Innervation of the Sheep Pineal Gland by Nonsympathetic Nerve Fibers Containing NADPH-diaphorase Activity

Abstract

SUMMARYWe used the NADPH-diaphorase histochemical method as a potential marker for nitric oxide synthase (NOS)-containing nerve fibers innervating the pineal gland of the sheep. Nerve fibers containing NADPH-diaphorase activity provide dense innervation of the sheep pineal gland. The nerve fibers were located in the pineal capsule, in the connective tissue septae separating the lobuli of the gland, and penetrating between the pinealocytes. The nerve fibers were either smooth or endowed with boutons en passant. After bilateral removal of the superior cervical ganglion, the dense network of NADPH-diaphorasepositive fibers was still present in the gland. Ganglionectomy affected neither the distribution nor the appearance of the NADPH-diaphorase-positive fibers. Most of the NADPH-diaphorasepositive fibers also contained peptide histidine isoleucine and vasoactive intestinal polypeptide, and a comparatively smaller fraction contained neuropeptide Y. Pinealocytes never exhibited NADPH-diaphorase activity. These results demonstrate a major neural input to the sheep pineal gland with NADPH-diaphorase-positive nerve fibers of nonsympathetic origin. (J Histochem Cytochem 45:1121-1128, 1997)

Generation of the Melatonin Endocrine Message in Mammals: A Review of the Complex Regulation of Melatonin Synthesis by Norepinephrine, Peptides, and Other Pineal Transmitters

“…NO is also synthesized in nonsympathetic (VIPergic) fibers of the sheep and rat pineal gland Lopez-Figueroa et al, 1997). In addition, neuronal NOS is present in the rat (Lin et al, 1994;Schaad et al, 1994Schaad et al, , 1995aLopezFigueroa and Møller, 1996) and cow (Maronde et al, 1995) pinealocytes (but not in the sheep: .…”

Characterization of basal nitric oxide production in living cells

“…The NADPH-d method was used as previously described by Lo ¨pez-Figueroa and collaborators [12]. Brie£y, cells were ¢xed in 2% paraformaldehyde (PA) in PBS for 10 min at room temperature (RT).…”

Nitrergic Neurons in the Spinal Cord of the Bottlenose Dolphin (Tursiops truncatus)

“…The diaphorase activity and consequently its distribution in the CNS is superimposed to nNOS immunoreactivity (Dawson et al, 1991;Vincent and Kimura, 1992;Giraldi-Guimarães et al, 1999;Bombardi et al, 2006Bombardi et al, , 2011. NADPH-d and nNOS containing neurons have been localized in the spinal cord in several mammalian species, including mouse, rat, rabbit, dog, cat, sheep, monkey, and human (Br€ uning, 1992;Valtschanoff et al, 1992a,b;Dun et al, 1992Dun et al, , 1993Spike et al, 1993;Terenghi et al, 1993;Saito et al, 1994;Vizzard et al, 1994;Wetts and Vaughn, 1994;Pullen and Humphreys, 1995;L opez-Figueroa et al, 1996L opez-Figueroa et al, , 1997Mars ala et al, 1998Mars ala et al, , 1999Kluchov a et al, 2000). Despite the previous studies, no information is available on the distribution of nitrergic neurons in the spinal cord of the cetaceans.…”