Ursodeoxycholic acid ameliorates erectile dysfunction and corporal fibrosis in diabetic rats by inhibiting the TGF-ß1/Smad2 pathway.

Corporal tissue fibrosis is critical in diabetes-associated erectile dysfunction. Transforming growth factor-ß1/Small mothers against decapentaplegic-2 (TGF-ß1/Smad2) contributes to the induction of fibrosis in corporal tissue. Smad7 is accepted as a general negative regulator of Smad signaling, although its role in corporal fibrosis is unknown. Ursodeoxycholic acid (UDCA) is a hydrophilic bile acid used for biliary and liver related disorders and has antifibrotic effects in the liver. This study investigated the effects of UDCA on diabetic erectile dysfunction. Forty-eight male Spraque Dawley rats were divided into six groups: nondiabetic (n = 6), nondiabetic+20 mg/kg UDCA (n = 6), nondiabetic+80 mg/kg UDCA (n = 6), diabetic (n = 10), diabetic+20 mg/kg UDCA (n = 10), diabetic+80 mg/kg UDCA (n = 10). Diabetes was induced by intraperitoneal injection of 60 mg/kg Streptozocin. UDCA (20 and 80 mg/kg/day) or saline was subsequently administered via oral gavage for 56 days. Erectile function was evaluated as measurement of maximum intracavernosal pressure (m-ICP)/mean arterial pressure (MAP) and total ICP/MAP. Corporal tissues were evaluated by Western blotting and Masson's trichrome staining. Electrical stimulation-induced m-ICP/MAP responses were higher in UDCA-treated diabetic rats compared to untreated diabetic rats, respectively (20 mg/kg; 4 V: 0.77 ± 0.11 vs 0.45 ± 0.09, p = 0.0001 and 80 mg/kg; 4 V: 0.78 ± 0.11 vs 0.45 ± 0.09, p = 0.0001) UDCA prevented the increase in phospho-Smad2 and fibronectin protein expressions in diabetic corporal tissue both at 20 mg/kg (p = 0.0002, p = 0.002 respectively) and 80 mg/kg doses (p < 0.0001 for both). Smad7 protein expressions were significantly increased in the UDCA-treated diabetic groups compared to the untreated diabetic group (20 mg/kg: p = 0.0079; 80 mg/kg: p = 0.004). Furthermore, UDCA significantly prevented diabetes-induced increase in collagen (20 mg/kg: p = 0.0172; 80 mg/kg: p = 0.0003) and smooth muscle loss (20 mg/kg: p = 0.044; 80 mg/kg: p = 0.039). In conclusion, UDCA has a potential protective effect on erectile function in diabetic rats by altering fibrotic pathways via inhibition of TGF-ß1/Smad2 and activation of Smad7.

Could Amifostine Prevent Experimental Radiotherapy-Induced Acute Pericarditis?

BACKGROUND: Amifostine is a powerful antioxidant that is one of the documented three chemo-radio prototectants recommended for clinical use. There is no data exploring amifostine in prevention of acute pericardial damage. We aimed to investigate whether amifostine has protective effect against acute pericardial injury due to radiotherapy in an experimental rat model. METHODS: Twenty-four rats were divided into four groups: control group, radiotherapy-only group, amifostine-only group, radiotherapy+amifostine group. In groups receiving radiotherapy, hearts were irradiated with a Co 60 teletherapy device at a distance of 80 cm and 20 Gy at a depth of 2 cm. Thirty minutes before interventions, 200 mg/kg amifostine or same volume 0.9% NaCl were administered intraperitoneally. Subjects were sacrificed 24 hours after the procedure. Pericardial histopathological changes were investigated by light microscopy. RESULTS: There was focal inflammation of >= 50% in all rats exposed-to-radiotherapy. All groups receiving radiotherapy revealed a significant increase in pericardial inflammation compared to the groups that did not receive irradiation (p<0.05). There was no difference between the radiotherapy-only group and amifostine+radiotherapy group for pericardial inflammatory response (p>0.05). CONCLUSION: Acute pericarditis was detected in all rats receiving radiotherapy. There was no positive effect of amifostine administration before radiotherapy on acute pericardial inflammation.

