PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Endocrine Effects”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources

Chronic administration of aqueous extract of Stevia rebaudiana (Bert.) Bertoni in rats: endocrine effects.

1. The effects of the active principles of S. rebaudiana (SR) on endocrine parameters of male rats were studied upon chronic administrations (60 days) of a concentrated, crude extract of its leaves, starting at prepubertal age (25-30 days old). 2. The following determinations were made: glycemia; serum levels of T3 and T4; available binding sites in thyroid hormone-binding proteins (T3R index); binding of [3H]R 1881 to prostate cytosol; zinc content in prostate, testis, submandibular salivary gland (SMG) and pancreas; water content in testis and prostate. The body weight gain and the final weight of testis, prostate, seminal vesicle, SMG and adrenal were also studied. 3. Results showed that the SR-treated group did not significantly differ from the control group, with exception to the seminal vesicle weight, which fell by about 60%. 4. It is concluded that if the SR extract does have some potential to decrease rat fertility at all, this effect is almost certainly not exerted on the male.

Animals↗

Endocrine effects of ventilation, oxygenation and cord occlusion in near-term fetal sheep.

The transition from fetal to newborn life is associated with significant endocrine changes. Some of these changes may be triggered by the effects of spontaneous respiration, increased oxygenation and removal of the placental circulation at birth. We, therefore, studied endocrine function during in utero ventilation, oxygenation and cord occlusion, in nine chronically-instrumented fetal sheep aged 137 to 140 days of gestation. During the sequential effects of in utero ventilation and oxygenation, plasma renin activity (PRA) and angiotensin II (AII) remained at control levels of 6.3 +/- 1.9 ng/ml per h and 66 +/- 15 pg/ml. After cord occlusion, PRA increased to 10.3 +/- 2.2 ng/ml per hr and AII increased to 86 +/- 24 pg/ml, the latter being non-significant. Plasma cortisol levels also increased from control levels of 3.5 +/- 1.0 to 6.7 +/- 0.8 g/dl during cord occlusion (P = 0.02). During the sequential effects of ventilation, oxygenation and cord occlusion, plasma epinephrine increased from control levels of 87 +/- 17 to 492 +/- 142 pg/ml (P = 0.04), and plasma norepinephrine levels increased slightly from 620 +/- 112 to 850 +/- 214 pg/ml. These data provide evidence that many of the changes in endocrine function seen at birth result from factors other than spontaneous respiration, oxygenation and umbilical cord occlusion.

Air↗

[Comparison of the cardiac, renal and endocrine effects of converting enzyme inhibition with those of a classical triple therapy in experimental renal hypertension].

In the rat model of hypertension induced by a clip on the right renal artery, sparing the left kidney, we compared the efficacity and the endocrine, renal and cardiac effects of classical therapy (CT) of hypertension (Clonidine 0.2 mg/kg and Dihydralazine 15 mg/kg in 2 daily subcutaneous injections and Furosemide 30 mg/kg/day in the drinking water), with inhibition of the angiotensin converting enzyme with a new drug, the S-9490-3 (0.5 mg/kg in one daily administration). The untreated animals (HT: n = 12) had an average systolic blood pressure (SBP) of 215 +/- 32 mmHg. After 1 month' treatment, S-9490-3 (n = 13) lowers SBP to 144 +/- 32 mmHg compared to CT (n = 12) which lowered SBP to only 172 +/- 18 mmHg. The average plasma renin concentrations of the HT animals was four times the normal value (39 +/- 33 ng/ml/h) and both treatment regimes increased it further (S-9490-3: 129 +/- 65 ng/ml/h; CT: 97 +/- 73 ng/ml/h). Angiotensin levels fell in proportion to the increase in renin concentration. Plasma aldosterone was normalised by S-9490-3 (460 +/- 320 pg/ml) but remained as high after CT (850 +/- 650 pg/ml) as in the untreated HT animals (830 +/- 260 pg/ml). Despite the Furosemide, plasma volume increased significantly in the CT group.(ABSTRACT TRUNCATED AT 250 WORDS)

Aldosterone↗

Metabolic and endocrine effects of the desogestrel-containing oral contraceptive Mircette.

