ROLE OF TESTOSTERONE IN THE SEXUAL DIMORPHISM OF ADRENAL ACTIVITY AT PUBERTY IN THE GUINEA-PIG

1980 ◽  
Vol 87 (3) ◽  
pp. 455-461 ◽  
Author(s):  
A. EL HANI ◽  
M. DALLE ◽  
P. DELOST
Keyword(s):  
Sexual Dimorphism ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
Plasma Cortisol ◽  
Binding Capacity ◽  
Metabolic Clearance ◽  
Response To Stress ◽  
Adrenal Response ◽  
Cortisol Levels

Sexual dimorphism in adrenal activity appeared during the pubertal period of the guinea-pig with plasma levels and binding of cortisol lower in male guinea-pigs compared with female, and metabolic clearance rate (MCR) of cortisol higher in male than in female animals. Gonadectomy of female guinea-pigs did not change the values of the parameters regulating adrenal activity. Castration of male guinea-pigs caused a rise in plasma cortisol levels by increasing the binding capacity of transcortin for cortisol and by decreasing cortisol MCR. Treatment of females with testosterone from day 24 produced a drop on day 50 in plasma cortisol levels following a decreased binding capacity of transcortin for cortisol and at the same time as cortisol MCR increased. Furthermore, the adrenal response to stress was higher in castrated than in control males and lower in testosterone-treated females compared with control females. Testosterone appeared to be the hormone responsible for sexual dimorphism in adrenal activity in the pubertal guinea-pig.

CHANGES IN CORTISOL BINDING AND METABOLISM DURING NEONATAL DEVELOPMENT IN THE GUINEA-PIG

1980 ◽  
Vol 85 (2) ◽  
pp. 219-227 ◽  
Author(s):  
M. DALLE ◽  
A. EL HANI ◽  
P. DELOST
Keyword(s):  
Guinea Pig ◽  
Clearance Rate ◽  
Guinea Pigs ◽  
Surgical Stress ◽  
Binding Capacity ◽  
Post Partum ◽  
Metabolic Clearance ◽  
Metabolic Clearance Rate ◽  
Male And Female ◽  
Free Cortisol

The metabolic clearance rate and the binding of cortisol in plasma of male and female guinea-pigs were estimated at five stages between birth and weaning. The metabolic clearance rate for cortisol remained low in both sexes until day 10 post partum but increased to adult values by day 20. The level of free cortisol in plasma and the cortisol binding capacity of the plasma were higher at birth than on day 10 post partum; the values found on day 20 were similar to those of the adult guinea-pig. Surgical stress increased levels of cortisol in plasma on day 20 but not at birth.

COMPARATIVE ASPECTS OF CORTISOL TRANSPORT: LACK OF FIRM BINDING TO PLASMA PROTEINS IN DOMESTIC RUMINANTS

1964 ◽  
Vol 28 (3) ◽  
pp. 301-320 ◽  
Author(s):  
H. R. LINDNER
Keyword(s):  
Guinea Pig ◽  
Plasma Cortisol ◽  
Room Temperature ◽  
Binding Capacity ◽  
Gel Filtration ◽  
Great Sensitivity ◽  
Published Data ◽  
Human Pregnancy ◽  
Cortisol Levels

SUMMARY The concentration of cortisol in peripheral plasma (μg./100 ml.) was 0·6 ± 0·1 (s.e.) in penned sheep accustomed to handling and 1·1 ± 0·2 in untrained grazing sheep, or about 1/10 of the basal level in man or the guinea-pig. Plasma cortisol in the goat (mean 1·2) and the ox (2·6 ± 0·3) was also low. Freely diffusible cortisol was distinguished from protein-bound hormone by gel filtration after equilibration of the plasma with 3H- or 14C-labelled steroid. The binding capacity (μg./100 ml.) of sheep plasma for cortisol at room temp. (1·7 ± 0·2) was only slightly above that of 5% ovine albumin solutions. It compared with 3·5 (2·2–4·6) in the goat, 6·1 ± 1·0 in the ox, 14–21 in the guinea-pig, 17–23 in normal human and 25–59 in human pregnancy plasma. These are minimal estimates, since partial dissociation of the transcortin-cortisol complex occurred under the test conditions. Sheep plasma showed no significant elevation in cortisol concentration or binding power during pregnancy, nor in response to oestrogen administration. At physiological cortisol levels and room temperature, 39 ± 5% of the cortisol in sheep plasma was protein bound, but values above 40% were associated with low plasma cortisol levels and hence confined to samples from trained or adrenalectomized sheep. ACTH administration or addition of very small amounts of cortisol to ovine plasma in vitro caused a sharp fall in this percentage. Moreover, at body temperature only 9 ± 2% of the plasma cortisol in the sheep was non-diffusible. This finding may account for the great sensitivity of target tissues to the changes of blood cortisol level in this species. In human pregnancy plasma 86–95% of plasma cortisol (> 14μg./100 ml.) was bound at room temperature and 60–74% at 37°. Published data and those now presented suggest that plasma level and biological half-life of cortisol in different animal species are directly related to binding capacity.

