Intact Nerve Supply Research Articles

Phosphoproteomics reveals conserved exercise-stimulated signaling and AMPK regulation of store-operated calcium entry.

Exercise stimulates cellular and physiological adaptations that are associated with widespread health benefits. To uncover conserved protein phosphorylation events underlying this adaptive response, we performed mass spectrometry-based phosphoproteomic analyses of skeletal muscle from two widely used rodent models: treadmill running in mice and insitu muscle contraction in rats. We overlaid these phosphoproteomic signatures with cycling in humans to identify common cross-species phosphosite responses, as well as unique model-specific regulation. We identified >22,000 phosphosites, revealing orthologous protein phosphorylation and overlapping signaling pathways regulated by exercise. This included two conserved phosphosites on stromal interaction molecule 1 (STIM1), which we validate as AMPK substrates. Furthermore, we demonstrate that AMPK-mediated phosphorylation of STIM1 negatively regulates store-operated calcium entry, and this is beneficial for exercise in Drosophila. This integrated cross-species resource of exercise-regulated signaling in human, mouse, and rat skeletal muscle has uncovered conserved networks and unraveled crosstalk between AMPK and intracellular calcium flux.

Change of substance P in portal vein during rectoanal inhibitory reflex

To investigate the change pattern of substance P (SP) in the portal vein during the rectoanal inhibitory reflex (RAIR), and its physiologic significance; the influence of external splanchnic nerve of rectum and anal to the RAIR. The rats were divided into seven groups, among them there were six groups, which were first divided into two big groups according to whether the external splanchnic nerve to the rectum and anal were cut off, one is no cut-off external splanchnic nerve group, the other is cut-off external splanchnic nerve group. Each group were further divided, according to the distance of the balloon-sac on Foley's tube in the rectum away from anal verge, into 2, 4, 6 centimeter groups; A control group with Foley's tube put into the rectum, but the balloon-sac on Foley's tube did not pumped up with water. Measure and compare the value and change of SP in the portal vein during the RAIR. The comparison of SP in portal vein, among the 2, 4 centimeter groups with cut-off external splanchnic nerve, all groups with intact external splanchnic nerve supply and control group, had no statistic difference (P>0.05). The comparison between the 6 centimeter group with intact external splanchnic nerve group and the 2, 4 centimeter groups with cut-off external splanchnic nerve, P<0.01, the statistic difference was significant. The comparison between 6 centimeter group of intact and cut-off external splanchnic nerve, P<0.01, the difference was significant. The reason for the stimulation on upper rectum dose not induce the RAIR is related with this stimulation result in the release of SP, the exciting mediator to internal sphincter. The external splanchnic nerve supply of rectum and anal canal have influence on the change of SP of the portal vein during RAIR.

Autologous diaphragm reconstruction with the pedicled latissimus dorsi flap

The latissimus dorsi (LD) muscle has been previously described to repair diaphragmatic defects, but as a "reverse" flap, relying on secondary blood supply from the perforating lumbar vessels rather than primary inflow from the dominant thoracodorsal artery. We report resection of a retroperitoneal synovial sarcoma, with reconstruction of the hemidiaphragm using the LD rotated on its primary neurovascular bundle. By using the dominant pedicle, the vascularity of the flap is improved, minimizing the chance of flap tip loss. Maintaining an intact nerve supply prevents atrophy. As the distal origin of the LD is broad and flat, it is ideally suited for diaphragm repair. A latissimus-sparing thoracotomy incision is required to enable this method of diaphragm reconstruction.

Childbirth and the pelvic floor: “the gynaecological consequences”

