47 research outputs found
The evolutionary implications of hemipenial morphology of rattlesnake Crotalus durissus terrificus (Laurent, 1768) (Serpentes: Viperidae: Crotalinae)
Most amniotes vertebrates have an intromittent organ to deliver semen. The reptile Sphenodon and most birds lost the ancestral penis and developed a cloaca-cloaca mating. Known as hemipenises, the copulatory organ of Squamata shows unique features between the amniotes intromittent organ. They are the only paired intromittent organs across amniotes and are fully inverted and encapsulated in the tail when not in use. The histology and ultrastructure of the hemipenes of Crotalus durissus rattlesnake is described as the evolutionary implications of the main features discussed. The organization of hemipenis of Crotalus durissus terrificus in two concentric corpora cavernosa is similar to other Squamata but differ markedly from the organization of the penis found in crocodilians, testudinata, birds and mammals. Based on the available data, the penis of the ancestral amniotes was made of connective tissue and the incorporation of smooth muscle in the framework of the sinusoids occurred independently in mammals and Crotalus durissus. The propulsor action of the muscle retractor penis basalis was confirmed and therefore the named should be changed to musculus hemipenis propulsor.The retractor penis magnus found in Squamata has no homology to the retractor penis of mammals, although both are responsible for the retraction of the copulatory organFAPESP, Fundação de Amparo a Pesquisa do Estado de Sao Paulo, #2011/11828-4CNP
Soluble Guanylate Cyclase Modulators, BAY 41-2272 and BAY 60-2770 Inhibited Human and Rabbit Prostate Contractility.
To evaluate the inhibitory effect of soluble guanylate cyclase (sGC) stimulator, BAY 41-2272 (5-cyclopropyl-2-[1-(2-fluorobenzyl)-1H-pyrazolo[3,4-b] pyridine-3-yl] pyrimidin-4-ylamine) or activator, BAY 60-2770 (4-({(4-carboxybutyl) [ 2-(5-fluoro-2-{[ 40-(trifluoromethyl) biphenyl-4-yl] methoxy} phenyl) ethyl] amino} methyl) benzoic acid), in human and rabbit prostate smooth muscle contractility. MATERIALS AND METHODS In rabbit or human prostate, contractions induced by electrical field stimulation or phenylephrine (PE) were carried out in the presence of sGC stimulator, BAY 41-2272, or sGC activator, BAY 60-2770. The potency (pEC(50)) and maximal response (E-max) values were determined. Immunohistochemistry analysis for sGC alpha 1-subunit and quantification of intracellular levels of cyclic guanosine monophosphate (cGMP) were also performed. RESULTS In rabbit prostate, BAY 60-2770 (30 and 300 nM) inhibited the contractions induced by PE and electrical field stimulation. The coincubation with sGC inhibitor, ODQ, produced greater inhibitions on PE-induced contractions in comparison with BAY 60-2770 alone, mainly due to greater cGMP accumulation (70-and 5.7-fold, respectively). BAY 41-2272 (300 nM) increased and decreased, respectively, cGMP levels and PE-induced contractions, but in the presence of ODQ these effects were reversed. In human prostate, immunohistochemistry analysis revealed the presence of sGC a1-subunit on the transition zone. BAY 60-2770 (300 nM) reduced significantly Emax induced by PE in human prostate. CONCLUSION sGC activator seems to be a promising alternative to treat benign prostatic hyperplasia because it increases cGMP levels even when sGC is oxidized94312U392CAPES - COORDENAĂĂO DE APERFEIĂOAMENTO DE PESSOAL E NĂVEL SUPERIORFAPESP - FUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULOsem informação2013/13907-4; 2014/02195-
Activation of haem-oxidized soluble guanylyl cyclase with BAY 60-2770 in human platelets lead to overstimulation of the cyclic GMP signaling pathway.
