Plasma and adrenal corticosterone levels during the different phases of the sexual cycle in normal female rats

1971 ◽  
Vol 27 (3) ◽  
pp. 339-340 ◽  
Author(s):  
D. Raps ◽  
P. L. Barthe ◽  
P. A. Desaulles
1971 ◽  
Vol 68 (1_Supplb) ◽  
pp. S77
Author(s):  
D. Raps ◽  
P. L. Barthe ◽  
G. Meglioli ◽  
P. A. Desaulles

2001 ◽  
Vol 91 (5) ◽  
pp. 2005-2009 ◽  
Author(s):  
Christian K. Roberts ◽  
Nosratola D. Vaziri ◽  
R. James Barnard

Dietary and humoral factors are thought to be involved in the development of hypertension. This study investigated the interaction between diet and gonadal hormone status in the development and reversibility of hypertension. Normal male and female and ovariectomized (OVX) female Fischer rats were placed on either a high-fat (primarily saturated), refined carbohydrate (sucrose) (HFS) or a low-fat, complex carbohydrate (LFCC) diet at 2 mo of age, and body weight and systolic blood pressure (BP) were measured. Male and OVX female rats were initially on the diets for 7 mo, whereas normal female rats were on the diets for 2 yr. After this initial phase, a group of rats from each of the normal HFS groups were converted to the LFCC diet for a period of 1 mo (males) and 2 mo (females). The OVX females were subcutaneously implanted with a 0.5-mg estradiol (E2) pellet for 1 mo. A significant rise in arterial BP occurred within 12 mo in female and only 2 mo in male rats on the HFS diet, exceeding 140 mmHg after 24 and 7 mo, respectively. Conversion from the HFS to the LFCC diet led to a normalization of BP in both female and male rats. HFS diet-induced hypertension was accelerated by OVX in female rats, approaching the pattern seen in male rats. The effect of OVX was completely reversed by E2replacement. BP did not significantly change in any of the LFCC groups at any time point, and E2 replacement had no effect on BP in the OVX LFCC group. All HFS groups had significantly greater body weight, with differences occurring sooner in the male and OVX rats compared with the female rats. Diet modification resulted in a partial but significant reduction of body weight, but E2replacement did not. These results demonstrate that long-term consumption of HFS diet induces hypertension in both genders and is reversible by diet modification. Hypertension is significantly delayed in females with functional ovaries. This protection is lost by OVX and restored by estrogen replacement. Thus hormone status contributes to the delayed onset of diet-induced hypertension in females compared with males.


1996 ◽  
Vol 271 (3) ◽  
pp. F527-F538 ◽  
Author(s):  
S. C. Borkan ◽  
Y. H. Wang ◽  
K. T. Lam ◽  
P. Brecher ◽  
J. H. Schwartz

In the present study, we provide immunohistochemical and immunologic evidence to localize an abundant, 15.5-kDa protein to the soluble protein fraction of the proximal tubule. This 15.5-kDa protein binds fatty acids in vitro and has identity with amino acids 10-117 of alpha 2 mu-globulin (A2 fragment), a 19-kDa protein synthesized predominantly in the male liver. With reverse transcription-polymerase chain reaction, mRNA for A2 was detected in male liver but not in the male kidney. De novo accumulation of the 15.5-kDa protein was observed in the renal cortex of female rats given intravenous injections of purified 19-kDa protein (A2), suggesting intrarenal processing of the larger protein. The potential role of this protein in the proximal tubule, a site that utilizes fatty acids as an important metabolic substrate, was determined in isolated proximal tubule segments. Fatty acid and glucose oxidation rates were measured in three experimental models in which the 15.5-kDa protein was virtually absent: 1) uninephrectomized male rats treated with deoxycorticosterone acetate and salt, 2) male rats subjected to bilateral adrenalectomy, and 3) normal female rats. In the absence of the 15.5-kDa protein, fatty acid oxidation rates decreased by 30-55%, whereas glucose oxidation significantly increased in all three models. In female renal cortex, depletion of the 15.5-kDa protein was associated with a rise in heart fatty acid binding protein, an alternative intracellular transporter of fatty acids. These data support the hypothesis that a proteolytic cleavage product of hepatic alpha 2 mu-globulin may facilitate the oxidation of oleate, a hydrophobic ligand, in the proximal tubule.


1956 ◽  
Vol 186 (1) ◽  
pp. 9-12 ◽  
Author(s):  
Max Kleiber ◽  
Arthur H. Smith ◽  
Theodore N. Chernikoff

On the basis of 926 respiration trials, metabolic rates of normal female rats are presented as means of 42 different age groups from birth to 1000 days of age. The means with their standard errors are given for the metabolic rates per rat, per kilogram weight, per unit of the 2/3 power of body weight (surface), and per unit of the 3/4 power of body weight (inter specific unit of metabolic body size). A minimum of 72.6 Cal/kg.3/4 occurs between the ages of 200 and 300 days. An equation with two exponentials predicts the metabolic rate of rats from 77–1000 days of age with a standard deviation between prediction and observation of 2.2% of the mean.


