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Biomedical subjects

E Kostiainen

Publications and source records attributed to E Kostiainen.

At least 19 recordsLinked to original sources

Relaxation of the bovine retractor penis muscle by a small K+ excess and the role of K+ in its neurogenic relaxation.

The mechanism of the relaxation of the bovine retractor penis muscle induced by 6.7 mM K+ as well as the role of K+ in the neurogenic relaxation of this muscle induced by nicotine, acetylcholine or electrical field stimulation, was studied. The relaxation induced by 6.7 mM K+ was, contrary to that induced by nicotine or electrical field stimulation, abolished by 10(-7) M ouabain. 15 min exposure to 10(-5) M NG-nitro-L-arginine, 3.2 x 10(-6) M tetrodotoxin, 5.0 x 10(-4) M hexamethonium, 5.3 x 10(-4) M methylene blue or hypoxia, all known to inhibit the neurogenic relaxation, did not affect the relaxation induced by 6.7 mM K+, which was also unaffected by 10(-5) M apamin, 3 x 10(-3) M 4-aminopyridine, 2.6 x 10(-2) M tetraethylammonium and 7.3 x 10(-4) M Ba2+. Exposure to K(+)-free solution reversibly abolished the neurogenic relaxations. The relaxations caused by 5.0 x 10(-7) M cromakalim and 2.0 x 10(-6) M pinacidil were totally blocked by 10(-5) M glibenclamide. Glibenclamide and apamin did not affect the tone of the muscle or its neurogenic relaxations. 4-Aminopyridine 4.0 x 10(-5) to 3.0 x 10(-3) M and tetraethylammonium 10(-4) to 2.6 x 10(-2) M raised the tone and enhanced the relaxations elicited by electrical field stimulation. The results indicate that the relaxation induced by 6.7 mM K+ is partly mediated by activation of Na(+)-K(+) ATPase and that its mechanism is thoroughly different from that of the neurogenic relaxations.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗

The use of the bovine retractor penis muscle for the assessment of ganglion-blocking activity of neuromuscular blocking and other drugs.

Inhibition of relaxation of strips of the bovine retractor penis muscle induced by a standard dose of nicotine (30 microM) was used for quantitative assessment of the ganglion-blocking activity of eight neuromuscular blocking agents that are in clinical use. The order of potency of the drugs studied was (+)-tubocurarine >> alcuronium > vecuronium > metocurine >> pancuronium > atracurium >>> suxamethonium > gallamine. The results have been compared to those obtained with other methods. On the basis of the present results, it is concluded that inhibition of the nicotine-induced relaxation of the bovine retractor penis muscle can be used as an alternative, sensitive in vitro method for the assessment of the ganglion-blocking activity of a neuromuscular blocking agent relative to that of, for example, (+)-tubocurarine. Earlier results have showed that this method is useful also for the assessment of the ganglion-blocking activity of other drugs, because it has yielded comparable and reproducible results at the quantitation of this property of actual ganglion-blocking and various antimuscarinic agents. In addition, this method may be useful for rapid screening of ganglion-blocking activity.

Animals↗

No effect on serum lipids by moderate and high doses of vitamin C in elderly subjects with low plasma ascorbic acid levels.

The influence of dietary supplementation with moderate (200 mg/day) and high (2,000 mg/day) doses of vitamin C on serum lipid levels was studied in 27 female long-stay hospital patients characterized by low plasma ascorbic acid levels during the preceding year. The two doses of vitamin C were compared with placebo in a double-blind, cross-over design during randomly determined 6-week periods followed by 2-week washout intervals. No effect was observed on serum cholesterol, HDL cholesterol, and triglyceride levels. Plasma ascorbic acid levels were highly significantly increased (p less than 0.001) by both doses of vitamin C. It is concluded that dietary supplementation with moderate or high doses of vitamin C does not affect serum lipids of persons who have low plasma ascorbic acid levels suggestive of possible marginal deficiency of vitamin C.

Aged↗

Boiled coffee increases serum low density lipoprotein concentration.

The effects of boiled coffee, filtered coffee, and tea on serum lipoprotein lipids and apoproteins were compared in 42 middle-aged hypercholesterolemic subjects (21 men and 21 women). The subjects consumed the beverages, eight cups a day, in random order during successive 4-week periods with 2-week run-in intervals in a crossover design. The diet was kept unchanged. Statistically significant differences were found between the periods in serum total cholesterol (P less than .0001 ANOVA), LDL cholesterol (P less than .01), and apoprotein B (P less than .01) levels. All differences were due to significantly higher levels during boiled coffee as compared with filtered coffee and tea. No statistically significant differences were found between the filtered coffee and tea periods. There were no differences in serum VLDL cholesterol or triglyceride, HDL cholesterol, and apoprotein A-I concentrations between the periods. Consumption of boiled coffee thus increased the concentration of low density lipoprotein in the serum without affecting its lipid-protein composition. The effect seemed to be determined by the method of brewing.

