The dose-dependent effect of chronic administration of haloperidol, risperidone, and quetiapine on sexual behavior in the male rat.

INTRODUCTION: Antipsychotic drug-induced sexual dysfunction is a common and problematic side effect, which may diminish quality of life and lead to treatment noncompliance. Up to date, there is still a scarcity of basic research regarding the chronic effects of most antipsychotic agents on sexual behavior. AIM: The present study investigated the effect of a range of doses of three antipsychotic drugs (haloperidol, risperidone, and quetiapine) on male rat sexual competence following chronic administration. METHODS: Twelve groups of Sprague-Dawley rats (n = 7 each) received by gavage haloperidol (0.25, 0.5, or 1 mg/kg), risperidone (0.125, 0.25, or 0.5 mg/kg), quetiapine (10, 20, and 40 mg/kg) or vehicle (distilled water) in the corresponding control groups, respectively, once daily for 21 days. Sexual function was evaluated by the copulatory behavior test 10 hours after the last dose. MAIN OUTCOME MEASURE: The male rat behavioral parameters of copulatory test. RESULTS: Sexual function was widely and significantly suppressed by high dose haloperidol (1 mg/kg) after 21 days administration compared with the control group, which included both frequency and latency of intromission and ejaculation. Only ejaculation latency was significantly impaired after administration with 0.5 mg/kg haloperidol. Compared with the control group, high dose risperidone (0.5 mg/kg) significantly decreased the frequency of mounting. There were no significant changes in sexual behavior with the lower doses of either haloperidol or risperidone. Sexual behavior was not influenced by any dose of quetiapine. CONCLUSIONS: Haloperidol and risperidone, but not quetiapine, could impair sexual competence in a dose-related manner in male rats.

The effect of chronic antipsychotic drug administration on nitric oxide synthase activity and gene expression in rat penile tissues.

Antipsychotic drug treatment may be associated with common and problematic sexual dysfunction, especially impotence, which can diminish quality of life and lead to treatment noncompliance. Nitric oxide synthase (NOS) is an important cellular modulator of erectile function. We have therefore investigated the effect of antipsychotic drug on activity and gene expression of NOS in rat penile tissues. The activity of constitutive NOS was significantly suppressed below control by a 21 days administration of 1 mg/kg haloperidol, which also significantly decreased expression of endothelial NOS (eNOS) and neural NOS mRNA. Risperidone at 0.5 mg/kg also reduced eNOS mRNA expression. Haloperidol or risperidone did not change gene expression and activity of inducible NOS (iNOS). Quetiapine significantly increased activity and mRNA expression of iNOS with 20 and 40 mg/kg doses. These preliminary results have important implications for enhancing our understanding of mechanisms by which antipsychotic drugs induce sexual dysfunction.

Preoperative TN staging of esophageal cancer: comparison of miniprobe ultrasonography, spiral CT and MRI.

AIM: To evaluate the value of miniprobe sonography (MPS), spiral CT and MR imaging (MRI) in the tumor and regional lymph node staging of esophageal cancer. METHODS: Eight-six patients (56 men and 30 women; age range of 39-73 years, mean 62 years) with esophageal carcinoma were staged preoperatively with imaging modalities. Of them, 81 (94 %) had squamous cell carcinoma, 4(5 %) adenocarcinoma, and 1(1 %) adenoacanthoma. Eleven patients (12 %) had malignancy of the upper one third, 41 (48 %) of the mid-esophagus and 34 (40 %) of the distal one third. Forty-one were examined by spiral CT in whom 13 were co-examined by MPS, and forty-five by MRI in whom 18 were also co-examined by MPS. These imaging results were compared with the findings of the histopathologic examination for resected specimens. RESULTS: In staging the depth of tumor growth, MPS was significantly more accurate (84 %) than spiral CT and MRI (68 % and 60 %, respectively, P<0.05). The specificity and sensitivity were 82 % and 85 % for MPS; 60 % and 69 % for spiral CT; and 40 % and 63 % for MRI, respectively. In staging regional lymph nodes, spiral CT was more accurate (78 %) than MPS and MRI (71 % and 64 %, respectively), but the difference was not statistically significant. The specificity and sensitivity were 79 % and 77 % for spiral CT; 75 % and 68 % for MPS; and 68 % and 62 % for MRI, respectively. CONCLUSION: MPS is superior to spiral CT or MRI for T staging, especially in early esophageal cancer. However, the three modalities have the similar accuracy in N staging. Spiral CT or MRI is helpful for the detection of far-distance metastasis in esophageal cancer.