OBJECTIVE: The purpose was to evaluate the metabolic effects of Mircette (brand of desogestrel/ethinyl estradiol and ethinyl estradiol), a low-estrogen, desogestrel-containing oral contraceptive. STUDY DESIGN: Women taking Mircette were evaluated to determine its effects on lipid profiles (n = 74), carbohydrate metabolism (n = 25), and endocrine parameters (n = 53). RESULTS: During cycles 3 and 6 of Mircette treatment, changes from baseline included mean increases in serum triglycerides and very low-density lipoprotein cholesterol ranging between 50% and 60%. Smaller mean increases were observed at these time points in high-density lipoprotein cholesterol subfraction 2 (range between 17% and 25%), total cholesterol (<10%), high-density lipoprotein cholesterol (range between 10% and 15%), and high-density lipoprotein cholesterol subfraction 3 (range between 9% and 13%), with only nominal changes (<6%) in low-density lipoprotein cholesterol and lipoprotein. Patients receiving Mircette showed no mean changes in fasting plasma glucose or serum insulin levels but did have modest increases in glucose and insulin levels after a glucose challenge. Mircette treatment suppressed follicle-stimulating hormone, luteinizing hormone, 17beta-estradiol, and progesterone to levels consistent with inhibition of ovulation and increased concentrations of thyroid- and cortisol-binding globulins. CONCLUSIONS: Overall, Mircette treatment was associated with expected effects on the pituitary-ovarian axis, triglycerides, and serum binding proteins; a modest decline in glucose tolerance; and a favorable effect on lipid profiles as a result of increases in total high-density lipoprotein cholesterol and high-density lipoprotein cholesterol subfraction 2 in the absence of changes in total cholesterol or low-density lipoprotein cholesterol.

Adolescent↗

Endocrine effects of laparoscopic ovarian electrocautery in patients with polycystic ovarian disease, resistant to clomiphene citrate.

Endocrine responses to laparoscopic ovarian electrocautery were studied in 14 patients with polycystic ovarian disease (PCOD), resistant to clomiphene citrate. Patients who did not conceive within 6 months of treatment were evaluated for up to that period. Testosterone and androstenedione levels decreased after electrocautery in a way which is comparable with the reduction in androgens after wedge resection of the ovary. Androstenedione levels tended to return to pretreatment values at 6 months; four of the five pregnancies were achieved within this period. The reduction in androgens may break the vicious circle of PCOD, and lead to normal menstrual cycles.

Clomiphene↗

Glucagon: endocrine effects and calcium involvement in cardiovascular actions in dogs.

Although the cardiovascular effects of glucagon are understood, its mechanism(s) of action remains unclear. We studied the effects of increasing doses of glucagon (0.001, 0.01, 0.1 mg/kg) on cardiovascular responses in dogs relative to concurrent measurements of circulating glucagon, cyclic AMP, glucose, norepinephrine, epinephrine, triiodothyronine, thyroxine, and cortisol levels. Glucagon-induced increases in plasma cyclic AMP, glucose, and catecholamine concentrations paralleled the heart rate response to glucagon administration. Further studies were conducted to evaluate the role of beta-adrenergic function as well as calcium in mediating glucagon's actions. The tachycardic effects of glucagon (0.01 mg/kg) were unaltered by prior beta-adrenergic receptor blockade with propranolol (3.5 mg/kg total dose). The calcium antagonist verapamil (0.2 mg/kg bolus then 7.5 micrograms/kg/min/infusion) prevented glucagon-induced increases in heart rate. However, the coadministration of glucagon (0.01 mg/kg) with calcium (1.0, 5.0, 10.0, or 50.0 mg/kg) did not alter glucagon's cardiovascular effects. These data indicate that glucagon is a potent tachycardiac agent that also elevates circulating endocrine-related substances. The antagonism of glucagon's tachycardiac effects by verapamil suggests that glucagon's action may be via glucagon-induced calcium movement through calcium channels, although extracellular calcium changes do not alter glucagon's effect. Furthermore, the persistence of glucagon's cardiovascular actions following beta-adrenergic blockade indicates the potential clinical utility of glucagon in reversing the adverse effects of beta-blocker overdoses, and its potential usefulness in treating circulatory shock in "beta-blocked" patients.

Animals↗

A 28-day oral dose toxicity study enhanced to detect endocrine effects of hexabromocyclododecane in Wistar rats.