This review addresses the effects of childbirth on the pelvic floor, urinary continence mechanisms and the perineum. Genitourinary prolapse affects 15% of women and stress incontinence 20–30%. The major risk factors are age and childbirth, with severity increasing with parity. There are three mechanisms of support for the pelvic organs and bladder neck. These are (i) the muscular component: levator ani and urethral sphincter with their intact nerve supply, (ii) the endopelvic fascial connections with the levator ani, and (iii) the posterior angulation of the vagina. Childbirth causes direct myogenic damage, dennervation and defects in the endopelvic fascia along with widening of the urogenital hiatus. Elective caesarean section without labour has in the past thought to be protective. More recent data suggests this effect to be less pronounced and antenatal stress incontinence appears the most important predictive factor for the development of postnatal stress incontinence. The targeting of pelvic floor exercises under direct supervision from a physiotherapist have shown a reduction in the development of short and long term stress urinary incontinence. Perineal trauma can effect up to 85% of women after vaginal delivery. The consequences of this include perineal pain and dyspareunia lasting up to 12 months postnatally. Nulliparity and the use of forceps have been identified as the major risk factors along with occipito-posterior position, macrosomia and episiotomy as secondary factors. The role of selective mediolateral episiotomy and methods of perineal repair are discussed.

Erectile dysfunction after fracture of the pelvis

Male sexual dysfunction after fracture of the pelvis is more common than previously supposed with rates as high as 30% reported when the complaint is specifically sought. With the increase in survival from major injuries, the long-term consequences of trauma are being seen with increasing frequency

Newts

Newts

Video-based spatio-temporal maps for analysis of gastric motility in vitro: effects of vagal stimulation in guinea-pigs.

Our aim was to evaluate topographically specific gastric motility changes induced by graded vagal activation. A recently developed method of constructing spatio-temporal maps of motility from video movies was adapted to the in vitro perfused guinea-pig stomach with an intact vagal nerve supply. In the unstimulated preparation, spontaneous activity was low or absent. Bilateral vagal stimulation with frequencies as low as 0.2 Hz triggered weak anally, and in some cases orally, propagating antral contractions at rates of about 5-6 min-1. Upon stimulation with higher frequencies, antral contractions increased significantly in length (starting more proximally) and amplitude, and produced large pressure peaks of up to 25 hPa, with maximal effects at 2-4 Hz. In contrast, the speed of propagation and the interval between peristaltic waves did not change with vagal stimulation at any frequency. Vagal stimulation also produced a significant and frequency-dependent enlargement of the fundus with a maximal effect at 4 Hz. It is concluded that a very low tonic vagal activity is apparently necessary and sufficient to express basic antral motility, while more sustained vagal activity is necessary for high-amplitude gastric contractions and significant sustained fundic relaxation. The constant interval between propagating contractions supports the concept that vagal input impinges on intrinsic enteric neural circuits that have a modulatory role in the myogenic mechanism underlying slow-wave peristalsis, rather than directly on gastric musculature.

Gustatory-salivary reflexes induce non-adrenergic, non-cholinergic acinar degranulation in the rat parotid gland.

In the presence of the muscarinic blocker atropine, the alpha-adrenoceptor blocker phentolamine and the beta-adrenoceptor blocker propranolol (2 mg kg(-1) of each, I.P.), the numerical density of parotid acinar secretory granules was reduced by 32 % in response to ascorbic acid (0.5 M) applied on the tongue every 30 s over 30 min in awake rats. This non-adrenergic, non-cholinergic (NANC) response was entirely dependent on an intact auriculo-temporal nerve supply. The NANC mechanisms were found to be potentially responsible for almost all of the exocytotic response that occurs in the absence of the three autonomic receptor blockers. No sympathetic contribution to the exocytotic response was found and furthermore, studies in parasympathetically denervated glands showed that the sympathetic contribution to the salivary flow was small. Experimental Physiology (2001) 86.4, 475-480.

Intact nerve supply for eczema: reply from authors

Intact nerve supply for eczema: reply from authors

Cloning and neuronal expression of a type III newt neuregulin and rescue of denervated, nerve-dependent newt limb blastemas by rhGGF2.

