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Biomedical subjects

B A Khalid

Publications and source records attributed to B A Khalid.

At least 37 records · Page 2Linked to original sources
PubMed1999

Naloxone and vitamin E block stress-induced reduction of locomotor activity and elevation of plasma corticosterone.

Normal rats, on being repetitively stressed by being restrained in a tight container for two hours, had higher levels of plasma corticosterone compared to pre stress values. These rats also reacted to the stress by a behavioral response in which there was marked decrease in locomotor activity assessed by the open field test (pre stress: 71.3 +/- 2.6 squares crossed versus post stress: 14.3 +/- 2.5 squares crossed) by counting the number of squares entered by the rat over 5 minutes. By the 6th to 7th exposures to the repetitive stress, the rats adapted to the stress and had normal plasma corticosterone levels and locomotor activity scores comparable to the pre stress values. These responses to stress were completely blocked by the administration of 0.32 microg/100 g BW of naloxone i.p at 10 minutes prior to the stress. In rats fed with rat chow supplemented with 90 mg/kg rat chow or 150 mg/kg rat chow of vitamin E, there was significant reduction of the plasma corticosterone levels and improvement in the locomotor activity. Stress thus caused opioid mediated increase in plasma corticosterone and reduction in locomotor activity which could be blocked by naloxone. These stress responses probably also involved generation of oxygen free radicals which were scavenged by the vitamin E, thus reducing the effects of repetitive stress on locomotor activity and serum corticosterone levels.

Animals↗
PubMed1999

Congenital hypothyroid screening using cord blood TSH.

BACKGROUND: Clinical diagnosis of congenital hypothyroidism (CH) is difficult at birth without neonatal screening. In line with the priorities of the national health services in Malaysia towards preventive medicine, early diagnosis and treatment of CH is emphasised. We conducted a pilot study at Kuala Lumpur's Maternity Hospital between April 1995 and November 1995 to estimate the incidence of CH and also evaluated the problems associated with large-scale neonatal screening using a commercial TSH kit on cord bloodspots. PATIENTS: A total of 11,000 newborns were screened using cord blood spots taken at birth. RESULTS: Two hundred and fifty newborns (2.27%) hand cord TSH > 20 mlU/L and had to be recalled for re-evaluation. Of these, 4 had cord TSH of > 100 mlU/L; three were confirmed to have congenital hypothyroidism and one had transient hyperthyrotropinaemia. Our study estimated the incidence of CH to be one in 3,666 live births in Kuala Lumpur, Malaysia. Clinical features of hypothyroidism are subtle during the early weeks of life. However, prolonged neonatal jaundice (3/3), widely opened posterior fontanelle (3/3) and dry skin (3/3) were the common features in all our cases by 2-6 weeks of life. CONCLUSION: This study suffered a high dropout rate. Twenty-six percent of the patients were not traceable after discharge and 48% did not respond to our recall. We stress the importance of public education and awareness in contributing to the cost-effectiveness of the screening program.

Congenital Hypothyroidism↗
PubMed1999

Effects of glycyrrhizic acid and steroid treatment on corticotropin releasing factor and beta-endorphin containing neurons of the hypothalamus of the rat.

Corticotrophin releasing factor (CRF) and beta-endorphin (beta EP) containing neurons are shown to be present in the hypothalamus and both neurons are found at the paraventricular nucleus (PVN). Steroid hormones have been found to alter the plasma level of these neurotransmitters. Glycyrrhizic acid (GCA) is the active component of liquorice. GCA inhibits the enzyme 11 beta-hydroxysteroid dehydrogenase (11HSD) which is needed for the inactivation of the steroid pathway, so therefore would cause changes to these neurons. The aim of this study was to investigate the effects of GCA as well as deoxycorticosterone (DOC) and dexamethasone (DM) on the modulation of CRF and beta EP containing neuron at the PVN of the hypothalamus. Rats were given either DM, DOC or GCA and adrenalectomized (ADX) and given either DM or DOC. At the end of treatment rats were transfused transcardially before sacrifice and the brain were dissected for immunohistochemical analysis. We found that immunostaining of the CRF containing neurons demonstrate a reduction in the number of positive neurons in DM treated rats. DOC and GCA treated rats showed the same result as in DM rats but the reduction is less. ADX, DM, DOC and GCA treated rats did not show any changes in the number of beta EP containing neurons but naloxone increased the number of beta EP containing neurons markedly. In conclusion, GCA and DOC have similar effects on CRF and beta EP containing neurons at the PVN.