A 28-day repeated dose study in rats (OECD407) enhanced for endocrine and immune parameters was performed with hexabromocyclododecane (HBCD). Rats were exposed by daily gavage to HBCD dissolved in corn oil in 8 dose groups with doses ranging between 0 and 200 mg/kg bw per day (mkd). Evaluation consisted of dose-response analysis with calculation of a benchmark dose at the lower 95% one-sided confidence bound (BMDL) at predefined critical effect sizes (CESs) of 10-20%. The most remarkable findings were dose-related effects on the thyroid hormone axis, that is, decreased total thyroxin (TT4, BMDL 55.5 mkd at CES--10%), increased pituitary weight (29 mkd at 10%) and increased immunostaining of TSH in the pituitary, increased thyroid weight (1.6 mkd at 10%), and thyroid follicle cell activation. These effects were restricted to females. Female rats also showed increased absolute liver weights (22.9 mkd at 20%) and induction of T4-glucuronyl transferase (4.1 mkd at 10%), suggesting that aberrant metabolization of T4 triggers feedback activation of the thyroid hormone system. These effects were accompanied by possibly secondary effects, including increased cholesterol (7.4 mkd at 10%), increased tibial bone mineral density (> 49 mkd at 10%), both in females, and decreased splenocyte counts (0.3-6.3 mkd at 20%; only evaluated in males). Overall, female rats appeared to be more sensitive to HBCD than male rats, and an overall BMDL is proposed at 1.6 mkd, based on a 10% increase of the thyroid weight, which was the most sensitive parameter in the sequence of events.

Administration, Oral↗

[Endocrine effects of neuroleptics].

The neuroleptic drugs used in anesthetics belong to the group of phenothiazines or butyrophenones. The endocrine response to their intravenous administration is still ill-known and usually only concerns the association of anesthetics and neuroleptics. However, as far as the catecholamines are concerned, it is known that neuroleptic drugs do not prevent either their secretion nor their liberation but, depending on their dosage, they block the dopaminergic receptors and the alpha-receptors and induce disturbances in the metabolism of the mono-amines. The injection of neuroleptics associated with analgesics, raises the blood levels of catecholamines, does not induce a rise in ACTH and cortisol levels in the absence of stress, but does not totally prevent their rise in cases of aggression. As far as growth hormone is concerned, the effects are variable depending on the association studied. There is a rise with droperidol + pethidine or pentazocine, no change with chloroprotixene-dextromoramide. In both cases, the blood sugar rises. As far as STH, or growth hormone, free fatty acids and insulin are concerned, one may note a rise with associations containing droperidol even in the absence of any stress and stability with a mixture of chlorprotixene and dextromoramide. With none of these well known associations was there any variation either in levels of pituitary thyreo-stimulin, nor in thyroxine levels. Testosterone becomes reduced with the association of droperidol + analgesics but this effect does not seem to be specific to droperidol. These responses are frequently disturbed in case of additional stress.

Adrenocorticotropic Hormone↗

Cardiovascular and endocrine effects of acupuncture in hypertensive patients.

It has been reported that acupuncture can decrease blood pressure in patients with hypertension, possibly by an endocrine mechanism. The aim of the present study was to investigate the effects of acupuncture on arterial blood pressure and the secretion of renin, vasopressin and cortisol in hypertensive patients. Acupuncture was performed in fifty untreated essential hypertensive patients resting in the supine position. Thirty min after acupuncture there were decreases in systolic pressure from 169 +/- 2 to 151 +/- 2 mm Hg, diastolic pressure from 107 +/- 1 to 96 +/- 1 mm Hg, and heart rate from 77 +/- 2 to 72 +/- 2 bpm (P < 0.01). Plasma renin activity decreased from 1.7 +/- 0.4 to 1.1 +/- 0.2 ng/ml/2h (P < 0.01), but there were no significant changes in plasma vasopressin or cortisol concentrations. These results confirm that acupuncture decreases blood pressure in hypertensive patients, and suggest that the decrease results, at least in part, from a decrease in renin secretion.

Acupuncture Therapy↗

Late endocrine effects of ovarian electrocautery in women with polycystic ovary syndrome.

OBJECTIVE: To examine the duration of the changes in endocrine indices produced by ovarian electrocautery in women with polycystic ovary syndrome (PCOS). DESIGN: Long-term observational study. SETTING: University hospital. PATIENT(S): Infertile women with PCOS. INTERVENTION(S): Ovarian electrocautery was performed through the laparoscope. Blood was sampled before the operation and at defined intervals thereafter. After the establishment of regular cycles, sampling was performed 1 week before the menstrual period. MAIN OUTCOME MEASURE(S): The patients were observed before and at defined intervals for up to 20 years after ovarian electrocautery. Serum concentrations of hypophyseal and ovarian hormones were determined, including sex hormone-binding globulin (SHBG). RESULT(S): There was a clear shift from anovulation to ovulatory cycles and a significant decrease in androgens and gonadotropins. The concentration of SHBG increased. These effects lasted for many years; after 18-20 years, two thirds of the women were still ovulating. CONCLUSION(S): Ovarian electrocautery for PCOS normalizes ovarian function, including androgen production, and the results seem to be stable for 18-20 years.

