SABIIA - Sistema Aberto e Integrado de Informação em Agricultura (Sabiia)

Tostes,R.C.; Nigro,D.; Fortes,Z.B.; Carvalho,M.H.C..

The cardiovascular protective actions of estrogen are partially mediated by a direct effect on the vessel wall. Estrogen is active both on vascular smooth muscle and endothelial cells where functionally competent estrogen receptors have been identified. Estrogen administration promotes vasodilation in humans and in experimental animals, in part by stimulating prostacyclin and nitric oxide synthesis, as well as by decreasing the production of vasoconstrictor agents such as cyclooxygenase-derived products, reactive oxygen species, angiotensin II, and endothelin-1. In vitro, estrogen exerts a direct inhibitory effect on smooth muscle by activating potassium efflux and by inhibiting calcium influx. In addition, estrogen inhibits vascular smooth muscle cell...

Gender-dependent effects of aging on the kidney

Palavras-chave: Sex hormones; Estrogen; Vascular smooth muscle; Endothelium nitric oxide; Endothelium-derived hyperpolarizing factor; Angiotensin; Endothelin-1; Calcium channels; Potassium channels.

Ano: 2003

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003000900002

Gava,A.L.; Freitas,F.P.S.; Meyrelles,S.S.; Silva,I.V.; Graceli,J.B..

It is well known that the kidney plays an important role in the development of cardiovascular diseases such as hypertension. The normal aging process leads to changes in kidney morphology, hemodynamics and function, which increase the incidence of cardiovascular events in the elderly population. These disturbances are influenced by several factors, including gender. In general, females are protected by the effects of estrogens on the cardiorenal system. Several studies have demonstrated the beneficial effects of estrogens on renal function in the elderly; however, the relationships between androgens and kidney health during one’s lifetime are not well understood. Sex steroids have many complex actions, and the decline in their levels during aging clearly...

Hormone-induced spawning of cultured tropical finfishes.

Palavras-chave: Sexual dimorphism; Renal function; Aging; Cardiovascular disorders; Sex hormones.

Ano: 2011

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2011000900012

Induction of ovulation and stimulation of spermation by LHRH or an LHRH analog associated or not with pimozide. Effects on some teleost fish.

Marte, C.

Commercially important tropical freshwater and marine finfishes are commonly spawned with pituitary homogenate, human chorionic gonadotropin (HCG) and semi-purified fish gonadotropins. These preparations are often administered in two doses, a lower priming dose followed a few hours later by a higher resolving dose. Interval between the first and second injections may vary from 3-24 hours depending on the species. Variable doses are used even for the same species and may be due to variable potencies of the gonadotropin preparations.

Tipo: Text

Palavras-chave: Teleostei; Pisces; Tropical fish; Induced breeding; Sex hormones; Animal reproductive organs; Marine fish; Freshwater fish; Fish culture.

Ano: 1989

URL: http://archimer.ifremer.fr/doc/1989/acte-1436.pdf

Liaison de l'oestradiol 17 beta dans les hepatocytes de truite Arc-en-ciel et induction de la vitellogenine et de son ARNm specifique

Billard, R; Weil, C; Barnabe, G.

Effectiveness of LHRH and one of its analogs (LHRH-A = D-Ala super(6) ethylamide) on induction of ovulation and stimulation of spermiation is reviewed here. LHRH was also combined with pimozide, an anti-dopaminergic agent, to try to cancel dopamine inhibition of gonatotropin (GtH) release. LHRH-A alone (50 mu g/kg) did not initiate ovulation but only oocyte maturation. When pimozide (10 mg/kg) and LHRH-A (50 mu g/kg) were combined, gonadotropic hormone secretion was significantly increased, causing ovulation and stimulating spermiation. This combination advanced ovulation in trout. Trout egg quality was markedly altered by the pimozide treatment; it remains to be tested in carp. In sea bass, LHRH-A was much more effective than LHRH, and ovulation was...

Tipo: Text

Palavras-chave: Salmonidae; Dicentrarchus labrax; Sparidae; Cyprinidae; Teleostei; Pisces; Inhibitors; Sex hormones; Sexual maturity; Spermatogenesis; Ovulation; Induced breeding; Sexual reproduction.

Ano: 1983

URL: http://archimer.ifremer.fr/doc/1983/acte-1218.pdf

Regulation of antioxidant enzyme activities in male and female rat macrophages by sex steroids

Maitre, J; Mercier, L; Dolo, L; Valotaire, Y.

In the liver of rainbow trout (Salmo gairdnerii ), vitellogenin (Vg) synthesis is influenced by oestradiol (E sub(2)) which is believed to act through the classical mechanism of steroid hormone action. After binding of the hormone to a soluble specific receptor protein, the oestradiol-receptor complex is translocated to the nucleus, where it interacts with DNA and modulates expression of Vg genes, leading to increased synthesis of specific mRNA and Vg. The authors show here: (i) the presence of specific oestrogen receptors in the cytosol of the male trout liver. (ii) The male liver, offering, an ideal experimental control of "zero" background, the authors followed - in the liver of male trouts - the kinetics of induction of Vg mRNA by hybridization with Vg...

Tipo: Text

Palavras-chave: Salmonidae; Pisces; Proteins; Liver; RNA; Steroids; Biosynthesis; Receptors; Sex hormones; Sexual reproduction.

Ano: 1983

URL: http://archimer.ifremer.fr/doc/1983/acte-1230.pdf

Reproductive ability of pubertal male and female rats

Azevedo,R.B.; Lacava,Z.G.M.; Miyasaka,C.K.; Chaves,S.B.; Curi,R..