Stress response of cougars to nonlethal pursuit by hunters

1992 ◽  
Vol 70 (1) ◽  
pp. 136-139 ◽  
Author(s):  
Henry J. Harlow ◽  
Frederick G. Lindzey ◽  
Walter D. Van Sickle ◽  
William A. Gern
Keyword(s):  
Stress Response ◽  
Treatment Group ◽  
Physiological Response ◽  
Plasma Cortisol ◽  
Adrenocorticotropic Hormone ◽  
The Other ◽  
Response Test ◽  
Felis Concolor ◽  
Adrenal Response ◽  
Cortisol Levels

Five cougars (Felis concolor) were captured and an adrenal response test was administered by injecting synthetic adrenocorticotropic hormone and monitoring plasma cortisol levels at 15-min intervals for 120 min. Three were selected for treatment and chased 5 or 6 more times to simulate the stress they might experience during a pursuit-only season; the other two served as controls and were chased only once more, at recapture. The adrenal response test was administered again at recapture. The cougars in the treatment group had a lowered plasma cortisol profile after the simulated pursuit season, indicating an altered physiological response of the adrenals to the stress of repeated chases.

Burn-induced alterations in cardiac beta-adrenergic receptors

1992 ◽  
Vol 262 (5) ◽  
pp. H1585-H1591 ◽  
Author(s):  
T. M. Kaufman ◽  
J. W. Horton
Keyword(s):  
Guinea Pig ◽  
Guinea Pigs ◽  
Adrenergic Receptors ◽  
Burn Injury ◽  
Binding Capacity ◽  
Total Body Surface Area ◽  
Scatchard Analysis ◽  
Beta Adrenergic Receptors ◽  
Binding Studies ◽  
Beta Adrenergic

Previous studies in our laboratory have demonstrated that burn injury (45% total body surface area, 3rd-degree scald burn) diminishes contractile and relaxation function in the isolated perfused guinea pig heart. The mechanisms responsible for the burn-mediated dysfunction are not well understood. Therefore the purpose of this study was to examine the inotropic response to isoproterenol, a beta-adrenergic agonist, and burn-induced alterations in beta-adrenergic receptors (beta-AR) in adult guinea pig hearts. Isoproterenol dose-response curves were generated in isolated perfused hearts from sham-burned and burned guinea pigs. In addition, binding studies were performed using [125I]iodocyanopindolol on hearts from sham-burned and burned guinea pigs. Both the functional response and sensitivity to isoproterenol were significantly diminished 24 h after burn injury. beta-AR density (binding capacity, Bmax) and affinity were determined by Scatchard analysis. Agonist competition curves were performed in the presence or absence of 0.1 mM 5'-guanylyl imidodiphosphate. There was no difference in Bmax in membranes from sham-burned and burned hearts; however, the affinity of beta-AR was significantly decreased after burn injury compared with sham burn [dissociation constant = 32.5 +/- 1.9 (mean +/- SE), n = 10, vs. 26.7 +/- 1.7 pM, n = 10, P = 0.039]. Furthermore, the fraction of receptors in a high-affinity state (those functionally coupled to Gs protein) was significantly decreased after burn injury compared with sham burn (41.2 +/- 4.7%, n = 9, vs. 54 +/- 2%, n = 9, P = 0.023).(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Regulatory roles of differentially expressed MicroRNAs in metabolic processes in negative Lens-induced myopia Guinea pigs

BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Dadong Guo ◽  
Meihua Ding ◽  
Xiaoli Song ◽  
Yuanyuan Sun ◽  
Guoping Li ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Signaling Pathways ◽  
Guinea Pigs ◽  
Messenger Rna ◽  
Differentially Expressed ◽  
Metabolic Processes ◽  
Ppar Signaling ◽  
Vision Defects ◽  
Guinea Pig Model

