Displaying publications 1 - 20 of 56 in total

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  1. Tan GJ, Kwan TK
    Contraception, 1987 Sep;36(3):359-67.
    PMID: 3677679
    The effect of oxytocin on testicular function was examined in the adult male long-tailed macaques (Macaca fascicularis). The monkeys were either infused with increasing concentrations of synthetic oxytocin (16-128 m.i.u./min for 3 h) or injected daily for a week with the same hormone (20 i.u., i.v.) and the plasma testosterone levels measured. The results of the present study show that acute infusion or chronic injection of oxytocin does not significantly affect the plasma testosterone levels, suggesting that systemic control of testicular endocrine function by oxytocin may be unimportant.
    Matched MeSH terms: Testosterone/blood*
  2. Tan TT, Lui SK, Satgunasingam N, Khalid BA
    Med J Malaysia, 1989 Dec;44(4):302-6.
    PMID: 2520038
    62 cases of polycystic ovary syndrome (PCO) were reviewed with regards to their clinical and endocrine features. The subgroup of patients with acanthosis nigricans (AN) was further studied in detail. The prevalence of the syndrome was significantly higher in the Indian (35.5% of cases). Obesity, AN, hirsutism, non-insulin dependent diabetes mellitus (NIDDM) and raised level of serum testosterone were present in 77.1%, 74%, 79%, 21% and 48% of the cases respectively. Patients with AN was associated with higher body mass index, serum testosterone level, and prevalence of hirsutism and NIDDM than patients without AN. These observations are in keeping with the hypothesis that hyperinsulinemia may be of importance in the pathogenesis of a sub-group of PCO associated with insulin resistant states.
    Matched MeSH terms: Testosterone/blood
  3. Chow WP, Loganath A, Peh KL, Chew PC, Gunasegaram R, Ratnam SS
    Med J Malaysia, 1993 Mar;48(1):56-63.
    PMID: 8341173
    This study investigated whether changes in circulating levels of immunoreactive oestradiol-17 beta (E2), progesterone (P) and testosterone (T) occur in women at follicular (n = 18, age 25 to 39 years) and luteal (n = 17, 25 to 39 years) phases of the normal menstrual cycles, experiencing laparoscopy after intravenous sedation with general anaesthesia. The pre- and intra-operative follicular phase plasma steroid hormone concentrations were 153.5 +/- 84.3 vs 297.4 +/- 220.8 pg/ml for E2, 2.0 +/- 3.2 vs 3.3 +/- 3.8 ng/ml for P and 746.6 +/- 415.9 vs 1325.8 +/- 535.1 pg/ml for T, respectively. The corresponding luteal phase steroid levels were 259.7 +/- 120.2 vs 382.7 +/- 188.7 pg/ml, 7.0 +/- 4.8 vs 9.9 +/- 6.1 ng/ml and 819.4 +/- 355.7 vs 1703.5 +/- 1058.1 pg/ml. Using the Wilcoxon rank sum test, intra-operative hormone levels with the exception of P in the luteal phase were found to be significantly elevated (p < 0.05). The results suggest that laparoscopy under general anaesthesia evokes increased secretion of ovarian hormones, possibly via the activation of hypothalamo-pituitary-ovarian axis.
    Matched MeSH terms: Testosterone/blood*
  4. Nwe KH, Morat PB, Hamid A, Fadzilah S, Khalid BA
    Exp. Clin. Endocrinol. Diabetes, 1999;107(5):288-94.
    PMID: 10482040
    The 11beta-hydroxysteroid dehydrogenase (11beta-HSD) protects the testis from the inhibitory effects of corticosterone on testosterone (T) production. The objectives of the present studies were to determine the effects of deoxycorticosterone (DOC) and its mechanism of actions on testicular 11beta-HSD activity and plasma T levels after 7 days of treatment. The results revealed that at the end of 7 days treatment, DOC significantly increased testicular 11beta-HSD activity and plasma T levels in normal rats. However, the time course showed that high plasma T levels lowered 11beta-HSD activity on day 14 and by 21 days both the levels normalized. In adrenalectomized (ADX) rats, only the enzyme activity increased significantly but not plasma T levels. Spironolactone, a competitive inhibitor of mineralocorticoid receptor (MR), did not change testicular 11beta-HSD activity in both normal and DOC treated rats suggesting that DOC did not act through MR in increasing 11beta-HSD activity. On the other hand, spironolactone significantly decreased plasma T levels in DOC treated rats. Progesterone (P), a competitive inhibitor of glucocorticoid receptors (GR) or corticosterone significantly suppressed testicular enzyme activity and plasma T levels in DOC treated normal rats. Carbenoxolone which is an inhibitor of 11beta-HSD activity significantly depressed testicular 11beta-HSD activity and plasma T levels in DOC treated normal rats. This paper suggests that DOC increased testicular 11beta-HSD activity through GR; whilst increase in plasma T levels required functioning adrenal glands. The testicular 11beta-HSD is one of the regulators of T levels and vice versa.
