Secretion of acetylcholinesterase and butyrylcholinesterase from the guinea-pig isolated ileum.

1. Strips of longitudinal muscle from guinea-pig ileum, retaining Auerbach's plexus, were superfused with oxygenated Krebs solution. Addition of 50 mM KCl led to a pronounced Ca2+-dependent increase in the activities of both acetylcholinesterase and non-specific cholinesterase (butyrylcholinesterase) in the perfusate but with no change in lactate dehydrogenase activity. 2. No release of acetylcholinesterase, either spontaneous or K+-evoked was observed in tissue freed of the nerve plexus, although release of butyrylcholinesterase still occurred. 3. Carbachol induced a marked Ca2+-dependent increase in the release of acetylcholinesterase but had no effect on the release of butyrylcholinesterase or lactate dehydrogenase. This carbachol-evoked increase in acetylcholinesterase release was blocked by hexamethonium but not by atropine. 4. Four readily soluble molecular forms of acetylcholinesterase and three soluble molecular forms of butyrylcholinesterase were present in innervated longitudinal muscle strips, but insignificant amounts of acetylcholinesterase were detected in denervated strips of muscle. Only one of the four molecular forms of acetylcholinesterase was recovered in the perfusates. 5. It is concluded that acetylcholinesterase is secreted from the nerves of Auerbach's plexus in response to depolarizing stimuli or to nicotinic cholinergic stimulation, while butyrylcholinesterase is secreted from non-neural elements, possibly the longitudinal muscle cells, of guinea-pig ileum in response to a depolarizing stimulus.     

6-Hydroxydopamine-induced turning behaviour in the rat: the significance of acetylcholinesterase in cerebrospinal fluid

In the substantia nigra, acetylcholinesterase may have a novel function related not to cholinergic transmission, but to the homeostasis of dopaminergic nigrostriatal neurones. The initial aim of this study was thus to see whether, in the rat, release of the enzyme into cerebrospinal fluid would reflect turning behaviour following unilateral 6-hydroxydopamine lesions of varying severity. It was found that acetylcholinesterase levels, lower than those in the cerebrospinal fluid of control rats, were accompanied by marginal circling behaviour and a small loss of striatal dopamine: on the other hand, elevated acetylcholinesterase activity was observed in the cerebrospinal fluid of rats displaying vigorous turning behaviour and with large depletion of striatal dopamine. It has already been demonstrated that exogenous acetylcholinesterase, applied locally to nigral neurones, has both electrophysiological and behavioural effects reminiscent of dopamine agonists. Hence it is possible that exogenous acetylcholinesterase could modify turning behaviour resulting from unilateral striatal dopamine depletion. Purified acetylcholinesterase, administered by cisternal puncture, attenuated circling behaviour for up to 7 days. The possible mechanisms are discussed by which endogenous acetylcholinesterase in cerebrospinal fluid could serve as an index of dopamine depletion in the nigrostriatal pathway and how exogenous enzymes might alleviate the accompanying motor dysfunction.     

Aggrecan,versican and type VI collagen are components of annular translamellar crossbridges in the intervertebral disc

The aim of this study was to undertake a detailed analysis of the structure of the inter and intra-lamellar regions of the annulus fibrosus. A total of 30 newborn to 6 year-old lumbar ovine intervertebral discs (IVDs) were fixed and decalcified en-bloc to avoid differential swelling artifacts during processing and vertical mid-sagittal, and horizontal 4 μm sections were cut. These were stained with toluidine blue to visualise anionic proteoglycan (PG) species, H & E for cellular morphology and picro-sirius red (viewed under polarized light) to examine collagenous organization. Immunolocalisations were also undertaken using anti-PG core-protein and glycosaminoglycan (GAG) side chain antibodies to native chondroitin sulphate (CS), Δ C-4-S and C-6-S unsaturated stubs generated by chondroitinase ABC digestion of CS, keratan sulphate (KS), and with antibodies to type I, II, VI, IX and X collagens. Trans-lamellar cross bridges (TLCBs), discontinuities in annular lamellae’s which provide transverse interconnections, stained prominently with toluidine blue in the adult IVDs but less so in the newborn IVDs. In adult discs TLCBs were evident in both the posterior and anterior AF where they extended from the outermost annular lamellae almost to the transitional zone extending across as many as eight lamellar layers displaying a characteristic circuitous, meandering, serpentine type course. There were significantly fewer TLCBs in 2 week-old compared with skeletally mature sheep and there was a further increase from 2 to 6 years. Immunolocalisation of perlecan delineated blood vessels in the TLBs of the newborn but not adult IVDs extending into the mid AF. In contrast adult but not 2 week-old TLCBs were immunpositive for C-4-S, C-6-S, KS, aggrecan, versican and type VI collagen. The change in number and matrix components of the trans-lamellar cross bridges with skeletal maturity and ageing suggest that they represent an adaptation to the complex biomechanical forces occurring in the annulus fibrosus.     

