Molecular genetic diagnostics of tuberous sclerosis complex in Bulgaria: six novel mutations in the TSC1 and TSC2 genes.

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by the development of hamartomas localized in various tissues which can occur in the skin, brain, kidney and other organs. TSC is caused by mutations in the TSC1 and TSC2 genes. Here we report the results from the first molecular testing of 16 Bulgarian patients and one Romanian patient in whom we found six novel mutations: four in the TSC22 gene, of which one is nonsense, two frame shift and one large deletion of 16 exons; and two in the TSC1 gene, one nonsense and other frame shift. In addition, we detected 10 previously reported mutations; some of which are described only once in the literature. Our data is similar to the previous studies with exception of the larger number of TSC1 mutations than that reported in the literature data. In total, 40% (4/10) of the mutation in the TSC2 gene are located in the GTPase-activating protein domain, while 50% (3/6) are in the TSC1 gene and clustered in exon 15. All the cases represent the typical clinical symptoms and meet the clinical criteria for TSC diagnosis. In 35% of our cases the family history was positive. Our results add novel findings in the genetic heterogeneity and pathogenesis of TSC. The genetic heterogeneity might correlate to the clinical variability among the TSC-affected families, which makes the genetic counselling a real challenge.

Intraperitoneal perfusion chemotherapy with hyperthermia in some malignant ascites.

Intraperitoneal administration of chemotherapeutic drugs with hyperthermia (HIPEC) increases their local effect on malignant peritoneal diseases and reduces systemic cytotoxicity. The most commonly used are cisplatin, doxorubicin, and mitomycin C. A major disadvantage of intraperitoneal chemotherapy is limited penetration of the drug in the tumor lesion depth (1-3 mm). Extended exposure and increased pressure in the abdominal cavity solution increases penetration of the agent into the tumor and hyperthermia has synergy with cytostatic agent on the permeability of cell membranes and metabolism of the drug. Real clinical hyperthermia is achieved at 41 degrees C. Of greatest importance is the concentration of the drug, but crucial for the prognosis is complete cytoreductive surgery. A major disadvantage of the closed technique is the uneven distribution of the perfusion solution in the peritoneal cavity, and the main advantage is better control of the perfusion, keeping of constant hyperthermia of the solution and regular repetition of manipulation, like intravenous chemotherapy. Laparoscopy determines the stage of the tumor process, refines the indications and preoperative selection for HIPEC, monitors the effects of treatment and determines locations for introducing catheters. In the review the results of the inraperitoneal chemotherapy with hyperthermia in gastric, colorectal, ovarian and other cancers are discussed as well as in diffuse malignant peritoneal mesothelioma and others.

Pleiotropic effects of sonic hedgehog on muscle satellite cells.

Muscle satellite cells are believed to form a stable, self-renewing pool of stem cells in adult muscle where they function in tissue growth and repair. A regulatory disruption of growth and differentiation of these cells is assumed to result in tumor formation. Here we provide for the first time evidence that sonic hedgehog (Shh) regulates the cell fate of adult muscle satellite cells in mammals. Shh promotes cell division of satellite cells (and of the related model C2C12 cells) and prevents their differentiation into multinucleated myotubes. In addition, Shh inhibits caspase-3 activation and apoptosis induced by serum deprivation. These effects of Shh are reversed by simultaneous administration of cyclopamine, a specific inhibitor of the Shh pathway. Taken together, Shh acts as a proliferation and survival factor of satellite cells in the adult muscle. Our results support the hypothesis of the rhabdomyosarcoma origin from satellite cells and suggest a role for Shh in this process.

Occupational and personal risk factors for musculo-skeletal disorders in fertilizer plant workers.