Nitric oxide-independent soluble guanylyl cyclase (sGC) activators reactivate the haem-oxidized enzyme in vascular diseases. This study was undertaken to investigate the anti-platelet mechanisms of the haem-independent sGC activator BAY 60-2770 in human washed platelets. The hypothesis that sGC oxidation potentiates the anti-platelet activities of BAY 60-2770 has been tested.Human washed platelet aggregation and adhesion assays, as well as flow cytometry for α(IIb)ÎČ(3) integrin activation and Western blot for α1 and ÎČ1 sGC subunits were performed. Intracellular calcium levels were monitored in platelets loaded with a fluorogenic calcium-binding dye (FluoForte).BAY 60-2770 (0.001-10 ”M) produced significant inhibition of collagen (2 ”g/ml)- and thrombin (0.1 U/ml)-induced platelet aggregation that was markedly potentiated by the sGC inhibitor ODQ (10 ”M). In fibrinogen-coated plates, BAY 60-2770 significantly inhibited platelet adhesion, an effect potentiated by ODQ. BAY 60-2770 increased the cGMP levels and reduced the intracellular Ca(2+) levels, both of which were potentiated by ODQ. The cell-permeable cGMP analogue 8-Br-cGMP (100 ”M) inhibited platelet aggregation and Ca(2+) levels in an ODQ-insensitive manner. The cAMP levels remained unchanged by BAY 60-2770. Collagen- and thrombin-induced α(IIb)ÎČ(3) activation was markedly inhibited by BAY 60-2770 that was further inhibited by ODQ. The effects of sodium nitroprusside (3 ”M) were all prevented by ODQ. Incubation with ODQ (10 ”M) significantly reduced the protein levels of α1 and ÎČ1 sGC subunits, which were prevented by BAY 60-2770.The inhibitory effects of BAY 60-2770 on aggregation, adhesion, intracellular Ca(2+) levels and α(IIb)ÎČ(3) activation are all potentiated in haem-oxidizing conditions. BAY 60-2770 prevents ODQ-induced decrease in sGC protein levels. BAY 60-2770 could be of therapeutic interest in cardiovascular diseases associated with thrombotic complications
Electrical field stimulation-induced contractions on Pantherophis guttatus corpora cavernosa and aortae.
A tetrodotoxin (TTX)-resistant mechanism is responsible for the electrical field stimulation (EFS)-induced contractions and relaxations of Crotalus durissus terrificus corpora cavernosa. Here it was investigated whether this mechanism also occurs in corpora cavernosa and aortae of the non-venomous snake Pantherophis guttatus corpora cavernosa and aortae. Corpora cavernosa and aortic rings isolated from Pantherophis guttatus snake were mounted in organ bath system for isometric tension recording. EFS-induced contractions in both tissues were performed in the presence and absence of guanethidine (30 ÎŒM), phentolamine (10 ÎŒM) and tetrodotoxin (1 ÎŒM). In another set of experiments, the endothelium was removed from aortic rings and EFS-induced contractions were performed in the denuded rings. Electrical field stimulation-induced contractions were frequency-dependent in Pantherophis guttatus corpora cavernosa and aortic rings. The contractions were significantly reduced in the presence of guanethidine (30 ÎŒM) or phentolamine (10 ÎŒM). Pre-treatment with tetrodotoxin had no effect on the EFS-induced contractions of either corpora cavernosa or aortic rings. Surprisingly, the EFS-induced contractions of aortic rings denuded of endothelium were almost abolished. These results indicate that the TTX-resistant mechanism is present in EFS-induced contractions of Pantherophis guttatus corpora cavernosa and aortae. The experiments performed in the aorta indicate that the endothelium is the main source for the release of catecholamines induced by EFS
Vas Deferens Smooth Muscle Responses To The Nitric Oxide-independent Soluble Guanylate Cyclase Stimulator Bay 41-2272.
