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Somatostatin (SRIH) cells in human somatotropic adenomas
Cell Biology
244
SOMATOSTATIN (SRIH) SOMATOTROPIC
P661
Jacques Y Li, Patrick Michard, Laurence Jean Racadot, and Laboratoire
CELLS IN HUMAN ADENOMAS
Pagesy, Odile Racadot,
levy,
Dominique
Fransoise d’Histologie,
Joubert
Peillon. Facult6
Myriam
(Bression),
INSERM de
U.223
Midecine
Piti&Salp&tri&re,
75634 Paris Cedex 13. adenomatous and normal anterior human pituitary may be the source of neuropeptides classically associated with the hypothalamus. Data from our laboratory have shown that the SRIH gene was transcribed in these tissues. Immunoreactive SRIH (IR-SRIH) was found in normal anterior pituitary tissue but was barely detectable in most adenomas. The present study focuses on 2 adenomas which stood out in a series of 30 somatotropic adenomas by their high levels of SRIH gene expression and SRIH content which allowed the characterization of the cells responsible for the synthesis of the neuropeptide. Surgical specimens were immediately frozen for peptide or mRNA extraction. The SRIH content was measured by RIA and the molecular forms were characterized by HPLC. The size of the SRIH mRNA transcripts was analyzed by Northern blots with oligonucleotide probes. Other fragments were fixed in 4 % paraformaldehyde, 0.5 glutaraldehyde. Fixed fragments were either embedded in Paraplast or osmicated and embedded in Epon. In situ hybridization was performed on paraffin sections with the same probes used in Northern blots. A very small number of cells expressing SRIH mRNA and containing IR-SRIH was identified. The comparison of homologous fields of serial sections showed that IR-SRIH was not colocalized in GH producing cells. The ultrastructure of the cells was analyzed by immunogold labeling. The existence of peculiar adenomatous cells producing SRIH favors their involvement in intraadenomatous regulatory mechanisms. The
P663
THE
RELATION BEIWEEN GASl-RIC ULCER AND ANTFtAL “G” AND “D” CELLS
Yurdagtil Canbsrk. Department of Histology and Embryology, Istanbul Faculty of Medicine, University of Istanbul, &paIstanbul/TURKEY Various researchers have reported some changes and relations between G and 0 cells in peptic and duodenal ulcer cases (Lanas A. et al. 1985, Rev.Esp.Enferm Apar Dig; Chsn Z.Y. et al 1986, Chung Hua Nei Ko Tsa Chih; Harty R.F.et al 1986, Gut). The ultrastructural findings of the light G cells were considered as signs of high functional activity (Creutzfeldt W et al., 1971; Eur J Clin Invest); those of the dark G cells suggest that these cells represent altered, probably exhausted cells (Bordi C. et al, 1978 Arch Pathol Lab Ned). In this study, the endocrine cells of the stomach (pylorus) gastrin (G) cells and somatostatin (0) cells were examined at the ultrastructural level, in the cases with gastric ulcer. In all cases, G cells were seen as the most affected cell type when compared with D cells. Even G cells were increased in number, they reflected a case of hyperstimulation, and hyperfunctian at the secretion and the secretory phases. G cells, dependent to their functions, were Seen in light and dark types. Dark cells which are in majority were observed with dense cytoplasmic matrix, with numerous free ribosomes, and were filled by empty secretory granules. In light cells, dependent to their secretory activity, many secretory granules were seen in different phases of maturation. In contrast to G cells, 0 cells were seen poor in secretory That finding was quits important in granules (degranular). reflecting the relationship between G and 0 cells. Gastrin secretion was increased when somatostatin secretion was low and that relationship was proved morphologically in our study. As a result, when compared wit6 the control group. a topographic relationship between G and Cl cells and the presence of some differences in secretion phases and activities in pathological cases were emphasized.
