| 1. |
- Lundquist, Ingmar, et al.
(författare)
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Monoamines in pancreatic islets of guinea pig, hamster, rat, and mouse determined by high performance liquid chromatography
- 1989
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Ingår i: Pancreas. - 0885-3177. ; 4:6, s. 662-667
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies on the occurrence of catecholamines and serotonin in pancreatic islets using various histochemical and chemical methods have given widely different results. We therefore performed a comparative analysis of these amines in whole pancreas and islet tissue from hamster, guinea pig, rat, and mouse by the use of high performance liquid chromatography. Whole pancreas of guinea pig, hamster, and rat had a norepinephrine concentration of approximately 1.1 [mu]mol/kg of pancreatic wet weight. The mouse pancreas had less than one-half of that concentration. Epinephrine and dopamine concentrations were on the order of 0.02 [mu]mol/kg of pancreatic wet weight in all four species. The serotonin concentration was 2.1 [mu]mol/kg of pancreatic wet weight in the guinea pig pancreas and approximately 0.2 [mu]mol/kg in the other three species studied. The catecholamine concentrations were much higher in the pancreatic islets than in the exocrine pancreas. Thus, the norepinephrine concentration was approximately 35 [mu]mol/kg of islet wet weight in hamster islets and 5-10 [mu]mol/kg in rat, guinea pig, and mouse islets. The epinephrine concentration in islet tissue ranged between 1 and 7 [mu]mol/kg of islet wet weight and the dopamine concentration between 0.5 and 4 [mu]mol/kg except for guinea pig islets (12 [mu]mol/kg). The islet tissue in the mouse, rat, and guinea pig contained disproportionately more epinephrine and dopamine relative to norepinephrine than did the exocrine pancreas. Chemical sympathectomy (6- hydroxydopamine treatment) in the mouse reduced the norepinephrine and epinephrine concentrations in islet tissue to nondetectable levels, whereas the dopamine concentration was essentially unchanged, thus suggesting an extraneuronal source of this amine in addition to its occurrence in adrenergic nerves. The islets of hamster, rat, and mouse contained no serotonin, whereas guinea pig islets contained approximately 275 [mu]mol/kg of islet wet weight. We conclude that, although species differences exist, the pancreatic islets have markedly higher levels of catecholamines than the exocrine pancreas, and that serotonin occurs in the exocrine pancreas of all four species studied but in the endocrine pancreas only in the guinea pig.
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| 2. |
- Agardh, Elisabet, et al.
(författare)
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The prevalence of retinopathy and associated medical risk factors in type I (insulin-dependent) diabetes mellitus
- 1989
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Ingår i: Journal of Internal Medicine. - 1365-2796. ; 226:1, s. 47-52
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Tidskriftsartikel (refereegranskat)abstract
- The prevalence of diabetic retinopathy and the associated medical risk factors, such as age at onset and duration of diabetes, metabolic control, blood pressure, albumin clearance and serum creatinine, were studied in 501 patients with type I diabetes mellitus. The prevalence of retinopathy, characterized as simplex, maculopathy, preproliferative, and proliferative, was 60.5%. Patients with retinopathy were younger at the onset of diabetes, and had a longer duration of disease. In patients with more than 10 years of diabetes, proliferative retinopathy was more frequent if onset was before they were 15 years old, despite the fact that the duration of diabetes did not differ. Patients with severe retinopathy had worse metabolic control, and were more frequently treated for hypertension. In addition, the systolic blood pressure was elevated in all groups of patients with any type of retinopathy, whereas the diastolic blood pressure was elevated only in patients with more severe forms. Patients with severe retinopathy also had higher levels of albumin clearance.
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| 3. |
- Torffvit, Ole, et al.
(författare)
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Exercise stimulation in insulin-dependent diabetics, normal increase in albuminuria with abnormal blood pressure response
- 1987
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Ingår i: Scandinavian Journal of Clinical & Laboratory Investigation. - 1502-7686. ; 47:3, s. 253-259
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Tidskriftsartikel (refereegranskat)abstract
- Increased urinary albumin excretion rate (AER), microalbuminuria, has been regarded as a sign of incipient nephropathy. The influence of exercise on AER was investigated in 10 male type I diabetics and in 12 age-matched male controls. The duration of diabetes was 7-31 years (median 14 years). The exercise tests were performed both as a combined submaximal workload-waterload test and as a maximal workload test. Urinary albumin was measured with an ELISA technique. During exercise in both tests, no difference was seen in the AER between diabetics and their controls. However, the increase in systolic blood pressure was significantly more marked in the diabetics. There was no correlation between the blood pressure response during exercise and the AER, neither in the diabetics, nor in their controls. It is concluded, that, increased blood pressure response during exercise does not necessarily result in increased AER in type I diabetics.