Abstract Background Myopia is one of the most common vision defects worldwide. microRNAs can regulate the target gene expression, influencing the development of diseases. Results To investigate the alterations of microRNA profiling in negative lens-induced myopia (NLIM) guinea pigs and to explore the regulatory role of microRNAs in the occurrence and the development of myopia, we first established the NLIM guinea pig model after induction for 2 weeks. Further, we isolated sclera to purify total messenger RNA (mRNA) in both NLIM and NLIM fellow sclera. Using next generation sequencing technique and bioinformatics analysis, we identified the differentially expressed microRNAs in NLIM guinea pigs, performed the bioinformatics annotation for the differentially expressed microRNAs, and validated the expression of differentially expressed microRNAs. As a result, we successfully established an NLIM model in guinea pigs, identified 27 differentially expressed microRNAs in NLIM guinea pig sclera, including 10 upregulated and 17 downregulated microRNAs. The KEGG annotation showed the main signaling pathways were closely associated with PPAR signaling, pyruvate and propanoate metabolisms, and TGF-beta signaling pathways. Conclusions Our findings indicate that the development of myopia is mainly involved in the disorder of metabolic processes in NLIM guinea pigs. The PPAR signaling, pyruvate and propanoate metabolism pathways may play roles in the development of myopia.

CHANGES IN THE CONCENTRATIONS OF CORTISOL AND CORTICOSTERONE IN THE PLASMA AND ADRENAL GLANDS OF THE GUINEA-PIG FROM BIRTH TO WEANING

1974 ◽  
Vol 63 (3) ◽  
pp. 483-488 ◽  
Author(s):  
M. DALLE ◽  
P. DELOST
Keyword(s):  
Adrenal Gland ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
Plasma Cortisol ◽  
Adrenal Glands ◽  
Post Partum ◽  
Cortisol Secretion ◽  
Male And Female ◽  
Steady Level ◽  
Very High

SUMMARY Concentrations of cortisol and corticosterone in the plasma and adrenal glands of male and female guinea-pigs were estimated throughout the first postnatal day and thereafter at intervals up to 3 weeks of age. In the guinea-pig, the basal level of cortisol secretion is established more slowly than in other species. The concentration of plasma cortisol is very high at birth, with a marked fall between days 1 and 10 post partum and then a steady level from day 10 to 20, the time of weaning. At day 10 the values for plasma cortisol and corticosterone approach the lower ones found in the adult. There were peaks in the amounts of corticosteroids found in the adrenal gland at 50 h, 4 and 7 days and these may have been due to increased hormonal synthesis between days 2 and 8.

Plasma cortisol-binding capacity in mental illness

1973 ◽  
Vol 3 (1) ◽  
pp. 53-65 ◽  
Author(s):  
David J. King
Keyword(s):  
Mental Illness ◽  
Affective Disorder ◽  
Genetic Marker ◽  
Affective Disorders ◽  
Plasma Cortisol ◽  
Binding Capacity ◽  
Psychiatric Patients ◽  
Total Plasma ◽  
Cortisol Levels

SynopsisPlasma cortisol-binding capacity (CBC) was determined in 18 psychiatric patients, including 14 who had affective disorders, and 18 controls. Men with unipolar depressive illnesses had significantly lower CBC values than men with bipolar illnesses and male controls. No other significant differences in CBC values were found and it was concluded that elevated total plasma cortisol levels in affective disorder were probably associated with increased levels of unbound cortisol. The possibility that low CBC values may be a genetic marker for certain types of affective disorder requires further investigation. The effect of certain drugs on CBC was also investigated.

Concentrations, metabolic clearance rates, production rates and plasma binding of cortisol in Antarctic phocid seals

1993 ◽  
Vol 129 (4) ◽  
pp. 356-359 ◽  
Author(s):  
Graham C Liggins ◽  
John T France ◽  
Robert C Schneider ◽  
Bruce S Knox ◽  
Warren M Zapol
Keyword(s):  
Binding Capacity ◽  
Plasma Concentrations ◽  
Human Values ◽  
Metabolic Clearance ◽  
Clearance Rates ◽  
Production Rates ◽  
High Production Rate ◽  
Free Cortisol ◽  
Phocid Seals ◽  
Cortisol Levels

We have reported previously that plasma of the Weddell seal, a member of the phocid family, contains a very high concentration of cortisol. The present study was undertaken to determine whether high cortisol levels were common to seals in the Antarctic environment, or to other phocidae, and to determine the mechanism of the hypercortisolaemia. High levels of cortisol (0.82–2.38 μmol/l) were found in 4 phocidae (Weddell, crabeater, leopard and Southern elephant seals), whereas levels in a member of the otariid family (Antarctic fur seal) were similar to human values. Metabolic clearance rates (MCR) and production rates (PR) of cortisol were determined in the field in Weddell (N = 1), crabeater (N= 3) and leopard (N= 3) seals following bolus injections of [3H] cortisol. The MCR and PR did not differ between the three phocids, but whereas the MCR of 410–590 1/day was twice that of human values, the PR of 460–1180 μmol·m−2·d−1 was up to 40-fold greater. The binding capacity of corticosteroid-binding globulin (CBG) was equal to or greater than the plasma concentrations of cortisol, resulting in relatively low concentrations of free cortisol. We conclude that hypercortisolaemia is maintained in phocid seals mainly by a high production rate—the highest (corrected for surface area) reported in any species. The relatively low cortisol levels in otariid seals studied in the same environment suggest that the high PR in phocidae is unrelated to the harsh climatic conditions, but may be part of their adaptation for diving to extreme depths. The phocid seals and New World primates have similarly high levels of cortisol and a high PR but CBG in the primates has low binding capacity and affinity and cortisol is mainly free.

