AIMTo investigate the role of motilin in paraventricular nucleus (PVN) of hypothalamus on the regulation of gastric motility and the mechanism.

METHODSImmunohistochemistry and microinjection of motilin into PVN were used to observe motilin neural cells in PVN, the neural path between PVN and dorsal vagal complex (DVC) and the changes of gastric motility in conscious rats.

RESULTS(1) There were motilin immunoreactive-cells in PVN and a significant increase was found in groups of fasting and HCL-perfusion into duodenum. (2) HRP-positive cells were found in PVN after microinjection HRP into dorsal nucleus of vagal nerve. It proved that there was neural relationship between PVN and DVC. (3) The amplitude and frequency of gastric motility increased significantly by microinjection motilin into PVN in conscious rats. The effects produced by motilin could be abolished by vagotomy.

CONCLUSIONAll these results presented imply that motilin in PVN may increase gastric motility through PVN-DVC-Vagal nerve axis.

Animals ; Female ; Gastrointestinal Motility ; physiology ; Hypothalamus ; physiology ; Male ; Motilin ; physiology ; Paraventricular Hypothalamic Nucleus ; physiology ; Rats ; Rats, Wistar

Animals ; Benzodiazepines ; pharmacology ; Ducks ; physiology ; Growth Hormone ; blood ; Insulin-Like Growth Factor I ; metabolism ; Serum ; metabolism ; Weight Gain ; drug effects

AIMTo observe the effect of cold stress on the splenic NK cell activity and the c-fos expression in rat brain.

METHODSRats were maintained in cold chamber at 4 degrees for 4 h. The 51Cr release assay from YAC-1 cells was used to determine the splenic NK cell activity and the double staining of ABC method was employed to observe the immunoreactive expression of Fos, arginine-vasopressin and tyrosine hydroxylase.

RESULTSCold stress could induce a marked suppression of splenic NK cell activity and a significant expression of Fos protein in hypothalamic paraventricular nucleus(PVN), as well as in the brainstem locus coeruleus (LC). Double staining showed c-expression of Fos and arginine-vasopressin in some of PVN neurons, and co-expression of Fos and tyrosine hydroxylase in the majority of LC neurons.

CONCLUSIONThe vasopressinergic neurons in PVN and the catecholaminergic neurons in LC might be probably involved in the suppression of splenic NK cell activity induced by cold stress.

Animals ; Arginine Vasopressin ; metabolism ; Brain ; metabolism ; Cold Temperature ; Killer Cells, Natural ; metabolism ; Male ; Proto-Oncogene Proteins c-fos ; metabolism ; Rats ; Rats, Wistar ; Spleen ; cytology ; immunology ; Stress, Physiological ; Tyrosine 3-Monooxygenase ; metabolism

Animals ; Asthma ; physiopathology ; Disease Models, Animal ; Mice ; Mice, Inbred BALB C ; Respiratory Function Tests ; instrumentation

AIMTo investigate membrane electro-physiological features in vestibular ganglion neuronal population using a voltage-sensitive dye and optical recording technique.

METHODSDissociated and cultured mouse vestibular ganglion neurons were stained with an absorption voltage-sensitive dye, RH 155, and were imaged in 16 x 16 elements Photodiode arrays (PDA) optical recording system.

RESULTSWhen the cells were depolarized during perfusion with 150 mmol/L potassium solution, optical absorption of the dye that bound to the external surface of neuron membranes increased. The relative ratio (delta I/I) of optical absorption change was 0.23% +/- 0.08% (x +/- s, n = 28). These optical responses were wavelength dependent. Under our experimental conditions, photo toxicity and pharmacological effects of the dye were either absent or insignificant.

CONCLUSIONOur results suggest that optical recording provides a new, practical and less toxic method to simultaneously monitor changes in membrane potential from several cultured vestibular ganglion cells.

Action Potentials ; physiology ; Animals ; Cells, Cultured ; Female ; Fluorescent Dyes ; Male ; Membrane Potentials ; physiology ; Mice ; Mice, Inbred ICR ; Neurons ; physiology ; Patch-Clamp Techniques ; methods ; Vestibular Nerve ; physiology

AIMTo investigate the influence of the vagus nerve on the electrophysiological properties in the Mauthner cell soma and the relationship between soma and viscus.

METHODSThe microelectrode recording technique was used to explore the electrophysiological properties in the Mauthner cell when stimulating the right vagus.

RESULTSAt lower stimulation strength a graded and compound excitatory postsynaptic potentials (EPSP), formed by two components with lower amplitude, were recorded on the Mauthner cell in a crucian carp. As the intensity of stimulus increased, the amplitude became larger and lasting time longer. With the stimulations high enough, action potentials (AP) were evoked on the EPSP.

