[Birth weight curves of singleton neonates with a gestational age of 24-42 weeks and their regional differences in 11 cities of China: an analysis of 93 720 cases]. / 中国11市93 720例胎龄24~42å‘¨å•èƒŽå„¿å‡ºç”Ÿä½“é‡æ›²çº¿åŠå ¶åœ°åŒºå·®å¼‚ç‰¹å¾.

OBJECTIVES: To develop the birth weight curve of singleton neonates with a gestational age of 24-42 weeks, and to investigate the regional differences of the birth weight curve. METHODS: A total of 11 maternal and child health hospitals with more than 7 000 neonates delivered annually were selected in 11 cities of China (Haikou, Guangzhou, Shenzhen, Liuzhou, Guilin, Quanzhou, Chongqing, Chengdu, Changsha, Ningbo, and Lianyungang), and all live singleton neonates delivered in the 11 hospitals from January 1, 2017 to December 31, 2020 were enrolled for the development of birth weight curves. RESULTS: A total of 93 720 singleton neonates with a gestational age of 24-42 weeks from the 11 cities were included in the study. The reference values of the 3rd-97th percentiles of birth weight of singleton neonates for the total of the 11 cities and for each of the 11 cities were established, and the birth weight percentile curves were drawn. The birth weight curve level of singleton neonates in Shenzhen and Quanzhou was almost the same as the average level of the 11 cities; the birth weight curve level of singleton neonates in Haikou, Guangzhou, Guilin, and Liuzhou was slightly lower than the average level of the 11 cities; the birth weight curve level of singleton neonates in Chongqing, Chengdu, and Changsha was slightly higher than the average level of the 11 cities; the birth weight curve level of singleton neonates in Ningbo and Lianyungang was higher than the average level of the 11 cities. The average birth weight curve level of singleton neonates in the 11 cities were very close to that of China Neonatal Cooperation Network in 2011-2014. CONCLUSIONS: The reference values of the 3rd-97th percentiles of birth weight of singleton neonates for the total of the 11 cities and for each of the 11 cities are developed, which can be used as a reference for evaluating the intrauterine growth of singleton neonates in the region. The level of intrauterine growth of neonates in some cities is different from the national level.

[Birth weights of singleton neonates of 14 Chinese ethnic groups in 11 cities of China]. / 中国11市14ä¸ªæ°‘æ—å•èƒŽå„¿å‡ºç”Ÿä½“é‡ç ”ç©¶.

OBJECTIVES: To develop the birth weight curves of the Chinese Han (26-41 weeks of gestation) and Zhuang (28-41 weeks of gestation) singleton neonates in 11 cities of China, as well as the birth weight means of full-term neonates of 14 Chinese ethnic groups. METHODS: The live singleton neonates who were born in 11 maternal and child health care hospitals from 11 cities of China between January 2017 and December 2020 were classified according to the mother's ethnic group. Birth weight means were calculated for the full-term neonates of each ethnic group. For the Han and Zhuang singleton neonates with a large sample size, the Lambda-Mu-Sigma (LMS) method was used to establish the birth weight percentile curves of the Han and Zhuang singleton neonates with different gestational ages. RESULTS: A total of 105 365 live singleton neonates were included, among whom the Han neonates had the highest number of 84 851 (26-41 weeks of gestation), followed by the Zhuang neonates (12 803 neonates with a gestational age of 28-41 weeks). The neonates of the other Chinese ethnic groups enrolled were live full-term singleton neonates, with a sample size of more than 100 neonates for each ethnic group. The 3rd-97th percentile curves of birth weight were established for the Han singleton neonates with a gestational age of 26-41 weeks and the Zhuang singleton neonates with a gestational age of 28-41 weeks. The birth weight curves of the Han singleton neonates at each gestational age were higher than those of the Zhuang singleton neonates. Birth weight means (3 199-3 499 g) and standard deviations were determined for 14 Chinese ethnic groups, i.e., Li, Mulao, Zhuang, Yao, Dong, Miao, Han, Buyi, Mongolian, Tujia, Yi, Hui, Man, and Korean ethnic groups. The Li ethnic group had the lowest birth weight, followed by the Mulao, Zhuang, Yao, Dong, Miao, Han, Buyi, Mongolian, Tujia, Yi, Hui, Man, and Korean ethnic groups. CONCLUSIONS: The 3rd-97th percentile curves of birth weight are developed for the Han (26-41 weeks of gestation) and Zhuang (28-41 weeks of gestation) singleton neonates in 11 cities of China, and birth weight means are determined for the full-term neonates of 14 Chinese ethnic groups in 11 cities of China, which provides a reference for evaluating the intrauterine growth of neonates in these ethnic groups.

