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Biomedical subjects

L M Dolan

Publications and source records attributed to L M Dolan.

At least 19 recordsLinked to original sources
PubMed2001

First-phase insulin release during the intravenous glucose tolerance test as a risk factor for type 1 diabetes.

OBJECTIVE: To determine the relationship between first-phase (1 minute + 3 minutes) insulin production during the intravenous glucose tolerance test (IV-GTT) and risk factors for developing type 1 diabetes. STUDY DESIGN: Relatives of persons with type 1 diabetes (n = 59,600) were screened for islet cell antibodies (ICAs). Subjects who had positive screening results underwent IV-GTT (> or =2 times), repeat ICA screening, insulin autoantibody (IAA) screening twice, and an oral glucose tolerance test. RESULTS: Of the 59,600 subjects in the study, 2199 (3.69%) had positive findings on initial ICA test. IV-GTTs were performed in 1622 subjects, with children <8 years having the lowest first-phase insulin release (FPIR) and subjects 8 to 20 years of age having the highest FPIR. The FPIR was lower for subjects with a confirmed positive ICA test result or a positive IAA test result, subjects with higher titers of ICA or IAA, and subjects who had an abnormal (impaired or diabetic) oral glucose tolerance test result. CONCLUSION: FPIR in the IV-GTT correlates strongly with risk factors for development of type 1 diabetes.

Adolescent↗
PubMed2001

Backache in gynaecologists.

The objectives of the study were to assess the overall prevalence of backache in gynaecologists and determine its impact on work, and to identify possible occupational risk factors. The sample comprised gynaecologists, both active and retired, listed as members of the Ulster Obstetrical and Gynaecological Society, who were asked to complete and return a postal questionnaire. The response rate was 94% (107/114). The prevalence of backache, which included pain arising in the thoracic and lumbosacral regions, was 72%. Fifty-three per cent of those with back pain blamed it on working in obstetrics and gynaecology. Overall, 32% of gynaecologists required a change of their work practice, 20% had taken time off work and 8% had required surgery. We conclude that significant morbidity results from backache in gynaecologists. This has economic implications and requires further assessment to improve prevention, with emphasis on individual training and ergonomic evaluation of work-related postures.

Adult↗
PubMed2001

The levonorgestrel intra-uterine system: therapeutic application in family planning.

OBJECTIVE: To assess the non-contraceptive benefits of the levonorgestrel intra-uterine system 12 months following insertion in a family planning setting. DESIGN: Postal questionnaire survey. SETTING: Family planning clinics at the Ulster and Bangor Hospitals. SUBJECTS: Eighty-six consecutive subjects fitted with the levonorgestrel intra-uterine system. RESULTS: Response rate 87.3%. Outcome measured in terms of compliance, satisfaction and menstrual symptomatology. Reasons for insertion were as follows: 21.7% contraception only; 65.2% menorrhagia, 24.6% dysmenorrhoea and 1.4% premenstrual syndrome. Duration of menses was 8.25 days pre-insertion and 2.41 days at 12 months. Of the subjects, 59.4% experienced at least one hormonal side effect; 10.1% of systems were removed within 12 months. At 12 months 86.9% of women were satisfied and 9.8% of women planned to discontinue. CONCLUSION: The levonorgestrel intra-uterine system was acceptable to almost 80% of women after 12 months, with significant reduction in duration of menses. Family planning clinics are an ideal setting to implement the guidelines for the initial management of menorrhagia.

Adolescent↗
PubMed1999

The type 2 family: a setting for development and treatment of adolescent type 2 diabetes mellitus.