    Matched MeSH terms: Testosterone/blood*
  5. Nwe KH, Norhazlina AW, Hamid A, Morat PB, Khalid BA
    Exp. Clin. Endocrinol. Diabetes, 2000;108(5):369-77.
    PMID: 10989957
    The effects of stress and corticosterone on testicular 11beta-hydroxysteroid dehydrogenase (11beta-HSD) oxidative activity have been controversial, whilst that of adrenocorticotrophic hormone (ACTH) have not been investigated before. Hence, the aim of the present study was to determine the in vivo effects of stress due to injection and sham operation, ACTH and corticosterone on testicular and hepatic 11beta-HSD oxidative activity and plasma testosterone levels in normal and adrenalectomized (ADX) rats and their possible mechanism of actions. Adrenalectomy reduced both testicular 11beta-HSD oxidative activity and plasma testosterone levels. The effects of injection and sham operation significantly increased plasma corticosterone levels with decreased testicular 11beta-HSD oxidative activity and plasma testosterone levels in normal but not in ADX rats. Likewise. ACTH or corticosterone treatment for 7 days decreased both testicular 11beta-HSD oxidative activity in a dose dependent manner and plasma testosterone levels in normal rats; but the values in ADX rats remained unchanged. However, none of the above values were significantly lower than that of the ADX levels. Corticosterone seems to maintain testicular 11beta-HSD oxidative activity within the range between normal and ADX rats. These changes are not attributable to diurnal rhythms, as the time of sacrifice has been fixed between 8:30 and 10:30 am. In the liver, no significant change in 11beta-HSD oxidative activity was observed with sham operation, ACTH or corticosterone treatment; but adrenalectomy significantly decreased it. In conclusion, in the intact normal rats, stress, ACTH or corticosterone modulates testicular (but not hepatic) 11beta-HSD oxidative activity indirectly through the adrenal glands and the physiological level of corticosterone is ideal for normal reproductive functions.
    Matched MeSH terms: Testosterone/blood
  6. Ng BH, Yuen KH
    PMID: 12906917
    A simple and sensitive high-performance liquid chromatographic (HPLC) method using ultraviolet detection was developed for the determination of testosterone in human plasma. Testosterone and the internal standard, griseofulvin, were extracted from 0.50 ml plasma sample using a mixture of dichloromethane-2,2,4-trimethylpentane (3:2, v/v). The mobile phase, consisted of 0.02 M sodium dihydrogenphosphate-acetonitrile-methanol (51:47:2, v/v) adjusted to pH 3.1 and delivered to a C(18) analytical column (150 x 4.6 mm I.D., 4 microm particles) at a flow-rate of 1 ml/min while the detection wavelength was set at 240 nm with a sensitivity range of 0.005 a.u.f.s. The method has a quantification limit of 1.6 ng/ml. Recoveries of testosterone were all greater than 92% over the linear concentration range of 1.6-400 ng/ml while that of griseofulvin was approximately 95%. The within- and between-day RSD values were all less than 8% while the accuracy values ranged from 96.0 to 106.0% over the concentration range studied. The method was applied to the analysis of early morning plasma testosterone levels of 12 healthy human male volunteers. The levels were found to range from 3.1 to 8.4 ng/ml, within the normal range reported in the literature.
    Matched MeSH terms: Testosterone/blood*
  7. Maneesh M, Dutta S, Chakrabarti A, Vasudevan DM
    Indian J. Physiol. Pharmacol., 2006 Jul-Sep;50(3):291-6.
    PMID: 17193902
    Ethanol is a testicular toxin and it causes fertility abnormalities with low sperm count and impaired sperm motility in men. The present study was designed to investigate plasma testosterone level and hypothalamic pituitary gonadal (HPG) axis function in alcoholic men and also effect of ethanol on systemic oxidative stress. Forty six male alcohol abusers in the age group 20-40 years were selected. Fifty five, males in the same age group served as control. Alcohol abusers had significantly low plasma testosterone with low luteinizing hormone and follicle stimulating hormone. In addition they had significantly high thiobarbituric acid reactive substances (TBARS), superoxide dismutase and glutathione S-transferase, and low glutathione, ascorbic acid, catalase, glutathione reductase and glutathione peroxidase. Moreover, serum testosterone level in alcoholics negatively correlated with duration of alcohol abuse, and TBARS. Duration dependent decreased serum testosterone level in alcohol abusers might be due to 1) increased oxidative stress which can damage Leydig and supporting Sertoli cells and 2) impaired HPG axis.