The nitric oxide-cGMP signaling pathway modulates the ejaculatory functions. The nitric oxide (NO)-independent soluble guanylate cyclase haem-dependent stimulator BAY 41-2272 potently relaxes different types of smooth muscles. However, no study investigated its effects in vas deferens smooth muscle. Therefore, we designed experiments to evaluate the in vitro relaxing responses of vas deferens to BAY 41-2272. The effects of prolonged oral intake with BAY 41-2272 in vas deferens contractions of rats treated chronically with the NO synthase inhibitor N(Ï)-nitro-L-arginine methyl ester (L-NAME) were also investigated. BAY 41-2272 (0.001-100 ÎŒM) produced concentration-dependent relaxations in the prostatic and epididymal portions of vas deferens, an effect markedly reduced by the soluble guanylate cyclase inhibitor ODQ (100 ÎŒM). BAY 41-2272 significantly increased cGMP levels that were fully prevented by ODQ. In separate protocols, rats received L-NAME (20mg/rat/day) concomitantly with BAY 41-2272 (10mg/kg/day, 4 weeks), after which vas deferens contractions to electrical-field stimulation and noradrenaline were achieved. Electrical-field stimulation (1-32 Hz) evoked frequency-dependent contractions that were significantly enhanced in L-NAME-treated rats. Co-treatment with BAY 41-2272 fully reversed the increased contractile responses in L-NAME group. Noradrenaline (0.01-100 ÎŒM)-induced contractions were also greater in L-NAME-treated rats, and that was normalized by BAY 41-2272. In conclusion, BAY 41-2272 potently relaxes in vitro rat vas deferens smooth muscle and elevates the cGMP levels in an ODQ-sensitive manner. Moreover, prolonged oral intake with BAY 41-2272 restores the enhanced contractile vas deferens activity in rats treated with L-NAME. NO-independent soluble guanylate cyclase stimulators may be an alternative treatment for premature ejaculation.68849-5
Electrical field-induced contractions on Crotalus durissus terrificus and Bothrops jararaca aortae are caused by endothelium-derived catecholamine.
Endothelium is the main source of catecholamine release in the electrical-field stimulation (EFS)-induced aortic contractions of the non- venomous snake Panterophis guttatus. However, adrenergic vasomotor control in venomous snakes such as Crotalus durissus terrificus and Bothrops jararaca has not yet been investigated. Crotalus and Bothrops aortic rings were mounted in an organ bath system. EFS-induced aortae contractions were performed in the presence and absence of guanethidine (30 ÎŒM), phentolamine (10 ÎŒM) or tetrodotoxin (1 ÎŒM). Frequency-induced contractions were also performed in aortae with endothelium removed. Immunohistochemical localization of both tyrosine hydroxylase (TH) and S-100 protein in snake aortic rings and brains, as well as in human tissue (paraganglioma tumour) were carried out. EFS (4 to 16 Hz) induced frequency-dependent aortic contractions in both Crotalus and Bothrops. The EFS-induced contractions were significantly reduced in the presence of either guanethidine or phentolamine in both snakes (p<0.05), whereas tetrodotoxin had no effect in either. Removal of the endothelium abolished the EFS-induced contractions in both snakes aortae (p<0.05). Immunohistochemistry revealed TH localization in endothelium of both snake aortae and human vessels. Nerve fibers were not observed in either snake aortae. In contrast, both TH and S100 protein were observed in snake brains and human tissue. Vascular endothelium is the main source of catecholamine release in EFS-induced contractions in Crotalus and Bothrops aortae. Human endothelial cells also expressed TH, indicating that endothelium- derived catecholamines possibly occur in mammalian vessels
Insulin Relaxes Bladder Via Pi3k/akt/enos Pathway Activation In Mucosa: Unfolded Protein Response-dependent Insulin Resistance As A Cause Of Obesity-associated Overactive Bladder.
We aimed to investigate the role of insulin in the bladder and its relevance for the development of overactive bladder (OAB) in insulin-resistant obese mice. Bladders from male individuals who were involved in multiple organ donations were used. C57BL6/J mice were fed with a high-fat diet for 10 weeks to induce insulin-resistant obesity. Concentration-response curves to insulin were performed in human and mouse isolated mucosa-intact and mucosa-denuded bladders. Cystometric study was performed in terminally anaesthetized mice. Western blot was performed in bladders to detect phosphorylated endothelial NO synthase (eNOS) (Ser1177) and the phosphorylated protein kinase AKT (Ser473), as well as the unfolded protein response (UPR) markers TRIB3, CHOP and ATF4. Insulin (1-100 nm) produced concentration-dependent mouse and human bladder relaxations that were markedly reduced by mucosal removal or inhibition of the PI3K/AKT/eNOS pathway. In mouse bladders, insulin produced