Gonadal hormone concentrations in northern phalaropes in relation to nuptial plumage

1970 ◽  
Vol 48 (2) ◽  
pp. 400-401 ◽  
Author(s):  
E. Otto Höhn
Keyword(s):  
Gonadal Hormone ◽  
Wilson’S Phalarope

A sample of prebreeding season gonads of northern phalaropes showed a high ovarian ratio of testosterone/estradiol, and a greater concentration of testosterone in the ovaries than in the testes. These features correspond to those found in the gonads of Wilson's phalarope and differ from those found in the gonads of four other species of birds. In conjunction with the earlier demonstration that the nuptial plumage in this species is androgen-dependent, these facts explain the more colorful nuptial plumage of the female compared to that of the male northern phalarope.

scholarly journals Brain reactivity during aggressive response in women with premenstrual dysphoric disorder treated with a selective progesterone receptor modulator

2021 ◽  
Author(s):  
Elisavet Kaltsouni ◽  
Patrick M. Fisher ◽  
Manon Dubol ◽  
Steinar Hustad ◽  
Rupert Lanzenberger ◽  
...  
Keyword(s):  
Progesterone Receptor ◽  
Negative Relationship ◽  
Premenstrual Dysphoric Disorder ◽  
Aggressive Response ◽  
Anterior Cingulate ◽  
Reproductive Age ◽  
Gonadal Hormone ◽  
Dorsal Anterior Cingulate Cortex ◽  
Response Condition ◽  
Receptor Modulator

AbstractPremenstrual dysphoric disorder (PMDD) is a psychiatric condition characterized by late luteal phase affective, cognitive, and physical impairment. The disorder causes significant suffering in about 5% of women in their reproductive age. Altered sensitivity of cognitive-affective brain circuits to progesterone and its downstream metabolite allopregnanolone is suggested to underlie PMDD symptomatology. Core mood symptoms include irritability and anger, with aggression being the behavioral outcome of these symptoms. The present study sought to investigate the neural correlates of reactive aggression during the premenstrual phase in women with PMDD, randomized to a selective progesterone receptor modulator (SPRM) or placebo. Self-reports on the Daily Record of Severity of Problems were used to assess PMDD symptoms and gonadal hormone levels were measured by liquid chromatography tandem mass spectrometry. Functional magnetic resonance imaging was performed in 30 women with PMDD, while performing the point subtraction aggression paradigm. Overall, a high SPRM treatment response rate was attained (93%), in comparison with placebo (53.3%). Women with PMDD randomized to SPRM treatment had enhanced brain reactivity in the dorsal anterior cingulate cortex and dorsomedial prefrontal cortex during the aggressive response condition. The fronto-cingulate reactivity during aggressive responses depended on treatment, with a negative relationship between brain reactivity and task-related aggressiveness found in the placebo but not the SPRM group. The findings contribute to define the role of progesterone in PMDD symptomatology, suggesting a beneficial effect of progesterone receptor antagonism, and consequent anovulation, on top-down emotion regulation, i.e., greater fronto-cingulate activity in response to provocation stimuli.

scholarly journals Food cravings and loss‐of‐control eating in youth: Associations with gonadal hormone concentrations

2021 ◽  
Author(s):  
Megan N. Parker ◽  
Marian Tanofsky‐Kraff ◽  
Ross D. Crosby ◽  
Meghan E. Byrne ◽  
Sarah LeMay‐Russell ◽  
...  
Keyword(s):  
Gonadal Hormone ◽  
Loss Of Control ◽  
Loss Of Control Eating ◽  
Food Cravings

Effects of in vivo gonadal hormone environment on in vitro hGRF-40-stimulated GH release

1985 ◽  
Vol 249 (3) ◽  
pp. E276-E280 ◽  
Author(s):  
W. S. Evans ◽  
R. J. Krieg ◽  
E. R. Limber ◽  
D. L. Kaiser ◽  
M. O. Thorner
Keyword(s):  
Female Rats ◽  
Male Rats ◽  
Gonadal Hormone ◽  
Base Line ◽  
Pituitary Cells ◽  
Intact Male ◽  
Castrate Male ◽  
Basal Release

The effects of gender and the gonadal hormone environment on basal and stimulated growth hormone (GH) release by dispersed and continuously perifused rat anterior pituitary cells were examined. Cells from intact male and diestrus day 2 female rats and from castrate male rats either untreated or treated with testosterone (T) or 17 beta-estradiol (E2) were used. Basal GH release (ng/min per 10(7) cells; mean +/- SE) by cells from diestrus day 2 female rats was less than by cells from castrate rats treated with T (4.3 +/- 0.6 vs. 11.4 +/- 2.7, respectively; P less than 0.025). No other differences in basal release were detected. Concentration-response relationships were documented between human GH-releasing factor 40 (hGRF-40; 0.03-100 nM given as 2.5-min pulses every 27.5 min) and GH release. Mean (+/- SE) overall GH release (ng/min per 10(7) cells) above base line was greater by cells from intact male rats (496 +/- 92) than by cells from castrate (203 +/- 37.3; P less than 0.0001), castrate and T-treated (348 +/- 52.8; P = 0.008), or castrate and E2-treated (58.1 +/- 6.8; P less than 0.001) male rats or by diestrus day 2 rats (68.6 +/- 9.5; P = 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