Human and animal immune functions present sex dimorphism that seems to be mainly regulated by sex hormones. In the present study, the activities of the antioxidant enzymes total superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were measured in intraperitoneal resident macrophages from adult male and female rats. In addition to comparing males and females, we also examined the regulation of these enzyme activities in macrophages by sex steroids. GSH-Px activity did not differ between male and female macrophages. However, both total SOD and CAT activities were markedly higher in females than in males (83 and 180%). Removal of the gonads in both males and females (comparison between castrated groups) increased the difference in...

Tipo: Info:eu-repo/semantics/other

Palavras-chave: Antioxidant enzymes; Macrophages; Sex hormones; Estrogen; Progesterone; Castration.

Ano: 2001

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001000500018

Zemunik,T.; Peruzovic,M.; Capkun,V.; Zekan,L.; Tomic,S.; Milkovic,K..

Ten Fisher rats 50 to 55 days of age made up the pubertal group, and ten rats 90 to 95 days of age served as the controls. The testicular and epididymal weights and volumes of the pubertal males were lower than those of the controls (P<0.001). There was also a difference in relative epididymal weight (P<0.001). The sperm of pubertal males was morphologically abnormal in 58.2% of cases, as opposed to only 3.8% in the controls (P<0.001). The mean number of spermatozoa in the control group was 11.9 × 10(6)/ml and their viability was 99.6%, while these values could not be determined for pubertal rats. Serum testosterone was higher in the pubertal animals than in the controls (2.52 ± 1.46 vs 0.92 ± 0.34 nM, P<0.01). The ovaries of control females...

Role of steroid hormones and external factors in the control of pituitary gonadotropic activity of female European eel (Anguilla anguilla ).

Palavras-chave: Puberty; Reproduction; Gonads; Sex hormones; Pregnancy.

Ano: 2003

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003000700007

The Effect of Walnut on the Weight, Blood Glucose and Sex Hormones of Diabetic Male Rats

Leloup, H; Fontaine, Y; Dufour, S; Querat, B.

Gonadotropic activity is relatively low in the female freshwater (FW) eel (A. anguilla ): pituitary GTH was about 15 ng equivalent cGTH/mg fresh tissue. Plasma GTH was always less than 1 ng equivalent cGTH/ml and often undetectable (< 0.2 ng equivalent cGTH/ml). Ovarian steroidogenesis in FW fish is similarly low; plasma concentration of both free testosterone (T) and free estradiol (E sub(2)) were less than 0.3 ng/ml as measured by RIA. Treatment with E sub(2) in FW fish caused a great increase in pituitary GTH, up to 1000 times control values, without changing plasma GTH. Stimulation of gonadotropic activity and ovarian development occur during the eel's migration to the Sargasso Sea. Adaptation to seawater (SW) caused a great increase of plasma E...

Tipo: Text

Palavras-chave: Anguilla anguilla; Anguillidae; Pisces; Migrations; Salinity; Environmental factors; Pituitary gland; Sexual reproduction; Ovaries; Sexual maturity; Steroids; Sex hormones; Facteurs externes; Steroids sexuels; Gonadotropine; Anguille.

Ano: 1983

URL: http://archimer.ifremer.fr/doc/1983/acte-1217.pdf

International Journal of Morphology

Ghorbani,R; Mokhtari,T; Khazaei,M; Salahshoor,M. R; Jalili,C; Bakhtiari,M.

Diabetes leads to reproductive dysfunctions by producing free radicals. It seems that using walnut can be effective in the damage induced by diabetes. The aim of the present study was to evaluate the effects of walnut consumption on sex hormones in diabetic Wistar male rats induced by STZ (streptozotocin). Diabetes animals were induced by STZ (60 mg/kg). Rats were randomly divided into 5 groups (n=6), including normal diet and healthy (Sham), Diabetic by normal diet (control) and diabetic by 6, 9 and 12% walnut in their diet (experimental groups), and were examined for 6 weeks. Body weight, blood glucose (3 times), and sex hormones (testosterone, FSH and LH) were measured. Overall, in terms of the mean index, there was a significant difference in the...

Tipo: Journal article

Palavras-chave: Walnut; Diabetes; Weight; Blood glucose; Sex hormones.

Ano: 2014

URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022014000300015

The hyperinsulinemia produced by concanavalin A in rats is opioid-dependent and hormonally regulated

Francisco-DoPrado,J.; Zambelli,J.E.; Melo-Lima,M.H.; Ribeiro-DaSilva,G..

The present study examines the effect of concanavalin A (Con A) on the blood insulin and glucose levels of rats. Male and female rats treated with Con A (62.5-500 µg/kg) for three days showed a dose- and time-dependent hyperinsulinemia that lasted more than 48 h. Male rats were more sensitive to Con A. Thus, 6 h after treatment with Con A the circulating insulin levels in male rats had increased by 85% (control: 10.2 ± 0.9 mU/l and Con A-treated: 18.8 ± 1 mU/l) compared to only 38% (control: 7.5 ± 0.2 mU/l; Con A-treated: 10.3 ± 0.9 mU/l) in females. An identical response was seen after 12 h. Con A (250 µg/kg) produced time-dependent hypoglycemia in both sexes but more pronounced in males. There was no correlation between the hypoglycemia and...

The sexuality of cultured hermaphroditic fish species: Analysis of morphological and endocrinological features in a protogynous hermaphrodite, Epinephelus microdon , as a basis for further research to control reproduction in the grouper

Palavras-chave: Concanavalin A; Hyperinsulinemia; Blood glucose alterations; Sex hormones; Endogenous opioids; Canatoxin.

Ano: 1998

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998000500015