The effect of simvastatin on picrotoxin-induced seizure in mice.

OBJECTIVE: To study the effect of simvastatin on picrotoxin-induce seizures in mice in order to understand the impact of gabaergic system on neuronal cell death. METHODS: The study was held between July and September 2011, at the Karadeniz Technical University in Trabzon, Turkey. Balb/c mice weighting 20-40g were randomly selected and divided into five groups of six each. The first group was designated as control group; and the second as the picrotoxin (10mg/kg; intraperitoneal) alone group. The rest of the groups were administered simvastatin in dozes of 10, 20 and 40mg/kg respectively. Onset, number and duration of seizures, and death time were measured in mice for one hour. At the end of the study, the brain was removed from mice and normal and degenerative pyramidal neurons were counted in hippocampal CA1, CA2, CA3 region by light microscope. Using SPSS 17, Mann=Whitney U and Chi square and student-T tests were performed for statistical analysis. RESULTS: Simvastatin (10mg/kg) significantly decreased the number and duration of picrotoxin-induced seizures in mice. In addition, Simvastatin (10, 20, and 40mg/kg) significantly reduced the total number of abnormal pyramidal cells in CA1 and CA3 hippocampal regions compared to the picrotoxin-alone group. CONCLUSION: The effect of simvastatin on picrotoxin-induced seizures may be the result of increase in gabaergic activity and decrease in glutamatergic activity. More studies are needed to validate these results.

The effects of sertraline on blood lipids, glucose, insulin and HBA1C levels: A prospective clinical trial on depressive patients.

BACKGROUND: In this study, we aimed to investigate the possible effects of sertraline on blood glucose and lipid levels as risk factors for cardiovascular disease in depressive patients. METHODS: Eight male and twelve female depressive patients, diagnosed according to DSM-IV criteria, were included in this study. The subjects aged 19-50 years, did not smoke, and had normal body mass index (BMI), homeostasis model assessment-estimated insulin resistance (HOMA-IR) values, blood pressure, blood glucose, insulin and lipid levels. Sertraline therapy (50 mg/day) was started. Patients with diabetes mellitus, heart disease, pregnancy, and those taking other drugs were excluded from the study. Blood glucose, insulin, high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), and triglyceride values were measured in patients before, and at the 4(th), 8(th) and 12(th) weeks after treatment with sertraline. Moreover, HbA1C levels were measured at the beginning and at the end of the treatment (at 12(th) weeks). RESULTS: There were no significant differences in physical examination (blood pressure, BMI, body weight, height, waist circumference) and laboratory findings (glucose, HDL-C, LDL-C, HOMA-IR and HbA1C levels) at the 12(th) week after of treatment with sertraline compared to pretreatment values. However, insulin levels at the 4(th), 8(th) and 12(th) weeks significantly increased compared with pretreatment values. Likewise, triglyceride levels at the 8(th) and 12(th) weeks significantly increased compared with pretreatment values. CONCLUSIONS: Sertraline-treated patients have to be followed up for blood insulin and triglyceride levels. In addition, their treatment plan needs to be adjusted as necessary to prevent possible metabolic changes.

Effects of papaverine and carbon dioxide alone or in combination on the blood flow of internal thoracic artery.