Urodele amphibians are the only vertebrates that can regenerate their limbs throughout their life. The critical feature of limb regeneration is the formation of a blastema, a process that requires an intact nerve supply. Nerves appear to provide an unidentified factor, known as the neurotrophic factor (NTF), which stimulates cycling of blastema cells. One candidate NTF is glial growth factor (GGF), a member of the neuregulin (NRG) growth factor family. NRGs are both survival factors and mitogens to glial cells, including Schwann cells. All forms of NRGs contain an EGF-like domain that is sufficient to activate NRG receptors erbB2, erbB3, and erbB4. To investigate the involvement of neuregulin in newt limb regeneration, we cloned and characterized one neuregulin isoform, a neuregulin with a cysteine-rich domain (CRD-NRG), from newt (Notophthalmus viridescens) spinal cord. Results of in situ hybridization showed that the newt CRD-NRG is highly expressed in dorsal root ganglia and spinal cord neurons that innervate the limbs. We also demonstrated the biological activity of recombinant human GGF2 (rhGGF2) in urodele limb regeneration. When rhGGF2 was injected into denervated, nerve-dependent axolotl blastemas, the labeling index (LI) of blastema cells was maintained at a level near to that of control, innervated blastemas, whereas without rhGGF2 the LI decreased significantly. In another experiment, rhGGF2 was delivered into denervated, nerve-dependent blastemas either by direct infusion into blastemas or by injection into the intraperitoneal cavity. The denervated blastemas were rescued into a regeneration response.

Involvement of nitric oxide in the mediation of NANC inhibitory neurotransmission of guinea-pig trachea.

1. The involvement of nitric oxide (NO) in the non-adrenergic non-cholinergic inhibitory (NANC-i) neurotransmission was evaluated in guinea-pigs anaesthetized with chloralose-urethane, using a tracheal pouch preparation. 2. The tracheal pouch, a surgically isolated segment of trachea with intact nerve and blood supply, is an in situ method to demonstrate NANC-i response after complete cholinergic and adrenergic blockade using atropine (5 mg kg(-1)) and propranolol (1 mg kg(-1)), respectively. Cervical vagi and sympathetic trunks were isolated and cut cranially. The distal ends of the vagi were positioned on bipolar electrodes for subsequent stimulation with 5 V pulses for 2 ms duration at 15 Hz for a total of 90 s. The relaxation response was measured as a pressure drop (cm of H2O) in the pouch. Each experimental group was composed of six animals. 3. NANC-i responses to two consecutive nerve stimulations at 25 min apart were reproducible. 4. Pouch relaxation responses to electrical nerve stimulations were determined before and after incubation of the pouch with N(omega)-nitro-L-arginine methyl ester (L-NAME; 10(-5) M), a NO synthase (NOS) inhibitor, for 30 min. L-NAME significantly, but not completely, inhibited the NANC-i response of the pouch, suggesting involvement of NO in the NANC-i neurotransmission. 5. The pouch relaxations to vagal stimulations were inhibited significantly after incubation with oxyHb indicating that NO was released. 6. The amount of methaemoglobin (metHb) formed from oxyhaemoglobin (oxyHb) during vagal stimulation was measured by spectrophotometry. Comparison of the values between the control and after nerve stimulation indicated a trend (P = 0.07) toward greater metHb formation in the pouch perfusate after nerve stimulation. 7. NANC-i responses were not significantly inhibited by incubation of the pouch with either of the guanylate cyclase inhibitors, methylene blue or 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ). However, a trend toward significance (P < or = 0.07) was observed. 8. This study demonstrated that NO is involved in NANC-i neurotransmission. However, the findings did not conclusively support the contention that NO is the sole neurotransmitter of NANC inhibition. It is possible that NO produced relaxation of guinea-pig trachea through a cGMP-independent mechanism.

Ileocecal segment transposition does not alter whole gut transit in humans.

We have recently described a reservoir for rectal replacement after total mesorectal excision for rectal carcinoma. The ileocecal segment with its intact extrinsic nerve and blood supply is placed between the ascending colon and the anal canal. This reconstruction has been shown to provide good defecation quality and anorectal function. Whether gastric emptying and small as well as large bowel transit are affected by this transposition remains unclear. Our aim was to quantify whole gut transit in such patients and compare it with that of a matched group of controls. Gastric emptying rates and small intestinal and colonic transit times were assessed scintigraphically in 12 patients aged 46 to 87 years with ileocecal reservoir reconstruction after total mesorectal excision and compared to a sex-matched group of asymptomatic healthy volunteers of similar age. Gastric emptying rates and small intestinal and colonic transit times were calculated as described previously. Data were compared using Wilcoxon's signed rank test for gastric emptying rates and small bowel transit or by analysis of variance for colonic transit; p < 0.05 was considered significant. Gastric time for half of the meal (T50) was 161 +/- 16 minutes for patients and 201 +/- 22 for the controls. Small bowel transit time was 150 +/- 15 minutes for patients and 177 +/- 22 for the controls. Geometric center at 6 hours was 1.53 +/- 0.13 for patients and 1.27 +/- 0.16 for the controls. Geometric center at 24 hours was 2.96 +/- 0.23 for patients and 2.57 +/- 0.25 for the controls. Data are mean +/- SEM. Gastric emptying rates and small bowel transit and colonic transit times (expressed as geometric center at 6 and 24 hours) were similar in patients with ileocecal reservoir reconstruction and in a sex- and age-matched group of healthy controls. We conclude that the transposition of an ileocecal segment with intact extrinsic neurovascular supply between the sigmoid colon and the anal canal does not alter whole gut transit, not even in any of the presumably key regions.

