% on skin flap that was induced by finasteride. Finasteride viability after ischemic injury and showed that primarily was marketed for the treatment of both treatments significantly reduced the ne- benign prostatic hypertrophy30, and this was crotic area of skin flap. Second part of the pre- derived from its inhibitory effects on 5-alpha- sent study suggested involvement of NO as a reductase activity.31 Enzyme 5-alpha-reductase possible second messenger in this protective is involved in catalyzing the testosterone to pathway, because pre-treatment with L-NAME, DHT conversion.32 Inhibition of DHT led to a non-selective iNOS inhibitor, abolished finas- increased expression of iNOS in testis and teride and azelaic acid 20% induced protection. epididymis of rats.17 In the present study, There are different molecules that are involved administration of L-NAME prior to the finas- in protection of different tissues against teride blocked its effects on reducing the flap ischemic injury and one of well-known path- necrotic area that suggested involvement of NO ways is induction of inducible NO synthase in this pathway. The role of nitric oxide in pro- (iNOS) and production of NO.22-23 Most of these tective effects of azelaic acid against ischemia studies carried on the cardiac tissue and dem- reperfusion injury in skin flap model also was onstrated that increased expression of inducible assessed and revealed that production of NO is iNOS and subsequent production of NO pro- essential for this effect, because this effect was tected against ischemia reperfusion injury.23 abolished by administration of L-NAME just However, in presence of L-NAME, this type of before topical application of azelaic acid. There tissue protection was lost.24 One of the best are some studies that ultimately support this studied pathways include elevated expression finding. An in vitro study on human skin using of nitric oxide synthase (NOS) and subsequent assay with 1,2[3H]-testosterone as substrate, has production of NO that consequently protects demonstrated that application of azelaic acid tissue by opening the ATP sensitive potassium induced potent inhibitory effect on 5-alpha- channels (KATP channels) and inducing of anti- reductase activity and this effect was detectable apoptotic proteins.25 The role of NO in protec- at concentrations as low as 0.2 mmol/l and was tion of skin flap against ischemic injury has complete at 3 mmol/l.19 A study conducted by been demonstrated in a study by Claytor RB et Kuntscher MV et al., to evaluate the effects of al., which demonstrated that increased tissue NO donor on skin flap protection, demon- survival is correlated with elevated levels of p38 strated that more flap survival can be achieved MAP kinase phosphorylation and interestingly, by intravenous administration of sper- this effect was inhibited by L-NAME that mine/nitric oxide complex before ischemia, prevents NO production.26 Involvement of NO while no protection produced when sper- in skin flap protection was demonstrated by mine/nitric oxide complex administered at the Kuntscher MV et al. in another study that end of the ischemic period or in the early reper- showed administration of NO-donor prior to fusion period.33 In the present study, blocking ischemia protected skin tissue and decreased the iNOS expression and NO production by L- necrotic area whereas L-NAME blocked NO NAME in azelaic acid or finasteride treated synthesis and abolished its' protective effects.27 flaps were correlated with increased flap ne- Similarly, application of L-NAME before azelaic crotic area in these groups. Therefore, it seems acid or finasteride, inhibited their protective that finasteride or azelaic acid by inhibition of properties and increased necrotic area of flaps 5-alpha-reductase activity and decreasing the (Figure 1). Next to the results of skin flaps pre- testosterone to DHT conversion has eliminated pared from finasteride treated and untreated the inhibitory effects of DHT on iNOS expres- rats that showed significant protection by finas- sion, and as a result, this NO dependent path- teride, we hypothesized nitric oxide as a gap way of protection has been triggered. Journal of Skin & Leishmaniasis, Spring / Summer 2010; Vol 1, No 1. Finasteride and Azelaic acid effects on skin flap Ajami
In summary, increased skin flap survival by tials for application in clinic on one hand and finasteride or azelaic acid pre-treatment which highlighted NO as an important signalling requires NO production, suggested their poten- molecule for flap protection on the other hand. References
1. Mimeault M, Batra SK. Recent progress on tissue-resident adult stem cell biology and their therapeutic implications.
Stem Cell Rev 2008; 4(1): 27-49. 2. Zheng Z, Hu DH, Xu MD, Zhu XX, Han JT, Dong ML, et al. Surgical therapy for massive deep skin and soft tissue
injuries. Zhonghua Shao Shang Za Zhi 2009; 25(1): 11-4. 3. Hold A, Kamolz L, Frey M. The need for flaps in burn surgery. Handchir Mikrochir Plast Chir 2009; 41(6): 343-7.