OBJECTIVE: The internal thoracic artery is frequently used as an arterial graft for coronary bypass. Spasms of internal thoracic artery may contribute to early myocardial ischemia. To prevent vasospasm and increase the blood flow, some vasodilatory agents (such as carbon dioxide or papaverine) are used. The aim of the study was to evaluate the combined effects of carbon dioxide and papaverine versus either alone on the blood flow of the internal thoracic artery. METHODS: One hundred patients undergoing coronary artery bypass grafting (28 women and 72 men) with similar characteristics were randomly divided into four groups. We used the classic technique without any vasodilatory management before surgery in group 1, papaverine injection into the endothoracic fascia in group 2, and carbodissection technique in groups 3 and 4. Initial free flows of the internal thoracic arteries were measured after cutting of the vessel. After the first measurement, the ITA pedicles were washed with papaverine solution and wrapped with gauze in the first and fourth groups. Blood flow measurements were repeated 15 minutes later in all groups. RESULTS: When vasodilatory management was applied during excision, the blood flows were significantly increased relative to group 1. The mean blood flows reached a significantly higher level in groups 1, 2, 3, and 4 at the second measurements. In groups 2 and 3, the increase at the first measurements compared to the first group's level was continuously high, but no additional increase was observed between the first and second measurements. In groups 1 and 4, regardless of whether a previous vasodilatory management was present, the increases measured at repeated measurements were significant versus each group's first measurements (P < .05). CONCLUSIONS: Vasodilatory management, such as injection of papaverine into endothoracic fascia or carbon dioxide insufflation applied during excision, increased the free blood flows of internal thoracic artery pedicles. Exogenously applied papaverine produces an additional and continuous vasodilatation regardless of whether a vasodilatory intervention was previously applied.

Cardioprotective effect of cold-blood cardioplegia enriched with N-acetylcysteine during coronary artery bypass grafting.

BACKGROUND: Cold-blood cardioplegia is a well-known method in coronary artery bypass graft surgery, and several authors have used various agents in the enrichment of cold-blood cardioplegia to decrease ischemia-reperfusion injury seen during surgery. N-acetylcysteine, which can increase glutathione levels, is one of the agents added to cardioplegic solutions to decrease myocardial injury. This study was planned to assess the efficiency of N-acetylcysteine-enriched cold-blood cardioplegia on early reperfusion injury in patients with ischemic heart disease undergoing coronary artery bypass grafting, using measurements of cardiac troponin I and malondialdehyde release. METHODS: Thirty patients (11 women and 19 men) with left ventricular ejection fraction greater than 0.40 scheduled for coronary artery bypass grafting were randomly divided into two groups. We used cold-blood cardioplegia enriched with N-acetylcysteine (50 mg per kilogram of body weight) in the first group and cold-blood cardioplegia alone in the second group. Hemodynamic variables and clinical properties of the patients were preoperatively and postoperatively evaluated. Enzyme releases were measured in the early hours after the operation. RESULTS: In the N-acetylcysteine-enriched group cardiac troponin I levels were lower than in the N-acetylcysteine-free group, and this difference was statistically significant. Cardiac troponin I levels increased in both groups in the 6th and 12th hours postoperatively, but there was a statistically significant difference between the two groups. Malondialdehyde levels were significantly higher in the N-acetylcysteine-free group after the 6th, 12th, 24th, and 48th hours postoperatively when compared with the N-acetylcysteine-enriched group. CONCLUSIONS: N-acetylcysteine-supplemented cold-blood cardioplegia minimizes myocardial injury in the early hours after and during the cardiac surgery.

The acute alterations in biochemistry, morphology, and contractility of rat-isolated terminal ileum via increased intra-abdominal pressure.

AIM AND SCOPE: To determine the acute effects of increased intra-abdominal pressure (IAP) on the biochemistry, morphology, and contractility of the isolated terminal ileum of rats. BACKGROUND: Laparoscopic procedures are used clinically in diagnostic and treatment modalities and experimentally as a model of ischemia-reperfusion injury induced by the elevation of IAP. Although some clinical and in vivo experimental studies investigate the results of ischemia-reperfusion injury whether induced by elevated IAP or clamping, there is no in vitro study that has investigated the acute effects of high IAP mimicked by a laparoscopic intervention in any of the intra-abdominal organs (like terminal ileum) on the basis of contractility which represents the motility. METHODS: Twenty-four adult with either sex Sprague-Dawley rats were divided into three groups. The control group (Group I) was not subjected to any IAP. In Groups II and III, an IAP of 10 and 20 mmHg, respectively, was established by carbon dioxide pneumoperitoneum for a period of 60 min. Thirty minutes after the desufflation, the terminal ileum was removed for in vitro pharmacological investigation, measurement of malondialdehyde (MDA) values, and histopathological examination. Statistical comparisons among groups were done using the Kruskal-Wallis variance analysis, with post hoc comparison performed with the Mann-Whitney U-test. RESULTS: Tissue MDA value and the damage scores of mucosa and submucosa were significantly increased in both IAP groups. The smooth muscle layer was significantly damaged only in Group III. The contractions obtained by electrical field stimulation (EFS) were inhibited in both IAP groups, and the contractions to acetylcholine were inhibited in Group III when compared to the control group. CONCLUSIONS: In conclusion, we can say that pneumoperitoneum induced IAP may inhibit contractile responses, cause structural alterations which may be related to ischemia-reperfusion injury in rat terminal ileum.