349-PA10 Effect of recurring pneumonia on ventilatory lung function in schoolchildren and young people

The effects evoked by intradermal injections of substance P (SP), neurokinin A (NKA) or calcitonin gene-related peptide (CGRP) were studied in 51 non-atopic subjects. SP and NKA produced flare and weal, and CGRP produced an indurated erythema. The reactions to SP were strong, the flare being maximal 3–5 min after injection and the weal after 10–15 min. NKA evoked a much weaker flare and a slightly weaker weal than did SP. CGRP produced a prominent long-lasting, indurated erythema with pseudopodia surrounded by a pallor edge. The mode of action of the three peptides was studied by pretreatment of the skin with the histamine-releasing compound 48/80, the H1-antagonist mepyramine or the local anesthetic xylocaine. The results suggest that mast-cell histamine and an intact sensory nerve supply are essential for the flare response to both SP and NKA. The weal response to SP was somewhat reduced by pretreatment with either 48/80 or xylocaine. The weal response to NKA, however, did not seem to depend upon either mast cells or sensory nerve fibres. The erythema evoked by CGRP was not suppressed by pretreatment with xylocaine, compound 48/80 or mepyramine, suggesting a direct action of CGRP on the blood vessels. The interaction between SP and CGRP was studied in subjects receiving a low dose of CGRP and increasing doses of SP or a low dose of SP and increasing doses of CGRP. CGRP did not potentiate the SP-evoked flare and weal and SP did not seem to enhance the response to CGRP.

451-PA10 Risk factors of chronic respiratory disorders in a sample of farmers of middle Italy

The effects evoked by intradermal injections of substance P (SP), neurokinin A (NKA) or calcitonin gene-related peptide (CGRP) were studied in 51 non-atopic subjects. SP and NKA produced flare and weal, and CGRP produced an indurated erythema. The reactions to SP were strong, the flare being maximal 3–5 min after injection and the weal after 10–15 min. NKA evoked a much weaker flare and a slightly weaker weal than did SP. CGRP produced a prominent long-lasting, indurated erythema with pseudopodia surrounded by a pallor edge. The mode of action of the three peptides was studied by pretreatment of the skin with the histamine-releasing compound 48/80, the H1-antagonist mepyramine or the local anesthetic xylocaine. The results suggest that mast-cell histamine and an intact sensory nerve supply are essential for the flare response to both SP and NKA. The weal response to SP was somewhat reduced by pretreatment with either 48/80 or xylocaine. The weal response to NKA, however, did not seem to depend upon either mast cells or sensory nerve fibres. The erythema evoked by CGRP was not suppressed by pretreatment with xylocaine, compound 48/80 or mepyramine, suggesting a direct action of CGRP on the blood vessels. The interaction between SP and CGRP was studied in subjects receiving a low dose of CGRP and increasing doses of SP or a low dose of SP and increasing doses of CGRP. CGRP did not potentiate the SP-evoked flare and weal and SP did not seem to enhance the response to CGRP.