4. Contaldo C, Harder Y, Plock J, Banic A, Jakob SM, Erni D. The influence of local and systemic preconditioning on
oxygenation, metabolism and survival in critically ischaemic skin flaps in pigs. J Plast Reconstr Aesthet Surg 2007; 60(11): 1182-92. 5. Harder Y, Amon M, Laschke MW, Schramm R, Rucker M, Wettstein R, et al. An old dream revitalised: precondition-
ing strategies to protect surgical flaps from critical ischaemia and ischaemia-reperfusion injury. J Plast Reconstr Aes-thet Surg 2008; 61(5): 503-11. 6. Ozyazgan I, Ozkose M, Baskol G. Nitric oxide in flow-through venous flaps and effects of L-arginine and nitro-L-
arginine methyl ester (L-NAME) on nitric oxide and flap survival in rabbits. Ann Plast Surg 2007; 59(5): 550-7. 7. Isken T, Serdaroglu I, Ozgentas E. The effects of the pentoxifylline on survival of the skin flaps in streptozotocin-
diabetic rats. Ann Plast Surg 2009; 62(4): 446-50. 8. Plock JA, Rafatmehr N, Sinovcic D, Schnider J, Sakai H, Tsuchida E, et al. Hemoglobin vesicles improve wound heal-
ing and tissue survival in critically ischemic skin in mice. Am J Physiol Heart Circ Physiol 2009; 297(3): H905-H910. 9. Contaldo C, Elsherbiny A, Lindenblatt N, Plock JA, Trentz O, Giovanoli P, et al. Erythropoietin enhances oxygenation
in critically perfused tissue through modulation of nitric oxide synthase. Shock 2009; 31(6): 599-606. 10. Pazoki-Toroudi H, Ajami M, Habibey R, Hajiaboli E, Firooz A. The effect of enalapril on skin flap viability is inde-
pendent of angiotensin II AT1 receptors. Ann Plast Surg 2009; 62(6): 699-702. 11. Oshima H. The influence of skin flap ischemia on serum nitric oxide concentrations. Microsurgery 1996; 17(4): 191-7.
12. Knox LK, Stewart AG, Hayward PG, Morrison WA. Nitric oxide synthase inhibitors improve skin flap survival in the
rat. Microsurgery 1994; 15(10): 708-11. 13. Gribbe O, Samuelson UE, Wiklund NP. Effects of nitric oxide synthase inhibition on blood flow and survival in ex-
perimental skin flaps. J Plast Reconstr Aesthet Surg 2007; 60(3): 287-93. 14. Du J, Jin J, Zhang S, Tao Z, Cheng A. [The effects of nitric oxide on the survival of a random pattern skin flap].
Zhonghua Zheng Xing Wai Ke Za Zhi 2002; 18(6): 353-6. 15. Cordeiro PG, Santamaria E, Hu QY. Use of a nitric oxide precursor to protect pig myocutaneous flaps from ischemia-
reperfusion injury. Plast Reconstr Surg 1998; 102(6): 2040-8. 16. Price VH. Treatment of hair loss. N Engl J Med 1999; 341(13): 964-73.
