摘要:

Quinacrine (QC) binds with high affinity to the intracellular storage granules of juxtaglomerular cells (JG‐cells) in the afferent arteriolus of the glomerulus of the kidney. The present study tests whether QC bound to JG‐cells can be released. The cells were stimulated by renal ischemia and hemorrhagic shock combined with immobilization stress. 1 h after onset of renal ischemia QC‐JGI (modified Hartroft&Hartroft 1953) in14C‐QC‐treated rats had decreased to about 40% in the ischemic kidney compared to a not ligated control kidney. The14C‐contents in the ischemic kidney had decreased to 33% of that in the untouched control kidney. Hemorrhagic shock was obtained by bleeding into a reservoir for 15 min or 1 h. Rats who received QC or14C‐QC 1 h before onset of bleeding showed no change in QC‐JGI (15 min shock) or14C‐contents (1 h shock) as compared to controls. This was probably due to formation of new QC‐binding granules, which took up still circulating quinacrine thereby masking a release. If the time between the QC injection and the onset of shock was extended to about 15 h, when circulating amounts of QC are very low, a decrease of QC‐JGI (about 30% of controls) was seen in the kidneys of the shocked rats. The results are compatible with the possibility that QC in vivo bound to granules of JG‐cells could be released together with the content of the granules following stimuli known to induce renin release. Quinacrine‐binding therefore possibly provides a new method to study endocrine cells in the way it has been used in the present study as a m

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1980.tb06640.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

The effect of dibutyryl cyclic AMP (dbcAMP) and PGE2on the content and release of lysosomal and non‐lysosomal enzymes was studied in a bone organ culture system using half calvaria from 6–7–day‐old mice. In parallel the effect of dbcAMP and PGE2on the release of calcium (Ca2+) and inorganic phosphate (P1), glucose consumption and lactate production was also followed. DbcAMP (2.5×10‐‐4M) decreased the telease ofβ‐glucuronidase, β‐N‐acetyl‐glucosaminidase, acid phosphatase, Ca2+and P1during the first day of culture. During the 3rd and 4th day dbcAMP increased all these parameters. In contrast no changes in the release of lactate dehydrogenase (LDH) and alanine amino‐transferase (ALAT) were seen. Glucose consumption and lactate production was not stimulated by dbcAMP until the 3rd and 4th day. On the other hand, PGE2(10‐‐7M) stimulated the release of β‐glucuronidase, β‐N‐acetylglucosaminidase, Ca2+and P1as well as glucose consumption and lactate production already after 24 h and this stimulation was maintained throughout the culture period. No effect by PGE2on the release of LDH and ALAT was registered. The activities of LDH in the bone explants after 96 h of culture were significantly augmented by both dbcAMP and PGE2. It is concluded that bone resorption stimulated by dbcAMP and PGE2, is associated with increased lysosomal e

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1980.tb06641.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Adipose tissue lipoprotein lipase and postheparin plasma triglyceride lipase activities were measured in 28 men differing in their physical training activity. They were divided into 4 subclasses based on their training intensity. The two most active classes (17 subjects) having regular heavy exercise at least 4 times a week were considered as the actively training group, and the other two (11 subjects) classes not training regularly as the control group. In postheparin plasma, the lipoprotein lipase activities were not different between the two groups, whereas training subjects had significantly (P<0.02) lower hepatic lipase activities. Adipose tissue lipoprotein lipase activity was in the training group at about 70% higher level on an average than in the controls (P<0.10). A significant positive correlation (r=0.38,P<0.05) was obtained between the adipose tissue lipoprotein lipase activity and the level of physical activity. Our data suggest that even moderate inter‐group differences in the physical training activity are reflected as measurable alterations in the adipose tissue lipoprotein lipase activity in ma

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1980.tb06642.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Experiments were performed on chloralosed, adrenalectomized cats, paralysed with gal‐lamine and artificially ventilated. Gastric motility was recorded by the balloon method. Efferent stimulation of the cut greater splanchnic nerve, well proximal to the celiac ganglion, could either increase or decrease gastric tone. The excitatory responses called for higher stimulation intensities than the inhibitory ones but were as a rule observed at lower frequencies only (1–4 Hz). They could be abolished by atropine but were not prevented by bilateral vagotomy, hexamethonium nor guanethidine. The latter twodrugs rather reversed inhibitory responses to excitatory ones which exhibited a hyperbolic frequency‐response relationship with maximal effects already at 24 Hz. Heating of a nerve trunk selectively activates thin afferents of the delta group and C‐class. Heating of the greater splanchnic nerve caused an increase in gastric motility which, like that caused by electric stimulation, was not prevented by hexamethonium nor guanethidine; nor was it eliminated by cutting the nerve centrally, nor by vagotomy, while it was abolished by atropine. These results suggest that the excitatory gastric responses to efferent splanchnic nerve stimulation are due to antidromic activation of thin afferent fibres. Their functional significance remains obscure but their peripheral arborizations may convey ‘axon reflexes’ influencing gastrointestin

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1980.tb06643.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

The effect of two convulsants, benzylpenicillin and pentylenetetrazol, was tested in potential clamp experiments on single rat myelinated nerve fibres. 10 mM concentrations did not affect the permeability properties of the nodal membrane. The convulsive action is therefore probably not mediated through changes in the excitability of central axons.