The contracting and relaxing responses of human internal mammary artery grafts harvested by two different methods.

Perioperative spasm of internal mammary artery is a common experience in coronary artery bypass grafting. Many techniques were described of harvesting the internal mammary artery to prevent vasospasm. We investigated the comparison of the contracting and relaxing responses of human internal mammary artery grafts harvested by two different methods. Patients were divided into two groups depending on the harvesting technique. In the first and second groups arteries were harvested by classical and carbon dioxide insufflation techniques, respectively. In both groups, endothelial function of arteries was assessed by precontracting the rings with phenylephrine (10(-5)M) and dilatating them by cumulative acetylcholine (10(-8) to 10(-5)M) concentrations. Cumulative concentration-response curves for phenylephrine (10(-8) to 10(-4)M), noradrenaline (10(-9) to 10(-4)M), and 5-hydroxytryptamine (10(-9) to 10(-4)M) were obtained in all groups. Endothelial integrity of arteries were histopathologically evaluated. In both groups, acetylcholine caused concentration-dependent relaxations in rings precontracted with phenylephrine (10(-5)M). In arteries harvested by carbon dioxide insufflation technique, acetylcholine caused significantly higher relaxations compared to the rings obtained by classical technique (p<0.05). In all rings of study groups, phenylephrine, noradrenaline and 5-hydroxytryptamine caused concentration-dependent contractions. There was not any significant difference in concentration-dependent responses of these contracting pharmacological agents between the groups. Histopathological evaluation revealed no major arterial damage in both groups. Carbon dioxide insufflation technique does seem not only to protect the integrity of the endothelium and the whole vessel, but also prevent the possible vasospasm of the internal mammary artery segments.

A case of rosiglitazone exposure in the second trimester of pregnancy.

AIM: Data about rosiglitazone use in pregnancy is limited. We aimed to present a pregnant woman who exposed to rosiglitazone in the second trimester and the fetal outcome. SUBJECT: The case was a 42-year-old, multigravid Caucasian woman with a history of diabetes mellitus type II for 4 years prior to her current pregnancy. Her diabetes was managed by diet and exercise and she has not received any drug therapy until the 13th week of her sixth (present) and unplanned pregnancy. The case was exposed to rosiglitazone (4 mg/day) between 13th and 17th gestational weeks. After the diagnosis of pregnancy at the 17th week, rosiglitazone was stopped and insulin therapy was started. At the 37th week, she had a healthy male infant (4500 g, 50 cm). The baby was examined and no major or minor malformations were observed. CONCLUSION: This is the first case present in the literature exposed to rosiglitazone in the second trimester of her pregnancy. The data from the present case may contribute to the existing limited knowledge about rosiglitazone in pregnancy.

Psychotropic drugs in pregnancy: a case-control study.

