L. Rashed

Effect of mesenchymal stem cell penile transplantation on erectile signaling of aged rats

Stem cell‐based therapy targeted at the penile tissue has been lately considered in preclinical studies. This work aimed to assess the effect of intracavernous administration of mesenchymal stem cells (MSCs) in aged rats (n = 100). They were subjected to single intracavernous injection (ICI) of 1.0 million MSCs, followed up for 3, 4 weeks, 3 and 4 months (each group 25 rats) and compared with both adult and aged controls (n = 50). In dissected cavernous tissues, cGMP and histopathology were assessed in addition to intracavernous pressure (ICP) measurement in some anaesthetised rats. The results showed that cavernous tissue cGMP was significantly increased in MSCs transplanted rats in all investigated groups compared with the controls. The mean cavernous cGMP levels after 3 and 4 months of MSCs transplantation were significantly increased compared with those after 3 or 4 weeks. Cavernous tissue ICP measurement showed significant increase in MSCs transplanted groups compared with the controls, more in the long‐term follow up than in the shorter one. Histopathological examination detected markedly dilated sinusoidal vascular spaces in the long‐term follow‐up study. It is concluded that stem cell‐based therapy is feasible for age‐associated erectile dysfunction and could improve erectile signaling.

Heme oxygenase enzyme activity in seminal plasma of oligoasthenoteratozoospermic males with varicocele.

This work aimed to assess seminal plasma heme oxygenase (HO) enzyme activity in oligoasthenoteratozoospermia (OAT) males with varicocele. Ninety‐three men were divided according to their sperm count and clinical examination into: healthy fertile controls (n = 34), OAT without varicocele (n = 37) and OAT associated with varicocele (n = 22). They were subjected to semen analysis and estimation of seminal plasma HO enzyme activity in the form of bilirubin concentration. Seminal plasma HO enzyme activity decreased significantly in OAT cases compared with controls. Seminal plasma HO in OAT cases associated with varicocele decreased significantly compared with OAT cases without varicocele and healthy controls (mean ± SD; 109.2 ± 29.5, 283.6 ± 88.4, 669.5 ± 236.1 nMol bilirubin/mg ptn/min, P < 0.001). There was positive correlation between seminal plasma HO enzyme activity and sperm concentration, per cent of motile spermatozoa, number of motile spermatozoas ml−1 and significant negative correlation with sperm abnormal forms per cent. It is concluded that varicocele has a negative impact on seminal HO enzyme activity. Therefore, improved seminal picture after correcting varicocele repair might be related, in part, to improved HO action(s).

Oral phosphodiesterase-5 inhibitors: effect of heme oxygenase inhibition on cGMP signalling in rat cavernous tissue.

This work postulated that heme oxygenase (HO) is partly responsible for controlling phosphodiesterase‐5 inhibitor actions by modulating cyclic guanosine monophosphate (cGMP) cavernous tissue levels. Five hundred and four male Sprague–Dawley rats, divided into five groups, were investigated. Group 1 (n = 72) included controls, group 2 (n = 72) received sildenafil citrate (ViagraR) orally, group 3 (n = 72) received vardenafil hydrochloride (LevitraR), group 4 (n = 72) received tadalafil (CialisR). Group 5 (n = 216), subdivided into three subgroups (A, B and C, 72 each), received the same dose of each drug with the HO inhibitor, Zn protoporphyrin. Eight rats from each group/subgroup were killed at 0.5, 1, 2, 3, 4, 6, 18, 24 and 36 h when cGMP levels in the cavernous tissues were estimated. Cavernous tissue cGMP levels increased significantly in sildenafil, vardenafil and tadalafil‐treated rats compared to the controls with significant decreases after HO inhibition. It is concluded that the effects of these PDE‐5 inhibitors in rat cavernous tissue are partly mediated through HO activity via the cGMP signalling pathway.