MEASUREMENT OF PLASMA CORTISOL LEVELS IN THE EEL ANGUILLA ANGUILLA IN RELATION TO OSMOTIC ADJUSTMENTS

1971 ◽  
Vol 50 (1) ◽  
pp. 75-96 ◽  
Author(s):  
J. N. BALL ◽  
I. CHESTER JONES ◽  
M. E. FORSTER ◽  
G. HARGREAVES ◽  
E. F. HAWKINS ◽  
...  
Keyword(s):  
Plasma Cortisol ◽  
Sea Water ◽  
Anguilla Anguilla ◽  
Plasma Cortisol Level ◽  
Hormonal Control ◽  
Total Cortisol ◽  
Competitive Protein Binding ◽  
Low Levels ◽  
Cortisol Levels

SUMMARY The competitive protein-binding radioassay (CPB method) of Murphy (1967) has been adapted to determine total cortisol levels in the plasma of the eel, Anguilla anguilla L. Validation of the method for this species depended in part on the development of a chromatographic—fluorimetric technique for eel cortisol, following classical procedures and using radioactive tracers; by this means, the specificity of the CPB method for cortisol in eel plasma was established. Accuracy, precision and sensitivity of the CPB method were also investigated and were shown to be satisfactory. Plasma total cortisol levels were determined in eels during osmotic adjustments after transfers from fresh water (FW) to sea-water (SW) and vice versa, and from FW to distilled water. Plasma osmotic pressure and/or sodium levels were monitored simultaneously, to follow the progress of osmotic regulation. In only one of the transfer situations did the plasma cortisol level change significantly, showing a marked transitory increase during the first few days after transfer from FW to SW, corresponding to the development and correction of an 'osmotic crisis'. Plasma cortisol levels were the same in eels adapted for long periods to FW and to SW. Plasma cortisol fell to extremely low levels after hypophysectomy. These results are discussed in the light of the literature on hormonal control of osmoregulatory mechanisms in the eel, with particular emphasis on the role of adrenocorticosteroids in ionic regulation of animals in SW.

The catecholamine response to spaceflight: role of diet and gender

2001 ◽  
Vol 281 (3) ◽  
pp. E500-E506 ◽  
Author(s):  
T. P. Stein ◽  
C. E. Wade
Keyword(s):  
Sexual Dimorphism ◽  
Catecholamine Excretion ◽  
Specific Effects ◽  
Catecholamine Response ◽  
Fluid Shifts ◽  
Response To Stress ◽  
And Gender ◽  
Gender Specific ◽  
Do So

Compared with men, women appear to have a decreased sympathetic nervous system (SNS) response to stress. The two manifestations where the sexual dimorphism has been the most pronounced involve the response of the SNS to fluid shifts and fuel metabolism during exercise. The objectives of this study were to investigate whether a similar sexual dimorphism was found in the response to spaceflight. To do so, we compared catecholamine excretion by male and female astronauts from two similar shuttle missions, Spacelab Life Sciences 1 (SLS1, 1991) and 2 (SLS2, 1993) for evidence of sexual dimorphism. To evaluate the variability of the catecholamine response in men, we compared catecholamine excretion from the two SLS missions against the 1996 Life and Microgravity Sciences Mission (LMS) and the 1973 Skylab missions. Results: No gender- or mission-dependent changes were found with epinephrine. Separating out the SLS1/2 data by gender shows that norepinephrine excretion was essentially unchanged with spaceflight in women (98 ± 10%; n = 3) and substantially decreased with the men (41 ± 9%; n= 4, P < 0.05). Data are a percentage of mean preflight value ± SE. Comparisons among males demonstrated significant mission effects on norepinephrine excretion. After flight, there was a transient increase in norepinephrine but no evidence of any gender-specific effects. We conclude that norepinephrine excretion during spaceflight is both mission and gender dependent. Men show the greater response, with at least three factors being involved, a response to microgravity, energy balance, and the ratio of carbohydrate to fat in the diet.

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