Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01275 (glucagon)
 26,492 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The role of glucose metabolism in sperm cell motility was examined in purified human spermatozoa from the perspective of elucidating its possible significance in spontaneous and experimental diabetes. After a 4-h incubation in the absence of D-glucose, the mean progressive velocity of human spermatozoa was 40% lower than that of control cells kept in the presence of D-glucose. The decline was rapidly overcome by the addition of D-glucose or D-fructose, the amplitude of this stimulatory effect being independent of the ambient hexose concentration. Between 1.4 and 16.7 mM glucose, spermatozoal glucose oxidation also proceeded independently of the extracellular glucose levels, whereas both insulin (100nM) and glucagon (100nM) failed to significantly affect the rate of glucose metabolism or cellular motility. It is speculated from these results that an alteration in seminal hexose concentrations or pancreatic hormone levels may be an unlikely cause for the reduced sperm motility that is characteristically observed in diabetic patients. Human spermatozoa rapidly incorporated D-glucose and 3-O-methyl-D-glucose but excluded the glucose-analogue alloxan, which may explain their resistance against the toxic effects of this diabetogenic drug, in spite of their intrinsic sensitivity to organic peroxides such as tert-butyl hydroperoxide.
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PMID:Glucose metabolism in human spermatozoa: lack of insulin effects and dissociation from alloxan handling. 351 12

Acting in vivo, adrenalin and noradrenalin cause a statistically significant and permanent decrease in the motility of mouse spermatozoa remaining in the vas deferens. Intratesticular injection of vasopressin, oxytocin, insulin, and glucagon results in a decrease in spermatozoa motility in vas deferens, removal the spermatozoa to PBS in vitro, and an increase in percentage of motile spermatozoa on incubation medium. Thyroxine, calcytonin, and TRH did not affect motility of mouse spermatozoa in vivo.
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PMID:Effects of selected hormones on the motility of spermatozoa in the mouse vas deferens. 785 64

Pituitary adenylate cyclase-activating-polypeptide (PACAP) is a new member of the secretin/glucagon/vasoactive intestinal peptide family of peptides; it occurs as two amidated forms with 38 (PACAP38) and 27 (PACAP27) amino acids. Rabbit antisera against synthetic PACAP27 were characterized by enzyme-linked immunosorbent assay. One of the antisera, using a high antibody titer, recognized both PACAP27 and PACAP38 and was found useful for immunohistochemistry. The distribution and ultrastructural localization of PACAP-like immunoreactivity (PACAP-LI) in the rat testes at different stages of spermatogenesis were studied with this antiserum. Four oligonucleotide probes, each complementary to a different region covering a different intron-exon junction, were chosen to maximize hybridization based on the predicted secondary structure of PACAP messenger RNA. PACAP-LI was detected in the developing germ cells but not in either Sertoli or Leydig cells. Intense PACAP-LI was found in spermatids situated near the lumen of the seminiferous tubules. Lower levels of PACAP-LI were detected in spermatogonia and primary spermatocytes, but no PACAP-LI was found in mature spermatids, testicular spermatozoa, or epididymal spermatozoa. In spermatids, PACAP-LI was detected during the cap phase and acrosome phase but not in the maturation phase. At the ultrastructural level, numerous gold particles representing PACAP-LI were found in both acrosomal granules and acrosomal caps of spermatids, while a few particles were found in the Golgi complex. Very few gold particles were seen in the acrosome of mature spermatids and spermatozoa. PACAP-LI decreased and finally disappeared from spermatids during the late developmental stages. In situ hybridization indicated that most of the signal was detected near the perimeter of seminiferous tubules in early developing germ cells, especially in spermatogonia and primary spermatocytes, suggesting that transcription of the PACAP gene occurs in spermatogonia and primary spermatocytes. The processing of the prohormone appears to be slow, and mature PACAP only appears in spermatids. These morphological findings suggest that PACAP-like substances, synthesized by germ cells, participate in spermatogenesis, particularly spermiogenesis, probably by an autocrine and paracrine mechanism. However, the possibility that PACAP acts on the Sertoli and/or Leydig cells cannot be excluded.
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PMID:Localization of pituitary adenylate cyclase-activating polypeptide and its messenger ribonucleic acid in the rat testis by light and electron microscopic immunocytochemistry and in situ hybridization. 807 Mar 75

Chemotaxis assays of mouse spermatozoa were performed in vitro. Amounts of calcitonin (5.0 IU/ml, 10.0 IU/mL) and acetylcholine (1.0 mg/ml) in Biggers-Whitter-Whittingham medium filled out wells of experimental plate were increased directly by migration of mouse spermatozoa to the medium containing these hormones. This effect was interpreted as chemotaxis of spermatozoa. Low concentrations of hormones were not attractants and high concentrations of acetylcholine (5.0 mg/mL) decreased spermatozoa migration. Glucagon and vasopressin results in a decrease in concentration of migrated spermatozoa. In low concentrations of these hormones differences in sperm migration were not observed. Presence of histamine and thyroxine in BWW medium did not affect the migration behavior of mouse spermatozoa in vitro.
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PMID:Chemotaction of mouse spermatozoa induced by certain hormones. 857 70

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a new member of the secretin glucagon-vasoactive intestinal peptide (VIP) family of peptides, being most homologous to VIP. PACAP exists in two amidated forms with 38 residues (PACAP38) and 27 residues (PACAP27), respectively. PACAP38 is the major form in tissues. There are two types of high-affinity receptors for PACAP: type I, which specifically binds to both PACAPs, and type II, which is shared with VIP. Type I PACAP receptors appear to have two subtypes: type IA, which binds to both PACAP38 and PACAP27, with slight preference for the latter, and type IB, with greater preference for PACAP38. Distribution of the type I PACAP receptor is different from that of VIP, and it is found in high concentrations in brain, spinal cord, anterior pituitary, adrenal medulla, spermatogonia at certain stages, mature spermatozoa, and some cell lines. Type II PACAP receptors are found in lung, liver, intestine, and other tissues, and their distribution is similar to that of the VIP receptor. Type II PACAP receptor might be similar to or identical with the VIP receptor.
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PMID:Receptors for pituitary adenylate cyclase-activating polypeptide: comparison with vasoactive intestinal peptide receptors. 1840 13

Energy homeostasis is crucial for all physiological processes. Thus, when there is low energy intake, negative health effects may arise, including in reproductive function. We propose to study whether caloric restriction (CR) changes testicular metabolic profile and ultimately sperm quality. Male Wistar rats (n = 12) were randomized into a CR group fed with 30% fewer calories than weight-matched, ad libitum-fed animals (control group). Circulating hormonal profile, testicular glucagon-like peptide-1 (GLP-1), ghrelin and leptin receptors expression, and sperm parameters were analyzed. Testicular metabolite abundance and glycolysis-related enzymes were studied by NMR and Western blot, respectively. Oxidative stress markers were analyzed in testicular tissue and spermatozoa. Expressions of mitochondrial complexes and mitochondrial biogenesis in testes were determined. CR induced changes in body weight along with altered GLP-1, ghrelin, and leptin circulating levels. In testes, CR led to changes in receptor expression that followed those of the hormone levels; modified testicular metabolome, particularly amino acid content; and decreased oxidative stress-induced damage in testis and spermatozoa, although sperm head defects increased. In sum, CR induced changes in body weight, altering circulating hormonal profile and testicular metabolome and increasing sperm head defects. Ultimately, our data highlight that conditions of CR may compromise male fertility.
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PMID:Caloric restriction alters the hormonal profile and testicular metabolome, resulting in alterations of sperm head morphology. 3177 15