Birth weight curves of twin neonates with a gestational age of 25-40 weeks and their regional differences in 11 cities of China: an analysis of 17 256 cases. / 中国11市17 256例胎龄25~40周双胎儿出生体重曲线及地区差异特征.

OBJECTIVES: To develop the birth weight curve of twin neonates with a gestational age of 25-40 weeks, and to investigate the regional differences of the birth weight curve. METHODS: A total of 11 maternal and child health care hospitals with more than 7 000 neonates delivered annually were selected in 11 cities of China (Haikou, Guangzhou, Liuzhou, Guilin, Quanzhou, Shenzhen, Chongqing, Chengdu, Changsha, Ningbo, and Lianyungang), and all live twin neonates delivered in the 11 hospitals from January 1, 2017 to December 31, 2020 were enrolled for the development of birth weight curves. RESULTS: A total of 17 256 twin neonates with a gestational age of 25-40 weeks from the 11 cities were included in the study. The reference values of the 3rd-97th percentiles of birth weight of twin neonates for the total of the 11 cities and for each of the 11 cities in China were established, and the birth weight percentile curves were drawn. The birth weight curve level of twin neonates in Liuzhou was lower than the average level of the 11 cities; the birth weight curve level of twin neonates in Ningbo was higher than the average level of the 11 cities; the birth weight curve level of twin neonates in Lianyungang was obviously higher than the average level of the 11 cities; the birth weight curve level of twin neonates in other 8 cities was almost the same as the average level of the 11 cities. CONCLUSIONS: The reference values of the 3rd-97th percentiles of birth weight of twin neonates for the total of the 11 cities and for each of the 11 cities are developed, which can be used as a reference for evaluating the intrauterine growth of twin neonates in the region. The level of intrauterine growth of twin neonates in some cities is different from the average level of the 11 cities of China.

A polyamide 6-organic montmorillonite composite sponge by large-scale solution foaming as a reusable and efficient oil and organic pollutant sorbent.

Effective removal of oil spills or organic pollutant oils from water is of global significance for environmental protection. However, traditional techniques usually suffer from the limits of low efficiency and high cost. In this study, sponge-like polyamide 6/organic montmorillonite (PA 6/OMMT) composite absorbents were fabricated through a large-scale solution foaming method. Aqueous sodium carbonate solution was injected into a PA/formic acid solution with well-dispersed nanoclay to generate CO2 and meanwhile initiate the phase separation of PA molecules from the solvent. Both mesopores and macropores existed in the prepared sponges. The effect of OMMT content on the microstructures and adsorption properties was investigated. Upon increasing the OMMT fraction in composite sponges, the pore size decreased and the fraction of mesopore increased. Better adsorption properties were thus obtained. When OMMT nanoplatelets accounted for 10%, the corresponding sponge had an uptake capacity of 12.5-22.1 g g-1 for diverse oils or organic solvents. Moreover, the composite sponges absorbed oils and organic solvents rapidly and reached saturation in 20 s. When it was coated with methyltrichlorosilane (MTS), the static water contact angle on the surface of the sponge increased from 88° to 115°. The selective absorption of oil from an oil/water mixture was improved. A greatly promising approach is provided to make commercial polyamide into highly porous functional materials for the cleanup of large-scale oil spills.

