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Negative energy balance in a male songbird, the Abert's towhee, constrains the testicular endocrine response to luteinizing hormone stimulation.

Davies S, Gao S, Valle S, Bittner S, Hutton P, Meddle SL, Deviche P - J. Exp. Biol. (2015)

Bottom Line: As the orchestrator of reproductive function, endocrine activity of the hypothalamo-pituitary-gonadal (HPG) axis is potentially an important mechanism mediating such effects.Previous experiments in wild-caught birds found inconsistent relationships between energy deficiency and seasonal reproductive function, but these experiments focused on baseline HPG axis activity and none have investigated the responsiveness of this axis to endocrine stimulation.Collectively, these observations suggest that energy deficiency has direct gonadal effects consisting of a decreased responsiveness to LH stimulation.

View Article: PubMed Central - PubMed

Affiliation: School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA Scott.Davies@asu.edu.

No MeSH data available.


Related in: MedlinePlus

Effect of photoperiod and food availability on pre-challenge plasma luteinizing hormone (LH) and testosterone. Towhees were either ad libitum fed (N=9) or food restricted (70% of ad libitum consumption; N=8) and initially exposed to short day lengths before being transferred to long days. The photostimulated increase in pre-challenge plasma luteinizing hormone (A) and testosterone (B) of adult male Abert's towhees was not significantly affected by food availability. Data points are means±s.e.m.
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JEB123042F2: Effect of photoperiod and food availability on pre-challenge plasma luteinizing hormone (LH) and testosterone. Towhees were either ad libitum fed (N=9) or food restricted (70% of ad libitum consumption; N=8) and initially exposed to short day lengths before being transferred to long days. The photostimulated increase in pre-challenge plasma luteinizing hormone (A) and testosterone (B) of adult male Abert's towhees was not significantly affected by food availability. Data points are means±s.e.m.

Mentions: Transfer from SD to LD increased pre-challenge plasma LH and testosterone in both ad libitum-fed and food-restricted birds (LH: F1,16=7.23, P=0.016; testosterone: F1,16=13.94, P=0.002; Fig. 2). However, there was neither a significant effect of food availability on pre-challenge plasma levels of these hormones (LH: F1,16=3.13, P=0.096; testosterone: F1,16=0.09, P=0.77; Fig. 2) nor a significant interaction between photoperiod and food availability (LH: F1,16=1.28, P=0.28; testosterone: F1,16=2.25, P=0.15; Fig. 2).Fig. 2.


Negative energy balance in a male songbird, the Abert's towhee, constrains the testicular endocrine response to luteinizing hormone stimulation.

Davies S, Gao S, Valle S, Bittner S, Hutton P, Meddle SL, Deviche P - J. Exp. Biol. (2015)

Effect of photoperiod and food availability on pre-challenge plasma luteinizing hormone (LH) and testosterone. Towhees were either ad libitum fed (N=9) or food restricted (70% of ad libitum consumption; N=8) and initially exposed to short day lengths before being transferred to long days. The photostimulated increase in pre-challenge plasma luteinizing hormone (A) and testosterone (B) of adult male Abert's towhees was not significantly affected by food availability. Data points are means±s.e.m.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4582157&req=5

JEB123042F2: Effect of photoperiod and food availability on pre-challenge plasma luteinizing hormone (LH) and testosterone. Towhees were either ad libitum fed (N=9) or food restricted (70% of ad libitum consumption; N=8) and initially exposed to short day lengths before being transferred to long days. The photostimulated increase in pre-challenge plasma luteinizing hormone (A) and testosterone (B) of adult male Abert's towhees was not significantly affected by food availability. Data points are means±s.e.m.
Mentions: Transfer from SD to LD increased pre-challenge plasma LH and testosterone in both ad libitum-fed and food-restricted birds (LH: F1,16=7.23, P=0.016; testosterone: F1,16=13.94, P=0.002; Fig. 2). However, there was neither a significant effect of food availability on pre-challenge plasma levels of these hormones (LH: F1,16=3.13, P=0.096; testosterone: F1,16=0.09, P=0.77; Fig. 2) nor a significant interaction between photoperiod and food availability (LH: F1,16=1.28, P=0.28; testosterone: F1,16=2.25, P=0.15; Fig. 2).Fig. 2.

Bottom Line: As the orchestrator of reproductive function, endocrine activity of the hypothalamo-pituitary-gonadal (HPG) axis is potentially an important mechanism mediating such effects.Previous experiments in wild-caught birds found inconsistent relationships between energy deficiency and seasonal reproductive function, but these experiments focused on baseline HPG axis activity and none have investigated the responsiveness of this axis to endocrine stimulation.Collectively, these observations suggest that energy deficiency has direct gonadal effects consisting of a decreased responsiveness to LH stimulation.

View Article: PubMed Central - PubMed

Affiliation: School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA Scott.Davies@asu.edu.

No MeSH data available.


Related in: MedlinePlus