Matti Kekki

Helsinki University Central Hospital, Helsinki, Southern Finland Province, Finland

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Publications (24)152.69 Total impact

  • Advances in Experimental Medicine and Biology 02/1977; 82:146-8. · 2.01 Impact Factor
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    ABSTRACT: 1. A selective immunochemical method was used to measure post-heparin plasma lipoprotein lipase and hepatic lipase activity in eighty-two normal subjects and in twenty patients with type IIb, IV or V hypertriglyceridaemia. In twenty-six normal subjects the activity of post-heparin plasma lipases was compared with the kinetic parameters of endogenous plasma triglyceride metabolism. 2. The activity of post-heparin lipoprotein lipase was significantly higher in normal females than in males, whereas the activity of hepatic lipase showed an opposite sex ratio. The activity of lipoprotein lipase decreased with age both in males and females, whereas no significant age variation was observed in the activity of hepatic lipase. 3. In normal subjects a highly significant negative correlation was present in both sexes between the activity of post-heparin plasma lipoprotein lipase and fasting serum triglyceride concentration, but not between the activity of post-heparin hepatic lipase and serum triglycerides. 4. The fractional removal rate of endogenous triglycerides was positively correlated to the activity of lipoprotein lipase but not to the activity of hepatic lipase. No relationship was found between the activities of post-heparin plasma lipases and the absolute turnover of serum triglycerides. 5. The mean activity of post-heparin plasma lipo-protein lipase was significantly lower in subjects with hyperprebetalipoproteinaemia than in normal individuals. However, many hypertriglyceridaemic patients had lipoprotein lipase within the normal range and there was no correlation between serum triglyceride concentration and the activity of post-heparin lipases. 6. All three patients with fasting chylomicronaemia had low post-heparin lipoprotein lipase activity. Several subjects with high post-heparin plasma hepatic lipase activity were present in the group with hyperprebetalipoproteinaemia, but the mean value of the hepatic lipase was not significantly different from normal.
    Clinical science and molecular medicine 05/1976; 50(4):249-60.
  • M Kekki, E A Nikkilä
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    ABSTRACT: Basal plasma total triglyceride and very low density lipoprotein (VLDL) triglyceride turnover rates were determined in 110 subjects whose triglyceride concentrations ranged from low normal to markedly elevated values. The mean total triglyceride turnover rate was 13.7 mg - kg-1- hr-1, whereas the mean VLDL triglyceride turnover rate was 13.2 mg - kg-1 - hr-1. A highly significant correlation was present between the two turnover rates (r equal + 0.75). The endogenous serum triglyceride transported in the other lipoproteins (LDL and HDL) may account for more than half of the circulating triglyceride mass, but its significance in the total triglyceride transport is small. In a selected subgroup of 31 healthy subjects the plasma VLDL triglyceride concentration did not exceed 160 mg/100 ml. The range of this group's triglyceride turnover rate was completely comparable with most data reported in the literature for total serum or VLDL triglyceride transport in normal human subjects. When the turnover rate was plotted against the VLDL triglyceride concentration, three kinetic subgroups could be separated in accordance with the earlier experience on total serum triglyceride transport kinetics.
    Scandinavian Journal of Clinical and Laboratory Investigation 04/1975; 35(2):171-9. · 2.01 Impact Factor
  • M. Kekki, E. A. Nikkilä
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    ABSTRACT: Kekki, M. & Nikkilä, E. A. Turnover of Plasma Total and Very Low Density Lipoprotein Triglyceride in Man. Scand. J. clin. Lob. Invest. 35, 171–179, 1975. Basal plasma total triglyceride and very low density lipoprotein (VLDL) triglyceride turnover rates were determined in 110 subjects whose triglyceride concentrations ranged from low normal to markedly elevated values. The mean total triglyceride turnover rate was 13.7 mg. kg−l. hr−1, whereas the mean VLDL triglyceride turnover rate was 13.2 mg · kg−1. hr−1. A highly significant correlation was present between the two turnover rates (r = +0.75). The endogenous serum triglyceride transported in the other lipoproteins (LDL and HDL) may account for more than half of the circulating triglyceride mass, but its significance in the total triglyceride transport is small. In a selected subgroup of 31 healthy subjects the plasma VLDL triglyceride concentration did not exceed 160 mg/100 ml. The range of this group's triglyceride turnover rate was completely comparable with most data reported in the literature for total serum or VLDL triglyceride transport in normal human subjects. When the turnover rate was plotted against the VLDL triglyceride concentration, three kinetic subgroups could be separated in accordance with the earlier experience on total serum triglyceride transport kinetics.