    Matched MeSH terms: Testosterone/blood*
  8. Ho CC, Rohaizak M, Zulkifli SZ, Siti-Aishah MA, Nor-Aini U, Sharifah-Noor-Akmal SH
    Singapore Med J, 2009 May;50(5):513-8.
    PMID: 19495523
    This study was conducted to determine the association between serum sex hormone levels and breast cancer.
    Matched MeSH terms: Testosterone/blood*
  9. Ikonomopoulou MP, Olszowy H, Hodge M, Bradley AJ
    PMID: 19247670 DOI: 10.1007/s00360-009-0347-3
    In this study on green turtles, Chelonia mydas, from Peninsular Malaysia, the effect of selected environmental toxicants was examined in vitro. Emphasis was placed on purported hormone-mimicking chemicals such as dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene, dieldrin, lead, zinc and copper. Five concentrations were used: high (1 mg/L), medium (10(-1) mg/L), low (10(-2) mg/L), very low (10(-6) mg/L) and control (diluted carrier solvent but no toxicants). The results suggest that environmental pesticides and heavy metals may significantly alter the binding of steroids [i.e. testosterone (T) and oestradiol] to the plasma proteins in vitro. Competition studies showed that only Cu competed for binding sites with testosterone in the plasma collected from nesting C. mydas. Dieldrin and all heavy metals competed with oestradiol for binding sites. Furthermore, testosterone binding affinity was affected at various DDT concentrations and was hypothesised that DDT in vivo may act to inhibit steroid-protein interactions in nesting C. mydas. Although the precise molecular mechanism is yet to be described, DDT could have an effect upon the protein conformation thus affecting T binding (e.g. the T binding site on the steroid hormone binding protein molecule).
    Matched MeSH terms: Testosterone/blood
  10. Zaid SS, Sulaiman SA, Sirajudeen KN, Othman NH
    PMID: 21194469 DOI: 10.1186/1472-6882-10-82
    Honey is a highly nutritional natural product that has been widely used in folk medicine for a number of therapeutic purposes. We evaluated whether Malaysian Tualang honey (AgroMas, Malaysia) was effective in reducing menopausal syndrome in ovariectomised female rats; an animal model for menopause.
    Matched MeSH terms: Testosterone/blood
  11. Yunianto I, Das S, Mat Noor M
    Clin Ter, 2010;161(3):235-9.
    PMID: 20589353
    Antifertility agents with safety and effectiveness in terms of minimum side effects have always been a subject of debate. Many studies have been conducted on plants to observe the antifertility effect, but majority of them were toxic. Pegaga or Centella asiatica L. is one of the popular herb traditionally consumed raw amongst people in Malaysia. The main objective of the present study was to investigate the effects of Centella asiatica L. extract on rat testis.
    Matched MeSH terms: Testosterone/blood*
  12. Ho CC, Singam P, Hong GE, Zainuddin ZM
    Asian J Androl, 2011 Jul;13(4):537-42.
    PMID: 21643001 DOI: 10.1038/aja.2010.135
    Sex has always been a taboo subject in Asian society. However, over the past few years, awareness in the field of men's sexual health has improved, and interest in sexual health research has recently increased. The epidemiology and prevalence of erectile dysfunction, hypogonadism and premature ejaculation in Asia are similar in the West. However, several issues are specific to Asian males, including culture and beliefs, awareness, compliance and the availability of traditional/complementary medicine. In Asia, sexual medicine is still in its infancy, and a concerted effort from the government, relevant societies, physicians and the media is required to propel sexual medicine to the forefront of health care.
    Matched MeSH terms: Testosterone/blood
  13. Tan WS, Ng CJ, Khoo EM, Low WY, Tan HM
    Aging Male, 2011 Dec;14(4):231-6.
