[5-HT(2A) receptor/protein kinase C pathway in mediating long-term facilitation of carotid sinus nerve discharge in chronic intermittent hypoxia rats]

Objective: To explore the role of 5-HT(2A)R/PKC pathway in mediating long-term facilitation (LTF) of carotid sinus nerve (CSN) discharge in chronic intermittent hypoxia (CIH) rats. Methods: With number table, 24 adult SD rats were randomly divided into saline control group (group A, n=6), 5-HT(2A)R antagonist (ketanserin) group (group B, n=6), PKC inhibitor (PKC θ-pseudosubstrate) group (group C, n=6) and combined ketanserin with PKC θ-pseudosubstrate group (group D, n=6). All rats were placed into the animal chambers for CIH treatment, 8 h per day (from 9: 00 to 17: 00) for 4 consecutive weeks. 28 days later, 5 min × 3 times of stimulation with acute intermittent hypoxia (AIH) were given, after that, stable CSN discharge activities were recorded and compared before and after intravenous injection of saline (group A), ketanserin (group B), PKC θ-pseudosubstrate (group C) or ketanserin + PKC θ-pseudosubstrate (group D), respectively. Results: There were no significant difference in the baseline (before AIH stimulation) average peak amplitude of CSN discharge among the four groups (P>0.05). In group A, the amplitude of CSN discharge at 30 min and 60 min after AIH were (5.01 ± 0.53) μV and (4.95 ± 0.34) μV respectively, which were significantly higher than that before AIH (P<0.01). The results implied that the CSN LTF could be induced by AIH in CIH pre-treatment rats. In group B, the amplitude of CSN discharge at 30 min and 60 min after AIH were (3.79 ± 0.42) μV and (3.73 ± 0.46) μV, respectively, which were still significantly higher than that before AIH (P<0.01), showing that carotid sinus nerve LTF couldn't be completely blocked by 5-HT(2A)R antagonist in rats. After injection of PKC θ-pseudosubstrate or ketanserin + PKC θ-pseudosubstrate in group C or D, there were no significant differences in CSN discharge amplitude before and after AIH (P>0.01), suggesting that inhibition of PKC alone or 5-HT(2A)R/PKC pathway could completely block the LTF of CSN. Conclusion: 5-HT(2A)R/PKC pathway was involved in mediating long-term facilitation of carotid sinus nerve discharge in CIH rats.

[Application of three questionnaires in screening obstructive sleep apnea in patients with chronic obstructive pulmonary disease]

Objective: To evaluate the clinical value of three questionnaires [Sleep Apnea Clinical Score (SACS), Berlin Questionnaire (BQ), and Epworth Sleepiness Scale (ESS)] in screening obstructive sleep apnea (OSA) in patients with chronic obstructive pulmonary disease (COPD). Methods: A total of 198 patients with COPD were assessed the likelihood of OSA by using the SACS, BQ, ESS, which was confirmed by the overnight polysomnography (PSG). The receiver operating characteristic curve (ROC) and the calculated likelihood ratios were used to compare the values of three scoring systems in predicting OSA in COPD patients. Results: The patients had an average age of (65.5±9.3) years and 92.9% (184 cases) of which were male, 14 cases (7.1%) were female; 27 cases (13.6%) had a high probability of OSA by SACS assessment, 61 cases (30.8%) had a high probability screened by BQ, and 72 (36.4%) had OSA high probability by ESS. The diagnosis of OSA in 75 patients (37.9%) were confirmed by PSG. OSA did not be accurately predicted by ESS screening in patients with COPD, with a ROC curve area under the curve of 0.592 (95% CI: 0.509-0.674, P=0.053). BQ had an area under the ROC curve of 0.706 (95% CI: 0.626-0.779, P<0.001). However, the prediction of SACS was much better, with an area under the ROC curve of 0.810 (95% CI: 0.737-0.871, P<0.001). Conclusion: SACS is superior to BQ and ESS in predicting OSA in this group of patients with COPD.

[Effect of sanhuang jiangtang recipe on insulin peripheral resistance in type II diabetics]

OBJECTIVE

To observe the effect of Sanhuang Jiangtang recipe (SHJT) on insulin peripheral resistance in type II diabetics.

METHODS

Ninety-five patients with type II diabetics were randomly divided into two groups. Fifty-three cases of SHJT group were given orally decoction and tablets of SHJT for 4-6 months. The efficacy was compared with that of 42 cases treated with Glipizide as the control. Before and after treatment standard steamed bread meal test was performed to measure the insulin peripheral sensitivity, insulin release to glucose and insulin sensitivity index.