    Scandinavian Journal of Clinical and Laboratory Investigation 03/1975; 35(2):171-179. · 2.01 Impact Factor
  • Esko A. Nikkilä, Matti Kekki
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    ABSTRACT: Plasma endogenous triglyceride transport has been measured in 74 adult patients with different types of diabetes and compared to similar data obtained in 35 healthy normoglyceridemic control subjects. The diabetic material was divided into subgroups by a number of criteria including ketoacidosis, insulin-dependence, relative body weight, control of blood glucose, and severity of hypertriglyceridemia. In ketoacidosis, a marked elevation of plasma triglyceride production rate was the rule, and this probably accounted for the moderate hypertriglyceridemia even though the fractional transport was simultaneously lowered. In uncontrolled but nonketotic juvenile-type diabetes the mean plasma triglyceride turnover rate and concentration were both significantly increased while the fractional turnover was in most cases within normal range. When the disease was brought into good control by insulin the production rate decreased but not completely in line with blood glucose. Patients with adult-onset-type diabetes showed also an increase of triglyceride turnover rate, and the magnitude of hypertriglyceridemia was consistent with this increment so that most patients were “on line” of the enzyme kinetic Michaelis curves extrapolated from the normal material. On the other hand, of nonketotic diabetics with severe hyperglyceridemia (more than 4.0 mM) some had an increased turnover rate, while others were characterized by a normal production rate. Therefore, it is probable that one minor group of diabetics has a true removal defect, while in other forms of diabetes, the hypertriglyceridemia, if present, is primarily due to enhanced hepatic secretion of triglycerides into plasma. The exogenous fat tolerance was tested in 15 uncontrolled diabetics and 10 control subjects with intravenous intralipid emulsion. The fractional disappearance rate was either normal or decreased in diabetes but, when compared at similar basal plasma triglyceride concentration, there was no difference in the elimination of exogenous particulate fat between diabetics and nondiabetics. The different mechanisms of hypertriglyceridemia associated with diabetes are discussed on the basis of the results obtained in this study. In this connection a new concept on the regulation of removal kinetics by plasma triglyceride production rate is suggested.
    Metabolism 02/1973; 22(1):1-22. · 3.61 Impact Factor
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    Esko A. Nikkilä, Matti Kekki
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    ABSTRACT: Plasma endogenous triglyceride transport kinetics were determined in 16 hyperthyroid and in 12 hypothyroid patients and the results compared with those of euthyroid control subjects. In addition, the removal of exogenous particulate fat (Intralipid; Vitrum, Sweden) from the circulation and the postheparin plasma lipolytic activity (PHLA) were studied in these patients for further characterization of the alterations of plasma triglyceride metabolism in thyroid disease. In thyrotoxicosis the average plasma triglyceride level was slightly but significantly increased above that of control subjects. This change was associated with augmented production of triglycerides whereas the mean fractional removal rate was not different from normal. There was a significant linear correlation between the concentration and turnover rate of plasma triglycerides in both hyperthyroid and euthyroid subjects but the concentration/turnover rate ratio was less in the former group suggesting that the efficiency of removal of triglycerides from the circulation was improved in thyroid hyperfunction. The elimination of intravenously administered particulate fat occurred more rapidly in untreated hyperthyroid patients than in euthyroid control subjects. The mean PHLA was also above normal in thyrotoxicosis. Upon adequate treatment of the hyperthyroid state the fasting plasma triglyceride concentration was further increased. Hypothyroid patients showed another pattern of alteration of triglyceride kinetics. The synthesis of plasma triglycerides was normal but the fractional removal of both endogenous and exogenous triglycerides was markedly reduced and this change seems to account for the hypertriglyceridemia associated with thyroid hypofunction. The plasma PHLA was also clearly decreased in the hypothyroid state. Plasma FFA and glycerol levels were increased in hyperthyroidism and plasma FFA was slightly decreased in hypothyroid patients, but these variables were not significantly correlated with any parameter of triglyceride metabolism. Endogenous triglyceride turnover rate was significantly correlated with serum protein-bound iodine (PBI) and T3 uptake in thyrotoxicosis but not in hypothyroidism. Removal of exogenous fat was not related to postheparin plasma lipolytic activity but the fractional endogenous triglyceride transport showed a highly significant relationship to this lipase activity in a mixed group of hyper- and hypothyroid patients. The results suggest that thyroid hormones control both production and removal of plasma triglycerides. Different mechanisms for these interactions are considered.