Blended learning in medical physiology improves nursing students' study efficiency.

The rapid development of mobile phones and communication networks is profoundly changing the lives of people in China. With the gradual growth of Wi-Fi on college and university campuses, Chinese schools are setting off a wave of teaching reform combining online material with traditional classroom instruction. We adapted a Chinese University massive open online course physiology course into a private university online course, specifically designed for second-semester bachelor's level nursing students at Taishan Medical University. This online course blended with classroom teaching was offered to 108 freshmen from two parallel reform classes. A third class of 55 students was offered the traditional classroom lecture-based course as a control. Impressive teaching effects were achieved in reform classes, as indicated by significant improvement in student performance on the final examination and positive student feedback. The student surveys showed that 68% of students preferred the blended course over traditional classroom courses. The most highly rated advantages of the blended course were flexible learning time (84%) and improvement of independent study skills (75%). As higher education enters the internet era, exploiting the high-quality cyber resources may be the fastest and most economical way to improve teaching efficiency and enhance students' study experience.

Arecoline excites the contraction of distal colonic smooth muscle strips in rats via the M3 receptor-extracellular Ca2+ influx - Ca2+ store release pathway.

Areca is a Chinese herbal medicine that is widely used for constipation. However the mechanisms of its action are not clear. We investigated the effects of arecoline, the most active component of areca, on the motility of rat distal colonic smooth muscle strips. In longitudinal muscle of distal colon (LMDC) and circular muscle of distal colon (CMDC), arecoline increased the contraction in a dose-dependent manner. Tetrodotoxin (TTX) did not inhibit the effects of arecoline. The contractile response to arecoline was completely antagonized by atropine. 4-Diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP) strongly depressed the response to arecoline, but gallamine and methoctramine did not. Nifedipine, 2-aminoethoxydiphenyl borate (2-APB), and Ca2+-free Krebs solution with EGTA partly inhibited the effects of arecoline. The sum of Ca2+-free Krebs solution, EGTA, and 2-APB completely inhibited the effects of arecoline. The results show that arecoline stimulates distal colonic contraction in rats via the muscarinic (M3) receptor - extracellular Ca2+ influx - Ca2+ store release pathway. It is likely that the action of areca in relieving constipation is due to its stimulation of muscle contraction.

Effective apatinib treatment of pleomorphic liposarcoma: A case report.

RATIONALE: Pleomorphic liposarcoma (PLS) is a rare and aggressive malignant tumor, and both radiation and conventional cytotoxic chemotherapy remain controversial for metastatic or unresectable disease. PATIENT CONCERNS: We presented an 81-year-old Chinese woman with advanced PLS who received apatinib after failure chemotherapy. DIAGNOSES: The patient was diagnosed as having PLS by biopsy. INTERVENTIONS: After a failed chemotherapy, apatinib started to be taken orally 425 mg per day. OUTCOMES: This patient achieved 3-month progression-free survival (PFS) and a higher quality of life. Meanwhile, this patient suffered grade 2 hypertension and grade 3 hand-foot syndrome (HFS). LESSONS: In this case, apatinib presented good efficacy and safety to treat PLS. Randomized clinical studies are required to confirm the efficacy and safety of apatinib in the treatment of PLS.

Arrestin-biased AT1R agonism induces acute catecholamine secretion through TRPC3 coupling.

Acute hormone secretion triggered by G protein-coupled receptor (GPCR) activation underlies many fundamental physiological processes. GPCR signalling is negatively regulated by ß-arrestins, adaptor molecules that also activate different intracellular signalling pathways. Here we reveal that TRV120027, a ß-arrestin-1-biased agonist of the angiotensin II receptor type 1 (AT1R), stimulates acute catecholamine secretion through coupling with the transient receptor potential cation channel subfamily C 3 (TRPC3). We show that TRV120027 promotes the recruitment of TRPC3 or phosphoinositide-specific phospholipase C (PLCγ) to the AT1R-ß-arrestin-1 signalling complex. Replacing the C-terminal region of ß-arrestin-1 with its counterpart on ß-arrestin-2 or using a specific TAT-P1 peptide to block the interaction between ß-arrestin-1 and PLCγ abolishes TRV120027-induced TRPC3 activation. Taken together, our results show that the GPCR-arrestin complex initiates non-desensitized signalling at the plasma membrane by coupling with ion channels. This fast communication pathway might be a common mechanism of several cellular processes.