Apolipoproteins↗

Effect of bacterial lipopolysaccharide on serum lipids and on the development of aortic atherosclerosis in rabbits.

The effect of repeated intravenous administration of bacterial lipopolysaccharide (LPS) on serum lipids and on aortic atherosclerosis was studied in rabbits on basal diet and on hypercholesterolemic diets containing 0.15-1.0% cholesterol. LPS (10 or 100 ng/kg body weight) was administered 3 times per week for 3 or 6 weeks. No difference was observed in serum lipid levels or in aortic atherosclerosis between LPS- and saline-treated animals. These observations do not support the hypothesis that LPS has an effect on the progression of atherosclerosis.

Animals↗

Levels of some biological risk indicators among elderly men in Finland.

A 25-year follow-up survey of the Finnish men examined in the Seven Countries Study and now 65-84 years old was carried out in the East and the South-West of Finland in 1984. The follow-up examinations were carried out as in the previous surveys. Systolic and diastolic blood pressures were now significantly lower in the East than in the South-West of Finland. Serum total cholesterol and HDL-cholesterol were on the same level in both areas. The East/South-West difference in serum cholesterol, observed in previous studies, had levelled off and that in the blood pressure level had even reversed among the study cohorts. The mean fasting serum glucose was higher in the East than in the South-West of Finland. The mean serum calcium level was the same in both areas.

Aged↗

Effects of coffee and tea on lipoproteins and prostanoids.

The effects of coffee and tea on serum lipoproteins, plasma and urinary prostanoids and thromboxane production by platelets were studied in 12 healthy volunteers aged 33-45 years. They consumed daily, during 3 successive periods of 3 weeks, 8 cups of either instant coffee (16 g/d), instant tea (2.8 g/d) or rosehip 'tea'. The daily dose of coffee yielded 520 mg caffeine, that of tea 200 mg caffeine, while no caffeine was detected in the rosehip 'tea'. No differences were observed between the study periods in the total serum or serum lipoprotein (VLDL, LDL, HDL2, HDL3) cholesterol or triglyceride concentrations. Plasma and serum concentrations and urinary excretion of prostanoids (plasma and urinary TXB2, PGE2 and 6-keto-PGF1 alpha and serum TXB2) remained constant during the three study periods. These results suggest that coffee or caffeine do not exert any detectable effects on serum lipids in healthy normolipidaemic individuals.

Adult↗

Dietary fat and blood pressure: an intervention study on the effects of a low-fat diet with two levels of polyunsaturated fat.

The role of dietary fat in human blood pressure control was studied among 84 middle-aged subjects (mainly couples) in two semirural communities in North Karelia, Finland. The families were randomly allocated into two groups that, after a baseline period of 2 weeks, changed their diet for a 12-week intervention period so that the proportion of energy derived from fats was similarly reduced in both groups, from 38 to 24%, but the polyunsaturated/saturated fatty acid (P/S) ratio was increased--from 0.2 to 0.9 in group I and to 0.4 in group II. After the intervention period, both groups switched back to their usual diet for a period of 5 weeks. During the intervention period, total serum cholesterol was reduced by 16% in group I and 14% in group II. Mean body weight and urinary sodium, potassium, calcium, and magnesium excretion changes were small or nonexistent. Mean systolic blood pressure decreased 4 mm Hg in group I (P less than 0.01) and 3 mm Hg in group II (P less than 0.01), and mean diastolic blood pressure decreased 5 mm Hg (P less than 0.001) and 4 mm Hg (P less than 0.01), respectively. The reductions were reversed during the switch-back period (P less than 0.01). These results confirm previous findings of the blood-pressure-reducing effect of a low-fat/high-P/S diet. Although a number of possible confounding factors can be ruled out, the dietary constituent accounting for the blood pressure change cannot be ascertained definitely. The results showed no significant further blood pressure reduction with more than a moderately increased P/S ratio when the saturated fat intake was markedly reduced.

Adult↗

Relation of alcohol, physical activity, dietary fat and smoking to serum HDL and total cholesterol in young Finnish men.