    PMID: 22115177 DOI: 10.3109/13685538.2011.597463
    The etiology of erectile dysfunction (ED) is multi-factorial. This paper examines the association between ED, testosterone deficiency syndrome (TDS) and metabolic syndrome (MS) in Malaysian men in an urban setting. One thousand and forty-six men aged ≥ 40 years from Subang Jaya, Malaysia were randomly selected from an electoral-roll list. The men completed questionnaires that included: socio-demographic data, self-reported medical problems and the International Index of erectile function (IIEF-5). Physical examination and the following biochemical tests were performed: lipid profile, fasting blood glucose (FBG) and total testosterone. The response rate was 62.8% and the mean age of men was 55.8 ± 8.4 (41-93) years. Ethnic distribution was Chinese, 48.9%; Malay, 34.5%; Indian, 14.8%. The prevalence of moderate-severe ED was 20.0%, while 16.1% of men had TDS (< 10.4 nmol/L) and 31.3% of men had MS. Indian and Malay men were significantly more likely to have ED (p  = 0.001), TDS (p  < 0.001) and MS (p < 0.001) than the Chinese. Multivariate regression analysis showed that elevated blood pressure, elevated FBG, low high-density lipoprotein and heart disease were predictors of ED while all MS components were independently associated with TDS. Malay and Indian men have a higher disease burden compared to Chinese men and were more likely to suffer with ED, TDS and MS. MS components were closely related to TDS and ED.
    Matched MeSH terms: Testosterone/blood
  14. Tambi MI, Imran MK, Henkel RR
    Andrologia, 2012 May;44 Suppl 1:226-30.
    PMID: 21671978 DOI: 10.1111/j.1439-0272.2011.01168.x
    In most countries, millions of people are relying on herbal medicines as remedy for numerous ailments. In South-East Asia, Eurycoma longifolia Jack, also known as 'Malaysian ginseng' or Tongkat ali, is used to combat stress and disease and to improve physical strength. Moreover, the compounds of the roots of this plant are reported to have aphrodisiac and testosterone enhancing effects in the rat. Considering that human studies are not available, 76 of 320 patients suffering from late-onset hypogonadism (LOH) were given 200 mg of a standardised water-soluble extract of Tongkat ali for 1 month. The Ageing Males' Symptoms (AMS) according to the standardised rating scale and the serum testosterone concentration were taken. Results show that treatment of LOH patients with this Tongkat ali extract significantly (P < 0.0001) improved the AMS score as well as the serum testosterone concentration. While before treatment only 10.5% of the patients did not show any complaint according to the AMS scale and 35.5% had normal testosterone levels, after the completed treatment 71.7% and 90.8% of the patients showed normal values, respectively. Thus, Tongkat ali extract appears to be useful as a supplement in overcoming the symptoms of LOH and for the management of hypogonadism.
    Matched MeSH terms: Testosterone/blood
  15. Tong SF, Ng CJ, Lee BC, Lee VK, Khoo EM, Lee EG, et al.
    Asian J Androl, 2012 Jul;14(4):604-11.
    PMID: 22635164 DOI: 10.1038/aja.2011.178
    This study aimed to investigate the effect of intramuscular injection of testosterone undecanoate on overall quality of life (QoL) in men with testosterone deficiency syndrome (TDS). A randomized controlled trial over a 12-month period was carried out in 2009. One hundred and twenty men aged 40 years and above with a diagnosis of TDS (serum total testosterone <12 nmol l(-1) and total Aging Male Symptom (AMS) scores ≥27) were invited to participate. Interventions comprised intramuscular injection of either placebo or 1000 mg testosterone undecanoate, given at weeks 0, 6, 18, 30 and 42. This paper presents the secondary analysis of QoL changes measured in the scores of Short-Form-12 (SF-12) scale at baseline, weeks 30 and 48 after the first injection. A total of 56/60 and 58/60 men from the active treatment and placebo group, respectively, completed the study. At week 48, before adjusting for baseline differences, the QoL of men in the treatment group improved significantly in five out of the eight domains on SF-12. The physical health composite scores improved 4.0 points from a baseline of 41.9±7.0 in the treatment group compared to 0.8 point from a baseline of 43.7±7.1 in the placebo group (F=3.652, P=0.027). The mental health composite scores improved 4.4 points from a baseline of 37.1±9.0 in the treatment group compared to 1.0 points from a baseline of 37.6±7.9 in the placebo group (F=4.514, P=0.018). After adjusting for baseline differences, significant improvement was observed in mental health composite scores, but not in physical health composite scores. Long-acting testosterone undecanoate significantly improved the mental health component of QoL in men with TDS.
    Study: Subang Jaya Aging Men's Health Study
    Funding: Bayer Schering Pharma
    Matched MeSH terms: Testosterone/blood
  16. Chin KY, Soelaiman IN, Mohamed IN, Ngah WZ
    Clinics (Sao Paulo), 2012 Aug;67(8):911-6.
    PMID: 22948459
    OBJECTIVES: Variations in sex hormones and the calcium balance can influence bone health in men. The present study aimed to examine the relationship between the calcaneal speed of sound and biochemical determinants of bone mass, such as sex hormones, parathyroid hormones and serum calcium.

