Structural and enzymatic properties of a gastric NADP(H)- dependent and retinal-active alcohol dehydrogenase

A class IV-type, gastric alcohol dehydrogenase (ADH) has been purified from frog (Rana perezi) tissues, meaning detection of this enzyme type also in nonmammalian vertebrates. However, the protein is unique among vertebrate ADHs thus far characterized in having preference for NADP(+) rather than NAD(+). Similarly, it deviates structurally from other class IV ADHs and has a phylogenetic tree position outside that of the conventional class IV cluster. The NADP(+) preference is structurally correlated with a replacement of Asp-223 of all other vertebrate ADHs with Gly-223, largely directing the coenzyme specificity. This residue replacement is expected metabolically to correlate with a change of the reaction direction catalyzed, from preferential alcohol oxidation to preferential aldehyde reduction. This is of importance in cellular growth regulation through retinoic acid formed from retinol/retinal precursors because the enzyme is highly efficient in retinal reduction (k(cat)/K(m) = 3.4.10(4) mM(-1) min(-1)). Remaining enzymatic details are also particular but resemble those of the human class I/class IV enzymes. However, overall structural relationships are distant (58-60% residue identity), and residues at substrate binding and coenzyme binding positions are fairly deviant, reflecting the formation of the new activity. The results are concluded to represent early events in the duplicatory origin of the class IV line or of a separate, class IV-type line. In both cases, the novel enzyme illustrates enzymogenesis of classes in the ADH system. The early origin (with tetrapods), the activity (with retinoids), and the specific location of this enzyme (gastric, like the gastric and epithelial location of the human class IV enzyme) suggest important functions of the class IV ADH type in vertebrates.

Temperament traits in male suicide attempters and violent offenders

With the purpose of comparing temperament traits in subjects who have been violent towards others and with subjects who have shown self-directed violence, 34 male suicide attempters and 34 male violent offenders were matched for age and psychiatric diagnosis. Violent offenders with a history of suicide attempts were excluded. Temperament traits were assessed by means of the Karolinska Scales of Personality. The temperament profiles of suicide attempters and violent offenders were very similar, with high trait anxiety and very low socialization. Violent offenders displayed significantly higher social desirability (P < 0.001). Suicide attempters tended to have higher indirect aggression and monotony avoidance. Impulsiveness, verbal aggression, and inhibition of aggression were within the normal range in both groups. There were substantial temperamental similarities between suicide attempters and violent offenders. In order to disentangle the differential mechanisms behind aggression towards self and others, we probably need to consider historical as well as current situation factors in a systematic way.

Some risk factors for non-Hodgkin's lymphoma

Non-Hodgkin's lymphoma (NHL) has been subject to several epidemiological studies and various occupational and non-occupational exposures have been identified as determinants. The present study is a pooled analysis of two earlier methodologically similar case-referent studies encompassing 199 cases of NHL and 479 referents, all alive. Exposure information, mainly on occupational agents, was obtained by mailed questionnaires to the subjects. Exposure to white spirits, thinner, and aviation gasoline as well as work as a painter was connected with increased odds ratios, whereas no increased risk was noted for benzene. Farming was associated with a decreased odds ratio and exposure to phenoxy herbicides, wood preservatives, and work as a lumberjack showed increased odds ratios. Moreover, exposure to plastic and rubber chemicals and also contact with some kinds of pets appeared with increased odds ratios. Office employment and housework showed decreased odds ratios. This study indicates the importance of investigating exposures not occurring very frequently in the general population. Solvents were studied as a group of compounds but were also separated into various specific compounds. The present findings suggest that the carcinogenic property of solvents is not only related to the aromatic ones or to the occurrence of benzene contamination, but also to other types of compounds.

Multivariate parameter evaluation of pharmaceutically important cellulose ethers

A set of nonionic cellulose ethers with varying hydrophobicity and molecular weight has been investigated by principal component analysis (PCA). Several experimental variables such as dynamic surface tension, diffusion coefficient, microviscosity as monitored by a fluorescence probe technique, and intrinsic viscosity are included in the analysis. The experimental variables and observations (polymer fractions) are analyzed in models with good predictive capacities. The apparent equilibrium surface tension correlates to the cloud point and to the critical aggregation concentration in the presence of surfactant. The microviscosity is shown to be a predictive parameter for the degree of hydrophobic substitution. The irreversible process of dynamic surface tension is dependent on the diffusion coefficient but to an even larger degree on the polymer concentration, which is well illustrated by the PCA models.

