Effects of Sympathectomy on Muscle

We have previously reported functional and histological studies in five beagle dogs with unilateral lumbar sympathectomy. Three months later, fatiguability in the gracilis muscles was increased on the denervated sides, and this was associated with an increase in the relative distribution of FT fibres. Biochemical studies now show that these changes were associated with an increase in cytosolic protein without change in DNA content; this is consistent with
an increase in cell size. There was a reduction in the proportion of slow myosin light chain isoforms from 50 ± 7 to 34 ± 6%. Noradrenaline levels were increased on the denervated sides but this may reflect greater vascularity. Calcium content did not correlate with fibre type but there was a positive relation with both noradrenaline content (r= 0·73;
P<0·05) and DNA content (r= 0·84; P<0·05). It is concluded that sympathectomy induces several biochemical changes in skeletal muscle which constitute a change and increase in fast myosin light chain synthesis and a corresponding fibre type transformation.

Clinical Physiology (Oxford, England) 1988 Apr; vol 8 (issue 2): pp 181-91

2.
The objective of this paper was to study the effect of sympathetic innervation on morphological and histochemical aspects of skeletal muscle tissue. Rabbit masseter muscle was studied using histochemical and immunohistochemical methods for periods of up to 18 months post-sympathectomy. The morphological and enzymatic characteristics of control masseter muscles were similar on both the left and right sides. The main features were muscle fibres with a mosaic pattern and a predominance of type IIa fibres, followed by type I. Type IIb fibres showed very low frequency. Sympathectomized animals showed varying degrees of metabolic and morphological alterations, especially 18 months after sympathectomy. The first five groups showed a higher frequency of type I fibres, whilst the oldest group showed a higher frequency of type IIb fibres. In the oldest group, a significant variation in fibre diameter was observed. Many fibres showed small diameter, atrophy, hypertrophy, splitting, and necrosis. Areas with fibrosis were observed. Thus cervical sympathectomy induced morphological alterations in the masseter muscles. These alterations were, in part, similar to both denervation and myopathy.

International Journal of Experimental Pathology
Volume 82, Issue 2, pages 123–128, April 2001

CNS activation following peripheral sympathectomy

Many studies have demonstrated that ablation of the sympathetic nervous

system (SNS) alters subsequent immune responses. Researchers have

presumed that the altered immune responses are predominantly the result

of the peripheral phenomenon of denervation. We, however, hypothesized

that chemical sympathectomy will signal and activate the central nervous

system (CNS). Activation of the CNS was determined by

immunocytochemical visualization of Fos protein in brains from male

C57BL/6 mice at 8, 24, and 48 h following denervation. A dramatic

induction of Fos protein was found in the paraventricular nucleus (PVN) of

the hypothalamus and other specific brain regions at 8 and 24 h compared

to vehicle control mice. Dual-antigen labeling demonstrates that

corticotrophin releasing factor (CRF)-containing neurons in the PVN are

activated by chemical sympathectomy; however, neurons containing

neurotransmitters which may modulate CRF neurons, such as vasopressin,

tyrosine hydroxylase, and adrenocorticotropin, do not coexpress Fos. Our

findings suggest an involvement of the CNS in sympathectomy-induced

alterations of immunity.

Central Nervous System Activation following Peripheral Chemical Sympathectomy: Implications for Neural–Immune Interactions

Brain, Behavior, and Immunity

Volume 12, Issue 3, September 1998, Pages 230-241

Changes in hemodynamics of the carotid and middle cerebral arteries before and after endoscopic sympathectomy in patients with palmar hyperhidrosis

There was a significant reduction in diastolic pressure after T-2 sympathectomy (p = 0.003), but not in systolic pressure or heart rate. The vessel diameter was increased after sympathectomy in the left CAs and right CCA. The T-2 sympathectomy led to significant elevation of blood flow volume and Rl in the left CCA. ICA, and ECA (p < 0.05). The authors found significant increases in maximum flow velocity and RI in the left MCA (p < 0.05). Conclusions. Patients who underwent T-2 sympathectomy demonstrated a significant increase in blood flow volume and flow velocities of the CAs and MCA, especially on the left side. Asymmetry of sympathetic influence on the hemodynamics of the CAs and MCA was noted.
Journal of neurosurgery
1999, vol. 90, no3, pp. 463-467 (38 ref.)