    Journal of Clinical Investigation 09/1972; 51(8):2103-14. · 13.77 Impact Factor
  • Esko A. Nikkilä, Matti Kekki
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    ABSTRACT: . The kinetics of plasma endogenous triglyceride transport were assessed in nine hyperglyceridaemic patients before and after treatment with an effective hypolipidaemic compound of the clofibrate group, phenolic ether Su-13437. The triglyceride turnover was measured by endogenous 3H-glycerol labelling technique and the results were compared to those obtained earlier in selected normal subjects. In the untreated stage the plasma triglyceride transport (production) rate was above the normal range in seven of the nine patients but it did not correlate with the triglyceride concentration. On the other hand, the logarithm of the concentration showed a significant inverse correlation with the fractional transport rate. During administration of the drug both the plasma triglyceride concentration and production rate fell in all subjects, the mean decreases being 52 and 35%, respectively. The response of the fractional transport rate to treatment was very variable and although the mean increase of 26% was significant the change did not correspond to the decrease in the triglyceride concentration. On the basis of these observations it is suggested that the primary defect in most cases of type IV endogenous hyperglyceridaemia is an increased inflow transport of plasma triglycerides but the actual plasma triglyceride level is ultimately determined by the inherent type of transport kinetics. The compound Su-13437 is an effective triglyceride-concentration-lowering agent which acts mainly by decreasing the production of plasma triglycerides.
    European Journal of Clinical Investigation 07/1972; 2(4):231-8. · 2.83 Impact Factor
  • Esko A. Nikkilä, Matti Kekki
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    ABSTRACT: . Since fructose is now marketed as a nutrient a study has been initiated to compare the effects of fructose, sucrose and starch at a conventional dietary intake level on the plasma triglyceride concentration and turnover in patients with endogenous hypertriglyceridemia. Preliminary results are presented here.Fructose or sucrose in a daily amount of 75 to 80 grams were added to the diet in an isocaloric exchange for starch in twelve hyperglyceridemic patients under hospital conditions. Each dietary period lasted for 10 to 20 days and the triglyceride turnover was studied by endogenous glycerol labeling technique at the end of each period. Five of the patients had manifest diabetes managed by diet or oral antidiabetic drugs.Plasma triglyceride response to fructose was variable and the average change from the level observed during fructose-free diet was not significant. However, in nondiabetic subjects a definite rising trend of triglyceride was noticeable. Sucrose caused a significant increase of triglyceride concentration above that measured during fructose and starch diets. Diabetics were not included into the sucrose group, however. The fractional removal rate of plasma triglycerides was identical during all three diets but the triglyceride production rate showed a rising trend during fructose and, particularly, during sucrose diet as compared to starch. Because of the limited number of subjects studied so far, these results do not justify any definite conclusions.
    Acta medica Scandinavica. Supplementum 02/1972; 542:221-7.
  • Matti Kekki, Esko A. Nikkilä
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    ABSTRACT: The effect of oral contraceptives on the concentration, production rate, and removal efficiency of plasma triglycerides was studied in premenopausal women using an endogenous labeling of triglycerides with tritiated glycerol. Thirteen subjects were studied while receiving the drug and seventeen normal healthy females served as controls. In some instances the study was made both before and during the drug or repeated after discontinuation of the treatment. The elimination of triglycerides from the circulation was characterized using the Michaelis constant, Km, which gives the plasma concentration at half-maximal removal velocity. The control group showed a polymorphism of plasma triglyceride kinetics being composed of three subgroups which had different maximal turnover rates. Treatment with oral contraceptives was associated with highly significant increases of concentration, rate of production, and efficiency of removal of plasma triglycerides whereas the maximal turnover rate was apparently unaffected. Thus, the increase of plasma triglyceride concentration (average 1.5-fold) observed in women receiving oral contraceptives is accounted for by a much enhanced influx (average 1.9-fold). The influence of the latter is partly compensated by a simulataneous acceleration of triglyceride efflux, however. The effects are produced already by one cycle of treatment but almost no reversion of the changes can be observed at 1 mo after discontinuation of the drug. The triglyceride concentration and production rate were significantly correlated to the duration of intake of contraceptive preparations while the removal efficiency was not.
