[Effect of Acupuncture on Histology of Thymus and Expressions of ANP and NPR-A in Anxiety Rats].

OBJECTIVE: To explore possible mechanism of electroacupuncture (EA) for regulating immune function in anxiety disorder (AD) rats by observing the effect of acupuncture on the histology of thymus and expressions of atrial natriuretic peptide (ANP) and natriuretic peptide receptor type A (NPR- A) in thymus. METHODS: Totally 34 SD healthy rats were randomly divided into the blank control group (n = 10), the model group (n = 12), the EA group (n = 12). Anxiety model was established in rats of the model group and the EA group by using chronic unpredictable stress (CUS) stimulation. EA (15/25 Hz) at Neiguan (PC6) and Shenmen (HT7) was performed in the EA group, with 15-min needle retaining, once every other day, 15 days in total. Needle was fixed at same acupoints for 15 min without electric stimulus in the other two groups. Anxiety-like behavior was measured by elevated plus-maze (EPM) test. Pathological changes of thymus tissue were observed by optical microscope. Expressions of ANP and NPR-A in thymus were measured by immunohistochemical assay. RESULTS: The thymus tissue in the model group was severely atrophied, with unclear structure of thymic lobules, unclear margin of thymic medulla, loosely arranged lymphocytes ,and obviously enlarged volume of thymic corpuscle. The thymus tissue in the EA group was mildly atrophied, with existent structure of thymic lobules, clear margin of thymic medulla, densely arranged lymphocytes in cortical region, and widened medullary area. Com- pared with the blank control group, the percentage of open-arms entries (OE%) in the total QE times ob- viously decreased in the model group (P < 0.05), ANP expression obviously increased (P < 0.05), and NPR-A expression obviously decreased (P < 0.01). Compared with the model group, OE% was obviously elevated (P < 0.05), ANP expression obviously decreased (P < 0.05), and NPR-A expression obviously increased (P < 0.01) in the EA group. CONCLUSION: EA not only could reduce anxiety of rats, but also could improve chronic stress induced thymus injury through intervening synthesis and secretion of ANP, as well as the expression of NPR-A (a specific receptor of ANP).

[Mechanism on atrial natriuretic peptide receptor in anti-anxiety with acupuncture based on its tranquilizing effect].

Anxiety disorder is one of the most common mental disorders and seriously impairs the physical and mental health of patients. Due to the efficacy of acupuncture for tranquilization, acupuncture displays its unique advantage on the treatment of anxiety disorder, but the relevant biological mechanism has not been elaborated. The modern medicine study has proved that the heart and brain have their own independent natriuretic peptide (NP) system. The dysfunction of ANP and its receptor are closely related to the occurrence of anxiety disorder. The ANP acts on anti-anxiety. Hence, focusing on the three aspects, named the anti-anxiety effect of acupuncture based on its tranquilizing effect, the anti-anxiety effect of ANP and the positive regulation of acupuncture on NP, the mechanism on ANP and its receptor was explored in anti-anxiety with acupuncture based on tranquilizing effect, and the idea was put forward on that the anti-anxiety effect of acupuncture was possibly based on its action of tranquilization through regulating the ANP and its receptor. As a result, it is expected to provide the theoretic support for the mechanism study on anti-anxiety with acupuncture based on its tranquilizing effect.

[Effects of Acupuncture Intervention on Levels of T Lymphocyte Subsets in Plasma and Thymus in Stress-induced Anxiety Rats].

OBJECTIVE: To observe the effect of electroacupuncture (EA) intervention on the levels of CD 4+ and CD 8+ lymphocytes in the plasma and thymus in anxiety disorder rats, so as to explore its mechanism underlying favorable regulation of immune function. METHODS: Thirty-four SD rats were randomly divided into control (n = 10) , model (n = 12) and EA (n = 12) groups. The anxiety model was established by using chronic unpredictable emotional stress stimulation (fasting, water-deprivation, shaking, tail-clamping, forced warm- and cool-water swimming, electrical shock stimulation, etc.) for 15 days. EA (15 Hz/ 25 Hz) was applied to "Neiguan" (PC 6) and "Shenmen" (HT 7) for 15 min, once every other day for 15 days. The anxiety-like behavior was measured by elevated plus maze test. Anxiety reduction in the plus-maze is indicated by an increase in the proportion of time spent in the open arms (time in open arms/total time in open or closed arms) , and an increase in the proportion of entries into the open arms (entries into open arms/total entries into open or closed arms). While the contents and expression of CD 4+ and CD 8+ in the plasma and thymus tissues were measured by ELISA and immunohistochemistry, respectively. RESULTS: The values of proportions of open-arm entries (OE%) and the content of plasma CD 4+ lymphocytes were obviously lower in the model group than in the control group (P < 0.05), and were significantly higher in the EA group than in the model group (P < 0.05). Whereas, the content of plasma CD 8+ lymphocytes was obviously higher in the model group than in the control group (P < 0.05) and markedly down-regulated in the EA group after the treatment (P < 0.05). The ratio of CD 4+/CD 8+ was decreased in the model group in comparison with the control group (P = 0.054), and was significantly up-regulated in the EA group after EA stimulation (P < 0.01). Compared with the control group, the expression levels (optical density, OD values) of CD 4+ and CD 8+ lymphocytes in the thymus tissue were obviously decreased in the model group (P < 0.01). After EA, the expression levels of thymus CD 4+ and CD 8+ were remarkably up-regulated in the EA group (P < 0.05). No significant changes were found in proportion of open-arm time (OT%, P > 0.05). CONCLUSION: EA can effectively relieve anxiety disorder in anxiety rats, which may be related to its effects in up-regulating plasma CD 4+ , thymus CD 4+ and CD 8' levels as well as CD 4+/CD 8+ ratio, and down-regulating plasma CD 8+ content.

