Adrenergic and cholinergic control of oxytocin release evoked by vaginal, vagal and mammary stimulation in lactating rats (author's transl)]

1. The amounts of oxytocin released during Ferguson and vago-pituitary reflexes are estimated by measurements of intramammary pressure. For the milk-ejection reflex, the gain in weight of the young over a period of 30 minutes is taken as an indirect index of the release of oxytocin. 2. Antagonists of specific cholinoceptors and adrenoceptors were injected into the third ventricle in order to delineate the role of the mediators and receptors in the control of oxytocin release. 3. The results suggest that three reflexes have a specific chemical transmission since: a) The Ferguson reflex is inhibited by the drugs that only block alpha and beta adrenoceptors. b) The vago-pituitary reflex is inhibited by the drugs that block alpha and beta adrenoceptors and muscarinic cholinoceptors. c) The milk-ejection reflex is inhibited by the drugs that block alpha adrenoceptors and muscarinic and nicotinic cholinoceptors.     

Assessment of the reflex vagal origin of broncho-constrictor effects of hypercapnia in cats (author's transl)

Breath-by-breath measurements of pulmonary resistance (RL) were used to study the bronchomotor effects produced by the inhalation of a CO2-enriched gas mixture in anaesthetized, spontaneously breathing cats. A significant increase in RL occurred from the second inhalation of the hypercapnic gas mixture. This bronchoconstrictor effect lasted about 18 seconds, then a marked decrease in RL was observed. The secondary bronchodilatation persisted during the entire hypercapnic test (4 min). After surgical suppression of the sensory vagal component at the level of the nodose ganglion (bilateral sensory vagotomy), the early bronchoconstrictor effect of CO2 disappeared, but the secondary bronchodilatation was unchanged. In other experiments, after procaine block of the nervous conduction in non-myelinated vagal fibers, the bronchomotor effects of CO2 were the same as those observed after sensory vagotomy. In contrast, an electrotonic block of both vagus nerves, which abolished nervous conduction in myelinated fibers, did not suppress the bronchoconstrictor response to hypercapnia. Thus, the early increase in RL, which follows inhalation of a hypercapnic gas mixture, seems to be reflexly mediated by vagal afferents, especially by non-myelinated fibers.     

Effect of alloxan in pancreatectomized rats (author's transl)]

Sensitivty to alloxan of pancreatectomized rats is studied injecting on the seventh day after surgical resection with different dose of monohydrated alloxan. Totally pancreatectomized rats develop a strong diabetes just the same as the control group, but the former present higher glycemias and longer survival.     

Multiple osteosarcoma in spontaneously hypertensive rats (author's transl)]

For period from 1971 to 1975, 18 cases of osteosarcoma were experienced among 9132 spontaneously hypertensive rats. The onset was at 72 to 145 days of age and death occurred before 423 days of age. The tumors were multiple being distributed in the skull (11 of 14 cases), caudal vertebrae (8 of 14 cases), and fore- and hind-limb. All the tumors were mainly composed of sarcomatous tissue with some osteoid and cartilage. Metastasis was never observed. Serum A1-P levels of tumor bearing animals were 2 times higher than those without tumor. Bronchiectasis and abscess formation of submaxillary lymph nodes were noted in most affected animals.     

Pattern stimulation and action potential of frog skin (author's transl)]

Experiments were carried out to investigate the relationship between the pattern of stimulus of efferent or afferent nerve and the size of action potential of frog's skin. Two kinds of preparations were used: the excised nerve skin preparation and the spinal preparation. In the range of moderate intervals of stimuli, the size of skin action potential of the nerve-skin preparation became larger with the increase of number of stimuli, (i) during a definite period of stimulation with various frequencies, or (ii) during various long periods of stimulation with constant frequency. The size of potential depended not only on number of stimuli but also on their interval. The latter property may be called pattern-sensitive. In some state of preparation the size of potential evoked by a constant number of stimuli was nearly constant, being independent from stimulus frequencies, that is, pattern insensitive. Both kinds of results were obtained in cases of the spinal preparation. Michaelis-Menten's equation could be applied to describe the relation between the size of potential and the number of stimuli. However, there was no reason to interprete this relation with a simple concentration-effect relationship. Another hypothesis was then testoned on the supposition that the response is composed of sequentially superposed unitary processes each of which was promptly evoked by each stimulus and decayed exponentially. The calculated response curve reasonably fit with the observed data. Slower processes commonly called accomodation were excluded from the present discussion and only the effect of relatively short period of stimulation was examined.     

Modification of the Hoffmann reflex in function of athletic training (author's transl)]

The present study measures the values of the Hoffmann reflex and principally the relationship between the maximum reflex response and the maximum direct motor response (H max/M max) and their evolution. The subjects were athletes, performing aerobic and anaerobic type activities, divided into six groups (swimmers; soccer players; tennis players; sprinters; middle and long distance runners; and nonspecific athletes). The results show the average values of the H max/M max (53%) to be not different from those of nonathletes. When separated into aerobic and anaerobic groups, significant differences were found: the values are significantly inferior for subjects participating in anaerobic sports (37%) whereas we found an increase (from 55-75%) in the relationship for swimmers performing aerobic activities after 3 years of regular training. The results suggest, in accordance with previous authors, the possibility of a correlation between the modifications of the H max/M max and the type of activities (aerobic or anaerobic).     

