+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Stress-induced inhibition of the hypothalamic-pituitary-thyroid axis is attenuated in the aged Fischer 344/N male rat



Stress-induced inhibition of the hypothalamic-pituitary-thyroid axis is attenuated in the aged Fischer 344/N male rat



Neuroendocrinology 62(5): 506-513



Aging is associated with a progressive decrement in the basal activity of the hypothalamic-pituitary-thyroid axis in male Fischer 344/N rats. The aim of this study was to determine whether stress influences the activity of this axis in young and old rats. As prolactin and growth hormone share some regulatory mechanisms with thyrotropin-releasing and thyroid-stimulating hormones, which are influenced by stress, the plasma levels of these two hormones were also determined during immobilization (Immo). To accomplish this, young (3-month-old) and old (23-month-old) male 344/N Fischer rats were immobilized for 2 h; blood was collected by cannulation from the tail artery at different intervals during Immo (0, 5, 30, 60, and 120 min), and brains were removed at the end of Immo. The basal plasma levels of thyroid-stimulating hormone were similar in both groups, but were significantly and progressively inhibited by Immo in young, but not in old rats. The baseline plasma levels of total triiodothyronine were slightly lower in old than in young rats; Immo caused a significant decrease of total triiodothyronine levels only in the young animals. The baseline plasma levels of free triiodothyronine were similar and were not altered by Immo in either age group. The paraventricular nucleus thyrotropin-releasing hormone mRNA levels were lower in old than in young rats under basal conditions; under stress they were significantly inhibited in young, but remained unchanged in old rats. The basal thyroid-stimulating hormone beta mRNA levels in the anterior pituitary were significantly lower in old than in young rats, but were not affected by Immo in either age group. The plasma prolactin levels were similar at baseline and were significantly increased by Immo in both age groups, but significantly more in old than in young rats. The plasma growth hormone levels were also similar at baseline; they were significantly decreased by Immo to a similar extent in both age groups. In summary, these data indicate that the stress-induced decrease in plasma thyroid-stimulating hormone is in part mediated at the level of the hypothalamic thyrotrophin-releasing hormone neuron and that this phenomenon is attenuated in the aged rat.

Please choose payment method:






(PDF emailed within 1 workday: $29.90)

Accession: 009462601

Download citation: RISBibTeXText

PMID: 8559282


Related references

Stress-Induced Inhibition of the Hypothalamic-Pituitary-Thyroid Axis Is Attenuated in the Aged Fischer 344/N Male Rat. Neuroendocrinology 62(5): 506-513, 1995

Effects of ethanol and control liquid diets on the hypothalamic-pituitary-thyroid axis of male Fischer-344 rats. Alcoholism, Clinical and Experimental Research 16(6): 1130-1137, 1992

Relation between the hypothalamic-pituitary-thyroid (HPT) axis and the hypothalamic-pituitary-adrenal (HPA) axis during repeated stress. Neuroendocrinology 81(3): 183-192, 2005

Anxiety and hypothalamic-pituitary-adrenal axis responses to psychological stress are attenuated in male rats made lean by large litter rearing. Psychoneuroendocrinology 36(7): 1080-1091, 2011

Depression and alterations in hypothalamic-pituitary-adrenal and hypothalamic-pituitary-thyroid axis function in male abstinent methamphetamine abusers. Human Psychopharmacology 28(5): 477-483, 2014

Hypothalamic pituitary adrenal axis age related changes in old male 344 fischer rats. Age 12(4): 156, 1989

Age-related alterations of hypothalamic-pituitary-adrenal axis function in male Fischer 344 rats. Endocrinology 134(3): 1528-1536, 1994

Mo1888 Inhibition of Mast Cells Degranulation Protects Liver From Lps Induced Inflammation Through Hypothalamic - Pituitary - Thyroid Axis. Gastroenterology 148(4): S-1171, 2015

Interleukin 6 Modulates lnterleukin-1 and Stress-Induced Activation of the Hypothalamic-Pituitary-Adrenal Axis in Male Rats. Neuroendocrinology 63(3): 227-236, 1996

A role for endocannabinoids in acute stress-induced suppression of the hypothalamic-pituitary-gonadal axis in male rats. Clinical and Experimental Reproductive Medicine 40(4): 155-162, 2014

Male Fischer 344/N rats show a progressive central impairment of the hypothalamic-pituitary-adrenal axis with advancing age. Endocrinology 134(4): 1611-1620, 1994

Stress-induced sensitization of the hypothalamic-pituitary adrenal axis is associated with alterations of hypothalamic and pituitary gene expression. Neuroendocrinology 80(4): 252-263, 2005

The prevalence of impaired glucose regulation in anxiety disorder patients and the relationship with hypothalamic-pituitary-adrenal axis and hypothalamic-pituitary-thyroid axis activity. Journal of Evidence-Based Medicine 2016, 2016

Involvement of the hypothalamic-pituitary-thyroid axis and its interaction with the hypothalamic-pituitary-adrenal axis in the ontogeny of avian thermoregulation a review. World'S Poultry Science Journal: 3, 309-321, 2008

Effects of the inhibition of cyclo-oxygenase 1 or 2 or 5-lipoxygenase on the activation of the hypothalamic-pituitary-adrenal axis induced by interleukin-1beta in the male Rat. Journal of Neuroendocrinology 12(8): 766-773, 2000