UNLABELLED: The aim of this study was to evaluate the impact of some personal and work-related risk factors for the occurrence and development of MSDs as well as to assess the prevalence and relative risk by means of odds ratio and 95% confidence interval. SUBJECTS: Of this comprehensive cross-sectional study were 921 workers and employees from the four main departments of the plant. The following complex of methods was applied: personal anamnesis, occupational history, physical examination, clinical laboratory testing, anthropometric examination, conventional radiography and statistical methods. RESULTS: Age is the first risk factor, discussed by authors. The data showed highly significant differences in the prevalence of MSDs--9.48% in the risk group versus 1.97% in the reference group (OR 5.21, 95% CI 2.42-11.61). Gender is the second risk factor strongly related to MSDs in combination with age. The prevalence of MSDs is higher for women over 40 years that for men over 40 years: OR is 6.43 with 95% CI 1.73-28.23 versus OR 4.66 with 95% CI 1.80-12.77). Obesity is the third risk factor for MSDs. The data showed highly significant differences in the prevalence of MSDs--7.03% in risk group versus 3.08% in reference group, OR 2.38 with 95% CI 1.10-5.30. Smoking for more than 20 years also increases the risk of developing MSDs. At this stage of the research, there is no proof of the impact of hypercholesterolemia, non-occupational or work-related strain on the development of MSDs. The authors' conclusion is that these results may support programs for health promotion and health prevention.

Somatotype and disease prevalence in adults.

We examined the association between the somatotype and its main components (endomorphy, mesomorphy and ectomorphy), and the prevalence of several chronic diseases. The data were obtained from a cross-sectional survey designed to assess somatotype and morbidity with special reference to most often diagnosed diseases. The study population comprised 524 men and 250 women. The subjects underwent laboratory tests and clinical and anthropometric examinations. Of all examined workers, 94.8% fell into the five somatotype categories; of these, 394 were endomorphic mesomorphs. The most common somatotype was endomorphic mesomorph for men and mesomorph-endomorph for women. In five disease groups, prevalence was significantly related to a somatotype. Mesomorphic endomorphs most frequently suffered from digestive system diseases (40.6%, p < 0.05), neuroses (30.1%, p < 0.05), and radiculitis lumbosacralis (15.4%). The prevalence of arterial hypertension in mesomorph-endomorphs (37.1%), endomorphic mesomorphs (35.5%), and mesomorphic endomorphs (34.3%) was equal. In both genders, those with the highest endomorphy and mesomorphy and the lowest ectomorphy, grouped by cluster analysis, were those who suffered most frequently from arterial hypertension and liver disease. The authors conclude that the somatotype having a dominant mesomorphy and marked endomorphy constitutes a risk factor as a particular predisposition toward certain diseases and requires body weight control.

Back disorders (low back pain, cervicobrachial and lumbosacral radicular syndromes) and some related risk factors.

UNLABELLED: The AIM of this study was to estimate the prevalence rates of low back pain (LBP), cervicobrachial and lumbosacral radicular syndromes (CBR and LSRS) in workers from a fertilizer plant and also to analyze the impact of several important work-related and non-occupational risk factors. SUBJECTS of this comprehensive cross-sectional study were 898 workers and employees from the four main departments of the plant. The following complex of methods was applied: neurologic history, complete neurologic status and statistical method. RESULTS: Age is the first risk factor, discussed by authors. The data showed highly significant differences in the prevalence of CBS-16.2% in the risk group vs. 10.0% in the referent group (OR 1.73, 95% CI 1.14-2.63); LBP-25.8% vs. 17.0% (OR 1.70, 95% CI 1.21-2.38) and LSRS-16.0% vs. 5.8% (OR 3.09, 95% CI 1.89-5.08). Gender is the second risk factor strongly related to LBP, CBS and LSRS. The prevalence of radicular syndromes is higher for women that for men: OR for CBS is 3.27 and 1.93 for LSRS. There is an interesting trend in the case of combined impact of age and gender among men and women of 40 or under and over 40--the risk, estimated by OR, is higher. In men over 40, overweight, obesity and heaviness of smoking, estimated by duration of smoking and daily cigarette consumption (more than 20 years and more than 20 cigarettes per day), increase the risk of developing back disorders (BD). At this stage of the research, there is no proof of the impact of hypercholesterolemia, non-occupational or work-related strain on the development of BD. The authors' CONCLUSION is that these results may support programs for health promotion and health prevention.

Complement factor I is upregulated in rat hepatocytes by interleukin-6 but not by interferon-gamma, interleukin-1beta, or tumor necrosis factor-alpha.

