Short-term fasting leads to inhibition of responsiveness to LH-stimulated testosterone secretion in the adult male bonnet monkey

2007 ◽  
Vol 69 (7) ◽  
pp. 791-801 ◽  
Author(s):  
R. Medhamurthy ◽  
G. Priyanka ◽  
M.K. Vinuthan ◽  
A.M. Manjunatha
Keyword(s):  
Adult Male ◽  
Short Term ◽  
Testosterone Secretion ◽  
Bonnet Monkey

Changes in urinary testosterone and corticosterone metabolites during short-term confinement with repeated handling in wild male cane toads (Rhinella marina)

2011 ◽  
Vol 59 (4) ◽  
pp. 264 ◽  
Author(s):  
Edward J. Narayan ◽  
Frank C. Molinia ◽  
John F. Cockrem ◽  
Jean-Marc Hero
Keyword(s):  
Adult Male ◽  
Reproductive Effort ◽  
Hormone Secretion ◽  
Reproductive Hormone ◽  
Cane Toad ◽  
Short Term ◽  
Rhinella Marina ◽  
Testosterone Secretion ◽  
Metabolite Concentrations ◽  
Corticosterone Metabolites

Stressors generally decrease testosterone secretion and inhibit reproduction in animals. Urinary testosterone and corticosterone metabolite concentrations were measured in adult male cane toads (Rhinella marina) at the time of capture from the wild and during 24 h of confinement with repeated handling. Mean urinary testosterone concentrations increased 2 h after capture, were significantly elevated above initial concentrations at 5 h, and then declined. Mean testosterone concentrations remained elevated 24 h after capture. Mean urinary corticosterone concentrations increased after capture, were significantly elevated above initial concentrations at 2 h, and remained elevated thereafter. This is the first report in amphibians of an increase in testosterone excretion after capture from the wild, with previous studies showing either no change or decline in testosterone. This finding may be associated with the mating strategy and maintenance of reproductive effort in the cane toad, a species that shows explosive breeding and agonistic male–male interactions during breeding. The finding that testosterone excretion increases rather than decreases after capture in male cane toads shows that it should not be generally assumed that reproductive hormone secretion will decrease after capture in amphibians.

THE INFLUENCE OF OVERCROWDING ON SPERMATOGENESIS, SIZE OF LEYDIG-CELL NUCLEI (HISTOMETRICAL INVESTIGATION), AND THE ADRENAL CORTICOSTERONE CONTENTS IN MICE

1973 ◽  
Vol 74 (4) ◽  
pp. 783-791 ◽  
Author(s):  
K. Gärtner ◽  
H. Reznik-Schüller ◽  
G. Reznik
Keyword(s):  
Population Size ◽  
Group Size ◽  
Adult Male ◽  
Leydig Cell ◽  
Relative Frequency ◽  
Seminiferous Tubules ◽  
Cell Nuclei ◽  
Nmri Mice ◽  
Testosterone Secretion ◽  
Adrenal Corticosterone

ABSTRACT Adult male NMRI-mice were kept alone or in groups of 5, 10, 20, 30, 40 and 60 animals for 28 days and were then sacrificed. The corticosterone levels of their adrenals were determined and their testes were examined histometrically. The corticosterone levels of the adrenals increased two-fold with increasing population size. Furthermore the increased population size caused a suppression of some testicular functions: the seminiferous tubules decreased up to 20 % and the relative frequency of the spermatids up to 10 % whereas the numbers of spermatocytes and spermatogonias increased correspondingly. A decrease of about 25 % of the testosterone dependent postmeiotic stages of spermatogenesis is assumed. Since the diameters of the Leydig-cell nuclei decreased about 20 %, a reduction of the testicular testosterone secretion can be projected. All measurements proved the group with 5 animals to be the most favourable group size.

scholarly journals In vitro pituitary and testicular effects of the leptin-related synthetic peptide leptin(116-130) amide involve actions both similar to and distinct from those of the native leptin molecule in the adult rat

2000 ◽  
pp. 406-410 ◽  
Author(s):  
M Tena-Sempere ◽  
L Pinilla ◽  
LC Gonzalez ◽  
J Navarro ◽  
C Dieguez ◽  
...  
Keyword(s):  
Body Weight ◽  
Adult Male ◽  
Body Weight Gain ◽  
Biologically Active ◽  
Male Rats ◽  
Male Rat ◽  
Gh Secretion ◽  
Adult Rat ◽  
Testosterone Secretion