RESULTS

(1) The total effective rates of improving insulin peripheral resistance and reducing blood sugar in SHJT group were 79.2% and 80.1%, which was equivalent to levels in the control group, but SHJT recipe was more effective in relieving symptoms of Qi deficiency and signs of blood stasis. (2) In SHJT group, the insulin peripheral sensitivity and insulin sensitivity index were significantly increased (P < 0.05 and P < 0.01), meanwhile the fasting blood sugar and blood sugar area were reduced (P < 0.05), but the change of insulin release to glucose was blunted. (3) The lowering of blood sugar in SHJT group was significantly negative correlated with the changing of degree of insulin peripheral sensitivity and index of insulin sensitivity (P < 0.01 and P < 0.05), but not with that of insulin area.

CONCLUSIONS

It suggested that the treatment of SHJT recipe might decrease insulin peripheral resistance (partial reversal) by means of reducing hyperinsulinemia and improving insulin sensitivity.

[Effects of supplemented taohe chengqi decoction in treating insulin resistance in rats with non-insulin dependent diabetes mellitus]

OBJECTIVE

To investigate the effect of Supplemented Taohe Chengqi Decoction (STHCQD) in treating non-insulin dependent diabetes mellitus (NIDDM).

METHODS

The model of rats with NIDDM was formed with injection of streptozotocin and fed on high calorie diet to study the effects of STHCQD on the release of insulin mediator from liver cell membranes, the glucose oxidation in adipocytes as well as the insulin sensitivity.

RESULTS

(1) Fasting serum glucose, serum insulin, intake of food and water were significantly decreased (P < 0.05-0.01) in STHCQD-treated diabetic rats as compared with untreated diabetic rats, while the insulin sensitivity was significantly increased (P < 0.05). (2) The liver cell membranes from STHCQD-treated diabetic rats released the quantity of insulin receptor which inhibited adenylate cyclase activity, but this effect was blunted in untreated diabetic rats (P < 0.05). (3) A significantly increased glucose oxidation in adipocyte of STHCQD-treated diabetic rats was found as compared with those of untreated diabetic rats (P < 0.05).

CONCLUSIONS

STHCQD therapy increased sensitivity and responsiveness of target cells to insulin, i.e., it might decrease insulin resistance at receptor sites and postreceptor sites in rats with NIDDM, but could not reverse the insulin resistance.

[Relationship between various syndrome-types and defect of erythrocyte insulin receptors in non-insulin dependent diabetes mellitus]

Fifty-seven patients of non-insulin dependent diabetes mellitus (NIDDM) were divided into various groups by Syndrome Differentiation in TCM and 18 cases of non-diabetes mellitus were taken as control. The relationship of Syndrome-types and defect of the erythrocyte insulin receptors were studied with the percentage of specific insulin binding to erythrocyte, number and average affinity of erythrocyte insulin receptors. The results showed: (1) The patients of NIDDM had defect of erythrocyte insulin receptors specified with decreased number of insulin receptors; (2)Mild defect of erythrocyte insulin receptors was found in Syndrome of Yin Deficiency and hyperactivity of Heat, but serious defect in the Syndrome of both Qi and Yin Deficiency, in the Syndrome of both Yin and Yang Deficiency. Above data suggested that the defect of erythrocyte insulin receptors was correlated with Syndrome-types of patients with NIDDM, the more serious Deficiency Syndrome, the more serious defect of erythrocyte insulin receptors.

[Clinical and experimental study of semen Persical decoction for purgation with addition in type II diabetes mellitus]

This paper reported the results of clinical observation on a treatment with Semen Persical decoction for purgation with addition (SPDPA) in type II diabetes mellitus. The effective rate of SPDPA on 106 cases of noninsulin dependent diabetes mellitus (NIDDM) was 79%. The efficiency of SPDPA was equivalent to glyburide. From the experimental study, it can be concluded that SPDPA could reduce blood sugar and relieve symptom in diabetic patients and rats. Its mechanism may be due to improving secretion of insulin, inhibiting production of glucagon, repairing insular endocrine cell, increasing endocrine pellet of insular B cell and improving composition of hepatic glycogen. In traditional Chinese medicine theory, the mechanism of therapeutic action of SPDPA in diabetes mellitus is based on synergistic regulation of benefiting Qi and nourishing Yin, activating blood circulation to dissipate blood stasis and loosening the bowel to relieve constipation.