International
Reports,
P662
Vol. 14, Abstracts
Supplement
1990
REGULATION
OF H202 GENERATION IN THE THYROID U. Bjbrkman, R. Ekholm. Department of Anatomy, University of GBteborg, Sweden. Hydrogen peroxide is required as electron acceptor in the oxidative reactions by which the thyroid hormones are formed. The production of Hz02 was measured with a chemiluminescence method in isolated follicles from pig and dog thyroids. In porcine follicles TSH stimulated Hz02 generation but only at high concentrations (>lOmU/ml) and in the presence of Ca2+; dibuturyl-CAMP had no effect. The Ca2+ ionophore A23187 as well as a diacylglycerol analogue and phorbol myristate acetate also stimulated Hz02 production. In addition, Hz02 generation was increased by addition of arachidonic acid and by melittin, an activator of phospholipase AZ. In dog thyroid follicles Hz02 generation was stimulated by high concentrations of TSH and by A23187 and activators of protein kinase C. These observations were considered to show that the major pathway activating H202 generation, both in pig and dog thyroids, is the Ca2 /phosphatidylinositol cascade. This interpretation was corroborated by the finding that carbam lcholine, which is known to I+ be an agonist of the Ca /phosphatidylinositol cascade in the dog thyroid, activated H202 formation in canine follicles. Carbamylcholine had no effect in pig follicles and plausible adrenergic agonists interfered with the luminescence technique. However, the existence of a similar receptortransducer system in the porcine follicles was indicated by the observation that NaF activated HZ02 generation which was reduced by neomycin, an inhibitor of phospholipase C.
IN-VITRO TESTOSTERONE SECRETION BY TRYPANOSOME-INFECTED MOUSE LEYDIG CELLS. E.N. Waindi & H. Odongo, Department of zoology, University of Nairobi, Box 30197, Nairobi, KENYA. Trypanosome infection in animals is associated with endocrine depression and gonadal malfunction. We report here low response to in-vitro LH stimulation of r. conqolense - infected mouse Leydig cells. The cells were mechanically isolated in cold Eagle's medium, preincubated for 1 h and further incubated for 3 h at 31°C with LH concentrations ranging from 18.8 to 300 uIu/ml. Mean secreted testosterone values assayed by RIA were significantly lower at all points for infected cells (p>OOl), varying from 0.56 f 0.05 to 0.88 f 0.12 n mol/L (SEM, n=6) as compared to corresponding control values of 1.37 + 0.18 and 3.90 & 1.56 (SEM, n=lO). Cell viability by trypan blue exclusion method did not indicate significant difference (p
P664
244
SOMATOSTATIN (SRIH) SOMATOTROPIC
P661
Jacques Y Li, Patrick Michard, Laurence Jean Racadot, and Laboratoire
CELLS IN HUMAN ADENOMAS
Pagesy, Odile Racadot,
levy,
Dominique
Fransoise d’Histologie,
Joubert
Peillon. Facult6
Myriam
(Bression),
INSERM de
U.223
Midecine
Piti&Salp&tri&re,
75634 Paris Cedex 13. adenomatous and normal anterior human pituitary may be the source of neuropeptides classically associated with the hypothalamus. Data from our laboratory have shown that the SRIH gene was transcribed in these tissues. Immunoreactive SRIH (IR-SRIH) was found in normal anterior pituitary tissue but was barely detectable in most adenomas. The present study focuses on 2 adenomas which stood out in a series of 30 somatotropic adenomas by their high levels of SRIH gene expression and SRIH content which allowed the characterization of the cells responsible for the synthesis of the neuropeptide. Surgical specimens were immediately frozen for peptide or mRNA extraction. The SRIH content was measured by RIA and the molecular forms were characterized by HPLC. The size of the SRIH mRNA transcripts was analyzed by Northern blots with oligonucleotide probes. Other fragments were fixed in 4 % paraformaldehyde, 0.5 glutaraldehyde. Fixed fragments were either embedded in Paraplast or osmicated and embedded in Epon. In situ hybridization was performed on paraffin sections with the same probes used in Northern blots. A very small number of cells expressing SRIH mRNA and containing IR-SRIH was identified. The comparison of homologous fields of serial sections showed that IR-SRIH was not colocalized in GH producing cells. The ultrastructure of the cells was analyzed by immunogold labeling. The existence of peculiar adenomatous cells producing SRIH favors their involvement in intraadenomatous regulatory mechanisms. The
P663
THE
RELATION BEIWEEN GASl-RIC ULCER AND ANTFtAL “G” AND “D” CELLS