CONCLUSION(1) Action potential can be induced on M cell by a direct stimulation on vagus nerve, which is in controversy with previous reports. (2) The neural pathway projecting from vagus to M cell is composed of a set of neuronal chains with excitatory and/or inhibitory members, the activation of M cell depends on the relationship between excitatory and inhibitory neuron.

Animals ; Carps ; physiology ; Excitatory Postsynaptic Potentials ; physiology ; Microelectrodes ; Neurons ; physiology ; Vagus Nerve ; physiology

AIMTo know the effect of cysteamine on the pancreatic secretion and enzyme activity in geese.

METHODSEight adult geese fitted chronic pancreatic and duodenal cannulas were used to evaluate the effect of cysteamine (CS) on the pancreatic secretion and enzyme activity. The experiment was consist of control and treated phase. CS was added in the diet at the dosage of 100 mg/kg bw on the first day of treated phase. The birds were free fed at daytime (8:00-20:00) and fasted at nighttime (20:00-8:00). The pancreatic juice samples were collected continuously for three days in each phase.

RESULTSCS increased the average rate of pancreatic secretion by 240.16% (P < 0.01), in which that of daytime was elevated by 234.45% (P < 0.01), while that of nighttime elevated by 253.70% (P < 0.01). The secretion volume at daytime was more than that of night. CS increased trypsin activity by 49.05% (P < 0.01), whereas lipase and amylase activity was reduced by 25.44% (P < 0.01) and 21.95% (P < 0.01) separately. The one hour total activity of trypsin, lipase and amylase were elevated by 406.88% (P < 0.01), 153.58% (P < 0.01) and 166.59% (P < 0.01) respectively. Ratios of pancreatic secretion were different between day and night.

CONCLUSIONThese results indicate that CS can affect the pancreatic juice secretion and pancreatic enzyme activity by depleting the somatostatin, so that benefits to improve the digestive foundation and supply more nutrition for quickly growing in geese.

Animals ; Cysteamine ; pharmacology ; Geese ; physiology ; Pancreas ; drug effects ; enzymology ; secretion ; Pancreatic Juice ; secretion ; Pancreatin ; metabolism

AIMTo study the effect of bupleurum root on epileptic seizure.

METHODSThe rabbits and rats were injected by pilocarpine as epileptic models, and observed the effect of bupleurum on the electroencephalogram (EEG) and hippocampal slice by electroencephalograph and glass microelectrode extracellularly.

RESULTSThe seizure time and duration of each major seizure of epilepsy were significantly shortened and the interval of seizure significantly prolonged (P < 0.05) after intraabdominal injection of bupleurum root. After instilling the injection of bupleurum root onto the slices could reduce the amplitude of evoked field potential in epileptic hippocampal slices remarkably, the average of fall is 20.41%, and restore in 6.86 minutes on average (P < 0.001).

CONCLUSIONBupleurum root can inhibit the brain electrical activities in epileptic model, it is suggest that bupleurum has the distinct effect of antiepilepsy.

Animals ; Brain ; physiopathology ; Bupleurum ; Disease Models, Animal ; Electroencephalography ; Epilepsy ; physiopathology ; In Vitro Techniques ; Plant Extracts ; pharmacology ; Rabbits ; Rats ; Rats, Wistar

AIMTo study the regulation effects of Momordica saponins on endocrine function in senile mice.

METHODS15-month Kunming mice (female), were divided into senile control group (SC), experimental group 1 and 2 (E1 and E2). 10 4-month mice were as young control group (YC). All mice were fed with general foodstuff, SC and YC drank tap water, while two experimental groups drank tap water supplied to 100 mg/L and 200 mg/L Momordica saponins respectively. Serum was assayed after 5 weeks. At the same time, levels of estrogen receptor and its mRNA were assayed in cultured thymocyte from 12-month rat.

RESULTSSerum ACTH and estradiol levels declined markedly in senile mice compared with young mice. ACTH levels increased in some extent in two experimental groups, while there had significant difference only in E2. Serum estradiol increased obviously, but there was no significant distinct between E1 and E2. The most important was that ER levels increased obviously, and there was no any change of ER mRNA levels in rat thymocyte cultured in medium contained different content of Momordica saponins.

CONCLUSIONMomordica saponins could improve endocrine function in senile mice by increasing ACTH level and expression of ER.

Adrenocorticotropic Hormone ; metabolism ; Aging ; drug effects ; Animals ; Female ; Mice ; Mice, Inbred Strains ; Momordica ; chemistry ; Receptors, Estrogen ; metabolism ; Saponins ; pharmacology ; Thymocytes ; drug effects ; metabolism

3T3 Cells ; Animals ; Cell Membrane ; metabolism ; Mice ; Patch-Clamp Techniques ; Potassium Channels, Calcium-Activated ; radiation effects ; Radiation, Ionizing ; Wound Healing ; radiation effects