Leptin concentrations in cord blood in normal newborn infants and offspring of diabetic mothers

Leptin has been implicated in the regulation of body weight and energy balance; Leptin is produced by adipocytes and placental tissue. Chronic fetal hyperinsulinemia and accelerated fetal growth with increased amounts of body fat are frequent findings in the offspring of diabetic mothers. In this study, we examined whether leptin levels in cord blood of infants of type 1 diabetic mothers (n = 29), gestational diabetic mothers (n = 6 and controls (n = 96) correlated with level of maternal glucose control, maternal leptin level at delivery, gender, fetal and placental size, and C-peptide in cord blood at birth. Leptin was significantly elevated in infants of type 1 diabetic (24.7 ng/ml) and gestational diabetic mothers (29.3 ng/ml) as compared to controls (7.9 ng/ml). C-peptide was also significantly higher in infants of type 1 diabetic (0.91 nmol/l) and gestational diabetic mothers (0.99 nmol/l) vs controls (0.34 nmol/l). Infants of type 1 diabetic mothers with a leptin level in cord blood above the upper normal range, i.e. > 30 ng/ml (n = 13), had an average maternal HbA1c level of 5.4% (normal < 5.5%) that was not different from 5.2% in infants with a leptin level < 30 ng/ml (n = 15). In both neonatal groups of diabetic mothers, leptin in cord blood did not correlate with maternal leptin concentrations, placental weight, birthweight, gender and cord blood C-peptide. In controls, leptin in cord blood was higher in girls than in boys (p = 0.044) and correlated significantly with birthweight (p = 0.41, p < 0.001) and cord blood C-peptide (p = 0.44, p < 0.001) but not with maternal leptin level or placental weight. The 3-4 times higher leptin levels in the offspring of diabetic mothers than normal could reflect increased adipose tissue mass and/or increased contribution from other sources such as placental tissue.

Effect of angiotensin converting enzyme inhibitor or beta blocker on glomerular structural changes in young microalbuminuric patients with Type I (insulin-dependent) diabetes mellitus

AIMS/HYPOTHESIS

To investigate the influence of angiotensin converting enzyme inhibitors and beta blockers on the progression of early diabetic glomerulopathy.

METHODS

Thirteen patients with Type I (insulin-dependent) diabetes mellitus (mean age 18.8 years) with microalbuminuria 31 (19-160) microg/min were randomised to treatment with enalapril (group 1, n = 7) or metoprolol (group 2, n = 6). Renal biopsies were taken before and after 38 (36-48) months of treatment. Albumin excretion rate, blood pressure and HbA1c were measured every third month. A reference group without antihypertensive treatment (group 3, n = 9), with similar age, diabetes duration and degree of microalbuminuria as group 1 and 2, had baseline and follow-up renal biopsies taken previously with an interval of 26-34 months, analysed at the same laboratory. Glomerular structures were measured by stereological methods.

RESULTS

Measurements of basement membrane thickness, mesangial and matrix volume fractions were similar among groups at baseline. Structural variables were only increased in group 3 at follow-up. Delta values in basement membrane thickness and diabetic glomerulopathy index per 24 months were lower in group 1 and 2 than in group 3 (p < 0.05). Microalbuminuria returned to normal in group 1 and 2 only. Decreased albumin excretion rate tended to inversely correlate with increased basement membrane thickness (p = 0.08) and diabetic glomerulopathy index (p = 0.05). Mean HbA1c was similar between groups. Mean diastolic blood pressure was lower in group 1 and 2 than in group 3 (p < 0.01). Mean HbA1c and mean diastolic blood pressure correlated to changes in basement membrane thickness, mesangial volume fraction and diabetic glomerulopathy index (p < 0.05).

CONCLUSION/INTERPRETATION

Contrary to findings in the group without antihypertensive treatment, no progression of glomerulopathy was seen in those treated with enalapril or metoprolol.

Quantitative investigation of the modular primer effect for DNA and peptide nucleic acid hexamers

The effect on oligonucleotide-template duplex stability upon cohybridization of adjacently annealing oligonucleotides, the modular primer effect, was studied with biosensor technology. DNA and peptide nucleic acid (PNA) hexamer modules and sensor chip-immobilized template DNA strands were designed for analysis of nick, overlap, and gap modular hybridization situations. The fast hybridization kinetics for such hexamer modules allowed for the determination of apparent duplex affinities from equilibrium responses. The results showed that the hybridizational stability of modular hexamer pairs is strongly dependent on the positioning, concentration, and inherent affinity of the adjacently annealing hexamer module. Up to 80-fold increases in apparent affinities could be observed for adjacent modular oligonucleotide pairs compared to affinities determined for single hexamer oligonucleotide hybridizations. Interestingly, also for coinjections of different module combinations where DNA hexamer modules were replaced by their PNA counterparts, a modular primer effect was observed. The introduction of a single base gap between two hexamer modules significantly reduced the stabilization effect, whereas a gap of two bases resulted in a complete loss of the effect. The results suggest that the described biosensor-based methodology should be useful for the selection of appropriate modules and working concentrations for use in different modular hybridization applications.