[Observation of course of placental separation by continuous dynamic ultrasonography during third stage of labor].

OBJECTIVE: To investigate the physiologic course of third stage of labor, and to judge the optimal time of natural placental separation permitted. METHODS: To observe and record the course of third stage of labor by continuous dynamic ultrasonography and to estimate the total amount of blood loss from placental separation within two hours after delivery by the method of weighing lost blood. RESULTS: Third stage of labor can be divided into four phases: the latent phase (4.37 +/- 3.78) min, the contraction phase (1.48 +/- 0.97) min, the detachment phase (0.50 +/- 0.00) min, and the expulsion phase (0.62 +/- 2.23) min. In 85% of the puerperas the third stage of labor takes about 10 minutes (average 6.94 minutes). The amount of postpartum hemorrhage and the risk of the patient increased prominently if the time of stage of labor was longer than 10 minutes (P < 0.01). CONCLUSION: The third stage of labor must be limited in 10 minutes to prevent postpartum hemorrhage.

[Inner ear morphological study of guinea pigs with acoustically evoked short latency negative response].

OBJECTIVE: To establish a model of ototoxicity in guinea pigs with acoustically evoked short latency negative response (ASNR) and verify the responsible organ of ASNR based on microscopic characteristics of basal membranes, saccules, utricles and ampulla canalis semicircularis of the inner ear. METHODS: Total of 45 guinea pigs were employed in the experiment, which were randomly divided into the control group (15 subjects, 30 ears) and the deafened group (30 subjects, 60 ears). Each animal experienced auditory brainstem response (ABR). A quick treatment was employed for deafened group consisting of a subcutaneous injection of kanamycin at a dose of 400 mg/kg followed by jugular vein injection of ethacrynic acid at a dose of 40 mg/kg one hour later. The animals were performed ABR test from 7 to 10 days after the drug administration. The deafened group was further divided into ASNR group and non-ASNR group based on the presence of ASNR. All the guinea pigs were sacrificed after ABR tests. The Corti organ, macula sacculi, macula utriculi and crista ampullaris were observed by light microscope. RESULTS: In the deafened group (60 ears), 3 subjects died postoperatively, 27 subjects (54 ears) provided full data. ASNR was elicited in 19 ears (35.2%, 19/54), the thresholds of ASNR were from 110 to 125 dBSPL with average of (121.7 ± 4.5) dBSPL. ASNR latency ranges were 1.80 - 2.08 ms, the average latency of thresholds were (1.93 ± 0.07) ms. The stretched preparation results: overall hair-cell density of macula saccule, macula utriculi and crista ampullaris decreased in order of normal control group, ASNR group and non-ASNR group. There was no difference between the normal group and ASNR group for cell density of macula saccule. Apart from this, statistical differences were found among other groups. CONCLUSIONS: The present study evoked ASNR in an ototoxicity guinea pig model which was profound hearing loss with normal saccular function and normal saccular hair cell density. It suggested that ASNR originates from the saccule and have no relation with cochlear, utricle and semicircular canal according to morphological study.

[Origin of acoustically evoked short latency negative response in guinea pigs].

OBJECTIVE: To establish a model of acoustically evoked short latency negative response (ASNR) in guinea pigs, a model of profound hearing loss with normal saccular functions, and verify the correlation between ASNR and vestibular evoked myogenic potential (VEMP). METHODS: Thirty-two healthy guinea pigs were employed in the experiment, which were randomly divided into control group (16 subjects) and deafened group (16 subjects). Each animal experienced auditory and vestibular tests including auditory brainstem response (ABR), VEMP and caloric test. A quick treatment was employed for deafened group consisting of a subcutaneous injection of kanamycin at a dose of 400 mg/kg followed by a jugular vein injection of ethacrynic acid at a dose of 40 mg/kg one hour later. The animals were received ABR, VEMP and caloric test 7 - 10 days following the drug administration. The deafened group was further divided into ASNR group and non-ASNR group, based on the presence of ASNR. RESULTS: In deafened group, five subjects died postoperatively, 11 subjects (22 ears) provided full data, ASNR was elicited in eight ears (36.4%), the threshold was 120 - 130 dB SPL with mean of (124.4 ± 4.96) dB SPL. Its latency range was 1.75 - 2.60 ms with mean of (2.15 ± 0.27) ms. The mean latency of threshold was (2.34 ± 0.18) ms. All eight ASNR ears presented with VEMP. The VEMP threshold, positive and negative potential latencies proved no statistical difference (P > 0.05) between ASNR group and control group. Significant difference was detected between the VEMP presence of ASNR group and non-ASNR group (P = 0.002). There was no statistically significant correlation between VEMP and caloric test neither between ASNR and caloric test in deafened group. CONCLUSIONS: This study evoked ASNR in an ototoxicity guinea pig model which has profound hearing loss with normal saccular functions. The presence of ASNR correlated with VEMP, however, not correlated with caloric test, suggesting that ASNR and VEMP are both originated from the saccule.