Complement factor I (FI) is a regulatory serine protease of the complement system which cleaves three peptide bonds in the alpha-chain of C3b and two bonds in the alpha-chain of C4b and thus prevents the assembly of the C3 and C5 convertases. We have investigated the proinflammatory cytokines IL-6, IL-1beta, TNF-alpha and IFN-gamma for their potential role in the regulation of FI expression. Of the investigated cytokines, only IL-6 increased the FI-specific RT-PCR signal in isolated hepatocytes, in the two rat hepatoma-derived cell lines FAO and H4IIE or in HUVECs. Quantitative competitive RT-PCR showed an IL-6 induced upregulation of FI-specific mRNA by about ten-fold. These data are in accord with Northern blot analyses in which the FI-mRNA was upregulated by IL-6 between five- and seven-fold. IL-6, but not IL-1beta, TNF-alpha or IFN-gamma also increased FI-protein levels in cell culture supernatants by about five-fold as determined by a semiquantitative immunoblot using a novel monoclonal antibody specific for rat FI.

Effect of long-term multiple nifedipine administration on the antinociceptive activity of acetaminophen.

The influence of long-term nifedipine administration on the antinociceptive activity of acetaminophen on hexobarbital sleeping time and liver monooxygenase and synthetase activities was studied in male albino mice. Nifedipine was administered orally at a dose of 25 mg/kg daily for 14 and 21 days. The nociceptive response was determined by the acetic acid writhing test. There was no significant difference in the antinociceptive effect of acetaminophen after treatment with nifedipine for 14 days. Nifedipine caused enzyme induction, which was demonstrated by shortened hexobarbital sleeping time, enhanced ethylmorphine-N-demethylase (EMND), aniline-4-hydroxylase (AH), ethoxycoumarine-O-deethylase (ECOD), UDP-glucuronyl transferase (UDPGT), glutathione-S-transferase (GST) and NADPH-cytochrome c reductase activity and increased content of cytochrome P450 and cytochrome b5. It is assumed that this effect of nifedipine on acetaminophen analgesia is associated with the changes (acceleration) in acetaminophen metabolism in the liver after repeated administration of the drug.

Induction of functional anaphylatoxin C5a receptors on hepatocytes by in vivo treatment of rats with IL-6.

In normal rat liver, anaphylatoxin C5a receptors (C5aR) are only expressed by nonparenchymal cells, mainly Kupffer cells and hepatic stellate cells, but not by parenchymal cells, i.e., hepatocytes (HC). Nevertheless, C5a stimulates glucose output by HC. This HC-specific defense reaction is induced indirectly via prostanoids secreted by the C5aR-expressing Kupffer cells and hepatic stellate cells. It is shown here that under inflammatory conditions simulated by in vivo treatment of rats with IL-6 C5aR mRNA and protein were induced in HC in a time-dependent manner. Maximal mRNA and protein expression were observed at 4-8 h and 8-10 h, respectively, after IL-6 injection. The newly expressed receptors were functional, because recombinant rat C5a significantly activated glycogen phosphorylase in HC isolated from IL-6-treated but not in HC from control rats. In perfused livers of IL-6-treated animals in contrast to control animals, recombinant rat C5a-induced glucose output was not impaired by inhibition of prostanoid synthesis and function with the cyclooxygenase inhibitor indomethacin and the thromboxane receptor antagonist daltroban. These results indicate that HC-specific defense reactions might be differently regulated under normal and inflammatory conditions as shown here for the indirect prostanoid-dependent or direct C5a-induced activation of hepatocellular glycogen phyosphorylase and glucose output in control or IL-6-treated rats, respectively.

Nutrition, nutritional behavior, and obesity.

THE PURPOSE: Of this investigation is to explore the effect of several alimentary factors--such as diet, nutritional habits, and personal preferences--upon the occurrence of obesity. SUBJECTS: Of the study were 264 workers (203 men and 61 women) from the ammonium production department of a fertilizer plant, divided into two age groups: under 30 years and over 30 years. METHODS: The data are collected by means of a questionnaire about daily nutrition, including the types and average quantity of food (Food Frequency Questionnaires--FFQ). All collected information is analyzed by means of a computer program with a database that includes the chemical structure of food products and takes into account the losses in their nutritional value that occurs in the course of preservation and thermal processing. The nutritional status is assessed on the basis of a Body Mass Index (BMI): group I--normal body mass--BMI 18.5-25 kg/m2; group II--overweight--BMI 25.1-30 kg/m2; group III--obesity--BMI > 30 kg/m2. RESULTS: The assessment of the individual energy intake shows that hyper-energetic nutrition is typical for 67% of the individuals examined. There is no significant age and/or gender difference. This is the result of extra-intake of fat (over 30 E%), which is observed for 87.9% of all workers, and over 40 E% for almost half of the women examined. All age and gender groups display hyper-protein nutrition with pronounced cellulose (fiber) deficit, high daily intake of sodium, and disbalance of mineral salts as well as a relative deficit of vitamin A, B1, and PP. The frequency of overweight individuals is 43.9%, while that of obese individuals is 23.1%. The majority of workers (70.1% of group I, 63.2% of group II, and 79% of group III) have three meals a day. For 43% of group III individuals dinner is the largest meal. A significantly higher percentage of group III individuals (21.3%) think that they overeat. CONCLUSIONS: Hyper-energetic, disbalanced nutrition, and incorrect nutritional-behavioral model are factors that determine the prevalence of overweight and obesity among the workers examined.