    Metabolism 10/1971; 20(9):878-89. · 3.61 Impact Factor
  • M Kekki, E A Nikkilä
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    ABSTRACT: . The kinetic parameters of plasma triglyceride metabolism were determined in 14 adult subjects with the nephrotic syndrome by endogenous labelling of circulating triglyceride with tritiated glycerol. The triglyceride production (turnover) rate and the apparent Km of removal were calculated from the slope of the radioactivity disappearance curve and compared to a normal control material studied previously. Plotting of the individual data in a log scale of triglyceride concentration versus turnover with the normal area and saturation curves in the background allowed a detailed characterization of the nature of kinetic alterations occurring in disease. It was found that in the majority of cases with the nephrotic syndrome the plasma triglyceride concentration and rate of influx are slightly above normal. However, the apparent Km of removal was significantly increased suggesting that efflux may also be somewhat impaired. In four cases the plasma triglyceride was produced at a rate which exceeded the value predicted by the normal saturation curves and it is believed that an uncontrolled overproduction of plasma triglyceride was present in these cases.—Complete remission of disease in one case brought both triglyceride concentration and turnover rate rapidly to normal values. An eight-hour infusion of human serum albumin in another patient promptly caused a return of high triglyceride turnover to normal.— The primary change behind the nephrotic hypertriglyceridaemia seems to be a controlled increase of plasma triglyceride synthesis. In some cases, however, this overproduction occurs in an uncontrolled fashion and in a number of patients decrease of removal efficiency contributes to the development of hyperglyceridaemia. All of these changes can be explained on the basis of an increased FFA/albumin molar ratio in plasma giving rise to the elevation of unbound FFA fraction.
    European Journal of Clinical Investigation 06/1971; 1(5):345-51. · 2.83 Impact Factor
  • Esko A. Nikkilä, Matti Kekki
    Scandinavian Journal of Clinical and Laboratory Investigation 05/1971; 27(2):97-104. · 2.01 Impact Factor
  • E A Nikkilä, M Kekki
    Annales medicinae experimentalis et biologiae Fenniae 02/1970; 48(4):246-8.
  • P Koskelo, M Kekki, O Wager
    Clinica Chimica Acta 10/1967; 17(3):339-47. · 2.76 Impact Factor
  • Pentti Koskelo, Matti Kekki, Odd Wager
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    ABSTRACT: The kinetic behaviour of extracellular myoglobin was studied by means of [131I]myoglobin in four healthy persons. Less than 3% of the injected myoglobin was found in the urine, the rest being most probably catabolized by the kidney. The degradation rate was rather rapid. The time in which all myoglobin in the i.v. compartment was catabolized varied from 49 to 224 min. The extravascular compartment was rather large indicating a relatively high concentration of myoglobin in lymphatic and extracellular spaces. The intravascular space contained from 4 to 13.4% of the extracellularly circulating myoglobin.
    Clinica Chimica Acta 09/1967; · 2.76 Impact Factor
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    ABSTRACT: The metabolism of glycerol was studied by intravenous and oral glycerol tolerance test (single dose of 5 g orally and 2.4 g intravenously) in 15 healthy and 17 diabetic subjects.- The intestinal absorption of glycerol was rapid, the maximum serum level of glycerol occurring 15 minutes after the intake. In diabetic subjects the increment of serum glycerol was significantly smaller than in control cases. However, three patients with hyperlipemia and diabetes formed a striking exception in having abnormally high peak glycerol levels. The plasma FFA level was not altered by oral glycerol. Blood glucose remained unchanged in the controls, but rose on an average 13 mg/100 ml in insulin-requiring diabetics. The intravenous glycerol disappearance curves were analysed by an electronic computer. With a few exceptions the result was compatible with a one-compartment kinetic model. The fractional disappearance rate of glycerol from this pool was significantly smaller in diabetics (0.041 min–1) than in control subjects (0.059 min–1). However, the total disappearance rate was twice as high in the diabetic as in the control group (mean values 3.85 and 1.73 molesper minute per kilogram, respectively).Bei 