Psychotropic drug exposure during pregnancy is a common problem. Among the 601 cases exposed to drugs during pregnancy, who were followed by our Toxicology Information and Follow-up Service, 124 cases had used psychotropic drugs for depression, anxiety, or psychotic disorders. As the control group, 248 women, who did not use any drugs were selected. Of the 124 cases, 80 (64.5%) had healthy babies, and 17 (13.7%) decided to terminate the pregnancy. Spontaneous abortions, intrauterine death (in the 38th week) and premature deliveries were observed in the 9 (7.3%), 1 (0.8%) and 3 (2.4%) cases, respectively, in the drug exposure group. Pregnancies of the 14 (11.3%) cases were continuing during the preparation of this manuscript. Of the 248 controls, 151 (60.9%) had healthy babies, 9 (3.6%) experienced spontaneous abortion and 3 (1.2%) decided to terminate their pregnancies, 3 (1.2%) had premature deliveries, and we observed one (0.4%) congenital abnormality, 81 (32.7%) cases were still pregnant. Odds Ratio (95% confidence interval) for spontaneous abortion was found to be 1.35 (1.27-11.82) in the cases exposed to psychotropic drugs (P=0.02). No developmental problems were observed in the babies followed for 12 months. These data may give information about the early- but not the late-term effects of psychotropic drugs used in pregnant women.

Newer antidepressants in pregnancy: prospective outcome of a case series.

Antidepressant drug choice in pregnancy is a complex problem especially for new drugs. Among 590 cases exposed to drugs during pregnancy who were followed by our center, 21 cases used newer antidepressants, i.e., venlafaxine, mirtazapine, nefazodone. We present the gestational findings and fetal outcomes of these cases. Ten cases had used venlafaxine, one case had used both venlafaxine and mirtazapine, eight had used mirtazapine alone or with some other drugs and two had used nefazodone, in the first trimester. Of the 21 cases, 17 (80.9%) had healthy babies, 3 (14.3%) decided to terminate the pregnancy, and 1 (4.8%) spontaneous abortion was observed in a case exposed to mirtazapine, alprazolam, diazepam and trifluoperazine. All obstetrical findings were normal during the pregnancy of each case. No congenital abnormality and developmental problem was observed in the babies followed up for 12 months. The aim of the present study is to contribute the data to the limited knowledge available in the literature regarding human pregnancy.

Sibutramine use in pregnancy: report of two cases.

BACKGROUND: Sibutramine is a drug used for the medical treatment of obesity. No data are available on sibutramine use in pregnancy. We report the fetal outcomes of two pregnant women exposed to sibutramine. CASES: The first woman was exposed to 10 mg/day of sibutramine during gestational weeks 4-6. The second woman was exposed to 10 mg/day of sibutramine during gestational weeks 5-8. At weeks 37 and 39, they delivered healthy infants. CONCLUSIONS: To our knowledge, this is the first report of sibutramine exposure in pregnancy. These cases may contribute to the knowledge about sibutramine use during pregnancy.

Normal pregnancy outcome following inadvertent exposure to rosiglitazone, gliclazide, and atorvastatin in a diabetic and hypertensive woman.

The subject is a diabetic and hypertensive woman treated early during an unplanned pregnancy with a multi-drug regimen that included three drugs with no prior history for use in pregnant women (rosiglitazone, gliclazide, atorvastatin). She was under care for chronic hypertension, which she suffered for 14 years, and diabetes mellitus, hypercholesterolemia, anxiety disorder, morbid obesity and epilepsia for 5 years. She was exposed to rosiglitazone (4mg/day), gliclazide (60mg/day), and atorvastatin (40mg/day) in addition to acarbose, spironolactone, hydrochlorothiazide, carbamazepine, thioridazine, amitryptiline, chlordiazepoxide, and pipenzolate bromide during the first 7 weeks of gestation while unaware of pregnancy. Pharmacotherapy was adjusted following clinical recognition of pregnancy during the 8th week. She gave birth to a normal healthy infant at the 36th week of gestation. This is the first reported case of human exposure to rosiglitazone, gliclazide, and atorvastatin during pregnancy. Although the normal pregnancy outcome does not address the safety of these drugs for use in pregnancy, these data contribute to a limited knowledge regarding human exposure to these antidiabetic drugs.

Use of polypharmacotherapy in pregnancy: a prospective outcome in a case.