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| 4. |
- Andersson, Sven
(författare)
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Cardiovascular responses to intravenous calcitonin gene-related peptide (CGRP) in the albino rabbit
- 1989
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Ingår i: Acta Physiologica Scandinavica. - 0001-6772. ; 137:2, s. 279-290
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Tidskriftsartikel (refereegranskat)abstract
- The regional sensitivity of different vascular beds to i.v. CGRP was investigated in the albino rabbit by using the microsphere method. Experiments were performed without pre-treatment on both conscious and pentobarbital-anaesthetized animals. In addition, in one series on conscious animals, rabbits were pre-treated with indomethacin in order to reduce the formation of prostaglandins. In another series, anaesthetized rabbits were subjected to ganglionic blockade with hexamethonium bromide in order to abolish reflexes involving the autonomic nervous system. 120 pmol kg-1 of CGRP was given to all the animals, the conscious animals receiving the peptide in one infusion lasting 4 min. In the anaesthetized animals, the dose was divided into first a 5-min infusion of 30 pmol kg-1 followed some minutes later by a 3-min infusion of 90 pmol kg-1. The most pronounced vasodilatory effects were seen in the pancreas, gallbladder, stomach, duodenum, tongue, teeth and the conjunctiva/nictitating membrane. In some series marked effects were also seen in the dura mater, choroid plexus and some parts of the brain. In the anaesthetized animals almost no statistically significant effects on local blood flows were seen following the first, smaller, dose, but following the larger dose more pronounced effects were observed. Pre-treatment with indomethacin did not to any great extent affect the responses, which contradicts the involvement of prostaglandins. The pattern of the responses was unaffected by the ganglionic blockade, but the variability of response was reduced. In conclusion there are great regional variations in the sensitivity to circulating CGRP. The patterns shows a resemblance to that obtained in other species, but there are some marked differences, The tissues most susceptible to the peptide are those easily exposed to noxious stimuli and containing CGRP in the sensory nerve endings, observations in agreement with the proposed role for the peptide in neurogenic defence mechanisms.
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| 5. |
- Andersson, Sven, et al.
(författare)
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Effects of intravenous calcitonin gene-related peptide (CGRP) and substance P on the blood-aqueous barrier in the rabbit
- 1989
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Ingår i: Acta Physiologica Scandinavica. - 0001-6772. ; 135:3, s. 349-357
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Tidskriftsartikel (refereegranskat)abstract
- The irritation response of the rabbit eye to trigeminal nerve stimulation, which includes a breakdown of the blood-aqueous barrier (BAB), seems to be due to the release of substance P (SP) and calcitonin gene-related peptide (CGRP). In order to assess the relative importance of these two peptides for the barrier effect, and the role of arachidonic acid metabolites (AAM) in the response, we have studied the effects of intravenous injections of the peptides on the permeability of the blood vessels of the anterior uvea and the BAB using labelled albumins. At a dose of 120 pmol kg-1 there was marked leakage of labelled albumin into the aqueous humour in animals under pentobarbital anaesthesia. The leakage was enhanced by sympathotomy. In conscious animals 5 pmol kg-1 CGRP caused enhanced leakage from the blood vessels of the ciliary processes in those pre-treated with biperiden in order to abolish the cholinergic vasoconstrictor tone in the anterior uvea. 24 and 120 pmol kg-1 CGRP caused marked leakage of albumin and a breakdown of the epithelial part of the BAB. These effects were not modified by biperiden pre-treatment, but markedly reduced by pre-treatment with indomethacin. The protecting effect of indomethacin was lost when biperiden was given as well. SP did not cause a leakage with 5 nmol kg-1 and only moderate leakage with 25 nmol kg-1. This effect was abolished by pre-treatment with indomethacin but not if indomethacin was combined with biperiden.(ABSTRACT TRUNCATED AT 250 WORDS)
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| 6. |
- Andersson, Sven
(författare)
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Effects of intravenous calcitonin gene-related peptide (CGRP) on local blood flow in the cat
- 1989
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Ingår i: Acta Physiologica Scandinavica. - 0001-6772. ; 137:2, s. 259-270
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Tidskriftsartikel (refereegranskat)abstract