Animals↗
PubMed1999

Markers of ventricular tachyarrythmias in patients with acromegaly.

INTRODUCTION: Sudden cardiac death is a known complication of acromegaly. Little is known of the exact mechanism leading to sudden cardiac death in these patients. Ventricular tachyarrhythmias may be an important cause. If this is so, clinical markers of ventricular tachyarrhythmias may be more common in this group of patients. The presence of these markers allow better risk stratification among acromegalic patients. METHODS: We performed signal averaged electrocardiography and analysed 12 lead electrocardiography for QT dispersion on 17 acromegaly patients who attended the UKM endocrine clinic within a period of 5 months and compared them with similar age matched controls. Signal averaged electrocardiogram was performed using Marquette Mac 12/15 ECG analyser and QT intervals were measured manually from 12 lead ECG tracings. Late potential positivity was defined by the standard Breithardt criteria. QT dispersion was defined as the longest minus the shortest QT interval from all 12 lead tracings. Echocariography was done to assess left ventricular hypertrophy in patients and controls. RESULTS: Late potential positivity was found to be more common in acromegaly patients compared with controls (chi-square, p < 0.05, n = 34) and QT dispersion was also found to be significantly higher in the acromegaly group compared with control s (mean +/- SE QT dispersion respectively 121.0 +/- 8.6 ms vs 86.2 +/- 7.0 ms, t-test, p < 0.05, n = 34). Left ventricular hypertrophy was present in five acromegaly patients and two in the control group. CONCLUSION: Acromegaly patients have a higher incidence of late potential positivity and higher QT dispersion compared with age matched controls. These findings might explain the increase susceptibility of these patients to sudden cardiac deaths from ventricular tachyarrhythmias.

Acromegaly↗
PubMed1998

Regeneration of adrenal cortical tissue after adrenal autotransplantation.

This study tested the possibility of adrenal autotransplantation in rats. Since the cortex and the medulla of the adrenal gland were from different origin embryologically, either whole adrenal glands (ADR), or capsule and cortex (CAP) or medulla (MED) were autotransplanted in the subcutaneous tissue. The functions of regenerated adrenal nodules were tested by measuring plasma corticosterone levels every fortnight. At the end of 9 weeks the rats were exposed to hypovolemic shock followed by naloxone injection to reverse the shock response. Results showed that rats transplanted with either cortex or whole adrenal started secreting corticosterone at 5 weeks post-transplantation (107.73 +/- 21.98 ng/ml, 126.04 +/- 48.41 ng/ml, respectively). Corticosterone levels increased to the value which were not significantly different from control by 9 weeks post-transplantation. However, rats transplanted with adrenal medulla showed very low corticosterone levels. Nine weeks post-transplantation, the mean blood pressure (MBP) of the CAP group was 135 +/- 13 mmHg and was not significantly different from sham-operated controls, whereas MBP of MED group was significantly lower than sham-operated animals (99 +/- 11 mmHg versus 141 +/- 9 mmHg). The MBP of the ADR group was also lower compared to sham-operated controls (112 +/- 17 mmHg P < 0.05). The MBP of the adrenal group was not statistically significant compared to the CAP group. After 1% body weight haemorrhage, the MBP decreased significantly in ADR (45 +/- 5 mmHg, P < 0.05) and MED group (36 +/- 9 mmHg, P < 0.001) compared to sham-operated rats (78 +/- 11 mmHg) but not in the CAP (56 +/- 9 mmHg). It was concluded that autotransplanted whole adrenal or adrenocortical tissues survived subcutaneously and produced sufficient corticosterone to alleviate haemorrhagic shock. Adrenal medullary tissue failed to regenerate subcutaneously and the presence of adrenal medullary tissue may suppressed the growth of transplanted adrenal gland.

Adrenal Cortex↗
PubMed1998

Insulin-like growth factor-binding protein-3 (IGFBP-3) but not insulin-like growth factor-I (IGF-I) remains elevated in euthyroid TSH-suppressed Graves' disease.