Immunohistochemical expression of SP-NK-1R-EGFR pathway and VDR in colonic inflammation and neoplasia

AIM:To determine the expression of neurokinin-1receptor(NK-1R),phosphorylated epidermal growth factor receptor(p EGFR),cyclooxygenase-2(Cox-2),and vitamin D receptor(VDR)in normal,inflammatory bowel disease(IBD),and colorectal neoplasia tissues from Puerto Ricans.METHODS:Tissues from patients with IBD,colitisassociated colorectal cancer(CAC),sporadic dysplasia,and sporadic colorectal cancer(CRC),as well as normal controls,were identified at several centers in Puerto Rico.Archival formalin-fixed,paraffin-embedded tissues were de-identified and processed by immunohistochemistry for NK-1R,p EGFR,Cox-2,and VDR.Pictures of representative areas of each tissues diagnosis were taken and scored by three observers using a4-point scale that assessed intensity of staining.Tissues with CAC were further analyzed by photographing representative areas of IBD and the different grades of dysplasia,in addition to the areas of cancer,within each tissue.Differences in the average age between the five patient groups were assessed with one-way analysis of variance and Tukey-Kramer multiple comparisons test.The mean scores for normal tissues and tissues with IBD,dysplasia,CRC,and CAC were calculatedand statistically compared using one-way analysis of variance and Dunnett’s multiple comparisons test.Correlations between protein expression patterns were analyzed with the Pearson’s product-moment correlation coefficient.Data are presented as mean±SE.RESULTS:On average,patients with IBD were younger(34.60±5.81)than normal(63.20±6.13,P0.01),sporadic dysplasia(68.80±4.42,P0.01),sporadic cancer(74.80±4.91,P0.001),and CAC(57.50±5.11,P0.05)patients.NK-1R in cancer tissue(sporadic CRC,1.73±0.34;CAC,1.57±0.53)and sporadic dysplasia(2.00±0.45)were higher than in normal tissues(0.73±0.19).p EGFR was significantly increased in sporadic CRC(1.53±0.43)and CAC(2.25±0.47)when compared to normal tissue(0.07±0.25,P0.05,P0.001,respectively).Cox-2 was significantly increased in sporadic colorectal cancer(2.20±0.23 vs 0.80±0.37 for normal tissues,P0.05).In comparison to normal(2.80±0.13)and CAC(2.50±0.33)tissues,VDR was significantly decreased in sporadic dysplasia(0.00±0.00,P0.001 vs normal,P0.001 vs CAC)and sporadic CRC(0.47±0.23,P0.001 vs normal,P0.001 vs CAC).VDR levels negatively correlated with NK-1R(r=-0.48)and p EGFR(r=-0.56)in normal,IBD,sporadic dysplasia and sporadic CRC tissue,but not in CAC.CONCLUSION:Immunohistochemical NK-1R and p EGFR positivity with VDR negativity can be used to identify areas of sporadic colorectal neoplasia.VDR immunoreactivity can distinguish CAC from sporadic cancer.     

Prevalence and prognosis of electrocardiographic left ventricular hypertrophy, ST segment depression and negative T-wave; the Copenhagen City Heart Study.

AIMS: To evaluate the prevalence and the independent prognosis of electrocardiographic left ventricular hypertrophy by voltage only, ST depression and negative T wave, isolated negative T wave and left ventricular hypertrophy plus ST depression and negative T wave for cardiac morbidity and mortality, without known ischaemic heart disease at baseline. METHODS and RESULTS: Follow-up data from the Copenhagen City Heart Study were used. Subjects were 5243 men and 6391 women, age range 25-74 years. End-points were (1) myocardial infarction, (2) ischaemic heart disease and (3) cardiovascular disease mortality. Relative risk was age- and sex-adjusted, and multivariately adjusted for known cardiovascular risk factors. During 7 years follow-up, left ventricular hypertrophy plus ST depression and negative T wave had an age-adjusted relative risk of 3.78 (95% confidence interval 2.29-6.25) for myocardial infarction, 4.27 (2.95-6.16) for ischaemic heart disease and 3.75 (2.41-5.85) for cardiovascular disease. A negative T wave, ST depression and negative T wave changes, and left ventricular hypertrophy with negative T wave also carry independent prognostic information for myocardial infarction, ischaemic heart disease and cardiovascular disease. CONCLUSIONS: Electrocardiographic left ventricular hypertrophy with ST depression and negative T wave changes are the electrocardiographic abnormalities with the greatest prognostic information for future cardiac events. Electrocardiographic negative T waves, ST depression and negative T wave abnormalities and left ventricular hypertrophy with negative T waves, also have prognostic information.     

Addition of Nitric Oxide Through Nitric Oxide-paracetamol Enhances Healing Rat Achilles Tendon

Nitric oxide is an important messenger molecule in many physiological processes. The addition of NO via NO-flurbiprofen enhances the material properties of healing tendon, however, flurbiprofen has a detrimental effect on healing. We asked if NO delivered by a cyclooxygenase 3 inhibitor (paracetamol/acetaminophen) would enhance healing in a rat Achilles tendon healing model. Rats were injected subcutaneously daily with NO-paracetamol, paracetamol or vehicle from two days before surgery to the day of tissue harvesting. Paracetamol had no effect on tendon healing compared with vehicle alone. NO-paracetamol did not change the failure load, but did decrease the water content, enhance the collagen content, reduce the cross-sectional area and improve the ultimate stress of healing tendon compared with paracetamol and vehicle. The collagen organization of the healing tendon in the NO-paracetamol group, as determined by polarized light microscopy, was enhanced. Our data suggests NO-paracetamol increases the total collagen content and enhances organization while decreasing the cross-sectional area of healing rat Achilles tendon and is consistent with human clinical trials where NO has improved the symptoms and signs of tendinopathy. One or more of the authors (GM,GT, MW) have received funding from a grant from the NiCox Corporation and by St George Hospital/South Eastern Sydney Area Health Service. Each author certifies that his or her institution has approved the animal protocol for this investigation and that all investigations were conducted in conformity with ethical principles of research.