Risk assessment of the occupational contact with ammonium.

The aim of the cohort retrospective study was to analyze and evaluate the influence of certain factors (age, profession, smoking) on the characteristics and the incidence rate of the upper respiratory tract diseases (URTDs) in the occupational contact with ammonium. Subjects were 180 men, divided into 3 professional groups. The average shift concentrations of ammonium were measured in the permanent work places and individually by personal passive dosemeters. The URTDs were classified into 15 groups according to localization and the stage of the inflammatory process. The relationships "time-response" and "dose (concentration)-response" were determined. The factor "cumulative exposure" was used in order to evaluate the actual noxious effect of NH3 on the mucose of the upper respiratory tract (URT). There was a statistically reliable difference found in the incidence rate of atrophic rhinitis, hypertrophic pharyngitis and laryngitis, and neoplasms of the URT in the workers with the highest cumulative exposure. For this group relative risk was 4.00, 2.22, 3.20 and 4.00, respectively, with 95% Cl. The "cumulative exposure" factor gives the best proofs for the toxic effect of ammonium and a possibility for assessment of the relative risk.

Somatotype, nutrition, and obesity.

UNLABELLED: The purpose of this investigation is to evaluate the somatotype characteristics of the studied group and search for a relation between somatotype, obesity, and particular features of nutrition. METHODS: Somatotype after Health & Carter (1990), nutritional status according to Body mass index (BMI), and nutrition determined by food-frequency questionnaires. RESULTS: Over 94% of the subjects in this study were distributed into five somatotype categories: 51.6% endomorphic mesomorphs, 17.1% mesomorph-endomorphs, 16.7% mesomorphic endomorphs, 6.1% balanced mesomorphs, and 3.0% ectomorphic mesomorphs, with a pronounced sexual dimorphism. Males were distributed into five categories: over 65% were endomorphic mesomorphs, and above 40 years of age the mesomorphy increased. Females were distributed into three somatotype categories: up to and above 40 years of age over 44% were mesomorphic endomorphs. In the most common somatotype categories, 1 of 5 subjects (from 21.4% to 19.9%) had normal body mass (< 25 kg/m2), 4 of 5 subjects (from 34.2% to 52.6%) were overweight (> 25 kg/m2) or obese (> 30 kg/m2) kg/m2 (from 44.4% to 27.5%). In the remaining eight categories, all subjects had normal body mass. Hyperenergetic, sodium- and fat-excess nutrition had an especially unfavorable influence.

Changes in rat liver monooxygenase activities after administration of atenolol, nifedipine and diltiazem alone and in combination.

The effects of the Ca2+ antagonists nifedipine (NF) and diltiazem (DL) and of the cardioselective beta 1-adrenergic blocking agent atenolol (AT) on the hexobarbital (HB) sleeping time and on the activity of some liver drug-metabolizing enzyme systems in male Wistar rats were studied. Two hours after single oral administration, atenolol (150 mg/kg) did not change hexobarbital sleeping time, while nifedipine (50 mg/kg) and diltiazem (30 mg/kg) prolonged it by 171.2 and 99.6%, respectively. Coadministration of atenolol with diltiazem or with nifedipine significantly prolonged hexobarbital sleep by 205 and 283%, respectively. Administered alone, atenolol decreased the ethylmorphine-N-demethylase (EMND) activity, but the amidopyrine-N-demethylase (APND) activity was not changed in any of the treated groups. Atenolol and nifedipine significantly increased aniline-4-hydroxylase (AH) activity and this effect was also observed with the combinations AT + NF and AT + DL. The NADPH cytochrome P-450 reductase activity was significantly decreased by nifedipine and diltiazem. Only nifedipine increased the total content of cytochrome P-450 (by 23.8%). Atenolol and diltiazem tended to increase the content of cytochrome b5 which was increased by nifedipine by 97.6%. The same effect was observed with the combinations AT + NF and AT + DL. The results suggest that NF, AT + NF and AT + DL produced the manifested changes in hepatic oxidative metabolism. The decreased EMND activity by atenolol, however, and the prolongation of hexobarbital sleeping time by nifedipine, diltiazem and their coadministration with atenolol did not correlate with enhanced microsomal P-450 and b5 content.