Thyroid hormones have been shown to be involved in the regulation of insulin-like growth factor-I (IGF-I) and IGF binding protein-3 (IGFBP-3) expression. This is a cross-sectional study to look at the effects of thyroid hormone status on the circulating levels of IGF-I and IGFBP-3 in a group of 127 patients, aged 20-80 years, who were hyperthyroid, hypothyroid, rendered euthyroid and clinically euthyroid with normal free thyroxine (fT4), but suppressed thyroid stimulating hormone (TSH) levels. TSH was measured by the IMx (Abbott) ultrasensitive assay, while radioimmunoassays for total T3 and T4 were performed using kits from ICN, USA; fT4 and fT3 using kits from DPC USA; IGF-I and IGFBP-3 using kits from Nichols Institute Diagnostics B.V., Netherlands. Differences in the levels of IGF-I between the 4 groups of patients were significant only in the patients aged 20-40. Mean (+/-SEM) IGF-I levels of hypothyroid patients (169+/-19ng/ml) was significantly lower than hyperthyroid (315+/-26 ng/ml, p=0.003), euthyroid patients (241+/-19 ng/ml, p=0.002) and patients with suppressed TSH (308+/-29 ng/ml, p=0.02). The IGF-I levels of the hyperthyroid and suppressed TSH patients were, however, comparable to age-matched normal subjects (281+/-86 ng/ml). Although there was no difference in mean IGFBP-3 levels between the 4 groups of patients, the levels in the patients aged 20-40 with hyperthyroidism (3.7+/-0.9 microg/ml) and suppressed TSH (3.9+/-1.2 microg/ml) were significantly higher (p=0.02) than age-matched normal subjects (3.1+/-0.8 microg/ml). The IGF-I levels of the thyroid patients aged 20-40 showed significant negative correlation to TSH and positive correlations to the thyroid hormones. Hence, whilst low IGF-I is associated with hypothyroidism, high IGFBP-3 is associated with hyperthyroidism. Our finding that IGFBP-3 remained significantly elevated in patients with suppressed TSH but normalised fT4 and fT3 is important as it suggests a prolonged tissue effect of thyroid hormones on IFGBP-3. As such patients have been shown to have higher risk for atrial fibrillation, the significance and possible role of IGFBP-3 in these conditions should be further elucidated in future studies.

Adult↗
PubMed1997

Different starting times of alpha-tocopherol and gamma-tocotrienol supplementation and tumor marker enzyme activities in the rat chemically induced with cancer.

1. alpha-Tocopherol (alpha-T) and gamma-tocotrienol (gamma-T) were supplemented continuously for 8 weeks in the diets of normal rats and rats chemically induced with cancer using diethylnitrosamine (DEN), 2-acetylaminofluorene (AAF) and partial hepatectomy. Hepatocarcinogenesis was followed by determining the plasma gamma-glutamyl-transpeptidase (GGT) and alkaline phosphatase (ALP) activities as well as placental glutathione S-transferase (PGST) and GGT activities histochemically, at 4-week intervals. 2. Male Rattus norvegicus were supplemented alpha-T and gamma-T at two different doses of 30 and 300 mg/kg diet. The supplementation was started at three different times: simultaneously with DEN administration; 4 weeks; and 8 weeks after DEN administration. 3. Elevation of plasma GGT activities and formation of PGST and GGT positive foci were attenuated significantly (P < 0.05) when alpha-T and gamma-T were supplemented simultaneously with cancer induction. Supplementation begun 4 and 8 weeks after cancer induction did not affect plasma enzyme activities and formation of enzyme-positive foci. 4. alpha-T was more effective than gamma-T, and a lower dose of 30 mg/kg was found to be more effective in reducing the severity of hepatocarcinogenesis.

Alkaline Phosphatase↗
PubMed1997

Opposite effects of sex steroids on 11 beta-hydroxysteroid dehydrogenase activity in the normal and adrenalectomized rat testis.

1. Sex steroids have been shown to regulate the biosynthesis of 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD). 2. In vitro studies showed that oestradiol (E2) or testosterone (T) can interfere with the bioassay of enzyme activity, but not progesterone (P4). 3. For in vivo studies, the activity of 11 beta-HSD in the testis of normal and adrenalectomized (ADX) adult male Wistar rats was determined following a daily IM injection of sex steroids for 7 days. 4. The 11 beta-HSD activity was significantly reduced (P < 0.01) either by E2 or T in normal and ADX rats. The enzyme activity in normal rats given both T and E2 was even lower (P < 0.001) than when E2 was given alone. 5. P4 given to normal and ADX rats increased the enzyme activity higher than normal (P < 0.001). 6. The presence of corticosteroids influenced the effects of E2, but not of T and P4, on 11 beta-HSD activity. 7. E2 and T downregulate 11 beta-HSD activity, whereas P4 increased it. E2 did not act through lowering T level.