Immunocytochemical detection and mapping of a cytokeratin 18 neo-epitope exposed during early apoptosis

A neo-epitope in cytokeratin 18 (CK18) that becomes available at an early caspase cleavage event during apoptosis and is not detectable in vital epithelial cells is characterized. The monoclonal antibody M30, specific for this site, can be utilized specifically to recognize apoptotic cells, which show cytoplasmic cytokeratin filaments and aggregates after immunohistochemistry with M30, while viable and necrotic cells are negative. The number of cells recognized by the antibody increases after induction of apoptosis in exponentially growing epithelial cell lines and immunoreactivity is independent of the phosphorylation state of the cytokeratins. The generation of the M30 neo-epitope occurs early in the apoptotic cascade, before annexin V reactivity or positive DNA nick end labelling. In a flow cytometric assay, the majority of the M30-positive cells appear in the 'apoptotic' subG1 peak. Tests with synthetic peptides define positions 387-396 of CK18, with a liberated C-terminus at the caspase cleavage site DALD-S, as the ten-residue epitope of M30. This epitope starts at the end of coil 2 of the predicted CK18 structure, at a probable hinge region, compatible with the sensitivity to proteolytic cleavage. The definition of a specific caspase cleavage site in CK18 as a neo-epitope can be used for quantification of apoptotic epithelial cells with immunocytochemical techniques and is applicable to both fresh and formalin-fixed material.

T-cell-epitope mapping of the idiotypic monoclonal IgG heavy and light chains in multiple myeloma

The idiotypic structures of the myeloma protein might be regarded as tumor-specific antigens. The present study was designed to map T-cell epitopes of the idiotypic myeloma protein to prove the existence of naturally occurring major-histocompatibility-complex-dependent idiotype (peptide)-specific T cells in multiple myeloma. The fine specificity of idiotype-reactive, interferon-gamma-producing blood T cells of a patient with multiple myeloma stage I was characterized by identification of idiotype (heavy and light chains)-derived MHC-restricted T-cell epitopes. T cells specifically reacting with peptides corresponding to each of the 3 complementarity-determining regions (CDRs) of the heavy-chain variable part (V(H)) of the autologous idiotype were found. In contrast, none of the peptides corresponding to the 3 CDRs of the light chain (V(L)) induced a specific T-cell response. The idiotype amino-acid sequence corresponding to the junction of the V(H), diversity (D), and joining (J) gene segments of the VH appeared to be an important target for T cells, since the sequence expressed MHC-class-I- as well as MHC-class-II-restricted epitopes. The study provides further support for the existence of MHC-restricted idiotype-specific T cells, which may target immunogenic CDR peptides in multiple myeloma. Such T cells could be an important part of the specific anti-tumor immune responses induced in idiotype vaccination protocols.

Structure and chromosomal assignment of the sterol 12alpha-hydroxylase gene (CYP8B1) in human and mouse: eukaryotic cytochrome P-450 gene devoid of introns

Sterol 12alpha-hydroxylase (CYP8B1) is a hepatic cytochrome P-450 that controls the ratio of cholic acid over chenodeoxycholic acid in bile and thus controls the solubility of cholesterol. Both the human and the mouse CYP8B1 complementary DNA and gene were cloned and structurally characterized. Surprisingly, the genomic DNA from both species was found to lack introns. The major transcript of the human gene was estimated to be 3950 bp, and the putative promoter region was estimated to be at least 1360 bp. The murine structural gene was found to span approximately 3 kb. By using FISH and radiation hybrid mapping techniques, the human CYP8B1 gene was located to chromosome 3p21.3-p22, whereas FISH mapped the murine counterpart to chromosome 9qF4, a region that is homologous to the third human chromosome. The results from the chromosome mapping and Southern blotting indicated that the gene is present in a single copy. Transcription of the mouse and human CYP8B1 genes was initiated from a position situated 51 and 35 bases, respectively, downstream of a consensus TATA box. A homology of 21% for the promoter regions of mouse and human may indicate differences in transcriptional regulation. Although a potent induction of CYP8B1 mRNA was observed upon starvation of mice, the mechanism behind this effect was not revealed by analysis of the promoter for potential cis-acting elements. In the human promoter, several possible cis-acting regions were identified but none of them could be directly related to bile acid metabolism. After transfection of COS cells with the human coding region, mRNA and enzymatic activity for the 12alpha-hydroxylase were identified. This is the first mammalian cytochrome P-450 gene reported to lack introns. The importance of this structural feature for evolution and gene regulation is discussed.