Effects of nifedipine, verapamil, diltiazem and trifluoperazine on the antinociceptive activity of acetaminophen.

The influence of the calcium channel blockers (CCBs) nifedipine, verapamil and diltiazem, and the calmodulin antagonist trifluoperazine on the antinociceptive activity of acetaminophen was studied in male albino mice. The nociceptive response was determined by the acetic acid writhing test. Nifedipine (50 or 20 mg/kg), verapamil (20 mg/kg), diltiazem (70 mg/kg) and trifluoperazine (3 mg/kg) were administered orally alone or 1 h before acetaminophen (100 mg/kg). Nifedipine (50 mg/kg), verapamil, diltiazem and trifluoperazine administered alone demonstrated significant antinociceptive effects compared to controls. Nifedipine, verapamil, diltiazem and trifluoperazine applied 1 h before acetaminophen potentiated its antinociceptive activity, which was strongest in mice injected with verapamil and nifedipine (20 mg/kg). It was established that 1 h after nifedipine (50 mg/kg) treatment, cytochrome P450 content, NADPH cytochrome c reductase and ethylmorphine-N-demethylase (EMND) activities were increased in the liver microsomes. Verapamil, diltiazem and trifluoperazine did not change the drug metabolizing enzymes studied. It is assumed that their effect on acetaminophen analgesia is not associated with the changes in acetaminophen oxidative metabolism in the liver.

In vitro effects of calcium channel blockers and beta-adrenergic blocking agents on microsomal lipid perocidation and cytochrome p-450 content.

The effects of the calcium channel blockers (CCB) nifedipine (N), verapamil (V) and diltiazem (D) and the beta adrenergic blocking agents (BAB) propranolol (P) and atenolol (A) administered alone or in combination on lipid peroxidation (LPO) and cytochrome p-450 content were studied in rat liver microsomes. The drugs were tested in concentrations of 1 mM. V, A and P alone significantly decreased TBARS formed after in vitro stimulation of LPO by Fe2+ and ascorbate, whereas no antioxidant effect was found for N and D. A correlation between the antioxidant capacity of the drugs and their ability to protect cytochrome p-450 after in vitro stimulation of LPO was observed except for propranolol. Moreover, propranolol abolished cytochrome p-450 protecting effect of verapamil when administered together. A direct, LPO-independent decreasing effect on cytochrome p-450 was observed upon in vitro incubation of microsomes with propranolol. The results are discussed in terms of LPO-dependent degradation of cytochrome p-450, formation of propranolol reactive metabolites and propranolol-dependent changes in cytochrome lipid environment.

Nutrition, nutritional habits, obesity, and prevalence of chronic diseases in workers.