11-beta-Hydroxysteroid Dehydrogenases↗
PubMed1997

Plasma renin and aldosterone in thyroid diseases.

The effect of thyroid hormones on the renin-angiotensin-aldosterone system has not been fully resolved. Highly specific immunoassays for measurement of renin, aldosterone, free T4 (fT4), free T3 (fT3) and ultrasensitive TSH enables a direct and more accurate measurement of these hormones. We investigated the relationship between plasma renin, aldosterone and thyroid hormones in the basal state and after intravenous frusemide. This is a cross-sectional study involving 37 patients with thyrotoxicosis, 42 rendered euthyroid with normal fT4, fT3 and TSH levels, 17 with euthyroid levels of fT4 and fT3 but suppressed TSH, and 11 with hypothyroidism. Basal plasma renin was significantly higher in thyrotoxicosis (63.4 +/- 9.8 microU/ml, mean +/- SEM) compared to euthyroid (32.7 +/- 4.4 microU/ml) and hypothyroid (26.7 +/- 9.8 microU/ml). Basal plasma renin for euthyroid with suppressed TSH (41.0 +/- 7.4 microU/ml) was significantly higher than hypothyroid (p = 0.02). Basal plasma aldosterones were not significantly different except for suppressed TSH (157.7 +/- 13 pg/ml), which was higher than normal (109.9 +/- 10.4 pg/ml; p = 0.04). Following frusemide, plasma renin and aldosterone were significantly increased in all groups. Plasma renin was highly correlated to fT3 (r = 0.405, p < 0.001), total T3 (r = 0.359, p < 0.001), fT4 (r = 0.331, p < 0.001) and TSH (r = 0.300, p < 0.001) in the basal state, but less to total T4 (r = 0.248, p < 0.01). Plasma renin correlated poorly to serum aldosterone (r = 0.212, p < 0.03). This study clearly showed that regulation of renin was mainly influenced by fT3, and that aldosterone response to frusemide was blunted in thyrotoxicosis despite normal electrolytes.

Aldosterone↗
PubMed1996

Usefulness and limitations of an in-house direct radioimmunoassay for 17-hydroxyprogesterone in serum.

Since conventional radioimmunoassays (RIA) for measurement of 17-hydroxyprogesterone (17-OHP) in serum samples require a laborious solvent extraction step, a direct and rapid in-house RIA was developed for early diagnosis and management of congenital adrenal hyperplasia (CAH). In-house rabbit anti-17-OHP antiserum, tritium labelled 17-OHP and dextran-coated charcoal were used in assay buffer with low pH 5.1 and preheated serum samples. Both inter- and intra-assay CVs were < 10% and the sensitivity was 1.2 nmol/l or 12 fmol/tube. Results from the direct assay correlated well with values from an extraction assay, r = 0.88 in samples from CAH patients, r = 0.85 in adults and children, 0.69 and 0.40 in term and preterm neonates respectively, 0.66 and 0.63 in luteal phase and third trimester pregnancy; p < 0.001 in all groups except p < 0.05 in preterm neonates. However, results from the direct assay were two to three times higher in serum samples from CAH patients, normal adults and children, but were five to seven times higher in pregnancy and term neonates and thirty times higher in preterm neonates. The markedly elevated levels measured by the direct assay are probably due to cross-reactivities with water-soluble steroid metabolites such as 17-hydroxypregnenolone sulphate and dehydroepiandrosterone sulphate (DHEAS). Although the direct assay is only useful as a screening test for preterm babies, it can be used for both diagnosis and monitoring of treatment of CAH in all other age groups.

17-alpha-Hydroxyprogesterone↗
PubMed1996

Measurement of androstenedione levels by an in-house radioimmunoassay.