PURPOSE: Little is known about the risks associated with prenatal exposure to atypical antipsychotics. Our objective is to present a case of exposure to risperidone and quetiapine in pregnancy, and additionally to some other drugs. CASE: Our case (36-year old) has suffered schizophrenia (DSM-IV) for 5 years and used these drugs (risperidone, quetiapine, mirtazapine, thioridazine, diazepam, hydroxyzine, clomipramine, fluvoxamine, alprazolam, carbamazepine, biperiden, haloperidol, ampicillin+sulbactam, enoxaparin, oxerutine) in her third pregnancy. Because of her psychotic condition, Mrs. N.B. was not aware of her pregnancy until 22nd week and the pregnancy could not be terminated. She had a female infant (3000 g, 50 cm) with APGAR scores of 8-9 at the first and fifth minutes at 37th week with an uncomplicated vaginal delivery. The baby was normal. CONCLUSION: This case may contribute to the existing knowledge regarding use of atypical antipsychotics in pregnancy.

Possible involvement of opioidergic and serotonergic mechanisms in antinociceptive effect of paroxetine in acute pain.

Antidepressant drugs, especially tricyclics have been widely used in the treatment of chronic pain, but not in acute pain. Because of numerous undesirable side effects, the selective serotonin reuptake inhibitors (SSRIs), with their favorable side effect profile, are preferred nowadays. An activation of the endogenous opioid mechanisms or potentiation of the analgesic effect mediated by serotonergic and/or noradrenergic pathways are thought to be involved in the antinociceptive action of SSRIs. In this study, the potential antinociceptive effect of paroxetine and its interaction with opioidergic system and serotonin receptors were evaluated. The antinociceptive effect of paroxetine was tested using a hot plate test in mice. Paroxetine, a SSRI antidepressant drug, induced an antinociceptive effect following i.p. administration. This antinociception was significantly inhibited by naloxone, an opioid receptor antagonist, suggesting the involvement of opioidergic mechanisms. While ondansetron (a 5-HT(3)-receptor antagonist) inhibited the effect of paroxetine, ketanserin (a 5-HT(2)-receptor antagonist) could not. In conclusion, paroxetine-induced antinociception, similar to morphine, suggests an involvement of direct or indirect action (via an increase in release of endogenous opioid peptide(s)) at opioid receptor sites and an involvement of serotonergic mechanisms mainly at the receptor level.

Paroxetine alters KCl- or ATP-induced contractile responses of isolated vas deferens in rats chronically treated with ethanol.

Chronic ethanol administration affects many organ systems, including sexual organs. One of these organs is the vas deferens whose contractility can also be altered by selective serotonin re-uptake inhibitors (SSRIs). The aim of the present study, is to evaluate whether paroxetine (PX), a SSRI, can modify the contractile responses of isolated vas deferens obtained from rats chronically treated with ethanol to the contractile agents, potassium chloride (KCl) and adenosine triphosphate (ATP). For 21 days, alcohol was applied with a modified liquid diet to sexually mature male Sprague-Dawley rats (200-240 g). The vas deferens of the rats were excised at the end of day 21 and suspended in the organ baths by classical pharmacological methods. The responses to contractile agents tested were decreased by chronic ethanol treatment in all groups compared to their untreated matches. PX (10(-7) and 10(-6)M) potentiated the contractions to KCl (20-180 mM) and ATP (10(-6) to 10(-3)M) in epididymal portion but its higher concentrations (10(-5) and 10(-4)M) inhibited the responses, both in the control and chronically ethanol treated rat groups. Prazosin (PR), an alpha adrenergic receptor blocker, could not inhibit PX-induced potentiation in lower concentrations of KCl but could inhibit the potentiation occurred at higher concentrations of KCl in epididymal portion both in the control and chronically ethanol treated rat groups. PR also inhibited PX-induced potentiation on the responses to ATP in epididymal portion both in the control and chronically ethanol treated rat groups. In conclusion, all the results obtained in this study, suggest that chronic ethanol treatment decreased the contractility of vas deferens but did not alter the action pattern of PX on responses to KCl and ATP in rat vas deferens. On the other hand, the potentiation of responses to contractile agents induced by PX can be partially considered as the result of inhibition of noradrenaline re-uptake.

