NEUROPHARMACOLOGY OF NICOTINE: EFFECTS ON THE AUTOREGULATION OF ACETYLCHOLINE RELEASE BY SUBSTANCE P AND METHIONINE ENKEPHALIN IN RODENT CEREBRAL SLICES AND TOXICOLOGICAL IMPLICATIONS

1995 ◽  
Vol 22 (4) ◽  
pp. 288-290 ◽  
Author(s):  
B. V. Rama Sastry
Keyword(s):  
Substance P ◽  
Acetylcholine Release ◽  
Methionine Enkephalin

Somatostatin modulation of peptide-induced acetylcholine release in guinea pig ileum

1984 ◽  
Vol 246 (5) ◽  
pp. G509-G514 ◽  
Author(s):  
D. H. Teitelbaum ◽  
T. M. O'Dorisio ◽  
W. E. Perkins ◽  
T. S. Gaginella
Keyword(s):  
Substance P ◽  
Guinea Pig ◽  
Myenteric Plexus ◽  
Acetylcholine Release ◽  
Longitudinal Muscle ◽  
Guinea Pig Ileum ◽  
Gut Motility ◽  
Release Of Acetylcholine

The peptides caerulein, neurotensin, somatostatin, and substance P modulate the activity of intestinal neurons and alter gut motility. We examined the effects of these peptides on acetylcholine release from the myenteric plexus and intestinal contractility in vitro. Caerulein (1 X 10(-9) M), neurotensin (1.5 X 10(-6) M), and substance P (1 X 10(-7) M) significantly enhanced the release of [3H]acetylcholine from the myenteric plexus of the guinea pig ileum. This effect was inhibited by tetrodotoxin (1.6 X 10(-6) M). Somatostatin (10(-6) M) inhibited caerulein- and neurotensin-evoked release of acetylcholine but did not inhibit release induced by substance P. Caerulein, neurotensin, and substance P caused contraction of the guinea pig ileal longitudinal muscle. Somatostatin inhibited the contractions induced by caerulein and neurotensin. In contrast, substance P-induced contraction was not inhibited significantly by somatostatin. Thus, in the guinea pig ileum, caerulein-, neurotensin-, and substance P-induced contractility is due, at least in part, to acetylcholine release from the myenteric plexus. The ability of somatostatin to inhibit peptide-induced contractility is selective, and its mechanism may be attributed to inhibition of acetylcholine release.

Cardiovascular interactions between methionine-enkephalin and Substance P in the conscious dog

Peptides ◽  
1985 ◽  
Vol 6 (1) ◽  
pp. 133-137 ◽  
Author(s):  
Gary E. Sander ◽  
Thomas D. Giles ◽  
Janet C. Rice
Keyword(s):  
Substance P ◽  
Methionine Enkephalin ◽  
Conscious Dog

Are Leydig cells of neural origin? Substance P-like immunoreactivity in human testicular tissue

1987 ◽  
Vol 115 (3) ◽  
pp. 373-377 ◽  
Author(s):  
Wolfgang Schulze ◽  
Michail S. Davidoff ◽  
Adolf-Friedrich Holstein
Keyword(s):  
Substance P ◽  
Local Control ◽  
Leydig Cells ◽  
Testicular Tissue ◽  
Control Mechanisms ◽  
Methionine Enkephalin ◽  
Selective Staining ◽  
Neural Origin ◽  
New Perspective

Abstract. Using the immunocytochemical peroxidase-antiperoxidase method we observed strong and selective staining of Leydig cells after incubation of human testicular tissue with an antiserum against substance P and a slightly weaker immunoreactivity against methionine-enkephalin. These results indicate that the embryologic origin of Leydig cells may require reconsideration and also offer a new perspective for research upon the local control mechanisms of spermatogenesis.

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