17-alpha-Hydroxyprogesterone↗

Neuro-endocrine effects of isotheoline.

Experiments are carried out to study the effect of isotheoline (IST) on the secretion of prolactin (PRL), somatotrophic hormone (STH) and testosterone, using cats and Wistar albino rats of both sexes. PRL, STH and testosterone using cats and wistar albino rats of both sexes. PRL, STH and testosterone were determined radioimmunologically at the 10th, 60th and 120th min after the administration of IST in doses of 0.5 to 5 mg/kg. Comparative experiments were carried out with bromocryptine and glaucine--1 mg/kg i.p., as well as experiments involving the administration of IST on the background of the dopaminergic antagonists haloperidol and pymoside--1 mg/kg i.p. The results obtained show that in doses not exceeding 1 mg/ks IST increases the plasma level of testosterone and, similar to bromocryptine, reduces the plasma level of PRL and increases that of STH. These effects are less pronounced for the 5 mg/kg dose and they are antagonized by the dopaminergic antagonists used. It is assumed that IST, similar to bromocryptine, achieves the described effects through selective stimulation of the D2 dopaminergic receptors involved in neuro-endocrine mechanisms responsible for the control and release of the hormones studied.

Animals↗

Hematological, metabolic, and endocrine effects of feeding vitamin A and lactoferrin in neonatal calves.

There are reports of important interactions among vitamin A, lactoferrin (Lf), and components of the insulin-like growth factor (IGF) system. Newborn calves are deficient in vitamin A and have a low Lf status. Colostrum contains vitamin A, Lf, and members of the IGF system, including IGF binding proteins (IGFBP), and these compounds may exert mutual interactions in neonatal calves. Effects of feeding different amounts of vitamin A and Lf on hematological, metabolic, and endocrine traits during the first 5 d of life were studied in neonatal calves. Calves were fed a milk-based formula without (F) or with added vitamin A [F(A); 351, 402, 490, and 490 micromol/kg dry matter (DM) on d 1, 2, 3, and 4, respectively], Lf (F(L); 3850, 1990, 660, and 660 mg/kg DM on d 1, 2, 3, and 4, respectively), or vitamin A + Lf (F(AL)) and colostrum (C). Blood samples were taken preprandially on d 1 to 5 and postprandially on d 1, 2, and 4 for the study of hematological, metabolic, and endocrine traits. As intestinal absorption of Lf in formula-fed calves was obviously lower than in colostrum-fed calves, Lf supplementation did not influence the metabolic and endocrine status. Plasma vitamin A concentrations increased from d 1 to 5 in F(A), F(AL), and C, but remained low in F and F(L). Addition of vitamin A to F affected concentrations of vitamin A from d 2 to 5; hemoglobin and triglycerides on d 3; and tended to influence IGFBP-3 levels on d 5. On d 1, preprandial insulin concentrations in F and F(L) were higher than those in F(A) and F(AL) and growth hormone concentrations on d 3 in F(A) were higher than in F(AL). In C, plasma Lf concentrations increased on d 1 and then decreased until d 5, whereas plasma urea and IGF-I concentrations remained stable. Compared with F-fed calves, C-fed calves had higher plasma concentrations of Lf from d 1 to 4, higher concentrations of vitamin A on d 5, higher concentrations of total protein from d 2 to 5, higher concentrations of triglycerides on d 3 and 4, and higher concentrations of IGF-I on d 4 and 5, but lower urea concentrations on d 4 and 5 and lower basal growth hormone concentrations than in F, F(L), and F(A). In conclusion, metabolite and hormone concentrations were influenced by differences in feeding. Addition of vitamin A influenced concentrations of vitamin A, hemoglobin, and triglycerides and tended to affect IGFBP-3 levels. Lactoferrin and vitamin A did not interact with respect to the IGF-I and IGFBP-3 status.

Animal Nutritional Physiological Phenomena↗