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Cerebral hemodynamic effects of aminophylline in the treatment of patients with hypertensive headaches
Southern
Society for Clinical
CEREBRAL HEMODYNAMIC EFFECTS OF AMINOPHYLLINE IN THE TREATMENT OF PATIENTS WITH HYPERTENSIVE HEADACHES. John H. Moyer and (by invitation) Sam I. Miller, Arthur B. Tashnek and Harvey Snyder. (From the Departments of Medicine and Pharmacology, Baylor University College of Medicine and the Jefferson Davis Hospital, Houston, Tex.) During the course of evaluating the cerebral effect of intravenous aminophylline@ it was noted that this drug gave prompt and complete relief of headaches associated with severe hypertension. For this reason a study on the effect of aminophylline (0.5 gm. intravenously) on cerebrovascular hemodynamics, cerebrospinal fluid pressure and cerebral metabolism was undertaken in nine patients exhibiting hypertensive headaches. Similar studies were conducted in seven patients to whom caffeine (0.5 gm.j was administered instead of aminophylline. Aminophylline caused a significant increase in cerebrovascular resistance and a decrease in cerebral blood flow (mean of 53 for the group reduced to 36 cc./100 gm./minute). Headache was relieved in all those patients in whom the cerebral blood flow decreased. This was also associated with a sharp reduction in cerebrospinal fluid pressure (mean of 210 reduced to 132 mm. water). The mean (group) jugular venous pressure decreased 13 mm. water. Cerebral metabolism as noted in oxygen and glucose uptake was not altered. Caffeine showed similar effects on cerebral dynamics but they were less dramatic and less consistent. These observations were interpreted to indicate that the cerebrospinal fluid pressure is decreased due to a reduction in arterial blood flow into the head, thus reducing the intravascular volume. The relief of headaches is probably due to reduced capillary and perivascular tissue pressure surrounding and distal to the constricted arterioles. HOMOGENOUS RENAL TRANSPLANTS AFTER BILATERAL NEPHRECTOMY. E. E. Muirhead. (From the Department of Pathology, Southwestern Medical School of the University of Texas, Dallas, Tex.) Dogs have been maintained by means of peritoneal irrigation after removal of both kidneys for intervals of approximately twelve or fourteen days. At this time a homogenous kidney was transplanted to the neck of the bilaterally nephrectomized animal and its activity appraised. Following bilateral nephrectomy and-the use NOVEMBER,
1952
Research
649
of peritoneal irrigation, hypertension and a moderate azotemia developed. The implantation of the homogenous kidney was followed by profuse diuresis, a recession of the azotemia to normal level and a precipitous drop in the blood pressure. These changes continued for several days and were followed subsequently by a reappearance of the hypertension and of the azotemia. The specific gravity of the urine from this kidney was increased during the first week but subsequently remained fixed and low. The urine urea concentration dropped from a normal level to a markedly low level. Beginning at approximately ten days, renal function deteriorated until eventually oliguria and anuria appeared during the third or fourth week. Homogenous kidneys have been more effective than peritoneal irrigation for the clearance of nitrogenous waste products up to ten days time. Homogenous kidneys have also affected a recession in the hypertension occurring after bilateral nephrectomy. INTEE-RELAT~ON~~P BETWEEN SPL.~NCHNIC BLOOD FLOW AND SPLANCHNIC METABOLISM. J. D. Myers and (by invitation) W. Jape Taylor. (From the Department of Medicine, Duke University School of Medicine, Durham, N. C.) Considerable experience has been accumulated with splanchnic (hepatic) blood flow (HBF) and splanchnic oxygen consumption (sp 02) under various physiologic and pathologic conditions. The normal sp 02, 58 ml. per minute, is maintained by an HBF of 1,330 ml. per minute and an hepatic A-V oxygen difference (A-V 0,) of 4.4 volumes per cent. These conditions are retained by most persons with Laennec’s cirrhosis, arterial hypertension, diabetes mellitus and erythremia. It is difficult to increase HBF without increasing sp 02. This may at times be accomplished in sudden and large expansion of the plasma volume. In general, HBF is not increased unless sp 02 is elevated (epinephrine, fever) or unless severe anemia is present. Other conditions which elevate sp 02 (hyperthyroidism, chronic leukemia with hepatosplenomegaly, and the intravenous administration of amino acids) do so by increased oxygen extraction (high A-V 0,) without augmenting HBF. These conditions are therefore associated with considerable degrees of unsaturation of hepatic venous blood. Where HBF is significantly reduced (low-output heart failure, some instances of Laennec’s cirrhosis, acute hepatitis and obstructive jaundice, as well