17. Kolasa A, Marchlewicz M, Kurzawa R, Glabowski W, Trybek G, Wenda-Rozewicka L, et al. The expression of induc-
ible nitric oxide synthase (iNOS) in the testis and epididymis of rats with a dihydrotestosterone (DHT) deficiency. Cell Mol Biol Lett 2009; 14(3): 511-27. 18. Gollnick HP, Graupe K, Zaumseil RP. Azelaic acid 15% gel in the treatment of acne vulgaris. Combined results of two
double-blind clinical comparative studies. J Dtsch Dermatol Ges 2004; 2(10): 841-7. 19. Stamatiadis D, Bulteau-Portois MC, Mowszowicz I. Inhibition of 5 alpha-reductase activity in human skin by zinc and
azelaic acid. Br J Dermatol 1988; 119(5): 627-32. 20. De Carvalho EN, Ferreira LM, de Carvalho NA, Alba LE, Liebano RE. Viability of a random pattern dorsal skin flap,
in diabetic rats. Acta Cir Bras 2005; 20(3): 225-8. 21. Mcfarlane RM, Deyoung G, Henry RA. The design of a pedicle flap in the rat to study Necrosis and ITS prevention.
Plast Reconstr Surg 1965; 35: 177-82. 22. Lochner A, Marais E, Genade S, Moolman JA. Nitric oxide: a trigger for classic preconditioning? Am J Physiol Heart
Circ Physiol 2000; 279(6): H2752-H2765. 23. Wang Y, Guo Y, Zhang SX, Wu WJ, Wang J, Bao W, et al. Ischemic preconditioning upregulates inducible nitric ox-
ide synthase in cardiac myocyte. J Mol Cell Cardiol 2002; 34(1): 5-15. 24. Ferdinandy P, Szilvassy Z, Horvath LI, Csont T, Csonka C, Nagy E, et al. Loss of pacing-induced preconditioning in
rat hearts: role of nitric oxide and cholesterol-enriched diet. J Mol Cell Cardiol 1997; 29(12): 3321-33. Journal of Skin & Leishmaniasis, Spring / Summer 2010; Vol 1, No 1. Finasteride and Azelaic acid effects on skin flap Ajami
25. Cohen MV, Yang XM, Liu GS, Heusch G, Downey JM. Acetylcholine, bradykinin, opioids, and phenylephrine, but
not adenosine, trigger preconditioning by generating free radicals and opening mitochondrial K(ATP) channels. Circ Res 2001; 89(3): 273-8. 26. Claytor RB, Aranson NJ, Ignotz RA, Lalikos JF, Dunn RM. Remote ischemic preconditioning modulates p38 MAP
kinase in rat adipocutaneous flaps. J Reconstr Microsurg 2007; 23(2): 93-8. 27. Kuntscher MV, Juran S, Menke H, Gebhard MM, Erdmann D, Germann G. The role of pre-ischaemic application of
the nitric oxide donor spermine/nitric oxide complex in enhancing flap survival in a rat model. Br J Plast Surg 2002; 55(5): 430-3. 28. Drury JE, Di Costanzo L, Penning TM, Christianson DW. Inhibition of human steroid 5beta-reductase (AKR1D1) by
finasteride and structure of the enzyme-inhibitor complex. J Biol Chem 2009; 284(30): 19786-90. 29. Smith AB, Carson CC. Finasteride in the treatment of patients with benign prostatic hyperplasia: a review. Ther Clin
Risk Manag 2009; 5(3): 535-45. 30. Matzkin H, Barak M, Braf Z. Effect of finasteride on free and total serum prostate-specific antigen in men with benign
prostatic hyperplasia. Br J Urol 1996; 78(3): 405-8. 31. Tarter TH, Vaughan ED, Jr. Inhibitors of 5alpha-reductase in the treatment of benign prostatic hyperplasia. Curr Pharm
Des 2006; 12(7): 775-83. 32. Bartsch G, Rittmaster RS, Klocker H. Dihydrotestosterone and the concept of 5alpha-reductase inhibition in human
benign prostatic hyperplasia. World J Urol 2002; 19(6): 413-25. 33. Kuntscher MV, Juran S, Altmann J, Menke H, Gebhard MM, Germann G. Role of nitric oxide in the mechanism of
preclamping and remote ischemic preconditioning of adipocutaneous flaps in a rat model. J Reconstr Microsurg 2003; 19(1): 55-60. Journal of Skin & Leishmaniasis, Spring / Summer 2010; Vol 1, No 1.

Source: http://jsl.mui.ac.ir/index.php/jsl/article/view/3/3