E Giacobini

University of Connecticut, Storrs, CT, USA

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Publications (5)11.34 Total impact

  • Article: Molecular forms of cholinesterases in cerebrospinal fluid, blood plasma, and brain tissue of the beagle dog.
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    ABSTRACT: In the present study we have investigated the activity of AChE and BuChE in the cisternal CSF of the Beagle dog and have outlined the characteristics of the molecular forms of both enzymes. The same enzymes were also investigated in samples from blood plasma and brain tissue. It is concluded that AChE in CSF originates from the spinal cord and brain tissues as a result of some secretory process. A combined origin from both blood plasma and brain tissue appears to be probable for the BuChE of the CSF.
    Journal of Neuroscience Research 02/1979; 4(1):19-24. · 2.74 Impact Factor
  • Article: Time course of appearance of alpha-bungarotoxin binding sites during development of chick ciliary ganglion and iris.
    V A Chiappinelli, E Giacobini
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    ABSTRACT: The binding of [125I]alpha-bungarotoxin (ABTX) to homogenates of ciliary ganglia and irises from embryonic and posthatching chickens has been examined. Specific, high-affinity binding was found in both tissues [KD (iris) equals 2.5 nM; KD (ganglion) equals 2.7 nM]. Binding is saturated above 10 nM toxin concentration and is inhibited by low concentrations of the nicotinic antagonist d-tubocurarine. The binding may be associated with a nicotinic cholinergic receptor in both tissues. The amount of binding in the iris begins to increase soon after functional innervation is first observed, at 12 days of incubation (d.i.), and continues to increase up to four months after hatching (a.h.), the oldest age tested. In contrast, ABTX binding in the ciliary ganglion increases fourfold between 7 and 11 d.i., after which the amount of binding remains unchanged up to four months a.h. When compared to the development of choline acetyltransferase (ChAc) and acetylcholinesterase (AChE) activities in the ganglion and iris, ABTX binding follows a pattern similar to that of AChE activity. The largest increases in ChAc activity occur later than those of the postsynaptic markers. After 16 d.i. there are approximately 3 x 10(6) toxin molecules bound per neuron in the ciliary ganglion.
    Neurochemical Research 09/1978; 3(4):465-78. · 2.24 Impact Factor
  • Article: Molecular forms of acetylcholinesterase in the ciliary ganglion and iris of the chick. Developmental changes and effects of axotomy.
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    ABSTRACT: Four molecular forms of acetylcholinesterase (AChE) have been observed in extracts from ciliary ganglion and iris by gel electrophoresis followed by Koelle's reaction and densitometry on gels. Forms I, II, and III (order of anodic migration) are present in the 'soluble fraction' (SF) while forms II, III, and IV appear in the 'membranous fraction' (MF). 10 days after postganglionic axotomy in young chickens, the relative proportions of the membranous forms were changed in both the ciliary ganglion and iris, with a marked reduction of form IV occurring. A characteristic evolution of both the soluble and membranous forms of AChE was evident through different developmental stages (10th day of incubation; 2nd, 11th and 56th day posthatching). In the ciliary ganglion the faster components were reduced in favor of form IV. Conversely, the relative proportion of the faster components was increased in the iris. The observed changes in the AChE forms are compared with changes in the structure and function of these organs known to occur in the conditions under study. Evidence is presented which suggests a junctional localization for the form IV in both the ciliary ganglion and iris.
    Developmental Neuroscience 02/1978; 1(3-4):133-41. · 3.63 Impact Factor
  • Article: Acetylcholinesterase activity in ventricular and cisternal CSF of dogs: effect of chlorpromazine.
    S R Bareggi, E Giacobini
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    ABSTRACT: Acetylcholinesterase (AChE) activity in dog plasma is significantly higher than in either ventricular or cisternal CSF. However, since protein levels in plasma are about 100-fold higher than in CSF, the specific activity of AChE is lower in plasma than in CSF. Acetylcholinesterase activity in plasma represents only 22% of total cholinesterase (ChE) activity, while preliminary findings indicate that in ventricular CSF it is 50-60%. Acetylcholinesterase activity in ventricular CSF is significantly lower than in cisternal CSF. Chlorpromazine (10 mg/kg, intravenous), a drug which increases acetylcholine turnover, increased AChE-specific activity in all dogs. Our results support the hypothesis of a neuronal origin of AChE activity in CSF.
    Journal of Neuroscience Research 02/1978; 3(5-6):335-9. · 2.74 Impact Factor
  • Article: Molecular Forms of Acetylcholinesterase in the Ciliary Ganglion and Iris of the Chick
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    ABSTRACT: Four molecular forms of acetylcholinesterase (AChE) have been observed in extracts from ciliary ganglion and iris by gel electrophoresis followed by Koelle's reaction and densitometry on gels. Forms I, II, and III (order of anodic migration) are present in the 'soluble fraction' (SF) while forms II, III, and IV appear in the 'membranous fraction' (MF). 10 days after postganglionic axotomy in young chickens, the relative proportions of the membranous forms were changed in both the ciliary ganglion and iris, with a marked reduction of form IV occurring. A characteristic evolution of both the soluble and membranous forms of AChE was evident through different developmental stages (10th day of incubation; 2nd, 11th and 56th day posthatching). In the ciliary ganglion the faster components were reduced in favor of form IV. Conversely, the relative proportion of the faster components was increased in the iris. The observed changes in the AChE forms are compared with changes in the structure and function of these organs known to occur in the conditions under study. Evidence is presented which suggests a junctional localization for the form IV in both the ciliary ganglion and iris.
    Developmental Neuroscience. 08/1970; 1(3-4):133-141.