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Biomedical subjects

H Gotoh

Publications and source records attributed to H Gotoh.

131 records · Page 8Linked to original sources
PubMed1978

Effect of atropine on cerebrovascular responsiveness to carbon dioxide.

Effects of cholinergic inhibition by atropine on cerebral circulation were studied in 15 baboons anesthetized with sodium pentobarbital. Intravertebral infusion of atropine, 0.1 mg/kg, did not cause any changes in cerebral blood flow (CBF), superior sagittal sinus wedge pressure (SSWP), epidural pressure (EDP), cerebral perfusion pressure, or cerebral vascular resistance under normal conditions. Cerebrovascular responsiveness to carbon dioxide (CO2) inhalation was not influenced by atropine. The presence of cholinergic nerve fibers has been proved in the cerebral blood vessels and the existence of cholinergic mechanism suggested in the brain stem, but it is not likely that the cholinergic nerves have tonic control of cerebral blood vessels in the resting state or affect cerebrovascular responsiveness to CO2. The changes in EDP and those in SSWP showed a very good correlation to each other. There was also a good correlation between the changes in CBF and those in EDP or SSWP.

Animals↗
PubMed1974

A statistical study of optical rotation for synthetic d,l-copolypeptide solutions.

The right-handed helical fraction H(L) in a D,L-copolypeptide chain is evaluated by a simple probability theory for each L-fraction, p. The curves of optical rotation at a single wavelength against p for poly(gamma-benzyl-D,L-glutamate) and D,L-copolyleucine of a series of different D:L ratios in several positive helix-solvents are calculated with a modified semi-empirical Moffitt equation. From the comparison between the rotations calculated by us and observed by Downie et al., it is shown that to reproduce the observed rotations, the minimum number of right-handed helical nuclei or sequences of L-residues appropriate to the Moffitt equation are eight and four for degrees of polymerization 320 and 1860, respectively.

Journal Article↗
PubMedDate not supplied

Bopindolol and its metabolite 18-502 attenuate regional myocardial acidosis during partial occlusion of the coronary artery in dogs.

The effects of bopindolol (a new, nonselective beta-adrenoceptor antagonist) and its active metabolite, 18-502, on the regional myocardial pH during coronary occlusion were studied. Mongrel dogs were anesthetized with pentobarbital and the thorax was opened to expose the heart. The left anterior descending coronary artery (LAD) was incompletely (or partially) occluded so that the LAD flow could be reduced to about one third of the original flow. Regional myocardial pH of the LAD area was continuously measured by a tissue pH monitor. Drugs were injected intravenously 30 minutes after LAD partial occlusion. The myocardial pH in the LAD area decreased in response to LAD partial occlusion (from 7.3-7.4 to 6.72-6.92), and the low pH value was sustained for 60 minutes after LAD occlusion. Atenolol (1 mg/kg) decreased heart rate markedly and attenuated the regional myocardial acidosis induced by LAD partial occlusion. Bopindolol (1 mg/kg) decreased heart rate and 18-502 (0.5 mg/kg) decreased heart rate and blood pressure. Both drugs attenuated to a similar degree the decrease of regional myocardial pH induced by LAD occlusion. In the dog whose heart rate was maintained constant, however, bopindolol (1 mg/kg) did not attenuate the decrease of regional myocardial pH induced by LAD occlusion. These results suggest that both bopindolol and 18-502 attenuate the ischemia-induced regional acidosis of the myocardium as does atenolol, and, hence, have an anti-ischemic action. The beneficial action of bopindolol on ischemia-induced myocardial acidosis is possibly due to a decrease of heart rate, which corresponds to a saving of energy in the myocardial cells.

Acidosis↗