OBJECTIVE: To identify physical, behavioral, and environmental features of adolescents (aged 11-17 years) with type 2 diabetes mellitus and their families to define the involvement of known risk factors and to define a profile of at-risk individuals. DESIGN AND METHODS: A total of 42 subjects from 11 families with an adolescent in whom type 2 diabetes was previously diagnosed participated. All subjects underwent anthropometric measurement and completed food frequency and eating disorder questionnaires, and were classified according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. In addition, laboratory tests to determine levels of hemoglobin A1c, fasting glucose, C peptide, insulin, and proinsulin were performed. RESULTS: Type 2 diabetes had been diagnosed in 5 of 11 mothers and 4 of 11 fathers before the study. Type 2 diabetes was diagnosed in 3 of the remaining 7 fathers during the study. In 3 families, both parents were affected with type 2 diabetes. As a group, participants were obese, with a body mass index higher than the 95th percentile for probands and fathers, and higher than the 85th percentile for mothers and siblings. The sum of skin fold measurements was above the 95th percentile for the probands, their siblings, and the parents. All groups had high fat intake and low fiber intake. None of the subjects participated in a structured or routine exercise program, and most reported no regular physical activity. Three of the probands met the criteria for binge-eating disorder, and 6 additional patients had notable characteristics of the disorder. Mothers affected with type 2 diabetes had markedly abnormal hemoglobin A1c levels, indicating poor control. There were no group differences in fasting concentrations of insulin, proinsulin, or C peptide. However, a third of the mothers with type 2 diabetes, and all but 1 of the siblings, had evidence of insulin resistance. CONCLUSIONS: Adolescents in whom type 2 diabetes has been diagnosed, as well as their first-degree family members, are obese. In addition, the incidence of diagnosed and undiagnosed type 2 diabetes or of insulin resistance in the families of adolescents with type 2 diabetes is striking. Probands and other family members have lifestyles characterized by high fat intake, minimal physical activity, and a high incidence of binge eating. These findings indicate that the families of adolescents with type 2 diabetes share many anthropometric and lifestyle risk factors. The design of treatment programs for adolescents with type 2 diabetes will need to address the lifestyle and health habits of the entire family.

Adolescent↗
PubMed1999

Urinary incontinence in Northern Ireland: a prevalence study.

OBJECTIVE: To determine the prevalence of urinary incontinence in a Northern Ireland community drawn from four neighbouring geographical areas and to assess factors predisposing to the development of urinary incontinence. SUBJECTS AND METHODS: A three-page self-administered postal questionnaire was sent to 1050 women (age range 35-74 years), recruited randomly from a target population of 43 829 women. The main survey was preceded by a pilot survey. Respondents and those not responding were compared. RESULTS: The overall response rate was 65.6% (689/1050); there was no significant difference between respondents and those not responding. Two-hundred and thirty-one women (33.5%) reported incontinence 'sometimes' and 161 (23.4%) 'often'. Of those who had urinary incontinence, sanitary protection was required by 21.7% (85/392). This equates to 12.3% (85) of the total study population. Age (chi2=20.34; P<0.001) and parity (Mann-Whitney U-test, P< 0.001) were associated with urinary incontinence, with a higher proportion of women aged 45-54 years having urinary incontinence. The menopause and postnatal pelvic floor exercises were not associated with urinary incontinence. Overall 19.9% (78/392) of women with urinary incontinence had consulted their general practitioner. Of those who required sanitary protection, 40% (34/85) had consulted their doctor. CONCLUSION: Urinary incontinence is common; it is sufficiently severe to require sanitary protection in 12% of women aged 35-74 years in a Northern Ireland community.

Adult↗
PubMed1998

Nocturnal blood pressure in young patients with insulin-dependent diabetes mellitus: correlation with cardiac function.

Lack of a decline in nocturnal blood pressure is associated with an adverse effect on end organs in adults with insulin-dependent diabetes mellitus (IDDM). The role of the decline in nocturnal blood pressure in young patients with IDDM is not known. We studied 25 white subjects with IDDM (age = 20.8 +/- 3.7 years, mean +/- SD), 8 of whom were female. The duration of IDDM in these subjects was 12.9 +/- 5.4 years (mean +/- SD). We determined the values for glycosylated hemoglobin (HgbA1), 24-hour ambulatory blood pressure, diastolic cardiac function (the ratio of peak E wave to peak A wave velocity (E/A) and indexed peak filling rate ¿PFR/SV¿ by Doppler echocardiography), and albumin excretion rate. The HgbA1 level was 10.9% +/- 1.9% (mean +/- SD; normal range = 4.5%-8.5%). The HgbA1 concentration was inversely correlated (p < 0.005) with the decline in systolic (r = 0.57) and diastolic (r = -0.55) nocturnal blood pressure. Diastolic cardiac dysfunction ¿E/A ratio [r = 0.42, p < 0.03) and PFR/SV (r = 0.52, p < 0.01)¿ correlated with a smaller decrease in nocturnal diastolic blood pressure. An inverse correlation between decline in nocturnal systolic blood pressure and log albumin excretion rate (r = -0.37, p = 0.07) approached statistical significance. We conclude that poor glycemic control adversely affects nocturnal blood pressure and that the latter may play an important role in cardiac and possibly renal dysfunction in early IDDM.

Adolescent↗
PubMed1998

Diastolic dysfunction in young patients with insulin-dependent diabetes mellitus as determined by automated border detection.