Sexual differences of the inhibitory effect of ethanol on gastrointestinal motility: in vivo and in vitro studies.

Female brain is more sensitive to the acute exposure of ethanol. This study aimed to investigate the sexual difference of the ethanol-induced inhibition of gastrointestinal motility. Wistar rats were fasted and allowed drinking water only 12 - 18 h before the experiments. In the in vivo experiments, by using an oral radiochromium motility marker, the liquid gastric emptying and intestinal transit were [corrected] measured 30 min after ethanol treatment. In the in vitro study, strips of stomach and duodenum smooth muscle were suspended in organ baths containing Krebs solution, and their isometric contractions were also examined. Systemic administration of ethanol (2 g/kg, i.p.) significantly inhibited the gastric emptying and intestinal transit, and the effect on female rats turned out to be greater than that on the male rats (P < 0.05). In an in vitro study, ethanol (0.38 x 10(-3) M - 1.34 x 10(-3) M) inhibited the motility of gastric antrum and duodenum in rats of both sexes, but there was no sexual difference in the inhibitory effect of ethanol on muscle strips. We concluded that sexual difference of the ethanol-induced inhibition of gastrointestinal motility was not resulted from the smooth muscle itself.

Oxytocin microinjected into dorsal motor nucleus of the vagus excites gallbladder motility via NMDA receptor-NO-cGMP pathway.

Our recent study indicated that, in the dorsal motor nucleus of the vagus (DMV), the N-methyl-D-aspartic acid (NMDA) receptor-nitric oxide (NO)-cGMP pathway participated in the regulation of gallbladder motility in rabbits. Oxytocin (OT) is involved as a neurotransmitter in autonomic regulation. The aim of the present experiments is to investigate the effect of OT microinjected into DMV on the gallbladder motility and the involvement of NMDA receptor-NO-cGMP pathway. A frog bladder connected with transducer was inserted into the gallbladder to record the gallbladder pressure. Microinjection of OT (10-50 nmol/L, 100 nl) dose dependently increased the strength of gallbladder phasic contraction. The excitatory effect of OT (10 nmol/L, 100 nl) was completely abolished by atosiban (10 mmol/L, 100 nl), the specific OT receptor antagonist, but was not influenced by [deamino-Pen(1), O-Me-Tyr(2),Arg(8)]-vasopressin (10 mmol/L, 100 nl), the V(1) receptor antagonist. Pretreatment of ketamine (10 mmol/L, 100 nl), the NMDA receptor antagonist, suppressed the gallbladder motor response to OT; but pretreatment of 6-Cyaon-7-Nitroquinoxaline-2,3-(1H,4H)-Dione (CNQX; 10 mmol/L, 100 nl), the non-NMDA receptor antagonist, did not affect it. Pretreatment of L-NAME (10 mmol/L, 100 nl), the nitric oxide synthase (NOS) inhibitor, or methyl blue (10 mmol/L, 100 nl), the guanylyl cyclase inhibitor, inhibited the excitatory effect of OT on gallbladder motility. Hence, we deduced that the microinjection of OT into the DMV enhanced the gallbladder motility through binding specific OT receptors and activating the NMDA receptor-NO-cGMP pathway.

Progranulin promotes colorectal cancer proliferation and angiogenesis through TNFR2/Akt and ERK signaling pathways.