The study was based on 471 men, aged 19 to 20 years, who started their compulsory military service in three military bases in Southwest, Southeast and Northern Finland in February 1982. The data were gathered by means of self-administered questionnaires. A fasting venous blood specimen was taken to determine serum HDL and total cholesterol, gamma-glutamyltransferase and thiocyanate. In this cross-sectional study a few variables based on the self-administered questionnaire explained 8% and 7% of the variation in serum HDL and total cholesterol, respectively. Our results show that easily measurable behavioural factors do contribute to serum HDL and total cholesterol levels in young men. In our study the impact of alcohol consumption on serum HCL cholesterol was greater than in most previous studies. Our findings give additional support to the hypothesis that even a very modest amount of regular physical exercise has the effect of increasing the serum HDL cholesterol level.

Adult↗

Concentration and composition of serum lipoproteins during a low-fat diet at two levels of polyunsaturated fat.

A 12-week dietary intervention was carried out among 40 families from North Karelia, a county in Finland with an exceptionally high rate of coronary heart disease and high serum cholesterol values. The proportion of dietary energy derived from fat was reduced during the 12-week intervention period from about 39% to 23% in all families. The families were randomly allocated into two groups. Twenty families consumed a diet with a polyunsaturated to saturated fat (P/S) ratio of 0.9 (group I), while the other 20 families had a diet with a P/S ratio of 0.4 (group II). Total serum cholesterol decreased by 16% and 9% in men of groups I and II, respectively, and by 16% in women of both groups. These changes were due to a decrease in both low density lipoprotein (LDL) and high density lipoprotein (HDL) cholesterol. LDL cholesterol and phospholipid reached minimum values after 6 weeks on both intervention diets, but LDL protein responded more slowly. Thus, after 6 weeks LDL had an altered composition containing less cholesterol and phospholipids and more protein and triglycerides than during the baseline diet. During the intervention, the linoleic acid content in the serum cholesteryl ester fraction increased, and the magnitude of this change correlated negatively with the changes in total and LDL cholesterol. The decrease in HDL cholesterol during the two intervention diets was due to a fall in the HDL2 cholesterol (29% and 24% in men, and 26% and 25% in women in groups I and II, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Acute effects of marathon running on levels of serum lipoproteins and androgenic hormones in healthy males.

The acute effects of marathon (42.2 km) running on serum lipid and lipoprotein levels, particularly high-density lipoprotein (HDL) subfractions HDL2 and HDL3, and on levels of serum androgenic hormones, luteinizing hormone (LH), and testosterone were studied in 20 healthy non- champion -class joggers participating in the First North Karelian Heart Marathon. Serum triglyceride and cholesterol levels were unchanged after the marathon, whereas the lipoprotein distribution of both lipids was significantly altered. Very-low-density lipoprotein triglyceride (VLDL-TG) and cholesterol (VLDL-C) levels decreased significantly, whereas low-density lipoprotein triglyceride (LDL-TG) but not cholesterol (LDL-C) levels were increased, suggesting an accumulation of VLDL remnants in the LDL density range. HDL cholesterol (HDL-C) level rose significantly owing to an increase in HDL2-C. HDL3-C level remained the same. Serum levels of apolipoproteins A-I and A-II, the main apolipoprotein constituents of HDL, did not change during the marathon but their distribution between the HDL subfractions differed, indicating a conversion of HDL3 to HDL2. Serum levels of LH, testosterone, and sex-hormone-binding globulin (SHBG) all decreased during the marathon. The changes in levels of serum lipoproteins and androgenic hormones were not interrelated. We concluded that the short-term regulation of HDL levels during acute exhaustive exercise is controlled not by changes in serum androgenic hormones but by enhanced degradation of triglyceride-rich lipoproteins.

Adult↗

Fat composition of the infant diet does not influence subsequent serum lipid levels in man.

The serum lipid concentrations have been followed until 5 years of age in children fed for between 1 and 6 months with breast milk (n = 35), a home-prepared cow's milk formula (n = 17) or proprietary formula with a low content of cholesterol and high content of linoleic acid (n = 32). The serum cholesterol concentrations were significantly lower in the proprietary formula-fed infants than in the infants fed with breast milk or cow's milk formula between 2 and 6 months of age, i.e. during the period of formula feeding. No differences were observed between the 3 groups in serum lipid values after 9 months of age. A statistically significant correlation was observed between cholesterol concentrations recorded before 6 months and after 3 years of age in children fed initially with the proprietary low-cholesterol formula, but not in the two other groups. It is concluded that the fat composition of the infant diet commonly used in the developed countries affects the contemporary serum cholesterol concentration, but does not influence the serum lipid or lipoprotein levels later in life.