- The effects of i.v. calcitonin gene-related peptide (CGRP) on regional blood flow, vascular resistance, heart rate and cardiac output in cats were studied using the microsphere method. Three series of experiments were performed. In the first there was no pre-treatment of the animals. In the second the animals were pre-treated with indomethacin (5 mg kg-1) in order to prevent the formation of prostaglandins. In the third series the ganglionic blocking agent hexamethonium bromide (80 mg kg-1) was given in order to prevent autonomic reflexes. CGRP was given as an i.v. infusion. Two doses were tested in each series. Animals with no pre-treatment and those pre-treated with indomethacin received first 60 pmol kg-1 infused over a 5-min period and then 180 pmol kg-1 infused over a 3-min period. Animals under ganglionic blockade received the same dose as the total infusions in the other series (240 pmol kg-1) infused over 4 min and a second infusion of 1.2 nmol kg-1 over 5 min. Vasodilatory effects were observed in most of the tissues tested, but there were marked differences in sensitivity. The most sensitive tissues seemed to be the lacrimal, submandibular and parotid glands, the nictitating membrane, the tongue and the gallbladder. The patterns of sensitivity were similar in all the series, indicating that neither prostaglandins nor autonomic reflexes were involved in the effects. In experiments with animals under ganglionic blockade, an increase in blood pressure, concomitant with an increase in heart rate, was seen 5 min after the infusions ended. Thus, it is likely that the peptide exerts a direct positive chronotropic effect on the feline heart.
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| 7. |
- Valdemarsson, Stig, et al.
(författare)
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Hepatic lipase and the clearing reaction: studies in euthyroid and hypothyroid subjects
- 1987
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Ingår i: Hormone and Metabolic Research. - 1439-4286. ; 19:1, s. 28-30
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Tidskriftsartikel (refereegranskat)abstract
- Eight patients with primary hypothyroidism were compared to eleven euthyroid subjects with regard to the effects of a single i.v. dose of heparin on plasma lipoprotein concentrations (the "clearing reaction"). The hypothyroid patients were moderately hypercholesterolemic but had normal plasma triglyceride levels. Maximal activities of hepatic lipase (HL) and lipoprotein lipase (LPL) were lower in the hypothyroid than in the normal subjects. The hypothyroid patients demonstrated a significant decrease in total plasma cholesterol levels after heparin injection (from 8.36 +/- 0.70 mmol/l to 7.55 +/- 0.62 mmol/l, P less than 0.02). The maximal activity of HL after heparin was significantly correlated to the decrease in plasma cholesterol levels (P less than 0.05) and in LDL-cholesterol levels (P less than 0.01). The euthyroid subjects demonstrated a smaller decrease in total plasma cholesterol concentrations (from 5.53 +/- 0.31 to 5.08 +/- 0.28 mmol/l, P less than 0.05). In this group, the fall in cholesterol levels was not correlated to maximal HL activity. The reduction in plasma triglyceride levels after heparin was similar and significant (P less than 0.01) in both groups. These data support the view that decreased activity of HL contributes to the dyslipoproteinemia seen in hypothyroidism. They are also in accordance with the notion that HL is involved in the elimination of cholesterol from plasma.
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| 8. |
- Valdemarsson, Stig, et al.
(författare)
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Increase in hepatic lipase activity after testosterone substitution in men with hypogonadism of pituitary origin
- 1987
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Ingår i: Acta Medica Scandinavica. - 0001-6101. ; 221:4, s. 363-366
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Tidskriftsartikel (refereegranskat)abstract
- Ten men with hypogonadism of pituitary origin were studied before and during testosterone substitution therapy with regard to effects on the activities of hepatic lipase (HL) and lipoprotein lipase (LPL) in postheparin plasma, and on plasma lipoprotein concentrations. The mean (+/- SEM) testosterone level increased from 1.8 +/- 0.5 to 16.3 +/- 2.4 nmol/l. The mean activity of HL rose from 327.1 +/- 35.2 to 432.8 +/- 57.2 mU/ml (p less than 0.02), while the activity of LPL did not change significantly, 71.0 +/- 9.1 mU/ml before and 62.2 +/- 3.8 mU/ml after treatment. No significant alterations in lipoprotein concentrations were recorded. These results indicate that a normal testosterone level is of importance for maintaining the activity of HL in men, thereby contributing to the sex difference previously recorded for HL activity.
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