Diastolic dysfunction is an early harbinger for systolic dysfunction in insulin-dependent diabetes mellitus (IDDM). To determine the role of automated border detection (ABD) in detecting diastolic abnormalities and whether IDDM control correlates with abnormalities, 21 young IDDM patients (22 +/- 4 years old) and 19 control subjects underwent echocardiography. ABD indices included the percent contribution to total left ventricular filling of the three phases of diastole (rapid filling, diastasis, and atrial contraction) and peak filling rate. Doppler indices included E/A ratio and peak filling rate. Rapid filling phase was lower in the IDDM patients compared with control subjects (73% +/- 5% versus 80% +/- 5%, p = 0.0006), and atrial contraction filling was higher (19% +/- 4% versus 14% +/- 3%, p = 0.0003). Doppler indexes showed similar changes. Glycosylated hemoglobin, insulin dosage, and duration of IDDM since puberty were associated with filling abnormalities. Young patients with IDDM have increased atrial contraction and reduced rapid filling phases detected by automatic border detection, and these diastolic abnormalities are related to the diabetic disease process.

Adult↗
PubMed1997

Diabetic ketoacidosis among obese African-American adolescents with NIDDM.

OBJECTIVE: To determine whether ketosis at the time of presentation occurs among African-American adolescents with NIDDM. RESEARCH DESIGN AND METHODS: We reviewed the charts of all islet cell antibody (ICA) negative patients diagnosed with NIDDM at Children's Hospital Medical Center (CHMC) between 1982 and 1995. RESULTS: Between 1982 and 1985, 70 adolescents were diagnosed with NIDDM. Of these, ICA determinations were available and negative on 42 subjects (28 African-American, 12 white). Twelve of 28 (42%) African-American patients presented with ketonuria, and seven of 28 (25%) presented with DKA. In comparison, none of the 12 white adolescents with NIDDM had ketonuria at presentation or during their subsequent course. Mean follow-up time for patients with ketosis at presentation was 24 months. There was no difference between the age, BMI, or sex distribution of patients with and without ketosis. Previously diagnosed hypertension was present in 42% of patients presenting with ketosis, compared with 17% of the general NIDDM population at CHMC. CONCLUSIONS: We conclude that ketosis may occur among African-American adolescents with NIDDM, as has been previously reported among African-American adults with NIDDM. Therefore, ketosis in obese young African-American patients with new-onset diabetes does not necessarily imply the presence of IDDM and insulin dependence.

Adolescent↗
PubMed1996

Increased incidence of non-insulin-dependent diabetes mellitus among adolescents.

OBJECTIVE: To determine whether a rise in the diagnosis of non-insulin- dependent diabetes mellitus (NIDDM) has accompanied the rise in obesity in the pediatric population, as it has among adults. STUDY DESIGN: Medical records of 1027 consecutive patients from birth to age 19 years with a diagnosis of diabetes from 1982 to 1995 at a regional, university-affiliated pediatric diabetes referral center were reviewed and classified according to criteria of the National Diabetes Data Group. RESULTS: The number of patients with a diagnosis of NIDDM rose from approximately 4% of new diagnoses of diabetes in patients from birth to age 19 years before 1992, to 16% in 1994. Among patients 10 to 19 years of age, NIDDM accounted for 33% of diagnoses of diabetes in 1994. The incidence of adolescent NIDDM in Greater Cincinnati increased tenfold, from 0.7/100,000 per year in 1982 to 7.2/100,000 per year in 1994. The mean (+/- SD) age and body mass index at presentation were 13.8 +/- 1.9 years and 37.7 +/- 9.6 kg/m2, respectively. The overall female/male ratio was 1.7:1, and female patients were seen 1 year earlier than male patients (p < 0.01). Male subjects had a higher body mass index than female subjects (p < 0.05). A first-degree relative with NIDDM was identified for 65% of patients. At presentation, 21% of the patients had had a diagnosis of at least one other condition associated with obesity. CONCLUSION: There is an increasing incidence of NIDDM among adolescents in Greater Cincinnati, accompanying the national rise in adolescent obesity. Obesity and strong family histories of NIDDM are important risk factors. Because NIDDM leads to long-term morbidity, the prevention of obesity as well as early identification of overt disease, is critical.

Adolescent↗
PubMed1996

6-Hydroxymelatonin sulfate excretion in human puberty.