    METHODS: Data from 549 subjects from the Malaysian Aging Male Study, which included Malay and Chinese men aged 20 years and older residing in the Klang Valley, were used for analysis. The subjects' calcaneal speed of sound was measured, and their blood was collected for biochemical analysis. Two sets of multiple regression models were generated for the total/bioavailable testosterone and estradiol to avoid multicollinearity.

    RESULTS: The multiple regression results revealed that bioavailable testosterone and serum total calcium were significant predictors of the calcaneal speed of sound in the adjusted model. After adjustment for ethnicity and body mass index, only bioavailable testosterone remained significant; the total serum calcium was marginally insignificant. In a separate model, the total testosterone and sex hormone-binding globulin were significant predictors, whereas the total serum calcium was marginally insignificant. After adjustment for ethnicity and body mass index (BMI), the significance persisted for total testosterone and SHBG. After further adjustment for age, none of the serum biochemical determinants was a significant predictor of the calcaneal speed of sound.

    CONCLUSION: There is a significant age-dependent relationship between the calcaneal speed of sound and total testosterone, bioavailable testosterone and sex hormone-binding globulin in Chinese and Malay men in Malaysia. The relationship between total serum calcium and calcaneal speed of sound is ethnicity-dependent.

    Matched MeSH terms: Testosterone/blood*
  17. Chin KY, Soelaiman IN, Naina Mohamed I, Shahar S, Teng NI, Suhana Mohd Ramli E, et al.
    Aging Male, 2012 Dec;15(4):240-5.
    PMID: 23098182 DOI: 10.3109/13685538.2012.724740
    OBJECTIVE: Variations in testosterone levels are associated with several outcomes of aging. The present study aimed to examine the relationship between age-related decline of testosterone levels and changes in bone health status, handgrip strength, body fat percentage and fat-free mass.
    MATERIALS AND METHODS: A total of 335 Malaysian Chinese and Malay men aged 40 years and above were recruited for this study. Their body compositions, calcaneal speed of sound and handgrip strength were measured and their blood was collected. Linear regression analysis was done to examine the relationship among age, testosterone levels and outcomes of aging.
    RESULTS: The results indicated significant changes in all testosterone measurements, sex hormone binding globulin level, calcaneal speed of sound, handgrip strength, body fat percentage and fat-free mass with age (p < 0.05). Age-dependent decline in bioavailable and free testosterone levels were significantly associated with reduction in calcaneal speed of sound, fat-free mass and handgrip strength (p < 0.05). Age-dependent decline in the total testosterone level was significantly associated with an increase in body fat percentage among the elderly men (p < 0.05).
    CONCLUSION: Testosterone levels are associated with changes in outcome of aging such as bone health status, muscle strength and body composition, and the relationships are age-dependent.
    Matched MeSH terms: Testosterone/blood*
  18. Shuid AN, El-arabi E, Effendy NM, Razak HS, Muhammad N, Mohamed N, et al.
    PMID: 22967165 DOI: 10.1186/1472-6882-12-152
    Eurycoma longifolia (EL) has been shown recently to protect against bone calcium loss in orchidectomised rats, the model for androgen-deficient osteoporosis. The mechanism behind this is unclear but it may be related to its ability to elevate testosterone levels or it may directly affect bone remodeling. The aim of this study is to determine the mechanism involved by investigating the effects of EL extract on serum testosterone levels, bone biomarkers, biomechanical strength and gene expression of Receptor Activator of Nuclear Factor kappa-B ligand (RANKL), Osteoprotegerin (OPG) and Macrophage-Colony Stimulating Factor (MCSF) in orchidectomised rats.
    Matched MeSH terms: Testosterone/blood
  19. Adebiyi FA, Siraj SS, Harmin SA, Christianus A
    Fish Physiol Biochem, 2013 Jun;39(3):547-57.
    PMID: 23010937 DOI: 10.1007/s10695-012-9718-x
    Plasma sex steroid hormonal profile and gonad histology were correlated to study the annual reproductive cycle of Hemibagrus nemurus. Hormones were measured by Enzyme Linked Immunosorbent Assay. Gonad tissues were observed by using light microscopy. The highest testosterone (T) value for male was observed in November and that of female was in October. 11-ketotestosterone (11-KT) and 17β-estradiol (E2) levels were highest in June and November, respectively. Hormonal profiles of T, 11-KT and E2 showed several peaks which indicated a non-seasonal pattern. There were significant differences (p 
    Matched MeSH terms: Testosterone/blood
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