Capsaicin-sensitive adrenal sensory fibers participate in compensatory adrenal growth in rats

2002 ◽  
Vol 283 (4) ◽  
pp. R877-R884 ◽  
Author(s):  
Yvonne M. Ulrich-Lai ◽  
Daniel J. Marek ◽  
William C. Engeland
Keyword(s):  
Splanchnic Nerve ◽  
Male Rats ◽  
Dorsal Spinal Cord ◽  
Afferent Limb ◽  
Afferent Nerves ◽  
Sham Surgery ◽  
Calcitonin Gene ◽  
The Right ◽  
Sensory Fibers ◽  
Dorsal Spinal

Compensatory adrenal growth, in which one gland undergoes hyperplasia after removal of the other, is mediated by a neural reflex. In the present studies, a method employing capsaicin to selectively remove adrenal sensory fibers was developed and applied to determine whether adrenal capsaicin-sensitive fibers participate in compensatory adrenal growth. The splanchnic nerves of anesthetized male rats were treated with capsaicin or vehicle. Capsaicin treatment selectively removed adrenal calcitonin gene-related peptide-positive fibers. One week after drug treatment, rats underwent left adrenalectomy or sham surgery and recovered for 5 days. Capsaicin treatment bilaterally or to the left splanchnic nerve alone (i.e., the afferent nerve in the reflex) impaired compensatory adrenal growth at 5 days compared with vehicle controls, whereas capsaicin treatment to the right splanchnic nerve alone did not affect growth. Moreover, left adrenalectomy induced c-Fos immunolabeling in ipsilateral dorsal spinal cord that was prevented by capsaicin treatment. These data suggest that adrenal capsaicin-sensitive afferent nerves participate in compensatory adrenal growth and that this effect is primarily on the afferent limb of the reflex.

Plasticity of calcitonin gene related peptide neurotransmission in the spinal cord during peripheral inflammation

1995 ◽  
Vol 73 (7) ◽  
pp. 1007-1014 ◽  
Author(s):  
V. S. Seybold ◽  
M. T. Galeazza ◽  
M. G. Garry ◽  
K. M. Hargreaves
Keyword(s):  
Spinal Cord ◽  
Calcitonin Gene Related Peptide ◽  
Peripheral Inflammation ◽  
Afferent Neurons ◽  
Dorsal Spinal Cord ◽  
Primary Afferent Neurons ◽  
Primary Afferent ◽  
Related Peptide ◽  
Calcitonin Gene ◽  
Dorsal Spinal

Injection of complete Freund's adjuvant (CFA; 75 μL) into the plantar surface of the hind paw of the rat results in a mild inflammation that lasts for several days and is accompanied by hyperalgesia. Multiple components of calcitonin gene related peptide (CGRP) neurotransmission in the spinal cord are altered during the course of this peripheral inflammation. The content of immunoreactive (i) CGRP in the dorsal horn of the spinal cord, where primary afferent neurons terminate, is significantly decreased within 2 days after injection of CFA but increases to a level greater than that of the control at 8 days. The early decrease in iCGRP in the spinal cord suggests that the release of CGRP from primary afferent neurons is increased during the period of maximal hyperalgesia that accompanies peripheral inflammation. Changes in the mRNA for CGRP suggest that the increase in spinal content of iCGRP is due to an increase in synthesis of the peptide as the level of mRNA for CGRP is increased from 2 to 8 days after injection of CFA. Despite the decrease in the content of iCGRP in the spinal cord, there is no apparent decrease in the amount of iCGRP that can be released from the dorsal spinal cord by capsaicin; in fact, capsaicin-evoked release is increased at 4 days. Measurements of the binding of 125I-labelled CGRP in the dorsal spinal cord indicate that high affinity binding sites for CGRP are downregulated at 4 days after injection of CFA. In total, these data support the hypothesis that the activity of CGRP-containing primary afferent neurons is increased during peripheral inflammation. CGRP released from primary afferent neurons in the spinal cord may contribute to cellular changes that accompany peripheral inflammation.Key words: calcitonin gene related peptide, dorsal root ganglion, hyperalgesia, inflammation, spinal cord.

scholarly journals Effects of Endurance and Resistance Training on Calcitonin Gene-Related Peptide and Acetylcholine Receptor at Slow and Fast Twitch Skeletal Muscles and Sciatic Nerve in Male Wistar Rats

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Abdolhossein Parnow ◽  
Reza Gharakhanlou ◽  
Zeinab Gorginkaraji ◽  
Somayeh Rajabi ◽  
Rasoul Eslami ◽  
...  
Keyword(s):  
Resistance Training ◽  
Sciatic Nerve ◽  
Wire Mesh ◽  
Male Rats ◽  
Calcitonin Gene ◽  
Significant Difference ◽  
Male Wistar Rats ◽  
The Right ◽  
Fast Twitch ◽  
Training Protocol

The aim of this study was to investigate effects of endurance and resistance training (ET and RT) on CGRP and AChRs at slow and fast twitch muscles and sciatic nerve in rats. Twenty-five male rats were randomly assigned into three groups including sedentary (SED), endurance training (ET), and resistance training (RT). Animals of ET exercised for 12 weeks, five times/week, and 60 min/day at 30 m/min. Animals of RT were housed in metal cage with 2 m high wire-mesh tower, with water bottles set at the top. 48 h after the last session of training protocol, animals were anaesthetized. The right sciatic nerves were removed; then, Soleus (SOL) and Tibialis anterior (TA) muscles were excised and immediately snap frozen in liquid nitrogen. All frozen tissues were stored at −80°C. Results showed that, after both ET and RT, CGRP content as well as AChR content of SOL and TA muscles significantly increased. But there was no significant difference among groups at sciatic nerve’ CGRP content. In conclusion, data demonstrate that ET and RT lead to changes of CGRP and AChR content of ST and FT muscles. The changes indicate to the importance of neuromuscular activity.

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