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1980.tb06644.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Using the14C‐deoxyglucose technique, we estimated local glucose consumption in the rat brain (1–CMRgl) in hypoglycemia of sufficient severity to cause cessation of spontaneous EEG activity, and in the recovery period following a 30 min period of such hypoglycemia. After 5 and 30 min of hypoglycemia, 1–CMRglwas markedly reduced in many cerebral structures (cerebral cortices, caudateputamen, thalamus, and hippocampus) but unchanged or only moderately reduced in other structures (cerebellar cortex, hypo thalamus, and pontine grey). The results indicate that differences in 1–CMRglwere caused by regional differences in the true or apparent kinetic constants for glucose transport, or that the consequences of a hypoglycemic derangement of cellular metabolism interfered with glucose transport in some regions. Local CMRglwas markedly heterogenous in the recovery period, induced by glucose administration in animals with a prior (30 min) period of hypoglycemia. In general, a reduced posthypoglycemic glucose consumption was correlated to low 1–CMRglvalues during hypoglycemia. However, the hippocampus provided an exception since its CMRglreturned to control values. A correlation with previous measurement of local cerebral blood flow (1–CBF) demonstrates that regions having a pronounced reduction in 1–CMRglduring hypoglycemia developed a mismatch between blood flow and metabolic rate in the recovery period, the flow showing a disproportio

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1980.tb06645.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

The output of bile and pancreatic enzymes after two mixed meals with different fat content was studied in 16 healthy volunteers of normal body‐weight. A quantitative multiple indicator dilution method was used. The delivery of more fat per time to the duodenum after the fat rich compared to the low fat meal was followed by the emptying of more bile but did not significantly increase the pancreatic response. The ratio between amylase and lipase was constant throughout the course of a single experiment but differed between the subjects. The ratio decreased with an increasing body weight, indicating a relative dominance of amylase over lipase in the lighter and the reverse in the heavy subjects. The same correlation was found when results from a previously reported series with a glucose containing mixed meal were reexamined. It is proposed that long time dietary differences might influence the enzyme composition of the postprandial pancreatic secretio

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1980.tb06646.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

We have used a bidirectional pulsed ultrasound doppler system which measures the instantaneous mean velocity across the lumen of a blood vessel in order to determine the relationship between alveolar Pco2(Paco2) and blood flow in the four arteries supplying the brain in humans. Both high and low Paco2values were explored. Six subjects, 3 males and 3 females (22–40 years) were studied by use of this non‐invasne technique. To increase the Paco2the subjects were breathing 4. 6 and 8% CO2in air. Paco2was reduced by voluntary hyperventilation down to a chosen end‐expiratory Pc value of about 2.2 kPa. We found a linear relationship between arterial blood flow expressed as a percentage of control level and Paco2in the range from 3.3 to 7.3 kPa. At the very lowest Paco2values a levelling off of the response, with flow values of 40 to 45%, was observed. The CO2‐reactivities in the 6 persons varied between 28.1 and 30.0%/kPa. The time course and the magnitude of the flow response were similar in all four a

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1980.tb06647.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Intravenous injections of different doses of tyramine induced hypothermia in the pigeon in the cold and a moderate hyperthermia in the warm environment. The hypothermia was correlated with a dose‐dependent decline in shivering. Hyperthermia was attributed to the chrono‐ and inotropic effects of tyramine. The indirect stimulatory effects of noradrenaline (NA) at the tissue level were studied. Pretreatment with α‐methyl‐para‐tyrosine (α‐MpT) and blocking α‐adrenoceptors with phentolarnine, diminished the hypothermia induced by tyramine in the cold. The results obtained indicate that the release of endogenous NA stimulated by tyramine might result either in hypothermia or hyperthemia, thus resembling similar effects obtained with exoge

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1980.tb06648.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Denervation of the extensor digitorum longus (EDL) muscle of the mouse by either nerve crush or nerve section produced: a reduction of the resting membrane potential (Em), alterations in the properties of muscle fibre action potentials and the development of tetrodotoxin (TTX)‐resistant action potentials. These changes in membrane electrical properties were accompanied by an increase in the endocytic activity of the muscle and an increase in the activities of the lysosomal enzymes cathepsin D and N‐acetylglucos‐aminidase (NAGA). Reinnervation of muscle was indicated at 9 days after nerve crush by the presence of miniature end‐plate potentials. The recovery of membrane electrical properties, beginning with the onset of reinnervation, were not temporally related. The Emincreased in two stages: an early rapid repolarization and a later slower repolarization. The muscle fibers were sensitive to the blocking action of TTX by 12 days after nerve crush, whereas the rate of rise (dV/dt) of the action potential did not approach values of innervated muscles until 21 days. Reinnervation resulted in a decrease in endocytosis and a decrease in the activities of cathepsin D and NAGA toward innervated values by 21 days after nerve crush. The results suggest that membrane alterations after denervation and during reinnervation may occur by endo‐ and exocytosis of membrane constituents and that the lysosomal system may play a role in the breakdown and/or recycling of these s

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1980.tb06649.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY