摘要:

Mature anadromous char (Salmo alpinus L.) of a specific population were tested in behaviour experiments with respect to attraction effects of smolts of the same population, smolt material, and chemical fractions of that material. The char reaction indicated preference for intestinal contents and possibly bile from own population over skin mucus material and food. Chemical fractions isolated from the intestinal contents were tested for attraction at a concentration of 1.5 × 10‐9g per 1. One of the fractions attracted the mature char. The results are discussed in relation to the “migration pheromone” hypothesis proposed by Nordeng (1971) as being crucial for the return of anadromous salmonids to their home river's spawning g

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1980.tb06508.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Monopolar DC‐recordings were made simultaneously from two positions on the olfactory bulb of chars (Salmo alpinus L.) and graylings (Thymallus thymallus L.) using bile acids and amino acids as olfactory stimulants. The bile acids induced responses with characteristic spatial differences from those of the amino acids. The distribution of responses to bile acids indicated a neuronal activity in the medial part of the bulb. In contrast, amino acids elicit responses in the lateral part of the bulb. Taurine conjugated bile acids were up to 1 000 times more potent as olfactory stimuli than methionine. The results suggest that olfactory receptors are of two types, one responding to bile acids, the other to amino acids. 3‐α‐hydroxysteroids are released from the fish into the water in quantities that suffice for detection by their olfactory system. The odorant potency of the bile acids, their evolutionary history and variability, together with their renowned adherent properties made them interesting candidates for specific signals in the aquatic envir

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1980.tb06509.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Retrograde axoplasmic transport, demonstrated by the “double ligature method” was studied in vitro in the motor neurons of rabbit vagus nerve, labelled with3H‐leucine. When a pressure barrier with a maximal pressure of 30 mmHg, induced by a fluid jet, was applied to a small section of the nerve at 38°C, retrograde flow was partially inhibited. More radioactivity was found in front of the barrier (with respect to direction of flow) than immediately behind it. This observation differs from findings in anterograde transport at the same pressure and tested with a similar technique, where most radioactivity was detected immediately behind the barrier (Hahnenberger

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1980.tb06510.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

The physiological preservation of the tenuissimus muscle preparation in cat during vital microscopy of the microcirculation is assessed, comparing the originally described technique with a modified approach. Differences in the compared techniques include modes of dissection and transillumination, room‐air exposure and moisturizing procedures. The original technique involves extensive dissection, inadequate temperature control and irrigation in open air. The modified technique involves less surgery due to a new illumination system, controlled heating and a Mylar foil cover on the preparation to minimize room‐air influences. Temperature measurements and analyses of energy metabolism (ATP, CP, glucose, G6‐P and lactate) are used as objective criteria of tissue normalcy. The microcirculation and metabolism are evaluated during anesthesia (α‐chloralose) at rest as well as in hemorrhagic shock. In the resting state, muscle temperature drops to 28°C with the irrigation technique, whereas the Mylar technique keeps the temperature at 34–35°C. Neither technique causes deviations in normal metabolism. In shock, however, the temperature in the irrigated tenuissimus muscle falls 8–9°C below deep muscle temperature and there is a significantly attenuated metabolic response to ischemia, while the Mylar preparation follows the changes of unexposed muscle, both in temperature

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1980.tb06511.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Skeletal muscle reactions to hemorrhagic shock were investigated in anesthetized cats (n= 23). The tenuissimus muscle was exposed for vital microscopy and shock was induced by single‐withdrawal of 45% of the blood volume. Muscle microcirculation, energy metabolism and cell membrane potentials were followed over a 2 h period along with blood pressure, hematocrit and blood leukocyte, platelet, glucose, pyruvate and lactate contents. Bleeding usually caused complete cessation of muscle blood flow for 5–20 min, while the animal compensated the blood pressure. Reflex constriction occurred in medium‐sized but not in terminal arterioles. When flow reappeared a marked maldistribution was evident in the capillary bed. Flow remained in 30–50% of the capillaries, permanently or intermittedly. Leukocytes could be found lodged in many arrested capillaries and also adhering to venules in large numbers. Erythrocyte or platelet plugs were not seen in the muscle microvasculature. Glucose and G6‐P contents doubled and lactate increased 5‐fold in muscle tissue during shock. CP was reduced by about 25% while the ATP‐level remained unchanged. Membrane potentials declined 12% in shock and the spread in potentials from adjacent fib

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1980.tb06512.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

