Changes in growth hormone (GH) release in response to L-dopa, TRH, arginine and LH-RH were studied in 15 patients with acromegaly to investigate the mechanism of so-called “paradoxi-cal decrease” of GH secretion often observed in acromegalics after the administra-tion of L-dopa. Among 15 patients, 11 showed GH increase with TRH, 8 with arginine, and 4 with LH-RH. On the other hand, six out of these 15 patients showed a distinct paradoxical GH decrease after L-dopa administration. Two cases showed an increase in GH on L-dopa as seen in normal subjects. The responses of GH release, either an increase or a decrease, was proved fairly constant when several patients had been examined repeatedly. Changes of GH induced by L-dopa were compared with those by TRH. arginine, and LH-RH. There were no correla-tion between the changes by L-dopa and those by TRH, arginine, and LH-RH when compared simply. But a significant negative correlation (r=-0.861) was found between percent changes by L-dopa and logarithm of increase ratio (peak value of GH after the stimulation/basal value) induced by TRH. More close correlation (r=-0.881) was obtained when the percent changes by L-dopa was compared with log T/A (logarithm of increase ratio on TRH/increase ratio on arginne).This result would imply that paradoxical GH decrease by L-dopa in acromegalic patients is more remarkable when their GH secretion is more responsive to TRH and less responsive to arginine. When this correlation is considered in connection with the reported effects of L-dopa on GH and thyroid stimulating hormone (TSH) in man, the following hypothesis might be proposed: L-dopa has two opposing actions on the hypothalamo-pituitary system; 1) inhibition of TRH release or suppression of GH release from TRH sensitive GH producing cells, and 2) arginine-like facilitation of GH release presumably via the stimulation of GH-RF. The paradoxical GH decrease in acromegalics on L-dopa is explained by the dominance of the former action.
The present study was carried out with an attempt to see what effects would he produced by various patterns of impulse trains other than pulses of a definite frequency in nerve-muscle systems of the crayfish. Single axons of nerves of the opener, the slow closer and the fast closer of the crayfish claw were stimulated and the tension development of muscles were recorded. The impulse trains tested are as follows: (i) the intermittent stimula-tion; e. g., paired (doublet) and triplet stimuli, (ii) the intercalated stimulation during stimulation by constant-frequency pulses and (iii) the adaptational type of stimulation, i. e. a train of pulses of which interval gradually increases as seen in the process of the adaptation in the sensory nerve. Results obtained are as follows. Intermittent doublet stimuli produced a greater tension than the monotonous stimulation of the same average frequency. Repetitive triplet or quadruplet stimuli caused further increments in the tension development. Intercalation of a stimulus during usual monotonous stimulation induced a catch-like effect on the tension. Intercalated triplet stimuli provoked a stronger catch action. With the adaptational type of stimulation, an initial rapid tension develop-ment occurred with a least latency and this was followed by a maintained ten-sion. There are certain temporal configurations of stimuli which produce a greater tension or a more physiologically meaningful time course of tension development. This suggests the significance of nervous coding.
The train of discharge in the nerve in the integrated nervous function is known to have a variable pattern. The question still remains open as to whether the pattern of discharge sequence plays some role like a word in communciation. The present study aimed to investigate the relationship between stimuli with various sequences and responses. The intermittent, intercalated and adaptational types of stimulation were given to the efferent or afferent nerves, and the tension of muscles of a nerve-muscle or a spinal reflex preparations of frogs was recorded. Enhancement of tension was observed when the appropriate intermittent or intercalated stimulation was applied. In the nerve-muscle preparation, this effect was made clearly detectable when the nerve-muscle prepara-tion was equilibrated with calcium-deficient Ringer solution. An appropriate type of adaptational stimulation evoked a rapid and long-lasting tension development which may be of physiological meaning in emergency. This fact may give a guide when man stimulates the nerve to examine the response.
Serum estradiol, progesterone, LH and FSH were concomitantly measured by radioimmunoassay in pre- and post-menopausal women in an attempt to study hormonal changes occurring in menopause. The level of serum estradiol in post-menopausal women was maintained at the same level as in pre-menopausal stage within one year after menopause and thereafter began to decrease to the senile minimal level. On the other hand, the mean serum levels of FSH and LH were elevated gradually after menopause. At the conclusion of this study, it was suggested that the key point of the mechanism of menopause may exist not only in the depletion of ovarian function but in the change of the regulatory mechanism of LH and FSH secretion by aging.
A, B and H(O) blood group antigens in some tissues are readily demonstrable by the specific red cell adherence test (SRCA) which is a modification of Coombs' mixed cell adherence technique. Paraffin-embedded tissue sections obtained from tumors of the urinary bladder were submitted to SRCA. Normal bladder epithelium adjacent to neoplastic lesions and the leukoplakia were found to contain the three antigens. The antigens were completely absent in 18 cases and partially present in one of the bladder carcinoma. It was also suggested that the prognosis of the tumor correlates with the antigen loss. SRCA is sensitive, reproducible and technically easy for detection of tissue antigens, and it would be expected to play a crucial role for demonstration of immunological dedifferentiation in tissues which normally keep the antigens.
Two patients with pancreatic cyst were treated by cystojejunostomy, two others with pancreaticolithiasis by pancreaticojejunoston-iy (side to side), and pancreato-duodenectomy was done in one patient with cancer of the duodenal papilla and in one patient with cancer of the intrapancreatic bile duct. All these patients made uneventful recovery. In all these cases, parotid gland function was found depressed. After the operation, four patients showed normal parotid gland function and in one patient it was abnormally elevated. Thus, as previously reported in animal experiments, the parotid gland function was presumed to return to normal or to be elevated in parallel with the improvement of the pancreatic function or lesions.