We investigated the relationship of urinary excretion rate of 6-hydroxymelatonin sulfate (SM), the main metabolite of melatonin, with pubertal development and determined the day to day variability of SM excretion. Healthy subjects 4-31 years old completed one or multiple timed overnight urine collections. SM excretion rate per body size was significantly higher in 99 prepubertal subjects (35.5 +/- 2.3 ng/h/kg and 0.97 +/- 0.06 microgram/hr/m2) than in 86 pubertal subjects (18.1 +/- 1.1 ng/hr/kg and 0.61 +/- 0.03 microgram/hr/m2) or in 29 adults (15.0 +/- 1.5 ng/hr/kg and 0.59 +/- 0.06 microgram/hr/m2); no significant difference was present in pubertal stages 2 to 5. Among the prepubertal children, SM excretion rate in mid childhood was significantly higher than in late childhood. The variability of SM and creatinine excretion examined in 52 children, adolescents and adults with three or four collections was defined as the mean of the 52 coefficients of variation for the multiple measures in each subject. The variability of total nocturnal SM (25.9 +/- 2.6%) was similar to that of total creatinine (21.7 +/- 2.3%) and neither was significantly correlated with the variability in start time or duration of urine collection. The results suggest that, relative to body size, melatonin secretion rate is higher in mid childhood, decreases during late childhood, and remains stable from pubertal stage 2 to adulthood. The decline in melatonin secretion rate occurs during the developmental phase of disinhibition of the gonadotropin releasing hormone pulse generator. Hence, we infer that melatonin may be a suppressive factor of puberty during childhood. The substantial individual variability observed for SM excretion calls for caution in using single urine collections in longitudinal studies or in studies of drug responses.

Adolescent↗
PubMed1995

Absence of molecular defect in the type II 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) gene in premature pubarche children and hirsute female patients with moderately decreased adrenal 3 beta-HSD activity.

To date the molecular basis and hormonal criteria for inherited mild late-onset 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) deficiency congenital adrenal hyperplasia (CAH) have not been defined. We have thus investigated the presence or absence of mutation in the type II 3 beta-HSD gene encoding adrenal/gonadal 3 beta-HSD in each of five premature pubarche children and hirsute female patients manifesting moderately decreased adrenal 3 beta-HSD activity. ACTH-stimulated hormonal levels in all patients compared with mean levels in pubertal stage-matched normal subjects were between 2.5 and 6.5 SD for 17-hydroxypregnenolone levels, and between 2.5 and 7 SD for dehydroepiandrosterone levels in all except one patient. 17-Hydroxypregnenolone to cortisol ratios were between 2.5 and 4.3 SD, and dehydroepiandrosterone to androstenedione ratios were between 3 and 8.6 SD. The type II 3 beta-HSD gene regions of a putative promoter, exons I, II, III, and IV, and exon-intron boundaries in all subjects were amplified by polymerase chain reaction and then sequenced. All patients had normal sequences of the type II 3 beta-HSD gene in both alleles. Three female patients heterozygotic for severe 3 beta-HSD deficiency CAH with one allele mutation of the gene demonstrated normal ACTH-stimulated hormone profiles. These data indicate that moderately decreased adrenal 3 beta-HSD activity resulting in modestly increased delta 5 precursor steroid levels and delta 5 to delta 4 steroid ratios in premature pubarche and hirsute patients is not caused by a mutation in the type II 3 beta-HSD gene.(ABSTRACT TRUNCATED AT 250 WORDS)

3-Hydroxysteroid Dehydrogenases↗
PubMed1994

Genotoxicity and carcinogenicity in rats and mice of 2-amino-3,6-dihydro-3-methyl-7H-imidazolo[4,5-f]quinolin-7- one: an intestinal bacterial metabolite of 2-amino-3-methyl-3H-imidazo[4,5-f]quinoline.

