ABSTRACT
<p><b>OBJECTIVE</b>To observe changes in surface tension of bronchoalveolar lavage fluids (BALF) in rabbits with hyperbilirubinemia and the influence of bile diluents and 5 different bile acids on BALF surface tension to provide better insight into the regulatory role of bile acids on respiratory function.</p><p><b>METHODS</b>Bronchoalveolar lavage with 0.9% normal saline was carried out in 30 male New Zealand rabbits and the surface tensions of BALF were measured. The changes in BALF surface tension was measured in rabbits with hyperbilirubinemia. Different concentrations of bile diluents, normal saline, or water solutions of 5 bile acids were added into the collected BALF to test their influence on the surface tension of BALF.</p><p><b>RESULTS</b>The BALF from rabbits with hyperbilirubinemia showed a significantly increased surface tension (P<0.05). The bile diluents (1:15, 1:10, and 1:5) added into the BALF increased the surface tension of the BALF by 21.15%, 26.09%, and 19.64%, respectively. Among the water solutions of the 5 bile acids, UDCA produced no significant influence on the surface tension of BALF while CDCA, CA, LCA, and DCA increased the surface tension by 16.10%, 21.66%, 14.21%, and 13.05%, respectively.</p><p><b>CONCLUSION</b>The surface tension of BALF increases significantly during hyperbilirubinemia. Bile diluents as well as the free bile acids CDCA, CA, LCA and DCA, but not UDCA, can increase the surface tension of BALF, suggesting that these bile acids may emulsify pulmonary alveolar surfactants to increase the alveolar surface tension.</p>
Subject(s)
Animals , Male , Rabbits , Bile , Bile Acids and Salts , Bronchoalveolar Lavage Fluid , Pulmonary Surfactants , Surface TensionABSTRACT
<p><b>OBJECTIVE</b>To compare the patterns of respiratory function variations resulting from the classical reflex of blood pressure fall and high blood levels of bile acid, so as to provide evidence for the regulation of respiratory function via bile acids.</p><p><b>METHODS</b>Seventy New Zealand male Rabbits, under general anesthesia with 20% urethane, were subjected to tracheal intubations and carotid artery cannulations via median incisions of the neck. Using a biological signal acquisition system, the changes in the breathing and blood pressure were observed in response to stimulation of the pneumogastric nerves or to ear vein injections of diluted bile acids or the water solutions of 5 dissociated bile acids.</p><p><b>RESULTS</b>Stimulation of the pneumogastric nerves and injections of diluted bile acids both lowered the blood pressure without significant differences in the total reaction time (T). However, the total respiratory reaction time of bile acids, RT(bile acids), was 9-10 times longer than the total reaction time of blood pressure T(bile acids) (P<0.001). The peak-peak values of respiratory range RR(bile acids) were higher than that RR(pneumogastric nerves)resulting from the classical reflex (P<0.001). In the interval of RT1(bile acids), the values of RR(bile acids) were significantly higher than those of RR(bile acids) in RT2(bile acids) interval. UDCA produced no significant influence on blood pressure or respiratory function (P<0.05) as the other 4 dissociated bile acid reagents did (P<0.001).</p><p><b>CONCLUSION</b>High blood levels of bile acids not only act through reflex factors but also have direct effects on respiratory function regulation. Under our experimental conditions, UDCA has no effect on blood pressure or respiratory function, but the other 4 dissociated bile acid reagents can all dose-dependently lower blood pressure and significantly affect respiratory function.</p>
Subject(s)
Animals , Male , Rabbits , Bile Acids and Salts , Blood , Blood Pressure , Reflex , Respiratory Function Tests , Vagus NerveABSTRACT
AIM: To study the effects of L-arginine on sebaceous gland hyperplasia in rats. METHODS: 10 mg?kg -1?d -11 of L-arginine was poured into the stomach in Sprague-Dawley rats for 7-14 d. The pathology phenomenon was observed in the rat skin. RESULTS: The backside skin of the male SD rats showed dewiness, greasiness and engrained yellow. The incidence was 100% for 7 d in the male SD rats, 80% in the female SD rats for 14 d, but 100% in the immature female SD rats for 14 d. CONCLUSION: L-arg nine can facilitate the hyperplasia of sebaceous gland in SD rats.
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AIM: To observe the effect of L arginine on blood pressure (BP) in stress rats. METHODS: Thirty rats were divided into three groups. L ARG+stress group: L arginine was added in drinking water and electric stimulus were given intermittently in rat foot plate for 15 days; stress group: electric stimulus was given as above; control group: no stress. The BP levels of tail artery were measured per two days, and the concentrations of nitric oxide (NO) of plasma were detected on 15th day. RESULTS: There were significantly differences on BP between control group and stress group in the 9th,11th,13th,15th day(P
ABSTRACT
AIM: To study the changes of NO concentrations of different ti ssues in stress rats. METHODS: Add stimulation with experiments employed electric food-shock and noise of busser as stressor for 15 days in SD rats,NO concentrations and BP were measured. RESULTS: In stress group, BPs increased before and after stress stimulation,but decreased levels NO concentrations of plasma, and there was no detectable amounts of NO in auricl e, ventricle, vessel and adrenal. In stress +L-arg group, BPs d id not increase before and after stress stimulation, NO concentrations of plasma increased, but auricle, ventricle, vessel and adrenal maintained the concentrat ions of NO. CONCLUSION: The stress stimulation can increase BP a nd low NO concentration, and L-arg can resist the response.