KIND-a non-redundant protein database

SUMMARY

KIND (Karolinska Institutet Nonredundant Database) is a protein database where identical sequences, both full length and partial, have been removed. The database contains nearly 274 900 sequences, half of which originate from the protein sequence databases Swissprot and PIR, while the other half come from translated open reading frames in GenPept and TrEMBL.

AVAILABILITY

KIND is downloadable from ftp://ftp.mbb.ki.se/pub/KIND.

Common structural features of MAPEG -- a widespread superfamily of membrane associated proteins with highly divergent functions in eicosanoid and glutathione metabolism

A novel superfamily designated MAPEG (Membrane Associated Proteins in Eicosanoid and Glutathione metabolism), including members of widespread origin with diversified biological functions is defined according to enzymatic activities, sequence motifs, and structural properties. Two of the members are crucial for leukotriene biosynthesis, and three are cytoprotective exhibiting glutathione S-transferase and peroxidase activities. Expression of the most recently recognized member is strongly induced by p53, and may therefore play a role in apoptosis or cancer development. In spite of the different biological functions, all six proteins demonstrate common structural characteristics typical of membrane proteins. In addition, homologues are identified in plants, fungi, and bacteria, demonstrating this superfamily to be generally occurring.

SDR and MDR: completed genome sequences show these protein families to be large, of old origin, and of complex nature

Short-chain dehydrogenases/reductases (SDR) and medium-chain dehydrogenases/reductases (MDR) are protein families originally distinguished from characterisations of alcohol dehydrogenase of these two types. Screening of completed genome sequences now reveals that both these families are large, wide-spread and complex. In Escherichia coli alone, there are no fewer than 17 MDR forms, identified as open reading frames, considerably extending previously known MDR relationships in prokaryotes and including ethanol-active alcohol dehydrogenase. In entire databanks, 1056 SDR and 537 MDR forms are currently known, extending the multiplicity further. Complexity is also large, with several enzyme activity types, subgroups and evolutionary patterns. Repeated duplications can be traced for the alcohol dehydrogenases, with independent enzymogenesis of ethanol activity, showing a general importance of this enzyme activity.

Species-specific autoantibodies in type 1 diabetes

GAD65 autoantibodies (GAD65Ab) are important markers for type 1 (insulin-dependent) diabetes mellitus. Although most patients have GAD65Ab at the time of clinical diagnosis, there are also GAD65Ab-positive individuals in the population at low risk of developing type 1 diabetes. The aim of this study was to test the hypothesis that the GAD65Ab reactivity to GAD65 cloned from human, mouse, and rat in newly diagnosed type 1 diabetic patients differ from antibody-positive healthy individuals. Sera from 254 new-onset 0- to 34-yr-old type 1 diabetic patients and 270 controls were assayed for their reactivity to human, mouse, and rat GAD65. Among the type 1 diabetic patients there was a significant better binding of human GAD65 compared to either mouse (P = 0.03) or rat GAD65 (P = 0.0005). The preference for human GAD65 increased with increasing age at onset (P = 0.0002). This differentiation was not observed in 88 GAD65Ab-positive control subjects. Our data indicate that recognition of epitopes by GAD65Ab in type 1 diabetes is different from that in nontype 1 diabetes, GAD65Ab-positive individuals.

Symptoms of depression are important to psychological adaptation and metabolic control in children with diabetes mellitus

AIMS

Sixty-two children (37 girls, 25 boys) between 9 and 18 years of age were enrolled to investigate: (1) the relationship between adaptation to diabetes mellitus (DM) and psychological functioning; (2) if adaptation or psychological functioning was related to metabolic control; and (3) if the patients' ability to cope with diabetes as assessed by physicians, was correlated to adaptation or psychological functioning.

METHODS

Psychological functioning was measured by three general psychological instruments for depressive symptoms, self-esteem and fear. Diabetes adaptation was evaluated by questionnaires and coping with diabetes by an assessment of the physicians. Metabolic control was expressed by the individual HbA1c measured during the last year.

