We could be able to obtain Leucocytic pyrogen (LP) from rabbit polymorphonuclear leucocytes (PMN) in vitro, and studied on some physiological properties in comparison with bacterial pyrogen. The following results have been obtained; (1) LP showed a mono-phasic fever curve which has no or short latent period, and did not show any dose-response over the limitted dose. (2) From the preliminary chemical analysis, crude LP consisted of protein, polysaccharide, sodium chloride, and trace of phosphorous and lipid. (3) LP did not cause fever tolerance as unlikely as bacterial pyrogen. (4) LP caused transient leucocytosis in rabbit, but bacterial pyrogen caused severe leucopenia. (5) In leucopenic rabbit response of bacterial pyrogen was decreased, but response of LP was almost unchanged.
Homotaurine (HT) elicited a cardio-stimulant action at high concentration on isolated frog hearts, guinea-pig atria and guinea-pig hearts, though it brought about no actions in the heart lung preparation of dogs. In rabbits, HT showed a mild cardiac-stimulating as well as a hypotensive effect. The hypotensive effect was likewise observed in rats and was shown to be more potent in experimental renal hypertensive rats than that in normal rats. These cardiovascular effects were decreased when it was administered repeatedly. The cardio-stimulant action of HT was retained after administration of adrenergic α and β-blocking agents, and, although HT showed a mild protective effect against the cardio-depressant action of dinitrophenol and large doses of CaCl2, cardiac action of autonomic drugs, CaCl2 and KCl were not affected by HT. From these results, it has been suggested that HT has a hypotensive and a cardiotonic effect, its cardiac effect being due to its direct action.
The relationship between the menbraneous exiability and metabolic activity of frog skeletal muscle was observed. Respiration was increased by a depolarzation and caffeine application below the thresold for producing a contracture, but it was not increased by catecholamine. Ouabain suppressed extro oxygen consumption at low values of depolarization. At higer values of depolarization and caffeine apprication was not suppressed by ouabain. It is proposed that the extra oxygen consumption by potassium depolarization or an application caffeine and anaccompanied by mechanical changes is related to the release of Ca from its bound form.
The masseteric monosynaptic reflex is inhibited with a latency of about 8 msec by conditioning stimulation of the superficial radial nerve (so called the cutaneous inhibition). The mechanism of inhibition was pharmacologically investigated using the three indicators: the masseter MSR at masseter nerve, field EPSP simultaneously recorded in trigeminal motoneuron pool evoked after single shock to the mesencephalic tract nucleus of trigeminal nerve and IPSP recorded (extra-or intracellularly) in the same motoneuron pool produced by the stimulation of the superfical radial nerve in the pentobarbital anesthetized or precollicularly decerebrated cat. The following points warrant consideration: 1) The cutaneous inhibition was prolonged about two times longer than control in time course and the amplitude of this MSR and the field EPSP was diminished after administration of physostigmine 0.15 mg/kg. 2) The field IPSP (N1) was increased in amplitude and became 1.4 times of the control, in addition to that, a new negative going potential (N2) appeared with a delay of about 30 msec following administration of physostigmine which was clearly distinguished from the N1 potential. The prolonged time curses of the cutaneous inhibition of MSR and field EPSP was corresponded to the total duration of N1 and N2 potential. 3) 1 mg/kg of atropine counteracted to these physostigmine effects upon not only the cutaneous inhibition but also the diminution of the MSR. 4) Several other drugs related to acetylcholine were tested. Dihydro-β-erythroidine, d-tubocurarine, gallamine triethiodide did not change the cutaneous inhibition and mecamylamine showed a slight influence upon it. Mephenesine blocked the cutaneous inhibition. Strychnine reversed the field IPSP to the positive potentials. 5) It was found that some reticulospinal neurons located in the Nucleus reticularis gigantocellularis with slow conduction velocity and responsive to the cutaneous nerve shock were sensitive to physostigmine and their enhanced activity was antagonized by atropine. These data suggests, that acetylcholine is related with the synaptic transmission pathway inducing the IPSP in the masseter motoneurone from the cutaneous nerve.
Influence of inflammation on O2 consumption of mouse skeletal muscle and action of non-steroidal anti-inflammatory drug on it were studied. O2 consumption of skeletal muscle was increased by inflammation and non-steroidal anti-inflammatory drug inhibited it without change of P/O ratio.
14C-methylglucose transport in skeletal muscle was decreased by phospholipase C treatment and 14C-methyl-glucose transport in intact skeletal muscle was increased by addition of phospholipid. 14C-methy l glucose transport increased by inflammation was inhibited by anti-inflammatory drug.
Role of phospholipid in O2 consumption of skeletal muscle was studied. O2 consumption of intact skeletal muscle was increased by addition of phospholipid, but O2 consumption of inflamed skeletal muscle was not changed. O2 consumption of skeletal muscle was decreased by phospholipase C treatment and restored by addition of phospholipid.
Role of phospholipid in 14C-α-aminoisobutyric acid transport of skeletal muscle and action of non-steroid anti-inflammatory drug on it were studied. 14C-α-aminoisobutyric acid transport in inflamed skeletal muscle was inhibited by phospholipase C treatment. 14C-α-aminoisobutyric acid transport in intact skeletal muscle was increased by addition of phospholipid. 14C-α-aminoisobutyric acid transport increased by inflammation was inhibited by non-steroid anti-inflammatory drug in vivo and in vitro.