CNS alpha 1 receptor in tonic pain during estrous cycle in rats.

Estrogen and progesterone are known to affect nociception. The plasma concentrations of these hormones vary during estrous cycle in rodents. The aim of the present study was to investigate the effect of evidence of alpha1 receptor agonist and antagonist on tonic pain in all phases of estrous cycle in female rats. Phenylephrine (alpha1 agonist) and prazosin (alpha1 antagonist) were administered via intracerebroventicular (ICV) injection. Adult female rats weighting 200-220 g were maintained on 12 h light/dark cycle for 10-14 days prior to the experiment. Food and water were made available ad libitum. Formalin test was performed in all phases of estrous cycle. Results showed that phenylephrine caused significant (P<0.05) reduction in pain sensitivity. This reduction was more pronounced during proestrus phase. Prazosin significantly (P<0.05) increased pain sensitivity, particularly during metestrus phase. It is possible that fluctuation in pain sensitivity during estrous cycle is related to the level of sex hormones during estrous cycle.

Evaluation of serum steroid hormones in schizophrenic patients.

BACKGROUND: Recent studies have implicated the abnormalities in the gamma-aminobutyric acid (GABA) neurotransmmiter system in the pathophysiology of schizophrenia. There are also evidences indicating that steroids of central or peripheral origin may modulate GABAergic system through direct interaction with the GABAA receptor complex. These raise the possibility that alternations in serum steroid hormones may contribute to the pathophysiological process in the schizophrenia. AIMS: The purposes of this study were first, to determine whether alternations in steroid serum levels occur in schizophrenic patients, and secondly to determine whether such alternations normalize with clinical improvement. METHODS AND MATERIAL: Serum concentrations of testosterone (T), estradiol (E), progesterone (P) and cortisol (C) were determined in male schizophrenic patients (N = 49) before treatment, during treatment and after recovery and in age-matched healthy male subjects (N = 17). All steroid hormones were assayed by ELISA method. Statistical analysis used: Differences in steroids concentrations between groups were assayed by One-Way Analysis of Variance (ANOVA), followed by Tukey's post hoc test. The level of significance was considered at P < 0.05. RESULTS AND CONCLUSION: The serum concentrations of E, P and C were significantly (P < 0.05) lower in male schizophrenic patients in all three stages of the study, compared with healthy subjects. Serum concentrations of T were significantly (P < 0.05) lower in male schizophrenic patients before and during treatment, but not after recovery, compared with healthy subjects. These findings support the occurrence of abnormal steroid concentrations in schizophrenic patients and suggest that lower T level in this disorder is related to the illness and normalizes with remission, while trait-related factors may contribute to lower serum E and C levels in schizophrenia.