The obese gene (ob) product, leptin, has recently emerged as a key element in body weight homeostasis, neuroendocrine function and fertility. Identification of biologically active, readily synthesized fragments of the leptin molecule has drawn considerable attention, as they may provide a powerful tool for detailed characterization of the biological actions of leptin in different experimental settings. Recently, a fragment of mouse leptin protein comprising amino acids 116-130, termed leptin(116-130) amide, was shown to mimic the effects of the native molecule in terms of body weight gain and food intake, and to elicit LH and prolactin (PRL) secretion in vivo. As a continuation of our previous experimental work, the present study reports on the effects of leptin(116-130) amide on basal and stimulated testosterone secretion by adult rat testis in vitro. In addition, a comparison of the effects of human recombinant leptin and leptin(116-130) amide at the pituitary level on the patterns of LH, FSH, PRL and GH secretion is presented. As reported previously by our group, human recombinant leptin(10(-9)-10(-7)M) significantly inhibited both basal and human chorionic gonadotrophin (hCG)-stimulated testosterone secretion in vitro. Similarly, incubation of testicular tissue in the presence of increasing concentrations of leptin(116-130) amide (10(-9)-10(-5)M) resulted in a dose-dependent inhibition of basal and hCG-stimulated testosterone secretion; a reduction that was significant from a dose of 10(-7)M upwards. In addition, leptin(116-130) amide, at all doses tested (10(-9)-10(-5)M), significantly decreased LH and FSH secretion by incubated hemi-pituitaries from adult male rats. In contrast, in the same experimental protocol, recombinant leptin(10(-9)-10(-7)M) was ineffective in modulating LH and FSH release. Finally, neither recombinant leptin nor leptin(116-130) amide were able to change basal PRL and GH secretion in vitro. Our results confirm the ability of leptin, acting at the testicular level, to inhibit testosterone secretion, and map the effect to a domain of the leptin molecule that lies between amino acid residues 116 and 130. In addition, we provide evidence for a direct inhibitory action of leptin(116-130) amide on pituitary LH and FSH secretion, a phenomenon not observed for the native leptin molecule, in the adult male rat.

Effect of modulating endogenous prolactin secretion on testosterone production in the adult male bonnet monkey (Macaca radiata):

Andrologia ◽  
2009 ◽  
Vol 22 (3) ◽  
pp. 251-259 ◽  
Author(s):  
A. Jagannadha Rao ◽  
C. S. Sheela Rani ◽  
N. Ravindranath ◽  
N. R. Moudgal
Keyword(s):  
Adult Male ◽  
Prolactin Secretion ◽  
Macaca Radiata ◽  
Testosterone Production ◽  
Bonnet Monkey

Inhibition of Aromatization Stimulates Luteinizing Hormone and Testosterone Secretion in Adult Male Rhesus Monkeys*

1984 ◽  
Vol 59 (6) ◽  
pp. 1088-1096 ◽  
Author(s):  
WILLIAM E. ELLINWOOD ◽  
DAVID L. HESS ◽  
CHARLES E. ROSELLI ◽  
HAROLD G. SPIES ◽  
JOHN A. RESKO
Keyword(s):  
Luteinizing Hormone ◽  
Adult Male ◽  
Rhesus Monkeys ◽  
Testosterone Secretion ◽  
Male Rhesus

Short-term glucocorticoid administration decreases both hypothalamic and pituitary galanin synthesis in the adult male rat

Metabolism ◽  
1999 ◽  
Vol 48 (6) ◽  
pp. 792-796 ◽  
Author(s):  
Rebecca S. Brogan ◽  
Lisa K. Coney ◽  
William B. Wehrenberg ◽  
Gianlorenzo Beretta ◽  
Andrea Giustina
Keyword(s):  
Adult Male ◽  
Male Rat ◽  
Short Term ◽  
Glucocorticoid Administration ◽  
Adult Male Rat

Effects of maternal hyperleptinaemia during lactation on short-term memory/learning, anxiety-like and novelty-seeking behavioral traits of adult male rats

2010 ◽  
Vol 206 (1) ◽  
pp. 147-150 ◽  
Author(s):  
Mabel C. Fraga-Marques ◽  
Egberto G. Moura ◽  
Juliana Oliveira Silva ◽  
Sylvio Claudio-Neto ◽  
Fernanda Pereira-Toste ◽  
...  
Keyword(s):  
Adult Male ◽  
Short Term Memory ◽  
Male Rats ◽  
Novelty Seeking ◽  
Short Term ◽  
Term Memory ◽  
Behavioral Traits ◽  
Learning Anxiety
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