The cause of maldistributed capillary perfusion in hemorrhagic shock was investigated in a combined in vivo and in vitro study. The cat tenuissimus muscle was observed by vital microscopy before and after withdrawal of 45% of the blood volume. The induced shock conditions reduced the number of perfused capillaries about 50%. Close examination of the scattered, nonperfused capillaries showed that they remained open and almost invariably contained one or several leukocytes. These cells were usually located at the bulgings of endothelial cell nuclei, and when occasionally dislodged, recirculation immediately occurred. Platelet or erythrocyte aggregates were not seen in the microvasculature in shock. To test whether the trapping of leukocytes reflected an impaired deformability of these cells in shock or was merely a pressure dependent phenomenon, deformability studies were performed on leukocytes in vitro. Central venous blood was drawn before and 2 h after bleeding and leukocytes were separated by sedimentation. The passage‐time of single leukocytes through a glass capillary stenosis at constant driving pressures was used as an index of cell deformability. No qualitative changes in stiffness were found after shock. The distribution of cell passage‐times indicated, however, that the stiffest portion of the leukocyte population was removed from the circulation in sh

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1980.tb06513.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

The interaction between the phase of the breathing cycle and the carotid baroreflex heart rate control was studied in fifteen healthy subjects with special reference to respiratory sinus arrhythmia (RSA). Carotid baroreceptors were stimulated by neck suction. With a standardized breathing pattern, two types of experiment were performed. (A) Neck suction applied in counter phase with the respiratory arterial pressure variations; this reduced the amplitude and shifted the phase of the transmural carotid arterial pressure oscillations but did not influence the RSA. (B) During active as well as ventilator assisted breathing, brief periods of neck suction were applied during either inspiration (insufflation) or expiration. Neck suction during active inspiration did not change the amplitude of the RSA but when applied during expiration, increased it by 6.8 beatsXmin‐1(P<0.001). In the ventilator experiments, neck suction during insufflation and expiration augmented the RSA equally, by 5.3 beatsXmin‐1(P<0.05). The results indicate a decreased sensitivity of the carotid arterial baroreflex during active inspiration, with no equivalent during assisted breathing, and suggest that the change in baroreflex sensibility is a prerequisite for the rise of the

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1980.tb06514.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

The connective tissue of two skeletal muscles having different contractile properties was investigated in trained and untrained rats. The animals to be trained were put to run on a treadmill 5 days a week for 4 weeks. The “slow” m. soleus (MS) showed higher malate dehydrogenase activity but lower lactate dehydrogenase activity compared to the “fast” m. rectus femoris (MRF). When whole muscles were taken into account, the concentrations of both hydroxyproline and hexosamines were higher for MS compared to MRF. In the middle section of MS there were more hexosamines than in that of MRF, but no similar difference existed in hydroxyproline. The histochemical staining of collagen, however, suggested that there is also more internal collagen for MS as against MRF. It can be supposed that collagen of MRF and MS is differently distributed in different muscle connective tissue components. Compared to MS, the solubility of collagen was higher in MRF, whereas no significant difference between the muscles existed in the prolyl hydroxylase activity. The concentrations of hydroxyproline and hexosamines or the solubility of collagen were not affected by the training given, but the activity of prolyl hydroxylase was increased in MS suggesting that the metabolism of collagen may be accelerated by physical t

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1980.tb06515.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

The effects of nerve stimulation on blood flow were studied in the dental pulp of anesthetized cats. Changes in iodide disappearance rate (k‐value) from dentinal cavities were used to determine changes in pulpal blood flow. Electrical stimulation of the distal end of the cut inferior alveolar nerve after α‐adrenoceptor blockade (phentolamine, 3 mg/kg) consistently resulted in a rapid increase in disappearance rate. The first stimulation produced the greatest response (an average increase in k‐values of 60%) and repeated stimulations showed a successive attenuation in response, the fourth stimulation usually having no effect. A progressive decrease in resting k‐values was observed after the first stimulation, indicating an impaired exchange function of the capillary vessels. Systemic pretreatment with propranolol (0.5–1 mg/kg), atropine (3 mg/kg), mepyramine (3 mg/kg) and cimetidine (3 mg/kg) did not influence the rapid increase in k‐values produced by the nerve stimulation. The experiments show that Vasodilatation in the cat dental pulp produced by stimulation of the inferior alveolar nerve is not mediated by common efferent vasodilatory mechanisms and strengthen the hypothesis that the sensory nerve axon reflex mechanism

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1980.tb06516.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1980.tb06517.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY