Factors contributing to gender differences in serum retinol and alpha-tocopherol in infertile couples

Oxidative stress is detrimental to fertility potential. Retinol and alpha-tocopherol are natural antioxidants that inhibit lipid peroxidation and protect against cell damage induced by oxidative stress. This study evaluated whether gender-related differences in antioxidant status exist among couples with infertility and, if so, to evaluate relevant factors that may contribute to such differences. Retinol and alpha-tocopherol in the sera of 40 couples and in the semen of 40 men were measured using high performance liquid chromatography. Serum retinol and alpha-tocopherol in women were significantly higher than in men (both P < 0.001). There was an inverse relationship between body mass index and serum retinol and alpha-tocopherol in both men and women. Heavy smokers (>or=20 cigarettes/day), compared with nonsmokers, had lower serum concentrations of retinol and alpha-tocopherol. Serum concentrations of retinol and alpha-tocopherol in men with normal sperm parameters were significantly higher than in those with oligozoospermia and asthenozoospermia (both P < 0.001). Lower serum retinol and alpha-tocopherol in men compared with their female partners could be related to their older age, higher body mass index and smoking habits. Low concentrations of these natural antioxidants were associated with abnormal semen parameters in men and anovulation in women.

Maternal–fetal transport and disposition of copper, iron, molybdenum, selenium and zinc in experimentally induced diabetic rats

OBJECTIVE

To assess maternal-fetal status of essential trace elements such as copper, iron, molybdenum, selenium and zinc, in experimentally induced diabetic and control pregnant rats, and to correlate the findings with those observed in human diabetic pregnancies. Fetal-maternal ratios of the elements and Cu:Zn and Cu:Fe ratios were also computed in control and study groups.

METHODS

Diabetes was experimentally induced in pregnant Sprague Dawley rats by injection of streptozotocin. A cocktail of essential trace elements along with antipyrine as internal reference marker were then injected intra-peritoneally to diabetic and matched control pregnant rats on the 20th day of pregnancy. Maternal and fetal blood and tissue samples were collected after sacrificing the animals at 30- and 60-minutes following cocktail injection. Concentrations of trace elements and antipyrine in various blood and tissue samples were then determined by atomic absorption spectrophotometry and colorimetry, respectively.

RESULTS

Concentrations of Cu, Fe, Mo, Se, Zn, and antipyrine averaged 2907.0 +/- 212.0 microg/L, 3950.0 +/- 766.0 microg/L, 15.8 +/- 1.7 microg/L, 74.8 +/- 6.5 microg/L, 726.4 +/- 67.4 microg/L, and 170.5 +/- 8.2 mg/L, respectively, in maternal blood in control pregnant rats (n = 5) at day 20 in the 30-minute study phase, while in the diabetic group (n = 5) the values of the various trace element concentrations and antipyrine averaged 2875.0 +/- 225.0 microg/L, 5875.0 +/- 688.0 microg/L, 21.2 +/- 2.1 microg/L, 116.0 +/- 3.6 microg/L, 753.0 +/- 71.3 microg/L, and 171.7 +/- 4.2 mg/L, respectively. Unpaired student's t-test showed that Fe and Se levels were significantly higher (p < 0.05) in the diabetic pregnant rats compared to controls. Cu, Mo and Zn values, however, were not significantly different (p > 0.05) between the two groups. Cu:Zn and Cu:Fe ratios showed varying differences between maternal and fetal samples in the control and study groups.

CONCLUSIONS

Considering the disparity of results in pregnant diabetic rats and pregnant diabetic women, we urge exercising caution when comparing data from animal studies to human situations.

Antioxidant therapy is associated with a reduction in the serum levels of mediators of renal injury following lithotripsy for renal calculi

OBJECTIVE

To investigate the effects of antioxidant therapy on the levels of mediators of shock wave induced renal injury in patients with renal calculi treated with extracorporeal shock wave lithotripsy (ESWL).

PATIENTS AND METHODS

One hundred and twenty patients with renal calculi were divided into three treatment groups: Group A patients (n = 39) served as a control group; Group B patients (n = 41) were given 2 capsules of Nature Made((R)) antioxidants 2 hours before, and 2 and 8 hours after ESWL and Group C patients (n = 40) were given 2 capsules of the antioxidants at 2 and 8 hours after ESWL. Blood and urine samples were obtained from all patients just before the start of treatment with ESWL, and at 2 and 24 hours and on day 7 and 28 after ESWL. Levels of mediators of renal injury such as serum alkaline phosphatase (ALP), C-reactive protein (CRP) and lactate dehydrogenase (LDH) were measured. Urinary levels of albumin and ALP were also determined as measures of renal tubular injury.

RESULTS

Patients given antioxidants had significantly reduced mean serum concentration of ALP (p < 0.001) at 24 hours, lower serum ALP and LDH on day 7 and 28, and lowest CRP on day 28 after ESWL. They also had higher urine albumin (p < 0.001) and ALP (p < 0.001) levels (from 24 hours to day 28) compared with patients who were not given antioxidants.

CONCLUSION

These findings suggest that oral antioxidant therapy prior to lithotripsy may reduce the severity of long term renal injury caused by the shock waves.

Prostate Cancer Risk: The Significance of Differences in Age Related Changes in Serum Conjugated and Unconjugated Steroid Hormone Concentrations Between Arab and Caucasian Men

INTRODUCTION

Factors responsible for the low incidence of clinical prostate cancer (3-8/100,000 men/year) in the Arab population remain unclear, but may be related to changes in steroid hormone metabolism. We compared the levels of serum conjugated and unconjugated steroids between Arab and Caucasian populations, to determine if these can provide a rational explanation for differences in incidence of prostate cancer between the two populations.

PATIENTS/METHOD

Venous blood samples were obtained from 329 unselected apparently healthy indigenous Arab men (Kuwaitis and Omanis) aged 15-80 years. Samples were also obtained from similar Arab men with newly diagnosed prostate cancer or benign prostatic hyperplasia (BPH). The samples were taken between 8:00 am and 12:00 noon. Serum levels of total testosterone, (TT), sex hormone binding globulin (SHBG), free androgen index (FAI); adrenal C19-steroids, dehydroepiandrosterone sulphate (DHEAS) and androstenedione (ADT) were determined using Immulite kits (Diagnostic Systems Laboratories Inc, Webster Texas, USA). The results obtained in Arab men were compared with those reported for similarly aged Chinese, German and White USA men.

RESULTS

In all four ethnic groups, median TT and FAI declined with age, while SHBG increased with age. However, the mean TT and SHBG was significantly lower (p < 0.01) and the FAI significantly higher in Arab men (p < 0.01) compared to German men only in 21-30 years age group. In the other age groups the levels of TT and SHBG were higher in the Germans but the differences were not statistically significant. In all the racial groups serum levels of DHEAS and ADT reached a peak by about 20 years of life, and then declined progressively. The mean DHEAS in American Caucasians aged 20-29 years was 11.4 micromol/l compared to 6.22 micromol/l in the Arabs (p < 0.001). The mean DHEAS in USA Caucasians aged 70-79 years was 2.5 micromol/l compared to 1.8 micromol/l (p < 0.03) in the Arabs. There was no significant difference in mean serum levels of DHEAS between German and USA men. Similarly, there was no significant difference in the level of the hormones between Arab and Chinese men. Arab men with newly diagnosed prostate cancer had high serum TT, SHBG and DHEAS compared to those without the disease.

CONCLUSIONS

The mean TT and SHBG was significantly lower in Arab men compared to Caucasian men especially in early adulthood. Caucasians have significantly higher serum levels of the precursor androgens DHEAS and ADT especially in early adulthood compared to Arab men. These observations of low circulating androgens and their adrenal precursors in Arab men may partially account for the decreased risk for prostate cancer among Arab men.

Allopurinol provides long-term protection for experimentally induced testicular torsion in a rabbit model

OBJECTIVE

To assess the effect of five antioxidants on exocrine function of rabbit testes retained in situ for 24 h and 3 months after experimental torsion.

MATERIALS AND METHODS

The left testes of peripubertal rabbits were clamped for 60 min, after which the clamps were removed and the testes allowed to reperfuse. The right testes served as internal controls. There were eight rabbits in each of the following experimental groups: (a) sham; (b) 60-min ischaemia followed by reperfusion; (c) 60-min ischaemia followed by left orchidectomy. In five further groups, rabbits were exposed to 60-min ischaemia followed by reperfusion, but received one of the following antioxidants before reperfusion: acetyl salicylic acid, ascorbic acid, allopurinol, quercetin or superoxide dismutase. Both testes were excised at 24 h or 3 months. The degree of lipid peroxidation, a measure of free radical damage, was assessed in testicular tissue homogenates by measuring the tissue levels of malondialdehyde (MDA). The Johnsen score was used to assess the morphological damage at 24 h and 3 months for each group.

RESULTS

At 3 months twisted viable testes allowed to reperfuse had higher MDA levels than controls; the left testes of rabbits treated with allopurinol had significantly lower MDA levels than untreated rabbits and rabbits given other antioxidants. Rabbits given quercetin, ascorbic acid or superoxide dismutase had lower (but not significantly) left testicular MDA levels than untreated rabbits, while rabbits given acetyl salicylic acid had even higher levels. Allopurinol-treated rabbits had a Johnsen score of > 7.6 and those given other antioxidants had scores of < 7.6 at 3 months.

CONCLUSION

The twisted viable testis treated by orchidopexy contains high free radical levels at 3 months. Of the antioxidants studied, only allopurinol had a beneficial long-term effect, by significantly reducing testicular MDA levels at 3 months.

Evidence for the Presence of Beta-3-Adrenoceptors Mediating Relaxation in the Human Oviduct

Beta1- and beta2-adrenoceptors mediate relaxation in the oviductal smooth muscle. This study examines the existence and function of beta3-adrenoceptors in the human oviduct. Ring segments of the oviduct were set up for isometric tension recording. The effect of isoprenaline and BRL 37344 on smooth muscle tone was examined. The expression of beta3-adrenoceptors in the oviduct was also examined. Isoprenaline and BRL 37344 concentration-dependently relaxed circular muscles of the oviduct. BRL 37344 was less potent than isoprenaline and was a partial agonist. Propranolol shifted isoprenaline but not BRL 37344 concentration-response curve to the right without reducing the maximum response. Cyanopindolol (1 micromol/l), a beta3-adrenoceptor antagonist, shifted the isoprenaline concentration response curve to the right. The -log K(B) value of 7.8 indicates activation of beta3-adrenoceptors by isoprenaline. mRNA for beta3-adrenoceptors was expressed in the oviduct. These results suggest that beta3-adrenoceptors, mediating relaxation, are expressed in the human oviduct.

Nitric oxide metabolites in preterm and induced labor

BACKGROUND

Nitric oxide has potent relaxant effects on the pregnant uterus and has been associated with a quiescent uterus in animal and human studies. Nitric oxide donors have been used to arrest preterm labor and a reduction in nitric oxide production has been reported before the onset of labor.

OBJECTIVE

The aim of the study was to estimate the serum levels of nitrate and nitrite in women undergoing spontaneous preterm labor and induced labor.

MATERIALS AND METHOD

Venous blood was drawn from 39 patients before the onset of labor (control) and also from 17 patients undergoing induction of labor who were in active labor (study group A), and 24 patients in spontaneous preterm labor (study group B). Serum concentrations of nitrate and nitrite were estimated in the samples using the HPLC method.

RESULTS

The maternal age of the patients was similar in all the groups. There was no significant difference in the mean gestational age at delivery between the control and group-A patients (38.86 vs. 38.29 weeks); however, there was a significant difference between the control and group-B patients (38.86 vs. 30.92; p < 0.0001), and between study groups A and B (38.29 vs. 30.92 weeks; p < 0.0001). The mean serum levels of nitrite in groups A and B (0.563 +/- 0.15 and 0.512 +/- 0.13, respectively) were significantly lower than the level in the control group (0.915 +/- 0.13; p < 0.0001). Although the serum nitrate levels in study groups A and B were lower than in the control group, this difference was not significant. The maternal outcome was satisfactory but, as expected, the mean birth weight of the babies in group B (1,665.73 +/- 863.84 g) was significantly lower than the birth weights in the control and group-A patients (p < 0.0001).

CONCLUSION

There is a drop in nitric oxide production in active preterm labor and induced labor. These findings need to be confirmed in larger studies to establish the role of nitric oxide in the initiation of labor.

Nitric oxide production is not altered in preeclampsia

BACKGROUND

Preeclampsia remains a disease of theories as the real aetiology has remained elusive. Altered nitric oxide production has been associated with preeclampsia although conflicting results showing elevation, decrease or no change in nitric oxide levels have emerged from previous studies.

OBJECTIVE

The aim of the study was to measure the serum levels of nitrate and nitrite in normal pregnancies and pregnancies complicated by pre-eclampsia.

MATERIALS AND METHODS

Venous blood was extracted from 39 normal pregnant women (control) and 34 women with preeclampsia (study group). Serum concentrations of nitrate and nitrite were determined using the HPLC method. Other special investigations including renal function tests were performed. The patients were managed according to protocol and the outcome of the pregnancies evaluated.

RESULTS

There was no significant difference in the mean maternal age and gestational age at delivery between the groups. However the mean systolic and diastolic blood pressure of the study group (150.5 mmHg and 98.8 mmHg) were significantly higher than the levels in the control group, (110.86 and 85.5), p<0.0001. There was no significant difference in the mean serum nitrate levels (19.157+/-13.407 vs. 19.189+/-16.805) p=0.993. The fetal and maternal outcomes were comparable.

CONCLUSION

Our study has demonstrated that there was no alteration in nitric oxide production in preeclampsia, thus contributing to the existing unresolved role of nitric oxide in the pathogenesis of preeclampsia. Further research is called for.

Significance of simultaneous determination of serum and seminal plasma alpha-tocopherol and retinol in infertile men by high-performance liquid chromatography

High-performance liquid chromatography was used for the simultaneous determination of alpha-tocopherol and retinol in serum and semen of 40 subfertile men. The serum levels of the two vitamins were significantly higher in serum than in semen (3- to 10-fold) (P < 0.001). The mean alpha-tocopherol levels were higher in the serum and semen of men with normal sperm parameters (20 +/- 5 and 5 +/- 4 mumol L-1) than those with oligozoospermia (10 +/- 4 and 3 +/- 2 mumol L-1), azoospermia (8 +/- 3 and 3 +/- 1 mumol L-1) and asthenozoospermia (9 +/- 6 and 3 +/- 2 mumol L-1) (P < 0.002). Mean retinol levels in serum were similar in men with normal sperm parameters (2.4 +/- 2 mumol L-1) as in those with defective sperm parameters such as oligozoospermia (2.5 +/- 2 mumol L-) and asthenozoospermia (2.1 +/- 1.0 mumol L-) (P = 0.15), but significantly lower in men with azoospermia (1.3 +/- 0.3 mumol L-1) (P < 0.05). The alpha-tocopherol:retinol ratio was significantly higher in semen than in serum of men with normal sperm parameters (11.5) and those with asthenozoospermia (10.3) compared with ratios in those with oligozoospermia (8.3) and azoospermia (6.3). This may be related to reduced antioxidant activity in sperm dysfunction as a result of lipid peroxidation, from increased generation of reactive oxygen species.

Effect of saline and glucose infusions of oxytocin on neonatal bilirubin levels

OBJECTIVE

To ascertain the effect of isotonic saline and glucose infusions of oxytocin on neonatal bilirubin levels.

METHOD

Eighty-two parturient Nigerian women requiring oxytocin infusion in labor were randomized into two groups receiving 0.9% saline or 5% glucose, respectively. A group of 82 women not requiring oxytocin were recruited for comparison. All had sodium and bilirubin estimations in cord plasma and neonatal bilirubin assay on Day 3.

RESULT

Analysis of variance revealed higher mean cord and neonatal bilirubin levels in the glucose group compared with the other two (P < 0.05). Significant inverse correlation was observed between cord plasma sodium and neonatal bilirubin levels in all groups. Hyperbilirubinemia occurred in 55% of babies in the glucose group compared with 21% and 22% in the saline and control groups, respectively (P < 0.001).

CONCLUSION

The use of isotonic saline rather than 5% glucose solution as vehicle for oxytocin infusion in labor appears to be associated with lower neonatal bilirubin levels.

A pilot study on the assessment of a progesterone/estradiol sustained release as once-a-month-injectable contraceptive

A pilot study to assess the use of natural hormones in macrocrystalline sustained release system was undertaken in normal menstruating women. Progesterone at a dose of 100 mg in combination with 5 mg estradiol-17 beta aqueous macrocrystalline suspension (3ml) of defined particle size range (100-250 microns) were administered to five female volunteers of reproductive age, on day 5 of their normal menstrual cycles and then every 28 days consecutively for the next two months. Peripheral venous blood samples were obtained from the women three times a week for 60 days after the third injection for the measurement of serum progesterone, estradiol-17 beta, LH and FSH. The menstrual bleeding patterns were closely monitored during the study period. The results obtained indicate that the exogenous hormone administration produces blood levels similar to those observed during the luteal phase of the menstrual cycle. Follicular maturation as assessed by endogenous estradiol rise, above 150 pg/ml, occurred 29.7 days s.d. 6.4 after the injection. Ovulation as measured by progesterone levels above 5 ng/ml was documented 34.4 days s.d. 4.3 after the third injection. The bleeding patterns were regular though initially shorter but these increased progressively towards normal pattern during course of the study. The data suggest that progesterone/estradiol-17 beta combination administered as an aqueous macrocrystalline suspension is capable of producing sustained ovulation inhibition and could be applied in the design of new once-a-month injectable contraceptives.

Clinical, hormonal and biochemical features of menopausal women in Ibadan, Nigeria

As a result of the general lack of information about the menopause in Nigeria this study was conducted to determine the prevalence of climacteric symptoms in a cohort of healthy perimenopausal women and also to evaluate the hormonal and biochemical profile of the subjects. Seventeen menopausal and 19 premenopausal women aged 40 years or more were interviewed and had venepuncture and collection of 24-h urine samples. Plasma from the blood samples was used for the assay of LH, FSH, progesterone, 17 beta-oestradiol, calcium and cholesterol while urinary calcium was determined from the 24-h urine samples. The data revealed a significant difference in the prevalence of the symptoms of vasomotor instability (hot flushes, palpitations and excessive sweating) among the menopausal group when compared with the premenopausal group. Furthermore, plasma gonadotrophin levels (LH and FSH) were significantly elevated while plasma oestradiol and progesterone levels were lower in the menopausal women than in the premenopausal group. With regards to the biochemical indices evaluated, only 24-h urinary calcium levels were found to be significantly different for the two groups, with higher levels in the menopausal women. The significance of these findings and the need for adequate screening and treatment of selected menopausal women are discussed.

Sequential hormone measurements after menstrual regulation in normal Nigerian women

The objective of this study was to examine the dynamics of the pituitary hormones (LH, FSH and Prolactin) and Progesterone in normal adult Nigerian women during the first cycle after a menstrual regulation for delayed periods. Hence, eleven healthy volunteers aged between 19 and 35 years were recruited. All the subjects had consulted the Family Planning Clinic for menstrual regulation. Venepuncture was performed immediately before and every other day after the procedure until the onset of the first menstrual period. Serum from the samples were stored at -20 degrees C and later assayed for LH, FSH, Prolactin and Progesterone. The results showed that nine patients (82%) had a demonstrable LH peak whilst seven patients (64%) had a luteal phase serum progesterone in excess of 6 nmol/l. These criteria were used for the diagnosis of ovulation. The combination of two or three indices i.e. LH + FSH peak (64%) LH + Progesterone (64%) LH + FSH + Progesterone (55%) did not seem to confer any special advantages in terms of the diagnosis of ovulation. These results are considered as further evidence for the need to provide contraception in the first cycle after an abortion in women who do not wish to get pregnant immediately.