The anorectic effect of fenfluramine is influenced by sex and stage of the estrous cycle in rats

2005 ◽  
Vol 288 (6) ◽  
pp. R1486-R1491 ◽  
Author(s):  
Lisa A. Eckel ◽  
Heidi M. Rivera ◽  
Deann P. D. Atchley
Keyword(s):  
Food Intake ◽  
Estrous Cycle ◽  
Female Rats ◽  
Male Rats ◽  
Gonadal Hormone ◽  
Estrous Female ◽  
Male And Female Rats ◽  
Daily Food ◽  
Hormone Status ◽  
Anorectic Effect

The controls of food intake differ in male and female rats. Daily food intake is typically greater in male rats, relative to female rats, and a decrease in food intake, coincident with the estrous stage of the ovarian reproductive cycle, is well documented in female rats. This estrous-related decrease in food intake has been attributed to a transient increase in the female rat's sensitivity to satiety signals generated during feeding bouts. Here, we investigated whether sex or stage of the estrous cycle modulate the satiety signal generated by fenfluramine, a potent serotonin (5-HT) releasing agent. To examine this hypothesis, food intake was monitored in male, diestrous female, and estrous female rats after intraperitoneal injections of 0, 0.25, and 1.0 mg/kg d-fenfluramine. The lower dose of fenfluramine decreased food intake only in diestrous and estrous females, suggesting that the minimally effective anorectic dose of fenfluramine is lower in female rats, relative to male rats. Although the larger dose of fenfluramine decreased food intake in both sexes, the duration of anorexia was greater in diestrous and estrous female rats, relative to male rats. Moreover, the magnitude of the anorectic effect of the larger dose of fenfluramine was greatest in estrous rats, intermediate in diestrous rats, and least in male rats. Thus our findings indicate that the anorectic effect of fenfluramine is modulated by gonadal hormone status.

scholarly journals Endocrine markers of semistarvation in healthy lean men in a multistressor environment

2000 ◽  
Vol 88 (5) ◽  
pp. 1820-1830 ◽  
Author(s):  
Karl E. Friedl ◽  
Robert J. Moore ◽  
Reed W. Hoyt ◽  
Louis J. Marchitelli ◽  
Lester E. Martinez-Lopez ◽  
...  
Keyword(s):  
Body Fat ◽  
Specific Binding ◽  
Thermal Strain ◽  
Young Male ◽  
Gonadal Hormone ◽  
Us Army ◽  
Igf I ◽  
Elevated Cholesterol ◽  
Group 2 ◽  
Group 1

We tested the hypothesis that key endocrine responses to semistarvation would be attenuated by changing only the food intake in a multistressor environment that also included sustained workload, inadequate sleep, and thermal strain. Serum hormones were compared within and between two groups of healthy young male volunteers participating in the 8-wk US Army Ranger course, with four repeated cycles of restricted energy intakes and refeeding: group 1 ( n = 49) and group 2 ( n = 48); energy deficits averaged 1,200 and 1,000 kcal/day, respectively. After 8 wk, most of group 1 achieved a minimum body fat, serum 3,5,3′-triiodothyronine (T3) was below normal (78 ± 20 ng/dl), testosterone (T) approached castrate levels (4.5 ± 3.9 nmol/l), insulin-like growth factor I (IGF-I) declined by one-half (75 ± 25 μg/l), and cholesterol rose from 158 ± 31 to 217 ± 39 mg/dl. Bioavailable T3 and T were further reduced by increases in their specific binding proteins in response to declining insulin. Refeeding, even with continuation of the other stressors, produced prompt recovery of T3, T, and IGF-I. Higher energy intakes in group 2 attenuated the subclinical hypothyroidism and hypercholesterolemia, whereas consistent luteinizing hormone suppression indicated centrally mediated threshold effects on gonadal hormone suppression. We conclude that low T, T3, and IGF-I remained reliable markers of acute energy deficits in the presence of other stressors; elevated cholesterol and cortisol provided information about chronic status, corresponding to diminishing body fat stores.

Protective effects of estrogen on gender-specific development of diet-induced hypertension

2001 ◽  
Vol 91 (5) ◽  
pp. 2005-2009 ◽  
Author(s):  
Christian K. Roberts ◽  
Nosratola D. Vaziri ◽  
R. James Barnard
Keyword(s):  
Body Weight ◽  
Female Rats ◽  
Male Rats ◽  
Gonadal Hormone ◽  
Normal Female ◽  
Humoral Factors ◽  
Diet Modification ◽  
Ovx Rats ◽  
Hormone Status ◽  
Induced Hypertension

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.

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