RESULTS

Adaptation to diabetes correlated to psychological functioning (depression, P<0.001; self-esteem, P<0.01; and fear, P<0.01). Multiple regression analyses showed that metabolic control was predicted by adaptation (P=0.0013) with monitoring of diabetes as the only significant aspect of the adaptation (P < or = 0.0001). In turn, adaptation was predicted by symptoms of depression and metabolic control (P<0.0001). In support of this observation, a depressed (n = 9) and a non depressed (n= 53) group showed significant differences in metabolic control (P < or = 0.01), adaptation (P < or = 0.001) and self-esteem (P < or = 0.001). The only significant variable for the physicians assessment was metabolic control, which explained 35 % of the variance (P < 0.001).

CONCLUSIONS

The major conclusion is that symptoms of depression affect both adaptation and metabolic control. It should be of concern to identify patients with depressive symptoms, offer treatment for their emotional difficulties and increase the support for taking care of their diabetes.

Insulin induced hypoglycaemia: comparison of glucose and glycerol concentrations in plasma and microdialysate from subcutaneous adipose tissue

AIMS

To investigate the dynamics between plasma and dialysate glucose during hypoglycaemia in children.

STUDY DESIGN

Six children in prepuberty or early puberty were investigated by multiple blood sampling and microdialysis of subcutaneous adipose tissue during a standard arginine-insulin tolerance test. Glucose and glycerol, as an index of lipolysis, were measured in samples from both compartments. Plasma concentrations of insulin and the main counterregulatory hormones were also measured.

RESULTS

Plasma and dialysate glucose concentrations were very similar at baseline and increased in concert after infusion of arginine, probably in response to glucagon release. After insulin injection, glucose in both plasma and dialysate fell in parallel. The subsequent hypoglycaemic stress response induced a rapid rebound in the plasma concentration with a mean (SD) delay in the dialysate of 16 (3) minutes. Plasma glycerol was approximately fivefold lower than in the dialysate and did not fluctuate significantly. Dialysate glycerol decreased with arginine infusion and reached a nadir immediately following insulin administration. Subsequently, the antilipolytic effect of insulin was overcome by the hypoglycaemic stress response, and lipolysis prevailed in spite of hyperinsulinaemia.

CONCLUSION

After rapidly induced hypoglycaemia, rebound of interstitial glucose concentrations is significantly delayed compared with plasma concentrations, and the antilipolytic effect of hyperinsulinaemia is opposed possibly by the hypoglycaemic stress response.

Surface activity and concentration dependent intestinal permeability in the rat

PURPOSE

To investigate the relation between intestinal effective permeability (P(eff)) and surface activity of fluvastatin and verapamil.

METHODS

P(eff)-values were determined for fluvastatin, antipyrine and D-glucose following colon perfusions in the rat in situ. The perfusion solitions differed regarding concentrations of fluvastatin (0-2500 microM) and surface tension (58.9-43.7 mN/m). A cellulose derivative, ethyl-(hydroxyethyl) cellulose (EHEC), was added to lower the surface tension of one of the perfusion solutions. The surface tension of perfusion solutions containing R/S-verapamil (8-814 microM) and R/S-verapamil + chlorpromazine (814 microM + 10 mM) were related to the corresponding P(eff)-values from the literature.

RESULTS

The P(eff)of fluvastatin correlated inversely (r2 = 0.985, p < 0.05) with the surface tension of the perfusion solutions below the critical micelle concentration (CMC, 1 mM). Decreasing the surface tension with EHEC increased the P(eff) of fluvastatin by 36% (p < 0.001), but not to the extent anticipated from the correlation between the P(eff) and the surface tension. EHEC also increased the P(eff) of antipyrine by 49% (p < 0.01 ) but not for D-glucose. The P(eff) of R/S-verapamil correlated inversely with the surface tension (r2 = 0.980, p < 0.001).

CONCLUSIONS

The ability of fluvastatin to decrease the surface tension at the membrane surface can partly explain the concentration dependent colonic P(eff) of fluvastatin. This study shows that the surface activity of the drug molecule itself is an important physicochemical factor that should be taken into consideration when evaluating drug absorption studies performed in vitro or in situ.