Effect of testosterone and frequent low-dose sildenafil/tadalafil on cavernous tissue oxidative stress of aged diabetic rats

This study aimed to assess the effect of testosterone (T) administration and chronic low‐dose sildenafil/tadalafil on cavernous tissue oxidative stress (OS) of aged diabetic rats. In all, 140 Sprague‐Dawley aged rats were subdivided into the following: controls; streptozotocin (STZ)‐induced diabetic rats; diabetic rats injected with T every 4 weeks; diabetic rats on sildenafil orally daily; diabetic rats on T and daily sildenafil; diabetic rats on tadalafil orally every other day; diabetic rats on T and tadalafil; diabetic rats on alternate sildenafil/tadalafil; and diabetic rats on alternate sildenafil/tadalafil with T. After 12 weeks, the rats were euthanised where in dissected cavernous tissues malondialdehyde (MAD), glutathione peroxidase (GPx) and cGMP (cyclic guanosine monophosphate) were estimated. Compared with controls, aged diabetic rats demonstrated significant increase in cavernous tissue MDA and significant decrease in GPx and cGMP where diabetic rats injected with T had marked improvement of these parameters. Diabetic rats on sildenafil, tadalafil or alternate sildenafil/tadalafil demonstrated significant increased cavernous tissue GPx, cGMP and decreased cavernous MDA that was further improved when supplemented with T. It is concluded that frequent low‐dose use of sildenafil and/or tadalafil supplemented with T has a marked impact on ameliorating cavernous OS in aged diabetic rats.

The role of bone marrow-derived mesenchymal stem cells in treating formocresol induced oral ulcers in dogs

BACKGROUND Mesenchymal stem cells (MSCs), a subpopulation of adult somatic stem cells, are an attractive stem cell source in regenerative medicine because of their multipotentiality. In this study, the effects of MSCs transplantation on oral ulcer healing were examined. METHODS Mesenchymal stem cells were isolated from bone marrow aspirates of dogs by dish adherence and expanded in culture. Oral ulcers were induced by topical application of formocresol in the oral cavity of dogs. Either autologous MSCs or vehicle (saline) was injected around the ulcer. The healing process of the ulcer was monitored clinically and histopathologically. Gene expression of vascular endothelial growth factor (VEGF) was detected in MSCs by reverse transcription-polymerase chain reaction. Expression of VEGF and collagen genes was detected in biopsies from all ulcers. RESULTS Mesenchymal stem cells expressed mRNA for VEGF MSCs transplantation significantly accelerated oral ulcer healing compared with controls. There was increased expression of both collagen and VEGF genes in MSCs-treated ulcers compared with controls. CONCLUSION Mesenchymal stem cells transplantation may help accelerate oral ulcer healing, possibly through the induction of angiogenesis by VEGF together with increased intracellular matrix formation as detected by increased collagen gene expression.

Seminal plasma oxytocin and oxidative stress levels in infertile men with varicocele.

This study aimed to assess seminal plasma oxytocin (OT) and oxidative stress (OS) levels in infertile men with varicocele (Vx). A total of 131 men were divided into fertile men (n = 20), fertile men with Vx (n = 17), infertile men without Vx (n = 40) and infertile men with Vx (n = 54). OT, malondialdehyde (MDA) and glutathione peroxidase (GPx) were estimated in seminal plasma. Mean levels of seminal OT, MDA were significantly decreased, and the mean level of GPx was significantly increased in fertile men with/without Vx compared with infertile men with/without Vx. Mean levels of OT, MDA were increased, and mean level of GPx was significantly decreased in Vx grade III cases compared with Vx grades I, II cases and in bilateral Vx cases compared with unilateral Vx. There was significant negative correlation between seminal OT with sperm count, sperm motility, seminal GPx and significant positive correlation with sperm abnormal forms, seminal MDA. It is concluded that seminal OT is significantly decreased in fertile men with/without Vx compared with infertile men with/without Vx. Seminal OT demonstrated significant negative correlation with sperm count, sperm motility, seminal GPx and significant positive correlation with sperm abnormal forms, seminal MDA. Seminal OT is associated with Vx grade and its bilaterality.

Effect of HO-1 cDNA-liposome complex transfer on erectile signalling of aged rats.

This work aimed to assess the efficacy of haeme oxygenase‐1 (HO‐1) cDNA‐liposome complex transfer as a mediator of erectile signalling in aged rats. One hundred and fifty aged white albino rats were equally divided into five groups: controls, rats receiving lipofectamine, rats receiving intracorporeal HO‐1 cDNA‐lipsome complex, rats receiving HO‐1 cDNA‐liposome complex plus nitric oxide synthase (NOS) inhibitor, and rats receiving HO‐1 cDNA‐liposome complex plus HO inhibitor. Six rats were killed from each group after 12, 24 and 48 h, and after1 and 2 weeks. In dissected cavernous tissues, the following were assessed: HO‐1 gene expression, Western blot for HO‐1, HO enzyme activity, cGMP and histopathology. The results showed that HO‐1 cDNA‐liposome complex transfer led to a significant increase in cavernous tissue HO‐1 protein, HO‐1 gene expression, HO enzyme activity and cGMP up to 1 week. NOS inhibition exhibited no effect on HO‐1 gene enhancement of cavernous tissue HO enzyme activity or cGMP, whereas inhibition of HO significantly decreased these parameters. Histopathology of cavernous tissue demonstrated a significant dilatation of helicine arteries in HO‐1 cDNA‐liposome complex treated group after 48 h compared with the controls. It is concluded that HO‐1 cDNA‐liposome complex transfer augments cavernous tissue cGMP with subsequent sinusoidal relaxation.

