Study on interactions of Nervous and humoral factors on the regulation of respiratory and cardiovascular systems.

Research Project

Project/Area Number	60570048
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	General physiology
Research Institution	University of Occupational and Environmental Health ; UOEH
Principal Investigator	HAYASHIDA Yoshiaki UOEH,School of Medicine,Professor, 医学部, 教授 (40047204)
Project Period (FY)	1985 – 1986
Project Status	Completed (Fiscal Year 1986)
Budget Amount *help	¥1,500,000 (Direct Cost: ¥1,500,000) Fiscal Year 1986: ¥400,000 (Direct Cost: ¥400,000) Fiscal Year 1985: ¥1,100,000 (Direct Cost: ¥1,100,000)
Keywords	Respiratory System / Circulatory System / Sympathetic Nerve / Humoral Factors / Interactions / Rabbit / 無麻酔犬
Research Abstract	Autonomic functions of the body are regulated both through the autonomic nervous system and humoral factors such as hormons, and there are interactions between them. In this project, the interactions of neuronal and humoral factors was studied on the regulations of the respiratory and cardiovascular systems. Anesthetized rabbits and dogs were used in the experiments. Rapid hemorrhage through the catheter inserted into the femoral artery was done for the stimulation of the baroreceptors. Renal sympathetic nerve activities and arterial P <O_2> and PC <O_2> together with respiratory movements were monitored continuously. Catecholamine contents(adrenalin and noradrenalin) in the bood were measured at certain interval of time before and after the rapid hemorrhage. The results of the study are as follows ; 1. Arterial pressure drop by the rapid arterial hemorrhage was regulated between 1 and 2 min thereafter not only through the increase in nerve activities but also through the increase in the … More catecholamine secretions. It was suggested by the experiments of the afferent denervation that there was increase in catecholamine secretions through some mechanisms to greater extents other than that as transmitters. 2.Stimulations of baroreceptors induced increase in P <O_2> and decreace in PC <O_2> through the increments of respiratory movements and suppressed the autonomic nervous activities during 1 to 2 min after rapid arterial hemorrhage. 3. Increase in the autonomic nervous activities was less in comparison to the magnitude of the arterial pressure drop.This result was due to (1) concomittant increase in the catecholamine contents which may inhibit the sympathetic activities. (2) Increased P <O_2> and decreased PC <O_2> which lowered the activites. (3) Inhibitory effects of the anesthetics used in this experiments on the nervous system itself or the receptors and effectors of the cardiovascular systems. Methodological advances were attained in the last project year to use the unanesthetized animals for the study of the autonomic functions. A success of the conscious recording of the renal nerve activities was routinely achieved in the dogs for a long period of time( during about one month). Less