Yurdagtil Canbsrk. Department of Histology and Embryology, Istanbul Faculty of Medicine, University of Istanbul, &paIstanbul/TURKEY Various researchers have reported some changes and relations between G and 0 cells in peptic and duodenal ulcer cases (Lanas A. et al. 1985, Rev.Esp.Enferm Apar Dig; Chsn Z.Y. et al 1986, Chung Hua Nei Ko Tsa Chih; Harty R.F.et al 1986, Gut). The ultrastructural findings of the light G cells were considered as signs of high functional activity (Creutzfeldt W et al., 1971; Eur J Clin Invest); those of the dark G cells suggest that these cells represent altered, probably exhausted cells (Bordi C. et al, 1978 Arch Pathol Lab Ned). In this study, the endocrine cells of the stomach (pylorus) gastrin (G) cells and somatostatin (0) cells were examined at the ultrastructural level, in the cases with gastric ulcer. In all cases, G cells were seen as the most affected cell type when compared with D cells. Even G cells were increased in number, they reflected a case of hyperstimulation, and hyperfunctian at the secretion and the secretory phases. G cells, dependent to their functions, were Seen in light and dark types. Dark cells which are in majority were observed with dense cytoplasmic matrix, with numerous free ribosomes, and were filled by empty secretory granules. In light cells, dependent to their secretory activity, many secretory granules were seen in different phases of maturation. In contrast to G cells, 0 cells were seen poor in secretory That finding was quits important in granules (degranular). reflecting the relationship between G and 0 cells. Gastrin secretion was increased when somatostatin secretion was low and that relationship was proved morphologically in our study. As a result, when compared wit6 the control group. a topographic relationship between G and Cl cells and the presence of some differences in secretion phases and activities in pathological cases were emphasized.
International
Reports,
P662
Vol. 14, Abstracts
Supplement
1990
REGULATION
OF H202 GENERATION IN THE THYROID U. Bjbrkman, R. Ekholm. Department of Anatomy, University of GBteborg, Sweden. Hydrogen peroxide is required as electron acceptor in the oxidative reactions by which the thyroid hormones are formed. The production of Hz02 was measured with a chemiluminescence method in isolated follicles from pig and dog thyroids. In porcine follicles TSH stimulated Hz02 generation but only at high concentrations (>lOmU/ml) and in the presence of Ca2+; dibuturyl-CAMP had no effect. The Ca2+ ionophore A23187 as well as a diacylglycerol analogue and phorbol myristate acetate also stimulated Hz02 production. In addition, Hz02 generation was increased by addition of arachidonic acid and by melittin, an activator of phospholipase AZ. In dog thyroid follicles Hz02 generation was stimulated by high concentrations of TSH and by A23187 and activators of protein kinase C. These observations were considered to show that the major pathway activating H202 generation, both in pig and dog thyroids, is the Ca2 /phosphatidylinositol cascade. This interpretation was corroborated by the finding that carbam lcholine, which is known to I+ be an agonist of the Ca /phosphatidylinositol cascade in the dog thyroid, activated H202 formation in canine follicles. Carbamylcholine had no effect in pig follicles and plausible adrenergic agonists interfered with the luminescence technique. However, the existence of a similar receptortransducer system in the porcine follicles was indicated by the observation that NaF activated HZ02 generation which was reduced by neomycin, an inhibitor of phospholipase C.
IN-VITRO TESTOSTERONE SECRETION BY TRYPANOSOME-INFECTED MOUSE LEYDIG CELLS. E.N. Waindi & H. Odongo, Department of zoology, University of Nairobi, Box 30197, Nairobi, KENYA. Trypanosome infection in animals is associated with endocrine depression and gonadal malfunction. We report here low response to in-vitro LH stimulation of r. conqolense - infected mouse Leydig cells. The cells were mechanically isolated in cold Eagle's medium, preincubated for 1 h and further incubated for 3 h at 31°C with LH concentrations ranging from 18.8 to 300 uIu/ml. Mean secreted testosterone values assayed by RIA were significantly lower at all points for infected cells (p>OOl), varying from 0.56 f 0.05 to 0.88 f 0.12 n mol/L (SEM, n=6) as compared to corresponding control values of 1.37 + 0.18 and 3.90 & 1.56 (SEM, n=lO). Cell viability by trypan blue exclusion method did not indicate significant difference (p
P664