To clarify the causes of SFD from the view-point of placental function, investigations were made on feto-maternal amino acid circumstances and on how cyclic AMP behaves in the placenta, particularly in relation to the transport of amino acid across the placenta. Amino acids were measured by gas liquid chromatography (hydrogen-flame ion detector), c-AMP by the binding protein method, adenyl cyclase activity by Krishna's method, and proteins by Lowry's method. Results show: (1) The levels of maternal amino acids were indistinctive between the SFD group and the normal pregnancy group. (2) The feto-maternal ratio of amino acid concentrations (f/m ratio) was lower in the SFD group than in the normal control. (3) The level of c-AMP in the placenta was lower in the SFD group than in the control. (4) The lower level of placental C-AMP in the SFD placenta seems partly attributable to the decreased adenyl cyclase activity. (5) There was a positive correlation (r=0.61) between the content of c-AMP in the placenta and the f/m ratio of amino acid concentrations. These findings suggest a decline in placental active transport of amino acids in SFD; adenyl cyclase and c-AMP in the placenta presumably play a key role in such course.
Experiments were carried out to examine whether the lung acts as a depot for circulating lipid, especially that absorbed from the intestine. When 0.5 ml of triolein was administered orally to rats, the triglyceride content of the lung increased 2-3 hr later, butt its increase in the lungs 2-3 hr later was only of about 1/10 of that in the liver. In the fed state the triglyeeride content of the lung was only about 1/8 of that of the liver. When [3H]palmitic acid was administered orally to mice its uptake by the lung 1 and 2 hr later was 1/25-40 of that by the liver. In the lung, it was incorporated into phospholipid more than into triglyceride, but in the liver it was predominantly incorporated into triglyceride. Most of the lipase activity in both the microsomal and soluble fractions of rat lung appeared to be due to lipoprotein lipase. Fasting did not decrease the lipoprotein lipase activity in either fraction. It was concluded that the lung is not important in removal of triglyceride from the blood, even during fat absorption from the intestine, and that the lung takes up circulating lipid for its own metabolism rather than for storage.
Five cases of malignant insulinoma and 2 cases of benign insulinoma were studied lipid-chemically. Tissues were collected by surgical operation or biopsy under peritoneoscopy. The total lipid was extracted from each tissue, and one part of each total lipid was separated into phospholipid, triglyceride and other lipid fractions by a thin-layer chromatography (TLC) on silica gel. The fatty acid composition and fatty acid content of each lipid fraction were measured by a gas-liquid chromatography (GLC). The most remarkable difference between malignant and benign insulinoma tissues was a higher percentage value of eicosatrienoic acid in the phospholipid of malignant insulinoma tissues when compared with that of non-malignant insulinoma tissues; the values mentioned above distributed between 9. 82 and 3. 32 in 5 malignant cases, but were 2. 89 and 2. 57 in 2 benign cases. Those changes in the phospholipid fatty acid composition of malignant insulinoma tissues may represent one of the mechanisms of malignant growth in the malignant neoplastic tissue.
Sera from children with various clinical categories of hepatitis were examined for hepatitis B surface (HBs) antigen (Ag) by radioimmunoassay and for antibody to HBsAg (anti-HBs) by the passive hemagglutination test. It was found that frequencies of HBsAg and anti-HBs in 56 cases of acute hepatitis were 55% (31/56) and 11% (6/56), respectively. All of 4 patients with chronic hepatitis were found to have persistent HBs antigenemia. As for hepatitis in infant under the age of 6 months HBs Ag was detected in 2 each of 31 cases of neonatal hepatitis and of 15 cases of anicteric hepatitis. The data suggest the importance of HB virus as an etiologic agent of acute and chronic hepatitis in children in this country, however, other agents were supposed to he responsible for hepatitis in early infancy. Anti-HBs Ab was first detected in 15% of a group of children aged from 3 to 5 years in Rishiri Island and in 12% of children aged from 6 to 9 years in Sapporo City. Frequency increased gradually through school age in both areas. Thus, RB virus infection seems to be common in the childhood population in urban as well as rural area of Hokkaido district.
Myocardial metabolism, blood flow distribution within the heart, and coronary and systemic circulations were observed during halothane anesthesia using 15 mongrel dogs. Pao, and Paco2 were maintained near 100 and 40 torr respectively throughout the study. As arterial halothane content increased, most parameters of systemic circulation were depressed significantly. Coronary blood flow was reduced in parallel with myocardial oxygen consumption (MVo2) (r=+0.89, p>0.001). Myocardial contractility decreased significantly as anesthesia deepened. MVo2 and myocardial CO2 production were reduced as arterial halothane concentration rose. Arterial-coronary venous difference in blood oxygen content remained unchanged even in deep stage. Lactate and pyruvate were continuously taken up by the myocardium, although the amounts of uptake were reduced as anesthesia progressed. Calculated excess lactate and redox potential did not show any signs of myocardial hypoxia even in deep halothane anesthesia. Among major hemodynamic parameters, left ventricular dp/dt max showed the closest correlation with MVo2. Microsphere injection method was used to observe blood flow distribution within the heart. Halothane did not influence the distribution significantly and I/O ratio of the left ventricular free wall remained near 1.0 during the study.