Progranulin (PGRN) has been shown to be involved in the process of inflammation, wound healing, and cartilage development; and its role in the progression of breast and ovarian cancer is also well established. However, the expression status of PGRN in colorectal cancers (CRCs) and its molecular mechanisms responsible for tumorigenesis have not been addressed so far. Herein, we demonstrated that PGRN was highly expressed and had clinical relevance with CRCs since its overexpression was associated with advanced stages of CRCs, poorer patients' prognosis, and increased expression of proliferation and angiogenesis markers. PGRN up-regulation significantly promoted the expression of Ki67 and vascular endothelial growth factor A (VEGF-A) as well as the growth rate in CRC cell lines, while PGRN down-regulation had the opposite effects. Strikingly, PGRN derived from CRCs could directly induce proliferation, migration, tubule formation, as well as VEGF-A expression in human umbilical vein endothelial cells (HUVECs). Furthermore, we provided mechanistic evidences that the regulation of Ki67 and VEGF-A expression by PGRN was mediated by tumor necrosis factor receptor 2 (TNFR2)/Akt and the ERK signaling pathways in both CRC cells and HUVECs. Taken together, these findings suggested that PGRN could promote proliferation and angiogenesis through TNFR2/Akt and ERK signaling pathways in CRCs, providing the new insight into the mechanism of PGRN in tumor proliferation and angiogenesis.

Effect of oxytocin on contraction of rabbit proximal colon in vitro.

AIM: To investigate the effects of oxytocin (OT) on isolated rabbit proximal colon and its mechanism. METHODS: Both longitudinal muscle (LM) and circular muscle (CM) were suspended in a tissue chamber containing 5 mL Krebs solution (37 degrees ), bubbled continuously with 950 mL x L(-1) O(2) and 50 mL x L(-1) CO(2). Isometric spontaneous contractile responses to oxytocin or other drugs were recorded in circular and longitudinal muscle strips. RESULTS: OT (0.1 U x L(-1)) failed to elicit significant effects on the contractile activity of proximal colonic smooth muscle strips (P>0.05). OT (1 to 10 U x L(-1)) decreased the mean contractile amplitude and the contractile frequency of CM and LM. Hexamethonium (10 micromol x L(-1)) partly blocked the inhibition of oxytocin (1 U x L(-1)) on the contractile frenquency of CM. N(omega))-nitro-L-arginine-methylester (L-NAME, 1 micromol x L (-1)), progesterone (32 micromol x L(-1)) and estrogen (2.6 micromol x L(-1)) had no effects on OT-induced responses. CONCLUSION: OT inhibits the motility of proximal colon in rabbits. The action is partly relevant with N receptor, but irrelevant with that of NO, progesterone or estrogen.

Effects of progesterone on gastric emptying and intestinal transit in male rats.

AIM: To study the dose-dependent of progesterone (P) effect and the interaction between the oxytocin (OT) and P on gastrointestinal motility. METHODS: In order to monitor the gastric emptying and intestinal transit, the SD male rats were intubated via a catheter with normal saline (3 ml/kg) containing Na(2)(51)CrO(4) (0.5 microCi/ml) and 10% charcoal. OT was dissolved into normal saline and P was dissolved into 75% alcohol. RESULTS: Low does of P (1 mg/kg, i.p.) enhanced the gastric emptying (75+/-3%, P<0.05) and high dose of P (5 mg/kg, i.p.) inhibit it (42+/-11.2%, P<0.01). P (1 mg/kg) increased the intestinal transit (4.2+/-0.3, P<0.05) while the higher dose (10-20 mg/kg) had no effect. OT (0.8 mg/kg, i.p.) inhibited the gastric emptying (23.5+/-9.8%, P<0.01). The inhibitory effects of P(20 mg/kg) (32+/-9.7%, P<0.05) and OT (0.8 mg/kg) on gastric emptying enhanced each other when the two chemicals were administrated simultaneously (17+/-9.4%, P<0.01). CONCLUSION: Low dose of P increased GI motility while high dose of P decreased it. During the later period of pregnancy, elevated plasma level of OT may also participate in the gastrointestinal inhibition.

Anatomical and functional study of localization of originating neurons of the parasympathetic nerve to gallbladder in rabbit brain stem.