Long-term use of sertraline leads to alterations in contractility of rat isolated vas deferens.

Previous experiments with rat isolated vas deferens have shown that sertraline pretreatment inhibits contractile responses to noradrenaline, KCl, serotonin and electrical field stimulation. In the present study, the aim was to investigate the effects of long-term use of sertraline on contractile responses of rat isolated vas deferens. Fifteen Sprague-Dawley rats were given long-term (21 days) sertraline treatment, while another 15 were used as control. Both vas deferens were excised. Epididymal and prostatic segments of each underwent electrical field and chemical stimulation (noradrenaline, serotonin, acetylcholine, adenosine-triphosphate). Epididymal and prostatic segments had different contraction characteristics. Long-term sertraline treatment inhibited contractile responses of vas deferens segments to electrical field stimulation. The responses to noradrenaline were amplified with a left shift on both segments. Responses to serotonin had only a left shift on epididymal segments, while no contractile responses were observed on prostatic segments of the groups. Long-term treatment with sertraline had peripheral effects on rat vas deferens contractility, and some of the effects may be through mechanisms other than the inhibition of serotonin re-uptake.

The effects of paroxetine on rat isolated vas deferens.

The aim of the present study is to evaluate whether paroxetine (a selective serotonin re-uptake inhibitor) can modify the contractile responses of isolated vas deferens. Some contractile agents, potassium chloride (KCl), adenosine 5'-triphosphate (ATP), noradrenaline (NA), and electrical field stimulation (EFS) caused contractions both in epididymal and prostatic portions of vas deferens. Paroxetine (PX) in concentrations 10(-7) and 10(-6)M potentiated the contractions to KCl and ATP only in epididymal portion but in higher concentrations (10(-5) and 10(-4)M) inhibited the responses in both portions. NA responses were inhibited by PX in all concentrations used, both in prostatic and epididymal portions. Prazosin (PR), an alpha adrenergic receptor blocking agent, inhibited PX-induced potentiation observed for higher concentrations of KCl. PR also inhibited PX-induced potentiation on the responses to ATP in epididymal portion. Pretreatment with PX (10(-7) to 10(-6)M) increased the contractions to EFS but in 10(-5) and 10(-4)M concentrations inhibited them. Even though the preparations were washed out, the inhibited responses of contractile agents could not be restored. After a washout period for PX, when Bay K 8644 (calcium channel activator) was added to the bath medium, the contractile responses to KCl were partially restored. In calcium-free medium, KCl caused contractions in concentrations higher than 80 mM with lower amplitudes which were not affected by PX. Reserpinization did not change the inhibitory pattern of PX's effect on exogenously applied NA in all concentrations tested. In reserpinized rats, the potentiation caused by PX in exogenously applied ATP responses was not observed. In conclusion, we can say that PX has two different effects: inhibition and potentiation of contractions to various agonists. The inhibitory effect of the drug can be explained by a calcium channel blocking activity. The potentiating effect of the drug is mainly related to its presynaptic action, such as NA re-uptake inhibitory effect.

Sex difference in susceptibility to picrotoxin-induced seizures in rats following octreotide.

It was previously reported that females with proestrous are more susceptible to picrotoxin-induced epileptic seizures than males, provided that the estrous cycle is taken into consideration (Tan & Tan, 2001). The sex difference in susceptibility to picrotoxin-induced seizures was reconsidered in the present study using rats with a previous octreotide (a stable somatostatin analogue) injection, as somatostatin is known to be involved in epileptic phenomena. Contrary to rats without octreotide, males were more susceptible to picrotoxin-induced seizures than females. Statistical analysis indicated that only males showed decreased latencies to seizures and increased seizure frequencies following octreotide; females were not affected by this experimental procedure. It was suggested that as a GABA antagonist, somatostatin may contribute to the occurrence of epileptic discharges in nervous system, creating a sex difference to epileptic seizures. These results may have implications for understanding the epileptic mechanisms, with possible therapeutic consequences.