Angiotensin II-mediated renal vasoconstriction amenable to α1-adrenoceptor blockade

Renal adrenergic interactions of intravenously and intrarenal arterially administered angiotensin II were studied in the anesthetized rabbit. Systemic arterial blood pressure and left renal blood flow were monitored. Bolus doses of angiotensin II, 50 and 100 ng/kg given intravenously, caused an immediate reduction in renal blood flow followed by a more sustained vasoconstrictor response. Prazosin, 5 μg/kg/min, infused intrarenal arterially, decreased both components of the reduced renal blood flow, suggesting adrenergic contribution to the response. Renal denervation reduced significantly the immediate response to angiotensin II without affecting the sustained response; administration of prazosin after denervation caused a further decrease in the response. Left adrenalectomy had no significant effect on the angiotensin II-induced renal blood flow response, ruling out the possible contribution of adrenal catecholamine release via the adrenal rete. In animals that had undergone renal denervation and left adrenalectomy, the renal blood flow response to intrarenal arterial injection of subpressor doses of angiotensin II (5 and 10 ng/kg) was reduced by the infusion of prazosin. It is concluded that angiotensin II-induced renal vasoconstriction is contributed to by adrenergic actions dependent in part on intact renal nerves, but also by a component not requiring an intact nerve supply.

Neurotrophic Factors in the Rat Penis

An intact nerve supply is essential for normal erectile function. We have undertaken a study to examine the presence and synthesis of growth factors of the penis that support neural function. Extracts were obtained from deskinned penises of Sprague-Dawley rats, aged 3, 6 and 10 weeks, representing prepubertal, pubertal and postpubertal states. Penile extracts were subjected to Northern blot analysis to evaluate expression of nerve growth factor-β (β-NGF)-mRNA, PC-12 bioassay to quantitate the nerve growth promoting activity and immunoassay to detect the amount of β-NGF protein. These initial experiments showed a disproportionately abundant level of nerve growth promoting activity as compared with the levels detected with the immunoassay. The PC-12 bioassay is sensitive to both β-NGF and fibroblast growth factors (FGFs). To further investigate these findings, the bioassay was conducted again after heparin chromatography, with β-NGF receptor blockade, or with the addition of anti-β-NGF, anti-basic-FGF, or anti-acidic-FGF. These studies confirmed that the abundant nerve growth promoting activity in the rat penis is due largely to basic FGF. In conclusion, the neurotrophin NGF is expressed in the rat penis at levels consistent with its expression in other peripheral tissues. Basic-FGF, on the other hand, has been detected at levels far in excess of NGF. Since erectile function is dependent on the integrity of the vascular structure and its intact innervation and since basic FGF presents as an abundant penile growth factor with both angiogenic and neurotrophic activities, basic FGF might play a significant role in erectile physiology.

Role of nitric oxide in neurally induced pancreatic exocrine secretion in pigs.

Formation of NO, enzymatically catalyzed by NO synthases in both endothelial cells and autonomic nerves, seems to explain some noncholinergic nonadrenergic tissue reactions. We studied the possible role of NO in vagally induced pancreatic exocrine secretion using isolated perfused porcine pancreas (n = 11) with intact vagus nerve (VN) supply. Electrical stimulation of the VN (8 Hz, 10 mA) and infusions of vasoactive intestinal polypeptide (VIP, 2 x 10(-9) M) were carried out before and after addition to the perfusate of the NO synthase inhibitors N omega-nitro-L-arginine methyl ester (L-NAME, 10(-4) M) or NG-nitro-L-arginine (L-NNA, 10(-5) M) with and without further addition of L-arginine (10(-3) M). We also studied the effects of L-arginine alone and of sodium nitroprusside (10(-4) M). In all experiments VN and VIP caused a profuse exocrine secretion (43 +/- 7 and 44 +/- 11 times basal secretion). The inhibitors increased vascular resistance approximately twofold but had no effect on the vascular relaxation caused by VIP and VN. The exocrine fluid response to VN was reduced to 19 +/- 5 and 4.7 +/- 1.8% (L-NAME and L-NNA), and response to VIP was reduced to 54 +/- 12 and 35 +/- 13%. Protein and bicarbonate outputs largely paralleled flow rate. Addition of L-arginine (no effects alone) to L-NAME restored the responses to VN (to 100 +/- 21% of controls) and increased VIP responses (to 65 +/- 11%).(ABSTRACT TRUNCATED AT 250 WORDS)

