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S R Chiocchio

Publications and source records attributed to S R Chiocchio.

42 records · Page 3Linked to original sources
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alpha-MSH and Pro-Leu-Gly-NH2 (PLG; MIF-1): influence on dopamine (DA) uptake in crude synaptosomal preparations from rat mediobasal hypothalamus (MBH) and caudate putamen (CP).

The uptake of tritiated dopamine [3H] (DMI insensitive DA uptake) by synaptosomal fractions isolated from rat mediobasal hypothalamus (MBH) and caudate putamen (CP) was measured in the presence of different concentrations of alpha-melanocyte stimulating hormone (alpha-MSH) and Pro-Leu-Gly-NH2 (PLG; MIF-1) which is an inhibitor of alpha-MSH release. Compared to control, [3H]DA uptake increased significantly when the synaptosomal fraction of CP was incubated with 0.1 and 1 microM of alpha-MSH and also when the rat was previously injected with alpha-MSH. A simultaneous reduction of endogenous dopamine content was observed. Kinetic studies suggest that the enhanced uptake induced by alpha-MSH 1 microM is the consequence of the rise in Vmax, without changes in the apparent km. The uptake of [3H]DA in hypothalamic (MBH) preparations on the other hand, was not modified by the presence of alpha-MSH. PLG did not have any significant effect on [3H]DA uptake either in the CP or in the MBH. alpha-MSH may act as a modulator of the dopaminergic nigrostriatal system and the results obtained incubating CP synaptosomes in its presence demonstrate a possible direct modulator action by alpha-MSH on the terminal area of the substantia nigra neurons.

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PubMedDate not supplied

Catecholamine distribution in adult rat testis.

Catecholamine distribution in the adult rat testis was examined using a sensitive radioenzymatic method. Norepinephrine was present in the capsule and the interstitial fluid, in higher concentrations than dopamine, while in the interstitial cell preparations only norepinephrine was found. Epinephrine was undetectable in all testicular compartments investigated. No catecholamines were found in the seminiferous tubules. Testicular denervation caused a significant decrease in capsular catecholamines, confirming the neural origin of these amines.

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PubMedDate not supplied

Monoaminergic and peptidergic contributions of the superior and the inferior spermatic nerves to the innervation of the testis in the rat.

Sections of the rat testis and whole-mounts of the testicular capsule were studied microscopically using the glyoxylic acid-induced fluorescence method, to detect monoamines, and immunohistochemical procedures for the detection of immunoreactivities to protein gene-product 9.5 (PGP 9.5), the C-terminal accompanying peptide of neuropeptide Y (CPON), and vasoactive intestinal polypeptide (VIP). Monoaminergic nerves were only observed around the intracapsular blood vessels: the initial segment of the testicular artery and the superior venous plexus, and in the anterior aspect of the upper and lower testicular poles. These capsular nerve networks were associated with the superior and inferior ligaments of the testis. Nerves displaying PGP 9.5 and CPON immunoreactivity appeared in the same sites and followed the same distribution as monoaminergic nerves. By contrast, VIP-immunoreactive fibers were only found in the nerve network of the lower pole. Observations done after different surgical denervation procedures demonstrated that the superior spermatic nerve was the source of fibers for testicular vessels and for the nerve network of the upper pole. On the other hand, fibers from the inferior spermatic nerve were restricted to the nerve network of the lower pole.

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