Elapid venom toxins: multiple recruitments of ancient scaffolds

Nigroxins A and B, two myotoxic phospholipases A2 (PLA2s) from the venom of the American elapid Micrurus nigrocinctus, belong to a new PLA2 subclass. Their primary structures were established and compared with those of PLA2s that have already been studied with respect to myotoxic activity. The combination of amino acid residues Arg15, Ala100, Asn108 and a hydrophobic residue at position 109 is present exclusively in class I PLA2s that display myotoxic activity. These residues cluster within a surface region rich in positive charges and are suggested to play a role in the interaction with the target membrane of the muscle fibers. It is concluded that the myotoxic PLA2s resulted from recruitment of an ancient scaffold. Dendrotoxins and alpha-neurotoxins are similarly derived from other old structures, which are, however, now also present in nontoxic proteins that are widely distributed throughout the animal kingdom. The evolutionary pathways by which elapid PLA2s acquired myotoxicity and dendrotoxins acquired K+-channel blocker activity are traced. They demonstrate how existing scaffolds were adapted stepwise to serve toxic functions by exchange of a few surface-exposed residues.

Sorbitol dehydrogenase of Drosophila. Gene, protein, and expression data show a two-gene system

The Drosophila melanogaster sorbitol dehydrogenase (SDH) is characterized as a two-enzyme system of the medium chain dehydrogenase/reductase family (MDR). The SDH-1 enzyme has an enzymology with Km and kcat values an order of magnitude higher than those for the human enzyme but with a similar kcat/Km ratio. It is a tetramer with identical subunits of approximately 38 kDa. At the genomic level, two genes, Sdh-1 and Sdh-2, have a single transcriptional start site and no functional TATA box. Expression is greater in larvae and adults than in pupae, where it is very low. At all three stages, Sdh-1 constitutes the major transcript. Sdh-1 and Sdh-2 genes were located at positions 84E-F and 86D in polytene chromosomes. The deduced amino acid sequences of the two genes show 90% residue identity. Evaluation of the sequence and modeling of the structure toward that of class I alcohol dehydrogenase (ADH) show altered loop and gap arrangements as in mammalian SDH and establishes that SDH, despite gene multiplicity and larger variability than the "constant" ADH of class III, is an enzyme conserved over wide ranges.

Male reproductive pattern in a glass producing area

The objective of the study was to evaluate the reproductive pattern among male crystal glassworkers in comparison to other males in a restricted area in the south-east part of Sweden. The parish register information was gathered for all men with job titles registered, decreased at the age above 20 years during 1950-1982. The comparison of reproductive patterns was made between groups of glassworkers, farmers and workers of other occupations. As an indicator of fertility, birth rates and time to first child-birth were calculated. Male sex ratios (number of boys/all child-births) were calculated as a measure of reproductive disturbances. The total birth rates as well as the birth rates for sons were slightly decreased among glassworkers when compared to the group of non-farmers/non-glassworkers and significantly decreased when compared to farmers. The total birth rate of the non-farmer/non-glassworker group was also significantly decreased compared to farmers. No differences in sex ratios among children born or in time to first child-birth were seen between the three groups. Among the glassworkers, the reduction in birth rates was most pronounced among engravers/grinders both in comparison to farmers and others. The results indicate that paternal exposure in crystal glassworks might somewhat negatively affect the male reproduction at least in a historical perspective. The mechanisms behind this cannot be concluded from this study.

Lactate, lactate/pyruvate ratio and catecholamine interrelations in cord blood at delivery in complicated pregnancies

The interrelationships between lactate, lactate/pyruvate (L/P) ratio and catecholamines (CA) in cord artery and vein blood were studied in 56 pregnancies who had complications in the antenatal period or during labour. This group of babies had higher CA levels and were more acidaemic than fetuses after normal pregnancies and labour. There were stronger correlations between lactate and noradrenaline (NA) (R = 0.56, P < 0.001), adrenaline (A) (R = 0.41, P = 0.002) and dopamine (DA) (R = 0.42, P = 0.001) in cord artery blood, than previously reported for normal deliveries. Correlations between L/P ratio and CAs were also significant, although weaker. Multiple regression analysis, using cord artery lactate as the dependent variable, revealed significant correlations for pH (P = 0.01) and pyruvate (P < 0.001) but not for the CAs. The subgroups with high lactate (> 75th centile) had significantly higher NA (P = 0.007) and DA (P < 0.001) in cord artery and NA (P < 0.001) and A (P < 0.001) in cord vein blood, as compared with the subgroup who had lower lactate concentrations. We conclude that fetal hypoxia induces fetal CA production as well as anaerobic metabolism with lactate production. However, the adrenergic stimulation seems not to contribute significantly to the fetal lactate production.