BACKGROUND: Compounds formed on the surface of fried or grilled meat and fish may be associated with increased risk of colon cancer. Normal intestinal bacteria can convert one of these compounds, 2-amino-3-methyl-3H-imidazo[4,5-f]quinoline (IQ), to the 7-hydroxy metabolite, 2-amino-3,6-dihydro-3-methyl-7H-imidazolo[4,5-f]quinolin-7-o ne (7-OHIQ), a direct-acting mutagen. PURPOSE: We studied the genotoxicity and carcinogenicity of 7-OHIQ to determine if it is responsible for the colon-specific activity of IQ. METHODS: The effects of pure, synthetic 7-OHIQ on DNA were evaluated in the Ames Salmonella typhimurium TA98 test, with and without an induced rat liver S9 fraction, and in the Williams DNA repair test using freshly explanted rat hepatocytes. 7-OHIQ was also subjected to an in vivo bioassay for 21 months by long-term intrarectal infusion in male F344 rats, using IQ and N-nitrosomethylurea (NMU) given intrarectally as positive tumor-producing controls. The standard NIH-07 rodent diet was supplemented with 15% corn oil to maximize any effect of the infused materials on the colon. A parallel bioassay involved intraperitoneal injection of 7-OHIQ in newborn mice, followed by dietary administration from week 11 to week 67. Again, IQ and NMU were used as positive controls. RESULTS: We confirmed that 7-OHIQ is a direct-acting mutagen in the Ames test, with added S9 liver fraction giving higher mutagenicity. 7-OHIQ was negative in the Williams test, whereas IQ was positive. 7-OHIQ did not induce colon cancer in rats, and in the newborn mouse test it produced only a low incidence of liver neoplasms. CONCLUSIONS: 7-OHIQ is not genotoxic, for to be so classified it must be definitely positive in both the Ames and Williams tests; moreover, it is not carcinogenic, in marked contrast to IQ and NMU.

Animals↗
PubMed1994

Cardiovascular status in young patients with insulin-dependent diabetes mellitus.

BACKGROUND: Although the existence of diabetic cardiomyopathy in adults is firmly established, the presence of cardiac abnormalities in young diabetic patients is not universally accepted. We sought to determine the early stages of cardiac derangement and whether they are associated with renal dysfunction. METHODS AND RESULTS: Thirty-nine patients (29 boys; mean age, 17.6 +/- 3.4 years) with insulin-dependent diabetes mellitus underwent echocardiography and timed overnight urine collection. Echocardiographic evaluation consisted of left ventricular mass, performance (shortening fraction, velocity of circumferential fiber shortening, stroke volume, and cardiac index), preload (end-diastolic dimension and volume), after-load (end-systolic wall stress and systemic vascular resistance), and contractility (velocity of fiber shortening relative to wall stress). Creatinine clearance and albumin excretion were measured from the urine sample. Glycosylated hemoglobin levels were measured; height and weight were measured; and Quetelet index (weight/height2) was calculated. These data were compared with control data. Left ventricular mass (26 +/- 6 versus 22 +/- 6 g/ht2.7, P < .01), the indexes of performance, blood pressure, and contractility (0.14 +/- 0.14 versus 0.003 +/- 0.03 circumference/s, P < .0003) were significantly higher in the diabetic patients than in control subjects. To evaluate the correlates of left ventricular mass and contractility in the diabetic patients, univariate and multiple regression analyses were performed. Significant univariate correlations of mass included albumin excretion (r = .36, P < .02), glycosylated hemoglobin (r = .35, P < .04), and stroke volume (r = .34, P < .03). A multivariate model included Quetelet index, albumin excretion, and duration of diabetes. Significant univariate correlations of contractility included insulin dosage (r = -.36, P < .02), creatinine clearance (r = .40, P < .02), and Quetelet index (r = .34, P < .03). A multivariate model included insulin dosage and creatinine clearance. CONCLUSIONS: Early onset of diabetes mellitus is associated with increased left ventricular mass, performance, contractility, and blood pressure. These cardiovascular findings are correlated with increased creatinine clearance and microalbuminuria. These relations suggest that alterations in cardiovascular and renal function may occur in parallel in adolescents with insulin-dependent diabetes mellitus.

Adolescent↗
PubMed1993

Distribution and correlates of creatinine clearance in children and adolescents with blood pressure elevation.

The kidney has been implicated as both an etiologic factor and as a target organ in patients with essential hypertension. Renal function has not been studied extensively in children and adolescents with essential hypertension. Eighty-eight subjects, aged 6 to 23 years, with blood pressure persistently above the 90th percentile for age were studied. Creatinine clearance was determined from a single 24-hour urine collection. The mean creatinine clearance was 129.3 +/- 55.3 ml/min per 1.73 m2. Multiple regression analysis was used to investigate potential correlates of creatinine clearance. Because creatinine clearance was not normally distributed, the logarithm of creatinine clearance was used as the dependent variable. Body mass index, resting heart rate, and basal supine plasma renin activity were significant direct independent correlates. Peripheral vascular resistance at maximal exercise was an inverse correlate of the logarithm of creatinine clearance. These findings are consistent with previous studies of adults and may provide the basis for strategies to identify young patients with essential hypertension who are at risk for the development of renal dysfunction.

Adolescent↗
PubMed1992

Maternal side effects of prenatal dexamethasone therapy for fetal congenital adrenal hyperplasia.