15 Gesunden und 17 Diabetikern wurde der Glycerinstoffwechsel mittels intravenser und oraler Glycerin-Toleranzteste (einmalige Gabe von 5.0 g oral und 2.4 g intravens) untersucht. Die Resorption des Glycerins aus dem Darm erfolgte rasch; das Maximum des Serumglycerinspiegels wurde 15 min nach der Aufnahme erreicht. Bei Diabetikern war der Anstieg des Serumglycerins signifikant kleiner als bei den Kontrollpersonen. Drei Patienten mit Hyperlipmie und Diabetes bildeten jedoch eine auffallende Ausnahme insofern, als sie abnorm hohe Gipfel des Serumglycerins zeigten. Der FFA-Spiegel im Plasma wurde durch die orale Glycerinabgabe nicht verndert. Bei den Kontrollen blieb der Blutzucker unverndert, whrend der bei den insulinbedrftigen Diabetikern im Mittel 13 mg% anstieg. -Die Kurven des Glycerinabfalls nach intravenser Gabe wurden mit einem elektronischen Computer analysiert. Mit wenigen Ausnahmen war das Ergebnis mit einem kinetischen Modell mit einem Verteilungsraum vergleichbar. Die Abfallrate des Glycerins dieses Pools pro Minute war bei Diabetikern signifikant kleiner (0.041 min–1) als bei den Kontrollen (0.059 min–1). Der Gesamtabfall war jedoch bei den Diabetikern doppelt so stark wie bei der Kontrollgruppe (Mittelwerte 3.85 bzw. 1.73 micromol/ min/kg.)Le mtabolisme du glycrol a t tudi l'aide d'un test de tolrance au glycrol administr par voie intraveineuse et orale (dose unique de 5 g par voie orale et de 2.4 g par voie intraveineuse) chez 15 sujets en bonne sant et chez 17 diabtiques. — L'absorption intestinale du glycrol tait rapide, le maximum du taux du glycrol srique se produisant 15 minutes aprs la prise. Chez les sujets diabtiques l'augmentation du glycrol srique tait significativement plus faible que chez les sujets tmoins. Cependant, trois patients atteints d'hyperlipmie et de diabte constiturent une exception frappante, car ils prsentaient des pics de glycrol anormalement levs. Le taux des FFA du plasma n'tait pas modifi par l'administration orale de glycrol. Le glucose du sang restait inchang chez les sujets tmoins, mais augmentait en moyenne de 13 mg/100 ml chez les diabtiques ncessitant un traitement par l'insuline. — Les courbes de disparition du glycrol intraveineux furent analyses par un calculateur lectronique. A quelques exceptions prs, le rsultat tait compatible avec un modle cintique un seul compartiment. La vitesse de la disparition fractionnaire du glycrol de ce pool tait significativement plus faible chez les diabtiques (0.041 min–1) que chez les sujets tmoins (0.059 min–1.Cependant la vitesse de disparition totale tait deux fois plus leve chez le groupe diabtique que chez le groupe tmoin. (Valeurs moyennes respectives, 3.85 et 1.73 micromoles par minute et par kilogramme.)
    Diabetologia 04/1967; 3(1):1-8. · 6.88 Impact Factor
  • Scandinavian Journal of Clinical and Laboratory Investigation 02/1967; 19(3):259-62. · 2.01 Impact Factor
  • Scandinavian Journal of Clinical and Laboratory Investigation 01/1967; 19(3):259-262. · 2.01 Impact Factor
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    ABSTRACT: The turnover kinetics of ceruloplasmin was studied by means of I131-labeled human ceruloplasmin in 2 patients suffering from Wilson's disease and in 8 control subjects. A complete kinetic analysis was made of the patients during penicillamine treatment and was repeated after withdrawal of the drug. There was no significant difference in the distribution of ceruloplasmin in the intravascular and extravascular compartments between the patients and the control subjects. Penicillamine had no effect on the distribution of ceruloplasmin. The fractional catabolic rate of ceruloplasmin without treatment was normal, whereas a clear acceleration of the catabolism during the treatment was seen. The daily turnover was strongly depressed and showed a slight tendency towards acceleration during the treatment.
    Metabolism 12/1966; 15(11):1029-33. · 3.61 Impact Factor
  • Diabetologia 11/1966; 2(3). · 6.88 Impact Factor
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    Journal of Investigative Dermatology 07/1966; 47(2):159-161. · 6.37 Impact Factor

Publication Stats

628 Citations
152.69 Total Impact Points

Institutions

  • 1972–1975
    • Helsinki University Central Hospital
      Helsinki, Southern Finland Province, Finland
    • Central Hospital Central Finland
      Jyväskylä, Province of Western Finland, Finland
  • 1966–1973
    • University of Helsinki
      Helsinki, Southern Finland Province, Finland