Horm Metab Res 2005; 37(4): 214-219
DOI: 10.1055/s-2005-861380
Original Basic
© Georg Thieme Verlag KG Stuttgart · New York

Effects of Different Culture Conditions and Leptin on GH mRNA Expression and GH Secretion by Pig Pituitary Cells

R.  Saleri1 , F.  Grasselli1 , C.  Tamanini2
  • 1 Dipartimento di Produzioni Animali, Biotecnologie Veterinarie, Qualità e Sicurezza degli Alimenti - Sezione di Fisiologia Veterinaria, Università degli Studi di Parma
  • 2 DIMORFIPA, Università degli Studi di Bologna, Italy
Further Information

Publication History

Received 31 August 2004

Accepted after revision 2 December 2004

Publication Date:
13 June 2005 (online)

Abstract

Growth hormone (GH) is enhanced in malnutrition; physiological increments in GH secretion seem to play an important role in regulating metabolism during fasting. Leptin has also been shown to play a role, amongst others, in modulating the somatotropic axis. In this study, we investigated how the composition of culture media could influence basal and leptin-stimulated GH secretion and expression in pig pituitary cells. Pituitary cells from 8-month-old sows were incubated for 48 h in presence and absence of 10 % fetal calf serum, either in DMEM/Ham’s F12, in arginine-free DMEM/Ham’s F-12, or in DMEM/Ham’s F12 Salts. Cells were then treated for 24 h with GHRH or recombinant human leptin (rhLep) individually or in association with GHRH; cell proliferation, nitric oxide (NO) production and GH expression and secretion were determined. The absence of nutritional factors induced a decrease in cell proliferation, but stimulated both GH secretion and expression. Furthermore, rhLep significantly increased GH expression and secretion irrespective of culture conditions. NO production was only significantly enhanced by leptin under DMEM/Ham’s F12 culture conditions. These observations lead us to hypothesize that the adaptive capabilities of pituitary cells may overcome the negative effects of undernutrition; in this context, leptin does not seem to depend on NO pathways in modulating GH secretion.

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Roberta Saleri

Dipartimento di Produzioni Animali · Biotecnologie Veterinarie · Qualità e Sicurezza degli Alimenti - Sezione di Fisiologia Veterinaria

Via del Taglio 8 · 43100 Parma

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Email: roberta.saleri@unipr.it