1977 ◽  
Vol 74 (2) ◽  
pp. 315-NP ◽  
Author(s):  
A. DANGUY ◽  
J. L. PASTEELS ◽  
F. ECTORS

A single injection of 1 mg of a complex of testosterone esters on day 5 of life was used to prepare constantly oestrous rats. Such androgenized female rats were then ovariectomized and submitted to stereotaxical implantation of 1 μg oestradiol benzoate, 5 μg testosterone isobutyrate or, as a control, 10 μg cholesterol in the anterior hypothalamic areas. The effects of the steroids on plasma and pituitary FSH and LH were assessed by radioimmunoassay. As reported previously by us in normal female and male rats, the preoptic–suprachiasmatic area (POA) was able to control synthesis and secretion of both gonadotrophins and did not lose its sensitivity to oestradiol and testosterone in androgenized rats. Evidence for enhanced prolactin secretion in androgenized rats was derived from immunofluorescence studies of the pituitary gland and from histology of the mammary glands. In this respect the condition of the androgenized females was opposite to that of the males. The present work demonstrated that stimulation of prolactin secretion in androgenized female rats resulted from oestrogen action due to permanent oestrus rather than from impairment of hypothalamo-hypophysial relationships. Indeed, prolactin stimulation was suppressed when the androgenized rats were ovariectomized and restored when they were subsequently implanted with oestradiol in the POA.


1985 ◽  
Vol 5 (3) ◽  
pp. 393-400 ◽  
Author(s):  
Astrid Nehlig ◽  
Linda J. Porrino ◽  
Alison M. Crane ◽  
Louis Sokoloff

The quantitative 2-[14C]deoxyglucose autoradiographic method was used to study the fluctuations of energy metabolism in discrete brain regions of female rats during the estrous cycle. A consistent though statistically nonsignificant cyclic variation in average glucose utilization of the brain as a whole was observed. Highest levels of glucose utilization occurred during proestrus and metestrus, whereas lower rates were found during estrus and diestrus. Statistically significant fluctuations were found specifically in the hypothalamus and in some limbic structures. Rates of glucose utilization in the female rat brain were compared with rates in normal male rats. Statistically significant differences between males and females at any stage of the estrous cycle were confined mainly to hypothalamic areas known to be involved in the control of sexual behavior. Glucose utilization in males and females was not significantly different in most other cerebral structures.


1979 ◽  
Vol 90 (1) ◽  
pp. 81-89 ◽  
Author(s):  
J. W. Janssen ◽  
C. van Hardeveld ◽  
A. A. H. Kassenaar

ABSTRACT T3 and T4 concentrations were determined in plasma and red and white skeletal muscle of the rat. Because of the small tissue samples (± 300 mg), the ultra-sensitive Wick radioimmunoassay (RIA) for serum was adapted for determination in ethanol extracts. The dilution curves of the plasma and tissue extracts showed excellent parallelism with the standard curves for both T3 and T4. The mean T4 level found in female rats (n = 6) was 22.6 ± 5.2 ng/ml in plasma and did not differ significantly between red (1.85 ± 0.28 ng/g) and white (1.90 ± 0.25 ng/g) skeletal muscle. The mean T3 level in 11 normal female rats was 0.629 ± 0.098 ng/ml in the plasma and was significantly higher in the red muscle (2.07 ± 0.26 ng/g) than in the white muscle (1.65 ± 0.20 ng/g). The higher T3 levels found in the red muscle as compared with the white muscle may help to elucidate the different responsiveness of these muscle types observed in altered thyroid states.


1986 ◽  
Vol 14 (03n04) ◽  
pp. 157-160 ◽  
Author(s):  
Akira Miyake ◽  
Jin-Woo Lee ◽  
Keiichi Tasaka ◽  
Shirou Ohtsuka ◽  
Toshihiro Aono

For examination of the effect on luteinizing hormone (LH) release of Wen-Jing-Tang, a traditional Chinese herbal medicine, the pituitary from normal female rats in diestrus was perifused alone or in sequence with the mediobasal hypothalamus (MBH) in a sequential double-chamber perifusion system. Wen-Jing-Tang at 5 or 500 μg/ml induced significant LH release (60-95 % increase) from the pituitary in series with the MBH, but had no effect on LH release from the pituitary perifused alone. These data suggest that Wen-Jing-Tang induces LH release from the pituitary through hypothalamic LH-RH.


1990 ◽  
Vol 126 (2) ◽  
pp. 269-274 ◽  
Author(s):  
D. Wynick ◽  
R. Critchley ◽  
M. S. Venetikou ◽  
J. M. Burrin ◽  
S. R. Bloom

ABSTRACT As the secretory granules of anterior pituitary cells fuse with the cell surface, there would appear to be sufficient hormone present on the cell surface to be labelled by polyclonal hormone antibodies and thus analysed by flow cytometry. We have therefore applied fluorescence-activated cell sorting to these labelled pituitary cells. Percentage purity and depletion of other cell types was assessed by immunocytochemistry and the reverse haemolytic plaque assay (RHPA). Results demonstrate that fluorescence-activated cell sorting allows almost complete purification of functional lactotrophs and somatotrophs to 96·7 ±1·7 (s.e.m.)% and 98±1·0% respectively by immunocytochemistry, and to 95·8 ±1·1% and 97±0·8% respectively by RHPA. Depletion of other anterior pituitary cell types to less than 2% was demonstrated by both immunocytochemistry and RHPA. Fluorescence-activated cell sorting to this degree of purity was routinely possible with cell yields of 91 ±3·4%. To obtain such purity/depletion, it was necessary to use specific antisera of high titre, at concentrations which ensured maximal cell-surface labelling associated with maximal stimulation of hormonal secretion by the appropriate hypothalamic stimulatory factor. Separating cells on the basis of the intensity of prolactin cell-surface labelling demonstrated a low level of binding of the prolactin antibody to gonadotrophs (but not of sufficient fluorescence intensity to be sorted into the prolactin enriched population), raising the possibility of prolactin receptors on gonadotrophs. We were unable to demonstrate the presence of mammosomatotrophs in the normal female rat, since purified lactotrophs did not contain or secrete GH nor did purified somatotrophs contain or secrete prolactin. Journal of Endocrinology (1990) 126, 269–274


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