The present study was to investigate the localization of preganglionic parasympathetic neurons of gallbladder in brain stem by anatomical and functional approaches. Male or female rabbits (n = 11) were anesthetized with sodium pentobarbital (30 mg/kg, i.v.). Cholera toxin B conjugated to horseradish peroxidase (CB-HRP) was injected into the gallbladder wall. Four days later, animals were re-anesthetized and perfused transcardially with paraformaldehyde solution in a 0.1 M phosphate buffer. The rabbit brain was then frozenly sectioned. The sections were processed for HRP label and stained with neutral red. Another group of rabbits (n = 54) were anesthetized by urethane (1 g/kg) after fasting for 18-24 hours, Gallbladder pressure (GP) was measured by inserting a frog bladder filled with normal saline into the gallbladder. Myoelectrical activity of the sphincter of Oddi (SO) was induced by a pair of copper electrodes. A glass tube (30 microm tip diameter) connected with a microsyringe was directed to the dorsal vagal complex (DVC) for microinjection. Majority of retrogradely labeled cells was found bilaterally in dorsal motor nucleus of the vagus nerve (DMV) throughout the length, except the rostral and caudal part. These cells were distributed in subnuclei parvicellularis or mediocellularis of DMV. Some labeled perikarya located in the medial subnucleus of the solitary tract (mNTS). Thyrotropin-releasing hormone (TRH, 1.3 mmol/L, 0.2 microl) microinjected into the rostral portion of the DVC (including DMV and NTS) enhanced the motility of gallbladder and SO. Microinjection of TRH at the middle part of DVC seldom induces excitatory effects on the gallbladder or SO. TRH microinjected into the caudal portion of the DVC elicited weaker response of gallbladder and SO than rostral portion. Our results indicated that DMV is one of the most important original nuclei of gallbladder's vagus nerves and mNTS may be also involved in the control of gallbladder's parasympathetic activity. Neurons that innervate the gallbladder distribute at most part of DVC, and are relatively dense at rostral and caudal position of DMV.

Nucleus raphe obscurus participates in regulation of gallbladder motility through vagus and sympathetic nerves in rabbits.

The aim of the present study is to investigate if the nucleus raphe obscurus (NRO) participate in regulating the gallbladder motility in rabbits. Rabbits were fasted for about 20-24 hours. After anesthetization with urethane, an incision was made at the middle of the abdomen and the gallbladder was exposed. A frog bladder connected with force transducer was inserted into the gallbladder through a small incision at the funds to record gallbladder motility (tonic contraction and phasic contraction). Glutamate and other chemicals were microinjected into NRO through a vitreous tube attached to a microsyringe. We found both the tonic contraction and phasic contraction of the gallbladder were enhanced after the glutamate was injected into NRO. GABA inhibited gallbladder motility if administrated in the same way. Microinjection of ketamine, NMDA (N-methyl-D-aspartate) receptor antagonist, into NRO inhibited the phasic contraction of gallbladder. Administration of CNQX (6-cyano-7-nitroquinoxaline-2, 3-dione), a non-NMDA receptor antagonist, enhanced the gallbladder tonic contraction. Pretreatment of ketamine into NRO attenuated the effect of glutamate, while pretreatment of CNQX had no effect on it. Intravenous injection of atropine or vagotomy completely abolished the effect of glutamate on gallbladder phasic contraction, while intravenous injection of phentolamine or transecting the spinal cord at T3-4 inhibited that on tonic contraction. Intravenous injection of propranolol did not influence the glutamate effect. These results suggested that glutamate in NRO participates in regulating the motility of the gallbladder through NMDA receptor. When excited, the NMDA receptors in NRO enhance the phasic contraction of the gallbladder through vagus nerve and peripheral M-receptors, and enhance the tonic contraction of the gallbladder through sympathetic nerve and peripheral alpha-receptors. GABA in NRO is also involved in the regulation of gallbladder motility.

Endogenous oxytocin excites phasic contraction of gallbladder in rabbits through oxytocin receptor.