Society for Clinical
CEREBRAL HEMODYNAMIC EFFECTS OF AMINOPHYLLINE IN THE TREATMENT OF PATIENTS WITH HYPERTENSIVE HEADACHES. John H. Moyer and (by invitation) Sam I. Miller, Arthur B. Tashnek and Harvey Snyder. (From the Departments of Medicine and Pharmacology, Baylor University College of Medicine and the Jefferson Davis Hospital, Houston, Tex.) During the course of evaluating the cerebral effect of intravenous aminophylline@ it was noted that this drug gave prompt and complete relief of headaches associated with severe hypertension. For this reason a study on the effect of aminophylline (0.5 gm. intravenously) on cerebrovascular hemodynamics, cerebrospinal fluid pressure and cerebral metabolism was undertaken in nine patients exhibiting hypertensive headaches. Similar studies were conducted in seven patients to whom caffeine (0.5 gm.j was administered instead of aminophylline. Aminophylline caused a significant increase in cerebrovascular resistance and a decrease in cerebral blood flow (mean of 53 for the group reduced to 36 cc./100 gm./minute). Headache was relieved in all those patients in whom the cerebral blood flow decreased. This was also associated with a sharp reduction in cerebrospinal fluid pressure (mean of 210 reduced to 132 mm. water). The mean (group) jugular venous pressure decreased 13 mm. water. Cerebral metabolism as noted in oxygen and glucose uptake was not altered. Caffeine showed similar effects on cerebral dynamics but they were less dramatic and less consistent. These observations were interpreted to indicate that the cerebrospinal fluid pressure is decreased due to a reduction in arterial blood flow into the head, thus reducing the intravascular volume. The relief of headaches is probably due to reduced capillary and perivascular tissue pressure surrounding and distal to the constricted arterioles. HOMOGENOUS RENAL TRANSPLANTS AFTER BILATERAL NEPHRECTOMY. E. E. Muirhead. (From the Department of Pathology, Southwestern Medical School of the University of Texas, Dallas, Tex.) Dogs have been maintained by means of peritoneal irrigation after removal of both kidneys for intervals of approximately twelve or fourteen days. At this time a homogenous kidney was transplanted to the neck of the bilaterally nephrectomized animal and its activity appraised. Following bilateral nephrectomy and-the use NOVEMBER,
1952
Research
649
of peritoneal irrigation, hypertension and a moderate azotemia developed. The implantation of the homogenous kidney was followed by profuse diuresis, a recession of the azotemia to normal level and a precipitous drop in the blood pressure. These changes continued for several days and were followed subsequently by a reappearance of the hypertension and of the azotemia. The specific gravity of the urine from this kidney was increased during the first week but subsequently remained fixed and low. The urine urea concentration dropped from a normal level to a markedly low level. Beginning at approximately ten days, renal function deteriorated until eventually oliguria and anuria appeared during the third or fourth week. Homogenous kidneys have been more effective than peritoneal irrigation for the clearance of nitrogenous waste products up to ten days time. Homogenous kidneys have also affected a recession in the hypertension occurring after bilateral nephrectomy. INTEE-RELAT~ON~~P BETWEEN SPL.~NCHNIC BLOOD FLOW AND SPLANCHNIC METABOLISM. J. D. Myers and (by invitation) W. Jape Taylor. (From the Department of Medicine, Duke University School of Medicine, Durham, N. C.) Considerable experience has been accumulated with splanchnic (hepatic) blood flow (HBF) and splanchnic oxygen consumption (sp 02) under various physiologic and pathologic conditions. The normal sp 02, 58 ml. per minute, is maintained by an HBF of 1,330 ml. per minute and an hepatic A-V oxygen difference (A-V 0,) of 4.4 volumes per cent. These conditions are retained by most persons with Laennec’s cirrhosis, arterial hypertension, diabetes mellitus and erythremia. It is difficult to increase HBF without increasing sp 02. This may at times be accomplished in sudden and large expansion of the plasma volume. In general, HBF is not increased unless sp 02 is elevated (epinephrine, fever) or unless severe anemia is present. Other conditions which elevate sp 02 (hyperthyroidism, chronic leukemia with hepatosplenomegaly, and the intravenous administration of amino acids) do so by increased oxygen extraction (high A-V 0,) without augmenting HBF. These conditions are therefore associated with considerable degrees of unsaturation of hepatic venous blood. Where HBF is significantly reduced (low-output heart failure, some instances of Laennec’s cirrhosis, acute hepatitis and obstructive jaundice, as well