a 3.0-fold increase in cGMP levels (P < 0.05) that was prevented by PI3K/AKT/eNOS pathway inhibition. Phosphoinositide 3-kinase (PI3K) inhibition abolished insulin-induced phosphorylation of AKT and eNOS in bladder mucosa. Obese mice showed greater voiding frequency and non-voiding contractions, indicating overactive detrusor smooth muscle. Insulin failed to relax the bladder or to increase cGMP in the obese group. Insulin-stimulated AKT and eNOS phosphorylation in mucosa was also impaired in obese mice. The UPR markers TRIB3, CHOP and ATF4 were increased in the mucosa of obese mice. The UPR inhibitor 4-phenyl butyric acid normalized all the functional and molecular parameters in obese mice. Our data show that insulin relaxes human and mouse bladder via activation of the PI3K/AKT/eNOS pathway in the bladder mucosa. Endoplasmic reticulum stress-dependent insulin resistance in bladder contributes to OAB in obese mice.5912259-7
Insulin relaxes bladder via PI3K/AKT/eNOS pathway activation in mucosa:Unfolded protein response-dependent insulin resistance as a cause of obesity-associated overactive bladder
We aimed to investigate the role of insulin in the bladder and its relevance for the development of overactive bladder (OAB) in insulin-resistant obese mice. Bladders from male individuals who were involved in multiple organ donations were used. C57BL6/J mice were fed with a high-fat diet for 10 weeks to induce insulin-resistant obesity. Concentrationâresponse curves to insulin were performed in human and mouse isolated mucosa-intact and mucosa-denuded bladders. Cystometric study was performed in terminally anaesthetized mice. Western blot was performed in bladders to detect phosphorylated endothelial NO synthase (eNOS) (Ser1177) and the phosphorylated protein kinase AKT (Ser473), as well as the unfolded protein response (UPR) markers TRIB3, CHOP and ATF4. Insulin (1â100 nm) produced concentration-dependent mouse and human bladder relaxations that were markedly reduced by mucosal removal or inhibition of the PI3K/AKT/eNOS pathway. In mouse bladders, insulin produced a 3.0-fold increase in cGMP levels (P < 0.05) that was prevented by PI3K/AKT/eNOS pathway inhibition. Phosphoinositide 3-kinase (PI3K) inhibition abolished insulin-induced phosphorylation of AKT and eNOS in bladder mucosa. Obese mice showed greater voiding frequency and non-voiding contractions, indicating overactive detrusor smooth muscle. Insulin failed to relax the bladder or to increase cGMP in the obese group. Insulin-stimulated AKT and eNOS phosphorylation in mucosa was also impaired in obese mice. The UPR markers TRIB3, CHOP and ATF4 were increased in the mucosa of obese mice. The UPR inhibitor 4-phenyl butyric acid normalized all the functional and molecular parameters in obese mice. Our data show that insulin relaxes human and mouse bladder via activation of the PI3K/AKT/eNOS pathway in the bladder mucosa. Endoplasmic reticulum stress-dependent insulin resistance in bladder contributes to OAB in obese mice
Role Of Pkc And Cav1.2 In Detrusor Overactivity In A Model Of Obesity Associated With Insulin Resistance In Mice.
Obesity/metabolic syndrome are common risk factors for overactive bladder. This study aimed to investigate the functional and molecular changes of detrusor smooth muscle (DSM) in high-fat insulin resistant obese mice, focusing on the role of protein kinase C (PKC) and Ca(v)1.2 in causing bladder dysfunction. Male C57BL/6 mice were fed with high-fat diet for 10 weeks. In vitro functional responses and cystometry, as well as PKC and Ca(v)1.2 expression in bladder were evaluated. Obese mice exhibited higher body weight, epididymal fat mass, fasting glucose and insulin resistance. Carbachol (0.001-100 ”M), α,ÎČ-methylene ATP (1-10 ”M), KCl (1-300 mM), extracellular Ca(2+) (0.01-100 mM) and phorbol-12,13-dibutyrate (PDBu; 0.001-3 ”M) all produced greater DSM contractions in obese mice, which were fully reversed by the Ca(v)1.2 blocker amlodipine. Cystometry evidenced augmented frequency, non-void contractions and post-void pressure in obese mice that were also prevented by amlodipine. Metformin treatment improved the insulin sensitivity, and normalized the in vitro bladder hypercontractility and cystometric dysfunction in obese mice. The PKC inhibitor GF109203X (1 ”M) also reduced the carbachol induced contractions. PKC protein expression was markedly higher in bladder tissues from obese mice, which was normalized by metformin treatment. The Ca(v)1.2 channel protein expression was not modified in any experimental group. Our findings show that Ca(v)1.2 blockade and improvement of insulin sensitization restores the enhanced PKC protein expression in bladder tissues and normalizes the overactive detrusor. It is likely that insulin resistance importantly contributes for the pathophysiology of this urological disorder in obese mice.7e4850