Heme oxygenase enzyme activity in human seminal plasma of fertile and infertile males.

This work aimed to assess heme oxygenase (HO) enzyme activity relationship with different human semen parameters. One hundred and twenty men were divided according to their sperm count and clinical examination into: obstructive azoospermia (n = 20), nonobstructive azoospermia (NOA) (n = 25), oligozoospermia (n = 35) and normozoospermia (n = 40). Semen analysis, western blot for HO‐1 and HO‐2, and estimation of seminal plasma HO enzyme activity chemically in the form of bilirubin concentration were carried out. Seminal plasma HO enzyme activity was very low in OA specimens, low in NOA, moderate in oligozoospermia while higher in normozoospermia (mean ± SD; 6.26 ± 2.2, 81.4 ± 35.5, 283.8 ± 90.1, 657.4 ± 227.6 pmol ml−1 min−1) with significant differences. Western blot analysis demonstrated HO‐2 expression in all studied groups whereas HO‐1 was highly expressed in fertile normozoospermic group compared with other groups. There was positive correlation between seminal plasma HO enzyme activity and sperm concentration, sperm motility percentage, motile spermatozoa ml−1 and sperm normal morphology per cent. It is concluded that HO enzyme activity in the human seminal plasma is related to spermatogenesis and sperm‐motility processes.

Seminal cyclooxygenase relationship with oxidative stress in infertile oligoasthenoteratozoospermic men with varicocele

This study aimed to assess the relation of seminal cyclooxygenase COX‐1, COX‐2 with oxidative stress in infertile oligoasthenoteratozoospermic (OAT) men with varicocele (Vx). In all, 128 men were allocated into fertile men, fertile men with Vx, infertile OAT men without Vx and infertile OAT men with Vx. They were subjected to history taking, clinical examination and semen analysis. Also, seminal COX‐1, COX‐2, malondialdehyde (MDA) and glutathione peroxidase (GPx) were estimated. Mean levels of seminal COX‐1, COX‐2 were over‐expressed, the mean level of seminal MDA was significantly increased, and the mean level of seminal GPx was significantly decreased in infertile OAT men with Vx compared with other groups. Seminal COX‐1 and COX‐2 were over‐expressed in cases with Vx grade III compared with Vx grades I, II cases and in cases with bilateral Vx compared with unilateral Vx. There was significant negative correlation between seminal COX‐1 and COX‐2 with sperm concentration, sperm motility, sperm normal morphology, seminal GPx and significant positive correlation with seminal MDA. It is concluded that seminal COX‐1 and COX‐2 are over‐expressed in infertile OAT men with Vx compared with fertile men with/without and infertile OAT men without Vx being associated with oxidative stress, Vx grade and Vx laterality.

Effects of paroxetine on intravaginal ejaculatory latency time in Egyptian patients with lifelong premature ejaculation as a function of serotonin transporter polymorphism

Premature ejaculation (PE) is a common ejaculatory complaint. The estimated rates among Turkish men reached 20%, although the severest type of PE (lifelong PE) usually does not exceed 2.3%. This could be seen in line with two survey studies involving five nations. They revealed that 2.5% of men had an intravaginal ejaculation latency time of <1 min and 6% of <2 min. Rapid ejaculation may be treated pharmacologically with a variety of different medications that act either centrally or locally to delay ejaculation and subsequent orgasm. Antidepressants, particularly members of the selective serotonin reuptake inhibitor class, retard ejaculation significantly. Recently, it was postulated that men with lifelong PE might result from a combination of polymorphisms of the serotonergic transporter and receptors, and other neurotransmitters and/or receptors. Our findings augment the significant effect of paroxetine in delaying ejaculation in the responders (P<0.001). Meanwhile, the findings do not suggest a positive association between such response and serotonin transporter gene promoter polymorphism.