UNLABELLED: Prenatal treatment of virilizing congenital adrenal hyperplasia in female fetuses via maternal dexamethasone (Dex) therapy (1-1.5 mg/day) from first trimester to birth was associated with excessive weight gain (47-56 pounds at 35-37 weeks gestation), Cushingoid facial features, severe striae resulting in permanent scarring, and hyperglycemic response (8-11.7 nmol/L) to oral glucose administration in all our experience (three cases). Other symptoms included hypertension, gastrointestinal intolerance, or extreme irritability. Previous pregnancies were uncomplicated by these problems. In each case, first or second trimester amniotic fluid 17-hydroxyprogesterone (17OHP, 17-41 nmol/L; normal less than 0.4 nmol/L), androstenedione (22-31 nmol/L, normal less than 5 nmol/L), and testosterone levels (0.54-0.7 nmol/L, normal less than 0.4 nmol/L) during Dex treatment were elevated regardless of the newborn genital outcome. Maternal serum estriol (E3) levels in one mother (normal newborn genitalia) were consistently low (less than 0.2 nmol/L) during the second and third trimester. In two mothers (partially virilized newborn genitalia) initial second trimester E3 levels were unsuppressed (11, 17.4 nmol/L) and suppressed (less than 1.4 nmol/L) following short-term increased dose. CONCLUSION: prenatal Dex treatment of virilizing congenital adrenal hyperplasia at a dose of 1-1.5 mg daily throughout gestation is associated with significant maternal side effects. Parents should be informed of these side effects before initiation of treatment. Careful monitoring for signs of side effects, medical intervention when necessary, and lowering of Dex dose during the second half of gestation would minimize the side effects. Maternal serum E3 levels appear useful for prediction of fetal outcome while amniotic fluid steroid levels may not.

Adrenal Hyperplasia, Congenital↗
PubMed1992

Profile of renal permselectivity by simultaneous enzyme-linked immunosorbent assay of albumin, transferrin, IgG, and alpha 1-microglobulin with a new microplate reader.

A competitive enzyme-linked immunosorbent assay (ELISA) is described for determining a renal permselectivity profile involving the urinary proteins albumin, transferrin, IgG, and alpha 1-microglobulin (alpha 1-m). The ELISA reader uses a computer-controlled array of multiplexed light-emitting diode (LED)-photodiode pairs for rapid measurements of absorbance on microplates. A 3,3'-dimethylnaphthidine reagent adapts the 3,5,3',5'-tetramethylbenzidine chromophore to monochromatic LED emission at 550 nm. We applied this ELISA to the determination of renal permselectivity in healthy children and young adults and in children with insulin-dependent diabetes mellitus. The geometric means (and SD) of protein excretion rates in a group of 85 normal subjects were as follows: albumin, 3.5 micrograms/min (1.83); transferrin, 173 ng/min (2.76); IgG, 1.11 micrograms/min (2.22), and alpha 1-m, 0.98 microgram/min (2.36).

Adolescent↗
PubMed1989

Atrial natriuretic factor during the perinatal period: equal depletion in both atria.

Data in the literature concerning atrial natriuretic factor (ANF) physiology in the fetus and newborn, although limited, suggest significant activity during the perinatal period. To characterize further ANF physiology during this time, we documented immunoreactive ANF (IR-ANF) concentrations in the right and left atria before and immediately after birth as well as in the hearts of immature and adult rats. There was a significant decrease in the concentration of IR-ANF in both right and left atria on the d before birth that persisted for the first 48 h of life [d 20 fetal right 570 (106, 90), left 580 (86, 75); d 21 fetal right 270 (70, 55), left 214 (117, 75); 1 d right 206 (39, 33), left 229 (41, 35); 2-d right 352 (35, 32), left 237 (26, 23) [geometric mean (upper SE, lower SE) in ng ANF/mg protein]. Repletion of ANF stores began in the right atrium on d 2 of life and in the left atrium between d 2 and 5. The highest levels of IR-ANF were observed at d 15 [d 5 right 1439 (53,51), left 1547 (83,79); d 15 right 2034 (90,86), left 1943 (108, 102); adult right 1380 (119, 109), left 963 (118, 105)]. In contrast to normal adult animals, factors mediating the observed change affect both atria equally during the perinatal period. The concentration of IR-ANF in the right and left atrium of the fetal, newborn, and immature animals was equal. These data document significant alterations in intraatrial IR-ANF concentrations in the perinatal period.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