This report deals with a study of the relative roles that the sympathetic nervous system and adrenal medulla play in the cardiac responses to experimental anemia. T HE study by Nahas 1 and preliminary reports from this and other laboratories suggested that the cardiovascular responses to both acute anemia and acute hypoxia are reduced by adrenalectomy, sympathectomy or autonomic blockade. The following experiments were done to re-evaluate the relative importance of the sympathetic nerves and the adrenal medulla in the cardiac responses of the dog to acute anemia produced by exchanging dog plasma or dextran for equal volumes of whole blood.
METHODSMongrel dogs weighing between 7.7 and 23.6 Kg. were used. Some of these were adrenalectomized several weeks before experiment and maintained on daily intramuscular injections of S ing. of cortisone acetate in saline suspension (Cortone) and 1.5 mg. of desoxycorticosterone trimethylacetate (Percorten trimethylacetate). The diet consisted of meat and fox chow with 0.6 per cent saline for drinking water.For the experiment all animals were maintained under light sodium pentobarbital anesthesia. The adrenalectomized dogs received a slow intravenous infusion of 50 mg. of hydrocortisone sodium hemisuccinate (Solu-Cortef) in 100 ml. of normal saline, and the intact dogs the same volume of saline during the 2.5-hour period that elapsed between the induction of anesthesia and the beginning of the experiment. The mean arterial pressure was recorded on a kymograph by a mercury manometer attached to a cannula in the right femoral artery and the mean pulmonary pressure (PAP) from a saline manometer attached to the catheter in the pulmonary artery. All pressure readings were expressed from the estimated level of the heart, which was arbitrarily chosen as 5 cm. above table level. Cardiac output From the
Reports on the effects of injections of blood fractions from schizophrenic patients into rats have been contradictory. The effects of samples of fresh serum or plasma from a group of chronic male schizophrenic patients and a group of apparently normal subjects have been compared with those of saline on conditioned responses in rats. No significant differences from the pre-injection trials were found with the rat rope-climbing and the conditioned avoidance techniques after any of the injections. Compared to saline, injections of fresh serum or of plasma reduced the responding rate of rats trained on operant schedules. No statistically significant differences could be demonstrated between the effects of the samples from schizophrenic and apparently normal subjects.
The 24-hour excretions of adrenaline, noradrenaline, and 17-hydroxycortico-steroids were measured in normals and in a) acute and b) chronic schizophrenics, (c) non-schizophrenic psychotics, d) psychoneurotic disorders, and e) a miscellaneous group composed primarily of personality disorders. Some patients were studied over a period of time and the changes in hormone excretion and in clinical conditions compared. On comparison between groups, no difference was found in adrenaline and noradrenaline output. Similarly, when the patients were grouped by dominant emotional reaction at the time of test, no significant differences were observed. The acute schizophrenics, however, did show a greater output of free corticoids, but not of total corticoids compared to the normals. When the same patients were studied over a period of time, there appeared to be a relationship between catecholamine excretion and emotional tension and/or stages of illness. Depressed patients showed a decreased adrenaline and noradrenaline output on admission to hospital but only that of adrenaline was significant. Both adrenaline and noradrenaline showed a marked, but not significant decrease in acute schizophrenics after recovery. In the chronic schizophrenics, there was, after four months of withdrawal of tranquillizers, a significant rise in the output of both; the total and free corticoids showed a similar increase which, however, was not significant. Although no significant differences in hormone excretion were observed among the groups studied, other than increased excretion of free corticoids in the acute schizophrenics, the longitudinal studies in several groups suggest significant correlations may occur between changes in clinical condition and/or emotional state and the excretion of some of the hormones measured.
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