The purpose of the present investigation is to reveal the specifics of the nutrition, nutritional behavior (habits), the prevalence of obesity and of certain chronic diseases among workers. The subjects were 264 workers (203 males and 61 females) from the ammonium production department of a fertilizer plant, divided into two age groups: under and over 30 years of age. The data were collected by means of a food-frequency questionnaire about daily nutrition and the average quantity of food. The nutritional status was assessed on the basis of BMI. All workers underwent clinical examinations conducted by a range of different experts, including an internal diseases specialist, a neurologist, a cardiologist, an opthalmologist, an otorhino-laryngologist, and a dermatologist. Twenty hematological and biochemical indicators in blood and serum were measured. Assessment of the individual energy intake showed that hyperenergetic nutrition was typical of 67% of workers because of extra intake of fat, which was seen in 87.9% of all individuals examined. The daily fat intake of over 40E% was typical for almost half the females (45.9%). All age and gender groups displayed hyperprotein nutrition with pronounced cellulose (fiber) deficit and a high daily sodium intake. The frequency of overweight individuals (BMI = 25, 1-30 kg/m2) was 43.9%, whereas that of obese individuals (BMI = > 30 kg/m2) was 23.1%. A total of 67% of workers had excessive body mass. The hypertension prevalence rose significantly from 6.9% in Group I to 34.5% in Group II, and to 57.4% in Group III. Coronary heart disease was rare, but the seven cases registered were among the overweight workers. The radiculitis prevalence among workers with normal body mass was two-fold lower in comparison with both groups (overweight and obesity). We conclude that hyperenergetic and unbalanced nutrition is a factor that determines the prevalence of overweight and obesity. A significantly higher percent of overweight and obese workers suffered from hypertension, liver disease, diabetes, coronary heart disease, and eye-vessel diseases. A tendency toward rising radiculitis and musculoskeleton system disease prevalence was seen that parallels the increase in BMI.

Combined effect of propranolol with nifedipine or with diltiazem on rat liver monooxygenase activities.

The effects of two Ca2+ antagonists nifedipine (NF) and diltiazem (DL) and of the nonselective beta-adrenergic blocking agent propranolol (PR) on the hexobarbital (HB) sleeping time and on the activity of some liver drug-metabolizing enzyme systems in male Wistar rats were studied. Two h after single oral administration PR (50 mg/kg) did not change HB sleeping time, while NF (50 mg/kg) and DL (30 mg/kg) prolonged it by 171.2 and 99.6%, respectively. Coadmistration of PR with DL or with NF significantly prolonged HB sleep by 240.7 and 129%, respectively. Only NF increased aniline 4-hidroxylase (AH) activity (by 92%) and the total P-450 content (by 24%). PR and NF increased cytochrome b5 content and this effect was also observed with the combinations PR + NF (by 109%) and PR + DL (by 102%). The NADPH cytochrome P-450 reductase activity was significantly decreased by NF and DL and after their combination with PR. The ethymorphine-N-demethylase (EMND) and amidopyrine-N-demethylase (APND) activities were not changed. The effects of PR, NF and DL administrated alone or in combination on liver oxidative metabolism are considered as possible mechanisms of drug interactions.

New competitive enzyme-linked immunosorbent assay for determination of metallothionein in tissue and sera.

Very little information is available concerning the relationship between metallothionein (MT) and diseases in humans. Several methods to measure MT levels exist but many of these assays are not sensitive to measure MT in human sera. A new sensitive competitive ELISA system has been developed using MT labeled with horseradish peroxidase as a conjugate and high-titre polyclonal antibodies obtained from rabbit immunoglobulin G for MT determination in human sera. The cELISA proposed here permits a reliable determination of MT in the range 10-2 000 000 pg ml(-1). The method was compared with Cd-hem assay and showed good agreement of results. The recovery of the assay was determined by spiking rat MT into rat and human sera, and comparing it with spiked diluent controls. The overall recoveries of the added MT were 101% for rat sera and 89% for human sera. The variation within-assay and between assay were 3 and 6%, respectively. A significant difference (P<0.001) was found between the MT-level in human sera from patient with essential hypertension (646+/-223 ng ml(-1), n=90) and normotensive subjects (21+/-18 ng ml(-1), n=236). A correlation between arterial hypertension and MT-level seems possible. A very sensitive new cELISA method was presented for determination of MT in sera and tissues. It enables investigation of possible correlations between sera MT-concentration and certain diseases.

Effect of multiple administration of calcium antagonists on lipid peroxidation in rat liver microsomes.

The effects of three calcium antagonists, nifedipine (NF), verapamil (VP), and diltiazem (DT), on the lipid peroxidation (LPO) in rat liver microsomes were studied. The drugs were administered in oral doses of 50, 40, and 30 mg/kg daily for 21 days in male Wistar rats. Nonstimulated LPO was significantly decreased by NF and was not changed by VP and DT. There was a correlation between the extent of the previously found enzyme-inducing action and the potency of the antioxidant effects of calcium antagonists. Fe2+/NADPH- and Fe2+/ascorbate-stimulated microsomal LPO was increased by the calcium antagonists studied in the following order: VP > DT > NF (the increase caused by NF was insignificant in Fe2+ NADPH stimulation).