These experiments were performed to study the effect of oxytocin (OT) and it's specific receptor on gallbladder motility in rabbits. The fasted New Zealand white rabbits (2.0-2.5 kg) were anaesthetized by urethane (1 g/kg). The gallbladder pressure was recorded continuously to monitor the gallbladder motility. Systemic OT (0.01, 0.02, 0.04 mg/kg, iv) did not affect the gallbladder pressure, but dose-dependently increased the frequency of phasic contraction. Five min after OT administration (0.04 mg/kg, iv), the strength of phasic contraction increased to 0.23 +/- 0.08 mmHg/min (P < 0.01, n = 6). The gallbladder motility returned to normal 15 min later after OT treatment. Intravenous injection of atosiban (0.04 mg/kg, iv), an OT receptor antagonist, decreased the strength of gallbladder phasic contraction but did not affect gallbladder pressure. Pretreatment of atosiban (0.04 mg/kg, iv) completely abolished the systemic OT effect on gallbladder. Vasopressin (VP) (0.1 - 0.5 IU/kg, iv) dose-dependently decrease the gallbladder pressure but did not affect the phasic contraction. MK-329 (0.4 mg/kg, iv), the CCK-A receptor antagonist, L-365, 260 (0.4 mg/kg, iv), the CCK-B receptor antagonist and atropine (0.2 mg/kg, iv), the M receptor antagonist, did not affect the OT effect on gallbladder motility. We suggest that endogenous OT regulates gallbladder phasic contraction through specific OT receptor. This effect is independent of the peripheral CCK and M receptors.

Participation of caudal ventrolateral medulla in the regulation of gallbladder motility in rabbits.

To investigate whether the caudal ventrolateral medulla (CVLM) participates in the regulation of gallbladder motility, we studied the effects of microinjection of L-glutamate and other agents into the CVLM on gallbladder pressure (GP) in anesthetized rabbits. A frog bladder connected with a force transducer was inserted into the gallbladder to record the change of GP. Microinjection of L-glutamate into the CVLM decreased GP, While micnoinjection of gamma-amino-butyric acid (GABA) increased GP. Microinjection of ketamine, a noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist, into CVLM increased GP, while microinjection of 6-cyano-7-nitroquinoxaline-2,3-(1H,4H)-dione (CNQX), a competitive (+/-)-a-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)/kainate receptor antagonist, had no significant effect on GP. The effects of L-glutamate was abolished by ketamine, but not by CNQX. Intravenous injection of phentolamine or transection of the spinal cord eliminated the effects of L-glutamate on GP. These results indicate that [1] CVLM participated in the regulation of gallbladder motility; [2] endogenous L-glutamate in CVLM is involved in the regulation mediated by NMDA receptors, the output of which is sent through sympathetic nerve and alpha-adrenergic receptors.

Arecoline excites the colonic smooth muscle motility via M3 receptor in rabbits.

Arecoline is an effective component of areca (betel nuts, a Chinese medicine named pinang or binglang). The purpose of this study was to investigate the effect of arecoline on the motility of distal colon in rabbits and its mechanisms involved. Strips of colonic smooth muscle were suspended in organ baths containing Krebs solution, and their isometric contractions were examined. The response of smooth muscle to arecoline in colonic strips was recorded. The effects of atropine, gallamine and 1,1-dimethyl-4-diphenylacetoxypiperidiniumiodide (4-DAMP) on arecoline-induced contraction were also observed. Arecoline (1 nM - 1 microM) produced a concentration-dependent contraction in both the longitudinal and the circular smooth muscle of rabbit colon. Atropine (10 microM) abolished the arecoline (80 nM)--induced contraction. M3 receptor antagonist, 4 - DAMP (0.4 microM), abolished the arecoline (80 nM)--related response, whereas M2 receptor antagonist, gallamine (0.4 microM), did not affect the effect of arecoline. These results suggest that arecoline excites the colonic motility via M3 receptor in rabbits.