Secretion of pancreastatins from isolated, perfused, porcine adrenal glands

Pancreastatin is a 49 amino acid peptide with a C- terminal glycine amide originally isolated from porcine pancreas. There are strong indications that pancreastatin is derived from chromogranin A, since the amino acid sequence 240–288 in porcine chromogranin A contains pancreastatin flanked by typical signals for proteolytic processing. Several molecular forms of immunoreactive pancreastatin have been reported to be present in porcine adrenal medulla, but no information on the secretion of the peptides is available. We studied stimuli for the release of immunoreactive pancreastatin from adrenal glands as well as the molecular nature of the released immunoreactivity using isolated, perfused, porcine adrenal glands with intact splanchnic nerve supply and a radioimmunoassay specific for the C- terminal glycine amide of porcine pancreastatin in combination with chromatography. Stimulation of the splanchnic nerves greatly enhanced the release of immunoreactive pancreastatin by a mechanism that seems to involve cholinergic nicotinic transmission. The pancreastatin immunoreactivity was due to large amounts of a N- terminally extended pancreastatin form, possibly corresponding to the chromogranin A(1–288) fragment and small amounts of pancreastatin and a C- terminal pancreastatin fragment. Adrenal extracts also contained unprocessed chromogranin A. We conclude that in the porcine adrenals at least 25% of chromogranin A is processed to smaller molecular forms with the pancreastatin sequence forming their C- terminus . These forms appear to be released in parallel with the catecholamines.

Interaction of insulin and exercise on glucose transport in muscle.

Glucose transport is the rate-limiting step for glucose utilization in muscle. In muscle and adipose tissue, glucose transport is acutely regulated by such factors as insulin and exercise. Translocation of glucose transporters (GLUT4) from an intracellular domain to the cell surface is the major mechanism for this regulation. Using immunocytochemistry, the intracellular distribution of GLUT4 under resting conditions is similar in adipocytes and myocytes. GLUT4 is concentrated in tubulovesicular structures either in the trans-Golgi region or in the cytosol, often close to the cell surface but not on the cell surface. After stimulation, cell surface GLUT4 labeling is increased by as much as 40-fold. GLUT4 is chronically regulated by altered gene expression. Neural and/or contractile activity regulates GLUT4 expression in muscle: 1) GLUT4 levels differ among muscles of different fiber type; 2) GLUT4 levels in muscle are increased with exercise training and decreased with denervation; and 3) cultured muscle cells, which lack an intact nerve supply, express very low levels of GLUT4. GLUT4 expression appears to be regulated in parallel with many oxidative enzymes in muscle, suggesting that there may be a unified developmental program that determines the overall metabolic properties of a particular muscle. Preliminary evidence suggests that impaired GLUT4 expression in muscle is not the primary defect associated with insulin resistance. Nevertheless, it is conceivable that the adaptive increase in muscle GLUT4 that is found with exercise training may have beneficial effects in insulin-resistant states such as non-insulin-dependent diabetes.

Outgrowth dependency of forelimb regeneration on nerves in adult African clawed frog, Xenopus laevis.

The relationship between the size and shape of regenerative outgrowth and the quantity of innervation was studied in adult Xenopus laevis. The forelimbs, of which the nerve supply was artificially altered, were amputated midway through the stylopodium and were kept for 1 year. The regenerative outgrowths that formed in normal limbs with an intact nerve supply were mainly spike-shaped and occasionally rod-shaped. However, when the nerve supply to the distal part of the forelimb was augmented by surgically diverting ipsilateral sciatic nerve bundles, the quantity of innervation was increased to about two and a half times that of the normal limb. These hyperinnervated outgrowths were somewhat larger than those of the normally innervated outgrowths and the majority of them were oar-shaped, a type hardly ever encountered in normal regeneration. In contrast, when partial denervation was performed concomitantly with limb amputation, by ablation of the N. radialis at the shoulder joint, the quantity of innervation decreased to about one half that of the normal limb. The outgrowths obtained were spike-shaped in all cases, with their size being about half that of the normally innervated outgrowths. Furthermore, when both the N. radialis and N. ulnaris were ablated in the same way, the amputated limbs were mostly non-regenerative, but some of them regenerated small conical outgrowths. Based on these results, a discussion is presented concerning the relationship between a regenerative outgrowth and the innervation of the forelimb in Xenopus.