An in-house radioimmunoassay (RIA) for the measurement of androstenedione levels in serum was established and validated. Levels of androstenedione were measured by RIA using serum samples from various normal population groups and patients with congenital adrenal hyperplasia (CAH). Analytical recovery and linearity results were > 95%, while intra- and inter-assay CVs were < 10% and < 22% respectively. The assay sensitivity was 0.5 nmol/l or 25 fmol/tube. In normal population groups, the highest androstenedione levels were found in preterm neonates (1.6-12.4 nmol/l), followed by adult females (1.5-10.2 nmol/l), adult males (1.6-8.0 nmol/l) and term neonates (0.8-8.8 nmol/l), while the lowest values were observed in prepubertal children (0.5-3.4 nmol/l). There were no significant differences in diurnal variation and between follicular and luteal phases. The range of androstenedione levels in untreated or poorly controlled CAH patients (7.6-355.0 nmol/l, median 42.5 nmol/l, n = 20) were significantly higher (p < 0.001) than the upper normal limit of 3.4 nmol/L for prepubertal children. The normal androstenedione reference ranges for paediatric and adult groups have thus been established.

17-alpha-Hydroxyprogesterone↗
PubMed1996

Changing prevalence of diabetes mellitus amongst rural Malays in Kuala Selangor over a 10-year period.

A cross-sectional study was carried out to determine the prevalence of diabetes mellitus and its relationship with age, physical activity, nutritional status and diet amongst rural Malays in Kuala Selangor. By simple random sampling 360 subjects were selected for the study. Besides guided questionnaires, subjects also underwent a 2 hours post prandial (2HPP) test to determine the diabetic status as recommended by WHO. The crude prevalence of diabetes mellitus was 14.6% which increases with age. The prevalence of diabetes adjusted for age was 12.2%. Physical activity status seemed to be a significant risk factor for diabetes. A greater proportion of diabetics was obese and their mean fat intake was higher than normal subjects (p < 0.05). The prevalence of diabetes mellitus in this study was significantly higher compared with data from 1984 (3.9%), representing a marked increment of 212.8 per cent over a 10-year period.

Adult↗
PubMed1996

Diabetic control among NIDDM patients in urban and rural areas in Malaysia.

Sixty three and fifty nine non-insulin dependent diabetes mellitus (NIDDM) patients in rural (land resettlement scheme) and urban areas respectively were studied to determine factors associated with diabetic control. The anthropometric and metabolic data (HbA1 and fructosamine levels) were analysed. After adjusting for gender, age, body mass index (BMI) and food intake, the fructosamine level which correlates with short term diabetic control, was significantly lower among patients in urban areas compared to patients in rural areas (p < 0.05). However, for longer term diabetic control (HbA1 level) the difference was not statistically significant (p > 0.05). The socio-economic status, level of education, BMI and types of food did not correlate with diabetic control in either group of patients. More diabetes education is needed together with socio-economic development and changes in lifestyles to enhance compliance towards health and dietary regimens and to achieve better metabolic control.

Body Mass Index↗
PubMed1996

Effects of iodine deficiency on insulin-like growth factor-I, insulin-like growth factor-binding protein-3 levels and height attainment in malnourished children.