Electronmicroscopical aspects of endometrial distrophy induced by oral contraceptives (author's transl)]

An electron-optical study on the endometrium of 5 controls and 25 patients subjected during 3-12 months to 0.25 mg norgestrel + 0.05 mg etinil-estradiol association treatment is performed. The most prominent electronmicroscopical features of endometrial changes are described, such as the asynchronical maturation of the epithelium and the stroma, the shorthening of the proliferative and secretory phases and the epithelial involution towards the last days of the cycle. Special emphasis is placed on the zonal distribution of these changes. An increase of the nostocitosis phenomena is reported and its significance as a complementary contraceptive mechanism is discussed.     

Changes of peripheral leukocyte-counts by electrically induced convulsion in rabbits (author's transl)]

Effects of electrically induced convulsion (EIC) in rabbits on peripheral leukocyte-count levels were studied. (1) Leukocyte-counts increased immediately after the EIC (phase-1) and 4 hours later (phase-2). In the examination of blood smear, phase-2 involved the shift to the left in neutrophils. This biphasic curve also showed by administration of convulsants. (2) Both phase-1 and the rise of transitory blood pressure disappeared by muscle relaxation. (3) Immediately after EIC, the circulating blood volume was significantly higher (about 7%, P less than .001) and the hematocrit was also higher. (4) Phase-1 was not affected by selective destruction of adrenergic nerve terminal with 6-hydroxydopamine (6-OHDA). Although, phase-2 was diminished by treatment with both 6-OHDA and reserpine. (5) An increase in leukocyte-counts occurred on the administration of serum obtained from rabbit during phase-2. These results seem to indicate that phase-1 occurs when circulating blood volume is higher due to convulsive muscle construction and thereby marginated granulocytes appear into the circulating blood. Aslo, it might be expected that phase-2 occurs chiefly by mobilizing of leukocytes from the storage pool in the bone marrow into the circulating blood by the humoral factor.     

Concanavalin A induced changes of lymphocyte p-nitrophenylphosphatase (author's transl)]

The effect of K+, Na+, Mg2+ and ATP on the p-nitrophenylphosphatase activity was investigated. As an enzyme preparation a microsomal fraction of sheep lymphocytes was used. Low concentrations of Mg2+, K+ and Na+ increased, whereas high concentrations decreased the enzyme activity. There was an inhibition of activity by ATP without Na+ in the incubation medium and an increase of enzyme activity at low K:Na-ratio. By concanavalin A in a concentration of 15 mug/ml the p-nitrophenylphosphatase activity was increased in intact cells and the microsomal fraction for 30-40%. The activation was not Na+, K+, Mg2+, p-nitrophenylphosphate or ATP dependent.     

Nutritional, cardiac and adrenergic changes induced by swimming training in rats (author's transl)

The effects of training were investigated in male Sprague Dawley rats group (N), fed ad libitum, by measuring the weight increase and food intake of the animals, biochemical parameters (myocardial triglycerides and glycogen levels), mechanical and metabolic properties of the heart, and adrenergic reactions to swimming stress. An other group of rats remaining sedentary served as control (T). Conditioned rats had been submitted to a one hour test swim 6 days a week for 9 weeks. Gradually additional weights were fixed to the thorax. At the end of training, the load reached 6% of the body weight. Both groups were sacrified by decapitation at the same time, thirty hours after the last swimming session. The study of mechanical performances and metabolic properties was achieved with isolated working heart preparation. Adrenergic reactions of swimming stress were evaluated from plasma, heart and adrenal catecholamine concentrations.     

Diaplacental passage of Sarcocystis antibodies in man and rats (author's transl)]

Sera of babies up to the age of 3 months were tested for Sarcocystis antibodies using the indirect immunofluorescence test (IIFT). In addition titre of the Sarcocystis antibody level of litters born to serologic Sarcocystis positive mother rats was compared to those of their mothers. The results are as follows: 1. 45 (= 14.6%) out of 308 sera from babies up to the age of 3 months reacted positively in the Sarcocystis antibody test. 2. 28 (= 62.2%) out of the 45 positive sera were from babies up to 2 weeks old, 13 (= 28.9%) were from babies older than 2 weeks but not more than 4 weeks old, and 2 (=4.4%) each were from babies whose ages ranged from 4 to 8, and 8 to 12 weeks respectively. 3. These babies acquired their Sarcocystis antibodies which decreased in the first 3 months of life from their mothers. 4. Litters born to serologic Sarcocystis positive mother rats also demonstrated Sarcocystis antibodies. The titres of these antibodies were at the same level as their mothers' at birth but reduced gradually so that most of these young rats were negative at the age of 3 months. 5. Suckling rats born to Sarcocystis negative mothers but positive fathers remained negative. 6. Serologic positive mother and father rats still demonstrated Sarcocystis antibodies in the sera at a time when their litters have become negative. 7. Sarcocystis antibodies could be passed onto the newborn from their positive mothers in both man and rats. 8. These antibodies were probably passed onto the newborn through the placenta but their passage through the colostrum and the mother's milk cannot be ruled out.