Animals↗

A double-blind evaluation of guar gum in patients with dyslipidaemia.

In a double-blind crossover study the effect of ingested guar gum granules, 15 g/d for 3 months, on blood lipids was evaluated in twelve obese hypercholesterolaemic patients. Serum total cholesterol decreased during the guar gum period in eight of the ten patients who completed the study. The mean serum cholesterol was 8.5 +/- 0.4 mmol/l after the guar gum period as compared to 8.9 +/- 0.3 mmol/l after the placebo period. The mean HDL-cholesterol or body weight showed no significant changes during either treatment period. Guar gum administration did not cause any significant changes in 24-h urinary excretion of sodium, potassium, calcium or magnesium. It is concluded that the administration of guar gum granules seems to reduce serum total cholesterol in hypercholesterolaemic patients without exerting an effect on HDL-cholesterol. The beneficial effect of guar gum is independent of the changes in body weight.

Adult↗

Effect of diet on serum lipoproteins in a population with a high risk of coronary heart disease.

The population of North Karelia, a county in Finland, has a high rate of coronary heart disease. It also has a high prevalence of hypercholesterolemia, but whether this reflects a diet rich in animal fats or is a result of genetic factors is unclear. We studied the effect on serum lipoproteins of a low-fat diet with a high ratio of polyunsaturated to saturated fatty acids in 54 middle-aged volunteers in North Karelia. Total serum cholesterol decreased, from 263 +/- 8 mg per deciliter (mean +/- S.E.) to 201 +/- 5 mg in men (P less than 0.0001) and from 239 +/- 8 to 188 +/- 8 mg in women (P less than 0.0001), along with low-density-lipoprotein cholesterol and apoprotein B. High-density lipoprotein decreased from 54 +/- 2 mg per deciliter to 44 +/- 2 in men (P less than 0.0001) and from 56 +/- 3 to 47 +/- 2 mg in women (P less than 0.0001). A small but significant reduction occurred in serum apoprotein A-I, whereas apoprotein A-II increased slightly. The individual changes in low-density-lipoprotein cholesterol correlated with those in high-density-lipoprotein cholesterol. The changes in serum lipids and apoproteins were reversed when the participants returned to their original diets. Our results suggest that the hypercholesterolemia characteristic of this population is due at least in part to dietary factors.

Adult↗

Vitamin E does not influence plasma lipoprotein metabolism in healthy subjects with normal nutritional status.

The effect of a 6-week treatment with large doses (600 IU/day) of vitamin E on plasma lipoprotein metabolism has been studied in six healthy middle-aged subjects. No consistent change was observed during the treatment in the plasma concentrations of cholesterol, triglycerides, high density lipoprotein (HDL) cholesterol or apolipoproteins AI, AII and B or in the activity of postheparin plasma lipoprotein lipase or hepatic lipase. It is concluded that vitamin E does not influence plasma lipoprotein metabolism in healthy subjects with normal nutritional status.

Adult↗

Lack of serum cholesterol-lowering effect of skimmed milk and butter milk under controlled conditions.

The effects of skimmed milk and butter milk on the plasma concentration of cholesterol, triglyceride and high density lipoprotein cholesterol were studied in voluntary male prisoners under carefully controlled conditions. No significant differences were observed in the serum lipid or lipoprotein levels between the groups ingesting the control diet and the diets containing 2.71 of skimmed milk or 2.01 of butter milk per day for 3 weeks.

Animals↗

Intrapartum stress lowers the concentration of high density lipoprotein cholesterol in cord plasma.

The concentration of cord plasma triglycerides, total cholesterol, high density lipoprotein (HDL) cholesterol, and apoprotein AI and AII has been measured in acidotic and non-acidotic full-term neonates without chronic maternal-fetal problems. The level of cord plasma triglycerides was significantly increased (P less than 0.05) and that of HDL cholesterol significantly decreased (P less than 0.001) in the newborns belonging to the quintile class with the lowest blood pH (less than or equal to 7.20). No differences were present between the acidotic and non-acidotic neonates in the plasma concentrations of total cholesterol or of apoprotein AI and AII. The concentration of triglycerides was increased (P less than 0.05) and that of HDL cholesterol was decreased (P less than 0.05) in the infants with the longest duration of labour. No correlation was observed between the concentration of glycerol and lipids or lipoproteins in cord plasma. The results suggest that intrapartum stress raises plasma triglycerides and induces qualitative and quantitative changes in the plasma high density lipoprotein fraction in the newborn.

Cholesterol↗