OBJECTIVE: The expression and synthesis of IGF-I and IGFBP-3 have been shown to be regulated by hormones and nutrition. We study the effects of malnutrition and iodine deficiency on these growth factors and the height attainment of a group of children. DESIGN: We measured serum IGF-I and IGFBP-3 levels in a group of Malaysian aborigine children from three jungle settlements; Sinderut and Pos Lanai are known for iodine deficiency and endemic goitre, and Gombak is an iodine replete area with better socioeconomic status. PATIENTS: A total of 246 children were studied, 188 in the age group 4-10 years and 88 in the age group 11-15 years. MEASUREMENTS: All children were assessed anthropometrically and height standard deviation score (SDS) were calculated using the CDC Anthropometric Software package. Malnutrition was confirmed clinically and according to the WHO definition of malnutrition. IGF-I and IGFBP-3 were determined by radioimmunoassay, and T4 and TSH by immunoradiometric assay. RESULTS: Based on the height SDS, Sinderut and Pos Lanai children were significantly more malnourished and stunted than the Gombak children P = 0.0001). T4 levels were significantly lower (P = 0.0001) amongst the 4-10-years old Sinderut (81 +/- 2 nmol/l) than in Pos Lanai (101 +/- 3 nmol/l) or Gombak (123 +/- 3 nmol/l) children. Similar findings were also seen in the older children; mean T4 levels of those from Sinderut and Pos Lanai (83 +/- 3 and 88 +/- 4 nmol/l respectively), were low (P = 0.0001) compared to Gombak (118 +/- 3 nmol/l). Conversely, TSH levels in both age groups of Sinderut children were significantly elevated (P = 0.0001) (3.5 +/- 0.2 and 3.9 +/- 0.3 mU/l respectively) compared to age-matched groups from Pos Lanal (2.1 +/- 0.1 and 2.2 +/- 0.2 mU/l respectively) and Gombak (1.5 +/- 0.1 and 1.5 +/- 0.2 mU/l respectively). IGF-I and IGFBP-3 correlated significantly with the height SDS of the children, In both the 4-10 (r = 0.400, P = 0.0001 and r = 0.365, P = 0.0001 respectively) and 11-15 years age groups (r = 0.324, P = 0.002 and r = 0.533, P = 0.0001 respectively). Correlation between IGFBP-3 and T4 levels was more significant in the younger children (r = 0.412, P = 0.0001). Association between IGF-I and T4 levels was significant only in the 4-10 years age group (r = 0.237, P = 0.001). CONCLUSIONS: Varying duration and degree of exposure to malnutrition and iodine deficiency resulted in different mean levels of T4, TSH, IGF-I and IGFBP-3 in the three areas. The strong positive associations between IGF-I and IGFBP-3 levels and height SDS suggest that these biochemical measurements are indeed useful indicators of growth and nutritional status in children. The significant correlations between T4 and IGFBP-3 and IGF-1 suggests the importance of thyroid hormones in regulating the synthesis of these growth factors. The age-related increase of these growth factors even amongst malnourished, iodine deficient children implies that age-matched reference ranges are essential for proper evaluation of laboratory results.

Adolescent↗
PubMed1996

The surgical treatment of adrenal diseases.

Between January 1978 to December 1993, 130 cases of adrenal diseases were diagnosed and surgically treated at the National University of Malaysia. They were 58 cases (44.6%) of Conn's syndrome, 40 cases (30.7%) of Cushing's syndrome, 20 cases (15.3%) of phaeochromocytoma and 12 cases (9.2%) of adrenocortical carcinoma (ACC). The commonest cause of Conn's syndrome was an adenoma (96.5%) which affected the left gland four times more than the right gland. Cushing's syndrome was caused by adrenocortical adenoma (32.5%), diffuse bilateral adrenal hyperplasia (40.0%), pigmented macronodular hyperplasia (20.0%) and adrenal carcinoma (7.5%). Twenty-five percent of the phaeochromocytomas were extraadrenal in origin arising mainly from the abdominal sympathetic chain. More than 50% of ACCs were non-functioning tumours. Fifty percent of the patients with ACC had inoperable tumours. The prognosis was poor even with adjuvant chemoradiotherapy. The main surgical approach was the anterior transabdominal route. There was no operative mortality or morbidity in all operated cases.

Adrenal Gland Diseases↗
PubMed1995

How I do it: an improved temporal bone holder.

Although some form of temporal bone holder is in use in virtually all ENT postgraduate teaching departments, a paucity of information in the literature may cause problems in selecting the most appropriate model to those responsible for equipping temporal bone laboratories. The bone holder which we describe is based on existing designs but incorporates a built-in irrigation system which offers considerable advantages to the unassisted operator.

Humans↗
PubMed1995

Mineralocorticoid and glycyrrhizic acid block stress induced hypotension in rats.

1. The aim of this study was to investigate the effect of repeated exposure to stress on tail blood pressure (TBP) of normal as well as GCA (glycyrrhizic acid) and steroid treated rats. Male Sprague-Dawley rats (250 g) were exposed to ether vapour to achieve light anaesthesia prior to TBP recording. Rats were injected with either normal saline or naloxone prior to exposure to stress. Tail blood pressure was recorded daily for 2 weeks. 2. We found that ether stress caused a transient drop in TBP in control as well as in dexamethasone (DEX) treated rats. The stress-induced fall in blood pressure was reduced by naloxone in control rats but not in DEX treated rats. However the transient drop in TBP following stress was not seen in either GCA or deoxycorticosterone (DOC) treated rats. 3. We conclude that first, the reduction in TBP was due to the release of endogenous opioids caused by stress. Second, DOC may block the release of such endogenous opioids, preventing the drop in TBP in response to stress, while DEX did not. Third, GCA caused a similar mineralocorticoid effect on reversing stress induced hypotension.

Animals↗